JP2007241659A - Power supply unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply unit low in power consumption while preventing the occurrence of noise. <P>SOLUTION: A power circuit 42 is electrically connected to a power supply 46 capable of supplying a direct current. A first integrated circuit 47 operated by applying specified voltage V<SB>IC1</SB>, and a second integrated circuit 48 operated by applying specified voltage V<SB>IC2</SB>are electrically connected in series to the power circuit 42. The power circuit 42 comprises a transistor 49 consumes electric power to step down voltage of the direct current supplied from the power supply 46. The power circuit 42 supplies the direct current with the voltage stepped down, to the first and second integrated circuits 47, 48. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power supply device for applying a predetermined voltage to an electronic component.

  In recent years, power supply devices for supplying voltage from a single power supply to a plurality of electronic circuits have been put into practical use. The power supply device is configured to be able to apply a predetermined voltage predetermined for each electronic circuit to each electronic circuit.

  FIG. 5 is a circuit diagram of the power supply device 1 according to the conventional first technique. The power supply device 1 is a so-called switching regulator and includes two power supply circuits 2 and 3. The power supply circuits 2 and 3 are connected in parallel to the power supply 4, and the integrated circuits 5 and 6 are electrically connected to the power supply circuits 2 and 3, respectively. Each of the power supply circuits 2 and 3 is a switching circuit, and steps down the voltage 12V of the power supply 4 to a specified voltage of the integrated circuits 5 and 6 connected to each of the power supply circuits 2 and 3, for example, 3V and 1.5V, Application is made to each of the integrated circuits 5 and 6. The power supply circuits 2 and 3 include a coil 7, a diode 8, a voltage dividing circuit 9, a transistor 11, a comparator 12, a Zener diode 13, and a resistor 14. The smoothing circuit 15 is configured by the coil 7, the diode 8, and the voltage dividing circuit 9, and the switch 16 is configured by the transistor 11, the comparator 12, the Zener diode 13, and the resistor 14. The switch 16 switches the on and off states of the switch based on the voltage divided by the voltage dividing circuit. By switching the on and off states of the switch, the voltage applied to the integrated circuits 5 and 6 is reduced to a specified voltage by the smoothing circuit (see, for example, Patent Document 1).

  FIG. 6 is a circuit diagram of a power supply device 21 according to a second conventional technique. The power supply device 21 is a so-called series regulator and has two power supply circuits 22 and 23. The power supply circuits 22 and 23 are connected in parallel to a 12V power supply 24, and the integrated circuits 25 and 26 are electrically connected to the power supply circuits 22 and 23, respectively. Each power supply circuit 22, 23 steps down the voltage 12 V of the power supply 24 to a specified voltage of each integrated circuit 25, 26, for example, 3 V and 1.5 V, and applies it to the integrated circuits 5, 6. Each power supply circuit 22, 23 includes a transistor 27, a voltage dividing circuit 28, a comparator 29, a Zener diode 31, and a resistor 32. In the power supply circuits 22 and 23, the power supply 24 and the integrated circuits 25 and 26 are electrically connected with the transistor 27 interposed therebetween. The transistor 27 has a collector connected to the power supply 24 and an emitter connected to the integrated circuits 25 and 26. A voltage dividing circuit 28 is electrically connected between the transistor 27 and the integrated circuits 25 and 26. In the comparator 29, the reference voltage given by the Zener diode 31 and the resistor 32 is given to the non-inverting input terminal, and the voltage divided by the voltage dividing circuit 28 is given to the inverting input terminal. The output terminal of the comparator 29 is electrically connected to the base of the transistor 27 and switches the conduction state between the emitter and the collector of the transistor 27.

  When the comparator 29 determines that the divided voltage is equal to or lower than the reference voltage, the comparator 29 switches the conduction state of the transistor 27 and causes a current to flow from the power supply 24 to the integrated circuits 25 and 26. At this time, the transistor 27 consumes power and converts it into heat, thereby stepping down the voltage applied to each of the integrated circuits 25 and 26 to a specified voltage. As a result, a prescribed voltage is applied to each integrated circuit 25, 26.

JP-A-9-304143

  The conventional power supply device 1 according to the first technology steps down the voltage by switching the state of the switch 16 when the voltage is stepped down to the specified voltage of each of the integrated circuits 5 and 6. By switching the state of the switch, the current flowing through the coil 7 fluctuates and electromagnetic waves are generated. In the integrated circuits 5 and 6, noise is generated with the electromagnetic wave, and this noise causes abnormal operation.

  In order to suppress the generation of such electromagnetic waves, the power supply device 21 according to the conventional second technique consumes power by the transistor 27 and supplies the voltage 12V of the power supply 24 to the specified voltage of each integrated circuit 25, 26, for example, 3 The voltage is stepped down to 0V or 1.5V. In the transistor 27, heat is generated when power is consumed, and the amount of heat increases as the power consumption increases. Therefore, the amount of heat generated in the transistor 27 is reduced by reducing the power to be consumed by the transistor 27.

  The objective of this invention is providing the power supply device with small power consumption, preventing generation | occurrence | production of noise.

The present invention (1) is a power supply circuit that supplies power by stepping down to a supply voltage by a step-down element that consumes power and steps down the voltage. A plurality of electronic components to which a predetermined specified voltage is applied are connected in series. A power circuit electrically connected;
Detection means for detecting a voltage applied to one electronic component;
Comparing means for comparing the detected voltage with a specified voltage of the electronic component to be detected;
Voltage control means for controlling the voltage applied to the electronic component to be detected to the specified voltage based on the comparison result of the comparison means,
The voltage control means includes a shunt circuit capable of shunting a direct current supplied to the electronic component to be detected and capable of changing a current value of the shunted direct current based on a comparison result of the comparison means. It is a power supply device.

In the present invention (2), the voltage control means
A DC circuit capable of supplying a DC current to the electronic component to be detected, and further comprising a supply circuit capable of changing the current value of the DC current to be supplied based on the comparison result of the comparison means;
When the comparison means determines that the detected voltage is less than the specified voltage, the current value of the direct current supplied by the supply circuit is increased, the current value of the direct current shunted by the shunt circuit is decreased,
When the comparison means determines that the detected voltage exceeds the specified voltage, the current value of the direct current supplied by the supply circuit is decreased, and the current value of the direct current divided by the shunt circuit is increased. To do.

The present invention (3) further includes a supply stopping means for stopping the supply of direct current to the electronic component to be detected,
The voltage control means is characterized in that, when supply of a direct current to the electronic component to be detected is stopped, a direct current to be supplied to the electronic component to be detected is commutated by a shunt circuit.

  According to the present invention (4), the power supply circuit has a function of converting an alternating current or a direct current supplied from a power supply into a direct current of a predetermined supply voltage.

Further, according to the present invention (5), the abnormal state in which the voltage applied to the electronic component to be detected is not included in the allowable voltage range that can be applied to the electronic component to be verified based on the detection result of the detecting means. Abnormality determining means for determining whether or not,
When the abnormality determining means determines that the state is abnormal, it further includes a stopping means for stopping the supply of the direct current from the power supply circuit.

  The present invention (6) is characterized in that an electronic component having a low impedance is arranged on the ground side with respect to an electronic component having a high impedance.

In the present invention (7), the power supply circuit is a series regulator in which the step-down element is a transistor.
The comparison means is a comparator,
The shunt circuit is a transistor that switches the current value of the DC current to be shunted based on the output signal of the comparator.
Moreover, this invention (8) is an electronic device provided with the said power supply device.

  According to the present invention (1), the direct current is stepped down to the supply voltage by the step-down element and supplied to the plurality of electronic circuits. Since the plurality of electronic circuits are electrically connected in series to the power supply circuit, the voltage of the direct current that is to be supplied from the power supply circuit to the plurality of electronic circuits, that is, the supply voltage, This is the sum of the prescribed voltages of each electronic circuit. Therefore, as compared with the case where a plurality of electronic circuits are connected in parallel to the power supply as in the conventional power supply device of the second technology, the voltage that the power supply circuit should step down can be reduced, and the power in the step-down element can be reduced. Consumption can be reduced. As a result, the utilization efficiency of the power supply voltage can be improved. For example, when the step-down element consumes electric power due to heat generation such as a transistor, the heat generation amount of the power supply circuit can be suppressed, and the temperature rise of the device including the power supply circuit can be suppressed. Further, since the voltage is stepped down by the step-down element, no noise is generated and malfunction of the electronic component can be suppressed.

  In the present invention (1), a direct current can be stepped down to a supply voltage by a step-down element and supplied to a plurality of electronic components. Since a plurality of electronic components are electrically connected in series to the power supply circuit, the voltage of the direct current that is to be supplied from the power supply circuit to the plurality of electronic components, that is, the supply voltage, in order to apply the specified voltage to each electronic component, respectively. This is the sum of the specified voltages of each electronic component. Therefore, as compared with the case where a plurality of electronic components are connected in parallel to the power supply as in the conventional power supply device of the second technique, the voltage to be stepped down by the power supply circuit can be reduced. Consumption can be reduced. As a result, the utilization efficiency of the power supply voltage can be improved. For example, when the step-down element consumes electric power due to heat generation such as a transistor, the heat generation amount of the power supply circuit can be suppressed, and the temperature rise of the device including the power supply circuit can be suppressed. Further, since the voltage is stepped down by the step-down element, no noise is generated and malfunction of the electronic component can be suppressed.

  Further, the comparison means compares the voltage detected by the detection means with the specified voltage of the electronic component to be detected, and the voltage control means is applied to the electronic component to be detected based on the comparison result of the comparison means. Control the voltage to the specified voltage. As a result, even if the voltage consumed by the electronic components other than the detection target fluctuates, the specified voltage can be applied to the detection target electronic component. Therefore, even when a plurality of electronic components are electrically connected in series to the power supply circuit, the specified voltage can be stably applied to the electronic component to be detected. For example, when the electronic component is an integrated circuit, the electronic component to be verified can be stably operated even when a plurality of integrated circuits are electrically connected in series.

  Further, according to the present invention (1), the current value of the direct current that is shunted by the shunt circuit can be changed based on the comparison result of the comparing means. As a result, the voltage applied to the electronic component to be detected can be changed, and the voltage applied to the electronic component to be detected can be controlled to a specified voltage. By controlling the applied voltage to a specified voltage, for example, when the electronic component to be detected is an integrated circuit, the electronic component to be detected can be stably operated and a voltage higher than the specified voltage is applied. This can prevent the detection-target electronic component from being broken.

  According to the present invention (2), when the voltage applied to the electronic component to be detected is smaller than the specified voltage, the current value of the direct current supplied by the supply circuit is increased, and the direct current divided by the shunt circuit is increased. The voltage applied to the electronic component to be detected is increased by decreasing the current value. In addition, when the voltage applied to the electronic component to be detected becomes larger than the specified voltage, the current value of the DC current supplied by the supply circuit is decreased, and the current value of the DC current divided by the shunt circuit is increased. The voltage applied to the electronic component is reduced. As a result, the voltage applied to the electronic component to be detected can be controlled to a specified voltage, and the specified voltage can be stably applied to the electronic component to be detected. Moreover, it is possible to prevent the detection-target electronic component from being damaged by applying a voltage higher than the specified voltage to the detection-target electronic component.

  According to the invention (3), when the supply of direct current to the electronic component to be detected is stopped by the supply stop means, the direct current to be supplied to the electronic component to be detected is commutated by the shunt circuit. . Even if a plurality of electronic circuits are electrically connected in series, even if the supply of DC current to the electronic component to be detected is stopped, this supply is achieved by commutation using a shunt circuit. A direct current can be supplied to electronic components other than the stopped electronic component. Thereby, for example, even when the electronic component to be detected stops applying the voltage before the other electronic component, the other electronic component can be stably applied with the specified voltage.

  Further, according to the present invention (4), since the alternating current can be converted into the direct current of the supply voltage, the power supply circuit can be electrically connected to a power supply capable of supplying the alternating current, whereby the supply voltage is supplied to a plurality of electronic components. A direct current can be supplied.

  According to the invention (5), when the abnormality determining means determines that the voltage applied to the electronic component to be detected is not included in the allowable voltage range based on the detection result, the stopping means removes the voltage from the power supply circuit. The supply of direct current to a plurality of electronic circuits is stopped. Accordingly, it is possible to prevent a state in which an abnormally high voltage is applied to each electronic component, and it is possible to prevent the electronic component from being damaged by applying such an abnormally high voltage.

  According to the present invention (6), the generation of noise is suppressed by arranging the electronic component having a lower impedance on the ground side. As a result, the specified voltage can be stably applied to the electronic component.

  Further, according to the present invention (7), it is possible to realize a power supply device that can reduce power consumed by the step-down element and can stably apply a specified voltage to an electronic component.

  Further, according to the present invention (8), it is possible to realize an electronic apparatus including a power supply device in which the power consumed by the step-down element is reduced while preventing the generation of noise.

  Hereinafter, a plurality of embodiments for carrying out the present invention will be described with reference to the drawings. Portions corresponding to the matters described in the preceding forms in each embodiment are denoted by the same reference numerals, and overlapping description may be omitted. When only a part of the configuration is described, the other parts of the configuration are the same as those described in the preceding section. In addition to the combination of parts specifically described in each embodiment, the embodiments may be partially combined as long as the combination is not particularly troublesome.

FIG. 1 is a circuit diagram showing a power supply device 41 according to the first embodiment of the present invention. The power supply device 41 is a device that is electrically connected to a plurality of electronic components and a power supply, and steps down the power supply voltage of the power supply to apply a predetermined voltage to each electronic component. Electronic components include electronic circuits such as integrated circuits and circuit elements such as resistors, capacitors and coils. The power supply device 41 is an electronic device 40 such as an electronic control unit (Electronic Control Unit).
Unit: abbreviated as ECU) and mounted on the vehicle. The power supply device 41 applies a specified voltage to each of a plurality of integrated circuits included in the electronic device 40. The power supply device 41 includes a power supply circuit 42, a voltage control circuit 43, and an abnormal stop circuit 44. In the power supply device 41, a main conductive path 45 is formed across the power supply circuit 42, the voltage control circuit 43, and the abnormal stop circuit 44.

  One end of the main conductive path 45 is electrically connected to the power source 46, and the other end is grounded. The power source 46 is, for example, a battery provided in the vehicle, and is a 12V battery in the present embodiment. However, the power source 46 is not limited to a secondary battery such as a battery, and may be a primary battery such as a dry battery. The power supply 46 has a high voltage side electrically connected to the main conductive path 45 and a low voltage side grounded.

  The power supply circuit 42 is electrically connected to a power supply 46, and a plurality of electronic components, in the present embodiment, two first and second integrated circuits 47 and 48 are electrically connected in series. The first integrated circuit 47 is, for example, an analog signal processing circuit, and the second integrated circuit 48 is, for example, a digital signal processing circuit. However, it is not limited to such a signal processing circuit. The power supply circuit 42 is a so-called series regulator, and is a circuit for applying a voltage to the first and second integrated circuits 47 and 48 by stepping down the power supply voltage of the power supply 46, which is 12V in the present embodiment. is there. The power supply circuit 42 includes a main conductive path first portion 45 a that is a part of the main conductive path 45, a transistor 49, a voltage dividing circuit 51, a reference voltage circuit 52, and a comparator 53.

  One end of the main conductive path first portion 45a is electrically connected to the power supply 46, and a transistor 49 is interposed. The transistor 49 is an npn-type transistor, and a collector is electrically connected to one end side of the main conductive path first portion 45a, and an emitter is electrically connected to the other end side. Further, a voltage dividing circuit 51 is electrically connected to the main conductive path first portion 45a. The voltage dividing circuit 51 is configured by electrically connecting two resistors 55 and 56 in series. One end of the voltage dividing circuit 51 is electrically connected to the other end side from the transistor 49 of the main conductive path first portion 45a, and the other end is grounded. Further, a reference voltage circuit 52 is electrically connected to the main conductive path first portion 45a. The reference voltage circuit 52 is configured by electrically connecting a resistor 57 and a Zener diode 58 in series. The reference voltage circuit 52 has one end, which is the end on the resistor 57 side, electrically connected to one end between the transistor 49 and the power supply 46 of the main conductive path first portion 45a, and the other end, which is the end of the Zener diode 58. Is grounded.

  The comparator 53 has an inverting input terminal electrically connected to the voltage dividing circuit 51 and a non-inverting input terminal electrically connected to the reference voltage circuit 52. Specifically, the comparator 53 has an inverting input terminal electrically connected between the two resistors 55 and 56 of the voltage dividing circuit 51, and a non-inverting input terminal connected to the resistor 57 of the reference voltage circuit 52 and a Zener diode. 58 is electrically connected. The output terminal of the comparator 53 is electrically connected to the base of the transistor 49 with a resistor 59 interposed.

  The voltage control circuit 43 is a circuit that is electrically connected to the first and second integrated circuits 47 and 48 and controls the voltage applied to the first and second integrated circuits 47 and 48. The voltage control circuit 43 includes a main conductive path second portion 45b which is a part of the main conductive path 45, a voltage dividing circuit 61, a first detection conductive path 62, a comparison circuit 63, a first shunt circuit 64, and a second A shunt circuit 65 is included.

  One end of the main conductive path second portion 45b is electrically connected to the other end of the main conductive path first portion 45a. The first and second integrated circuits 47 and 48 are electrically connected in series to one end side of the main conductive path second portion 45b. Specifically, the first and second integrated circuits 47 and 48 are electrically connected in series, one end on the first integrated circuit 47 side is electrically connected to the main conductive path second portion 45b, and the second integrated circuit The other end on the 48 side is grounded. A voltage dividing circuit 61 is electrically connected to the other end side of the main conductive path second portion 45b. The voltage dividing circuit 61 is configured by electrically connecting two resistors 66 and 67 in series. One end of the voltage dividing circuit 61 is electrically connected to the other end of the main conductive path second portion 45b, and the other end is grounded. One end of the first detection conductive path 62 is electrically connected between the first and second integrated circuits 47 and 48. The comparison circuit 63 which is a comparison means is constituted by a comparator, the inverting input terminal is electrically connected to the other end of the first detection conductive path 62, and the non-inverting input terminal is the two resistors 66, 67 is electrically connected.

  The first shunt circuit 64 is configured by an npn-type transistor, and is electrically connected to the main conductive path second portion 45 b and the first detection conductive path 62. Specifically, the collector of the first shunt circuit 64 is electrically connected between the first integrated circuit 47 and the voltage dividing circuit 61 of the second part 45b of the main conductive path, and the emitter is the first detection conductive path 62. Is electrically connected. The second shunt circuit 65 is configured by a pnp transistor and is electrically connected to the first detection conductive path 62. Specifically, the second shunt circuit 65 has an emitter electrically connected to the first detection conductive path 62 and a collector grounded. In the present embodiment, the emitters of the first shunt circuit 64 and the second shunt circuit 65 are electrically connected. The first shunt circuit 64 corresponds to a shunt circuit for the first integrated circuit 47 and corresponds to a supply circuit for the second integrated circuit 48. The second shunt circuit 64 corresponds to a shunt circuit. The first and second shunt circuits 64 and 65 correspond to voltage control means.

  The output terminal of the comparison circuit 63 is electrically connected to the bases of the first and second shunt circuits 64 and 65, respectively. The bases of the first and second shunt circuits 64 and 65 are electrically connected in parallel to the output terminal of the comparison circuit 63. Resistors 68 and 69 are interposed between the output terminal of the comparison circuit 63 and the bases of the first and second shunt circuits 64 and 65, respectively.

  The abnormal stop circuit 44 is electrically connected to the power supply circuit 42 and the first and second integrated circuits 47 and 48. The abnormal stop circuit 44 stops the power supply circuit 42 when an abnormally high voltage is applied to the first and second integrated circuits 47 and 48, and the direct current to the first and second integrated circuits 47 and 48 is reduced. This circuit stops supply. The abnormal stop circuit 44 includes a main conductive path third portion 45c, which is a part of the main conductive path 45, a voltage dividing circuit 71, a second detection conductive path 72, a first allowable voltage comparison circuit 73, and a second allowable voltage comparison. A circuit 74, an abnormality detection circuit 75, a power supply determination circuit 76, a release signal transmission circuit 77, a reset detection circuit 78, and a stop determination circuit 79 are included.

  One end of the main conductive path third portion 45c is electrically connected to the main conductive path second portion 45b, and the other end is grounded. The voltage dividing circuit 71 is interposed in the main conductive path third portion 45c. The voltage dividing circuit 71 is configured by electrically connecting three resistors 81, 82, and 83 in series from one end side of the main conductive path third portion 45c. One end of the second detection conductive path 72 is electrically connected to the first detection conductive path 62 and is a conductive path having the same potential as the first detection conductive path 71.

  The first allowable voltage comparison circuit 73 is configured by a comparator, and its inverting input terminal is electrically connected between the two resistors 81 and 82 on one end side of the third part of the main conductive path of the voltage dividing circuit 71. The inverting input terminal is electrically connected to the second detection conductive path 72. The second detection conductive path 72 and the first detection conductive path 62 correspond to detection means. The second allowable comparison circuit 74 is configured by a comparator, and its inverting input terminal is electrically connected to the other end of the second detection conductive path 72, and the non-inverting input terminal is the main conductive path third portion 45c of the voltage dividing circuit 71. Between the two resistors 82 and 83 on the other end side. The abnormality detection circuit 75 is configured by an OR operation circuit (OR gate) having two input terminals, and the output terminals of the first and second allowable voltage comparison circuits 73 and 74 are electrically connected to the input terminals, respectively. ing.

  When the power determination circuit 76 operates a reset button for returning the electronic device 40 on which the power supply device 41 is mounted to an initial state, or a power switch for supplying and stopping power supply to each component of the electronic device 40. , A circuit for transmitting a high-level power supply signal. The reset button and the power switch are provided in the electronic device 40. The power supply signal is a voltage signal. The release signal transmission circuit 77 is a circuit that transmits a release signal at a high level when a release button provided in the electronic device 40 is pressed. The release signal is a voltage signal. The reset detection circuit 78 is configured by a logical sum operation circuit (OR gate) having two input terminals, and a power source determination circuit 76 and a release signal transmission circuit 77 are electrically connected to each input terminal. The power determination circuit 76 is configured to be able to transmit a power signal to the reset detection circuit 78, and the release signal transmission circuit 77 is configured to be able to transmit a release signal to the reset detection circuit 78.

  The stop determination circuit 79 includes a reset set flip-flop (RS-FF), and includes a reset terminal (R terminal), a set terminal (S terminal), a non-inverted output terminal (Q1 terminal), and an inverted output terminal (Q2 terminal). Prepare. The stop determination circuit 79 has a set terminal electrically connected to the output terminal of the abnormality detection circuit 75 and a reset terminal electrically connected to the output terminal of the reset detection circuit 78. The first allowable voltage comparison circuit 73, the second allowable voltage comparison circuit 74, the abnormality detection circuit 75, and the stop determination circuit 79 correspond to the abnormality determination means 80.

  The abnormal stop circuit 44 further includes a stop unit 85 and a notification unit 86. The stopping means 85 is composed of an npn transistor, the collector is electrically connected to the output terminal of the comparator 53, and the emitter is grounded. Specifically, the collector of the stopping means 85 is electrically connected between the transistor 49 and the resistor 59. Further, the base of the stop means 85 is electrically connected to the non-inverting output terminal of the stop determination circuit 79 via a resistor 87. The notification means 86 includes a switching element 88 and a notification element 89. In the switching element 88, the emitter of the pnp transistor 88 is electrically connected to one end side from the resistor 57 of the reference voltage circuit 52, and the collector is grounded. A resistor 91 and a notification element 89 are electrically connected in order from the reference voltage circuit 52 side between the emitter of the transistor 88 and the reference voltage circuit 52. The notification element 89 is a phototransistor.

The first and second integrated circuits 47 and 48 are configured to operate when the prescribed voltages V _IC1 and V _IC2 are applied, respectively. In the present embodiment, the specified voltage V _IC1 of the first integrated circuit is 3.3V, and the specified voltage V _IC2 of the second integrated circuit is 1.5V. However, the specified voltage of the integrated circuit is not limited to such a value. The specified voltage may be 5.0 V, for example, and the sum of the specified voltages of the plurality of integrated circuits may be less than or equal to the power supply voltage V0 of the power supply 46. The impedance of the first integrated circuit 47 is larger than the impedance of the second integrated circuit 48. The first and second integrated circuits 47 and 48 are, for example, a microprocessor and a semiconductor memory. However, the first and second integrated circuits 47 and 48 are not limited to these, and may be formed by combining a plurality of circuit elements.

In the power supply device 41 configured as described above, in the power supply circuit 42, the reference voltage circuit 52 controls the power supply voltage V0 to the reference voltage V1. The reference voltage V1 is a Zener voltage of the Zener diode 58. The power supply voltage V0 is stepped down to the supply voltage V2 by the transistor 49, and the voltage dividing circuit 51 divides the stepped down supply voltage V2 into the voltage V3 to be compared. The resistance values of the two resistors 55 and 56 of the voltage dividing circuit 51 are determined so that the voltage V3 to be compared matches the reference voltage V2 when the supply voltage V2 is a specified total voltage. The prescribed total voltage is the sum of prescribed voltages of a plurality of integrated circuits. In this embodiment, the prescribed total voltage is the sum 4.8V of the prescribed voltages V _IC1 and V _IC2 of the first and second integrated circuits 47 and 48.

  In the comparator 53, the reference voltage V1 is applied to the non-inverting input terminal, and the compared voltage V3 is applied to the inverting input terminal. The comparator 53 compares the reference voltage V <b> 1 and the voltage to be compared V <b> 3, and transmits an open / close signal, which is a current signal, to the transistor 49 from the output terminal via the resistor 59 based on the comparison result. The transistor 49 controls the supply voltage V2 according to the open / close signal. Specifically, the comparator 53 transmits a low-level open / close signal to the transistor 49 when the compared voltage V3 is greater than the reference voltage V1, and the high level to the transistor 49 when the compared voltage V3 is less than the reference voltage V1. Transmits an open / close signal. The transistor 49 decreases the supply voltage V2 when a low-level open / close signal is input, and increases the supply voltage V2 when a high-level open / close signal is input. In this way, the supply voltage V2 is controlled to the specified total voltage by increasing or decreasing the supply voltage according to the open / close signal by the transistor 49. In this way, in the power supply circuit 42, the supply voltage V2 is controlled to the specified total voltage.

Based on the controlled supply voltage V2, the first application voltage V4 and the second application voltage V5 are applied to the first and second integrated circuits 47 and 48, respectively. Specifically, the supply voltage V2 is stepped down by the first application voltage V4 by the first integrated circuit 47 to become the second application voltage V5, and this second application voltage V5 is applied to the second integrated circuit 48. When the prescribed voltages V _IC1 and V _IC2 are applied to the first and second integrated circuits 47 and 48, the integrated circuits 47 and 48 are operable.

In the voltage control circuit 43, the second applied voltage V 5 is detected by the first detection conductive path 62, and the second applied voltage V 5 is applied to the inverting input terminal of the comparison circuit 63. The voltage dividing circuit 61 divides the supply voltage into the divided voltage V 6 and applies the divided voltage V 6 to the non-inverting input terminal of the comparison circuit 63. The resistance values of the two resistors 66 and 67 of the voltage dividing circuit 51 are determined so that the divided voltage V6 matches the specified voltage V _IC2 of the second integrated circuit 48 when the supply voltage V2 is the specified total voltage. The

  In the comparison circuit 63, the divided voltage V6 is applied to the non-inverting input terminal, and the second applied voltage V5 is applied to the inverting input terminal. The comparison circuit 63 compares the divided voltage V6 with the second applied voltage V5, and based on the comparison result, a current control signal that is a current signal from its output terminal is passed through the resistors 68 and 69. To the first and second shunt circuits 64 and 65, respectively. The first and second shunt circuits 64 and 65 control current values to be shunted according to the current control signal.

Specifically, when the second applied voltage V5 is larger than the divided voltage V6, the comparison circuit 63 transmits a low-level current control signal to the first and second shunt circuits 66 and 67, and the second applied voltage V5. Is smaller than the divided voltage V6, a high-level current control signal is transmitted to the first and second shunt circuits 64 and 65. When a low-level current control signal is input to each of the shunt circuits 64 and 65, the first shunt circuit 64 decreases the current value of the shunt current, and the second shunt circuit 65 sets the current value of the shunt current. increase. That is, when the second applied voltage V5 exceeds the specified voltage V _IC2 of the second integrated circuit 48, the first applied voltage V4 is increased by the first shunt circuit 64, and the second applied voltage V5 is decreased by the second shunt circuit 65. Let When a high-level current control signal is input to each of the shunt circuits 64 and 65, the first shunt circuit 64 increases the current value of the shunt current, and the second shunt circuit 65 sets the current value of the shunt current. Decrease. That is, when the second applied voltage V5 is less than the prescribed voltage V _IC2 of the second integrated circuit 48, the first applied voltage V4 is decreased by the first shunt circuit 64, and the second applied voltage V5 is reduced by the second shunt circuit 65. increase. In this way, each of the shunt circuits 64 and 65 controls the current value of the shunt current based on the magnitude relationship between the second applied voltage V5 and the specified voltage V _IC2 of the second integrated circuit 48, and the first applied voltage. V5 is controlled to the specified voltage V _IC1 of the first integrated circuit 47, and the second applied voltage V5 is controlled to the specified voltage V _IC2 of the second integrated circuit 48.

  The supply voltage V2 is divided by the two resistors 81 and 82 into the first abnormal reference voltage V7 in the voltage dividing circuit 71 of the main conductive path third portion 45c. The first abnormal reference voltage V7 is applied to the inverting input terminal of the first allowable voltage comparison circuit 73. The second applied voltage V <b> 5 is applied to the non-inverting input terminal of the first allowable voltage comparison circuit 73 via the second detection conductive path 72. When the second applied voltage V5 exceeds the first abnormality reference voltage V7, the first allowable voltage comparison circuit 73 transmits a high-level first abnormality signal to the abnormality detection circuit 75. The first allowable voltage comparison circuit 73 transmits a low-level first abnormality signal when the second applied voltage V5 is less than the first abnormality reference voltage V7. The first abnormal signal is a voltage signal.

  Further, the supply voltage V2 is divided into the second abnormal reference voltage V8 by the two resistors 82 and 83 in the voltage dividing circuit 71 of the main conductive path third portion 45c. The second abnormal reference voltage V8 is applied to the non-inverting input terminal of the second allowable voltage comparison circuit 74. The second applied voltage V <b> 5 is applied to the inverting input terminal of the second allowable voltage comparison circuit 74 via the second detection conductive path 72. The second allowable voltage comparison circuit 74 transmits a high-level second abnormality signal to the abnormality detection circuit 75 when the second applied voltage V5 becomes less than the second abnormality reference voltage V8. When the second applied voltage V5 exceeds the second abnormality reference voltage V8, the second allowable voltage comparison circuit 74 transmits a low-level second abnormality signal. The second abnormal signal is a voltage signal.

  The first abnormal reference voltage V7 is the upper limit value of the voltage at which the second integrated circuit 48 can operate, and the second abnormal reference voltage V8 is the lower limit value of the voltage at which the second integrated circuit 48 can operate. The allowable voltage range of the second integrated circuit 48 is a second abnormal reference voltage V8 or more and a first abnormal reference voltage V7 or less, and is a predetermined voltage range within a range where the integrated circuit does not cause an abnormal operation.

  When the second applied voltage V5 is outside the allowable voltage range, the abnormality detection circuit 75 receives a high-level first and second abnormality signal from at least one of the first and second allowable voltage comparison circuits 73 and 74. Is transmitted. Accordingly, the abnormality detection circuit 75 determines that the second applied voltage V5 is outside the allowable voltage range, and determines that it is difficult for the second integrated circuits 47 and 48 to operate normally. When determined in this way, the abnormality detection circuit 75 transmits a high-level abnormality detection signal to the set terminal of the stop determination circuit 79. The abnormality detection signal is a voltage signal.

  When a high level abnormality detection signal is input to the set terminal, the stop determination circuit 79 transmits a high level stop signal from the non-inverted output terminal to the stop means 85 via the resistor 87, and from the inverted output terminal. A low level notification signal is transmitted to the notification means 86 via the resistor 92. The stop signal and the notification signal are current signals. When this high level stop signal is input, the stop means 85 makes the collector and the emitter conductive, and grounds the output terminal of the comparator 53. As a result, the stopping means 85 prevents transmission of the open / close signal from the comparator 53 to the base of the transistor 49. The emitter-collector of the transistor 49 becomes non-conductive, and current supply from the power supply circuit 42 to the first and second integrated circuits 47 and 48 is blocked. In this way, the stopping unit 85 stops the supply of current from the power supply circuit 41 to the first and second integrated circuits 47 and 48. Further, when the notification means 86 receives the low level notification signal, the notification device 89 makes the emitter-collector of the switching element 88 conductive, causes the notification element 89 to emit light, and stops supplying the current from the power supply circuit 42. Inform.

  When the reset button or the power switch is operated after the supply is stopped, a high-level power signal is transmitted from the power determination circuit 76 to the reset detection circuit 78, and when the release button is operated, the release signal transmission circuit 77 A high level release signal is transmitted to the reset detection circuit 78. The reset detection circuit transmits a high-level reset signal to the set terminal of the stop determination circuit 79 when at least one of a high-level power supply signal and a release signal is input. The reset signal is a voltage signal. When a high-level reset signal is input to the reset terminal, the stop determination circuit 79 transmits a low-level stop signal from the non-inverting input terminal of the stop determination circuit 79 to the stop means 85 and notifies the informing means 86 from the inverting input terminal. A high level notification signal is transmitted. When a low-level stop signal is input, the stop unit 85 brings the emitter and collector into a non-conductive state and restarts the supply of the direct current from the power supply circuit 41. In addition, when a high-level stop signal is input to the notification unit 85, the emitter and collector of the switching element 88 become non-conductive. As a result, the notification element 89 is prevented from emitting light, and a notification is given that current is being supplied from the power supply circuit 41.

  Further, the abnormality detection circuit 75 transmits a low-level first abnormality signal from the first allowable voltage comparison circuit 73 and transmits a low level from the second allowable voltage comparison circuit 74 when the second applied voltage V5 is within the allowable voltage range. The second abnormal signal is transmitted. Accordingly, the abnormality detection circuit 75 determines that the second applied voltage V5 is within the allowable voltage range, and determines that the second integrated circuit 48 can operate normally. If determined in this way, the abnormality detection circuit 75 transmits a low-level abnormality detection signal to the stop determination circuit 79. Further, when the supply of the direct current from the power supply circuit 41 is stopped, the abnormality detection circuit 75 transmits a low-level abnormality detection signal to the set terminal of the stop determination circuit 79. When the release button, the reset button, and the power button are not operated, the reset detection circuit 78 transmits a low level reset signal to the reset terminal of the stop determination circuit 79.

When a low level abnormality detection signal is input to the set terminal and a low level reset signal is input to the reset terminal, the stop determination circuit 79 transmits a signal output from the inverting input terminal and the non-inverting input terminal. continue. That is, when the supply of current from the power supply circuit 41 is stopped, the release button, the reset button or the power switch is not pressed.
The state where the supply of current is stopped continues. In the state where the current from the power supply circuit 41 is supplied, the supply of current from the power supply circuit 41 is continued if the second applied voltage V5 is within the allowable voltage range. In this way, the abnormal stop circuit 44 determines whether or not the second applied voltage V5 is within the allowable voltage range, and prevents the second integrated circuit 47 from being applied with a voltage outside the allowable voltage range.

Below, the effect which the power supply device 41 comprised in this way has is demonstrated. According to the power supply device 41 of the present embodiment, the direct current can be stepped down to the supply voltage V2 by the transistor 49 and supplied to the first and second integrated circuits 48 and 49. Since the first and second integrated circuits 47 and 48 are electrically connected in series to the power supply circuit 42, the power supply circuit 41 is used to apply the prescribed voltages V _IC1 and V _IC2 to the integrated circuits 47 and 48, respectively. The supply voltage V2 of the direct current to be supplied to the first and second integrated circuits 47 and 48 is the sum of the prescribed voltages V _IC1 and V _IC2 of the first and second integrated circuits 47 and 48. Therefore, as compared with the case where the first and second integrated circuits 25 and 26 are connected in parallel as in the power supply device 21 of the conventional second technology, the voltage to be stepped down by the power supply circuit 41 can be reduced. Thus, power consumption in the transistor 49 can be reduced. As a result, the utilization efficiency of the power supply voltage V0 can be improved. The transistor 49 converts consumed power into heat, but can reduce power consumption. Therefore, the amount of heat generated by the power supply circuit 42 can be suppressed, and an increase in temperature of a device including the power supply circuit 42 can be suppressed. As a result, a cooling device for cooling the power supply circuit 42 can be made smaller than before.

According to the power supply device 41 of the present embodiment, the direct current can be stepped down to the supply voltage by the transistor 49 and supplied to the first and second integrated circuits 47 and 48. Since the first and second integrated circuits 47 and 48 are electrically connected in series to the power supply circuit 42, the power supply circuit 42 is used to apply the specified voltages V _IC1 and V _IC2 to the integrated circuits 47 and 48, respectively. The supply voltage V2 of the direct current to be supplied to the first and second integrated circuits 47 and 48 is the sum of the prescribed voltages V _IC1 and V _IC2 of the integrated circuits 47 and 48. Therefore, as compared with the case where the first and second integrated circuits 25 and 26 are connected in parallel as in the power supply device 21 according to the conventional second technique, the voltage to be stepped down by the power supply circuit 42 can be reduced. Thus, power consumption in the transistor 49 can be reduced. As a result, the utilization efficiency of the power supply voltage V0 can be improved. Further, although the power consumed by the transistor 49 is converted into heat, since the power consumption is reduced, the amount of heat generated by the power supply circuit 42 can be suppressed, and the temperature rise of the device including the power supply circuit 42 can be suppressed. it can.

Further, the comparison circuit 63 compares the second applied voltage V5 detected by the detection conductive path 62 with the specified voltage V _IC2 of the second integrated circuit 48, and based on the comparison result of the comparison circuit 63, the first and first voltages are compared. The second applied voltage V5 is controlled to the specified voltage V _IC2 by the two shunt circuits 64 and 65. As a result, even if the first applied voltage V4 fluctuates, the specified voltage V _IC2 can be applied to the second integrated circuit 48, and the first and second integrated circuits 47 and 48 are electrically connected in series to the power supply circuit 42. Even if connected, the specified voltage V _IC2 can be stably applied to the second integrated circuit 48 to stably operate.

According to the power supply device 41 of the present embodiment, the current value of the direct current divided by the second shunt circuit 65 can be changed based on the comparison result of the comparison circuit 63. As a result, the second applied voltage V5 applied to the second integrated circuit 48 can be changed, and the second applied voltage V5 can be controlled to the specified voltage V _IC2 . By controlling the second applied voltage V5 to the specified voltage V _IC2 , the second integrated circuit 48 can be stably operated, and a voltage higher than the specified voltage V _IC2 is applied to the second integrated circuit 48 and malfunctions. Can be prevented.

According to the power supply device 41 of the present embodiment, when the second applied voltage V5 applied to the second integrated circuit 48 becomes smaller than the specified voltage V _IC2 , the first shunt circuit 64 supplies the second integrated voltage 48 to the second integrated circuit 48. The current value of the DC current is increased, the current value of the DC current shunted by the second shunt circuit 65 is decreased, and the second applied voltage V5 applied to the second integrated circuit 48 is increased. When the second applied voltage V5 applied to the second integrated circuit 48 becomes larger than the specified voltage V _IC2 , the current value of the direct current supplied to the second integrated circuit 48 by the first shunt circuit 64 is decreased, and the second The current value of the direct current shunted by the shunt circuit 65 is increased, and the second applied voltage V5 applied to the second integrated circuit 48 is lowered. This second integrated circuit can control the second applied voltage V5 applied to the specified voltage V _{IC 2} to 48, it can be stably to apply a prescribed voltage V _{IC 2} to the second integrated circuit 48. In addition, it is possible to prevent the second integrated circuit 48 from being damaged by applying a voltage higher than the specified voltage V _IC2 to the second integrated circuit 48.

  According to the power supply device 41 of the present embodiment, when the abnormality detection circuit 75 determines that the second applied voltage V5 applied to the second integrated circuit 48 is not included in the allowable voltage range, the power is stopped by the stop unit 85. The supply of direct current from the circuit 42 to the first and second integrated circuits 47 and 48 is stopped. As a result, it is possible to prevent a state in which an abnormally high voltage is being applied to each of the integrated circuits 47 and 48 from being continued, and the integrated circuit fails due to such an abnormally high voltage being continuously applied. Can be prevented.

According to the power supply device 41 of the present embodiment, noise generation is suppressed by arranging the second integrated circuit 48 having a lower impedance on the ground side. As a result, the specified voltage V _IC2 can be stably applied to the electronic component.

According to the power supply device 41 of the present embodiment, a power supply device that can reduce the power consumed by the transistor 49 and can stably apply the specified voltages V _IC1 and V _IC2 to the integrated circuits 48 and 47 is provided. Can be realized.

  According to the power supply device 41 of the present embodiment, it is possible to realize the electronic device 40 including the power supply device 41 in which the power consumed by the transistor 49 is reduced while preventing the generation of noise.

According to the power supply device 41 of the present embodiment, the power consumed by the transistor 49 of the power supply circuit 42 can be reduced, and the amount of heat generated in the power supply circuit 42 can be reduced. Specifically, when connected in parallel as in the conventional second technique, the power W ₁₁ consumed by the transistor 27 of the power supply circuit 22 is:
W ₁₁ = (12-3.3) × I1 = 8.7 × I1 (1)
It is. The power W ₁₁ is obtained by multiplying the difference between the power supply voltage V 0 and the specified voltage V _IC1 of the first integrated circuit 25 by the current flowing between the emitter and collector of the transistor 11, specifically, the rated current I 1 of the first integrated circuit 25. Value. Similarly, the power W ₁₂ consumed by the transistor 27 of the power supply circuit 23 is
W ₁₁ = (12−1.5) × I2 = 11.5 × I2 (2)
It is. The power W ₁₁ is obtained by multiplying the difference between the power supply voltage V 0 and the specified voltage V _IC2 of the second integrated circuit 26 by the current flowing between the emitter and collector of the transistor 27, specifically, the rated current I 2 of the second integrated circuit 26. Value. Therefore, the total power consumption W ₁ consumed by the power supply circuits 22 and 23 of the power supply device 21 is
W ₁ = 8.7 × I1 + 11.5 × I2 (3)
, And the case of I1 = I2, the total power consumption W ₁ is,
W ₁ = 19.2 × I1 (4)
It is.

On the other hand, the power consumed by the transistor 49 is the power W ₂ consumed when stepping down from the power supply voltage V0 to the supply voltage V2, and the power W ₂ is
W ₂ = (12-3.3-1.5) × I3 = 7.2 × I3 (5)
It is. The power W ₂ is a current flowing between the emitter and the collector of the transistor 49, specifically, the first and second currents, which is the difference between the power supply voltage V0 and the prescribed voltages V _IC1 and V _{IC2 of} the first and second integrated circuits 47 and 48. 2 The value obtained by multiplying the rated current I3 of the integrated circuits 47 and 48. Therefore, the power W ₂ consumed by the power supply device 41 of the present embodiment is smaller than the power W ₁ consumed by the conventional power supply device 21. Further, in the power supply devices 21 and 41, when the power is consumed, the consumed power is converted into heat by the transistor. Therefore, the power supply device 41 of the present embodiment having a small power consumption can further reduce the heat generation amount.

According to the power supply device 41 of the present embodiment, the power efficiency is higher than that of the conventional power supply device 21 of the second technology, and the power is efficiently used. Specifically, in the power supply device 21 of the conventional second technology, the power W _1t supplied from the power supply is
W _1t = 12 × I1 + 12 × I2 (6)
And when I1 = I2, the power W _1t is
W _1t = 24 × I1 (7)
It is. The power efficiency η ₁ of the power supply device 21 is
η ₁ = (24 × I1-19.2 × I1) / (24 × I1) × 100
= 20% (8)
It is. The power efficiency η ₁ is a percentage of the power consumed by the first and second integrated circuits 25 and 26 divided by the power supplied from the power source.

On the other hand, in the power supply device 41 of the present embodiment, the power W _2t supplied from the power supply 46 is
W _2t = 12 × I3
It is. The power efficiency η ₂ of the power supply device 41 is
η ₂ = (12 × I3−7.2 × I3) / (12 × I3) × 100
= 40% (9)
It is. The power efficiency η ₂ is a percentage obtained by dividing the power consumed by the first and second integrated circuits 47 and 48 by the power supplied from the power source. Thus, the power efficiency η ₂ of the power supply device 41 of the present embodiment is higher than the power efficiency η ₁ of the power supply device 21 of the conventional second technology, and the power use efficiency is high.

  Further, according to the power supply device 41 of the present embodiment, the power supply voltage V0 is stepped down to the supply voltage V2 by consuming power by the transistor 49. Therefore, when the power supply voltage V0 is stepped down to the supply voltage V2 as in the conventional power supply device 1 of the first technology, no noise is generated, and the first and second integrated circuits 47 and 48 caused by this noise are erroneous. Operation can be prevented.

Further, according to the power supply device 41 of the present embodiment, the first shunt circuit 64 and the second shunt circuit 65 are controlled by the comparison circuit 63. That is, the supply and shunting of the direct current to the second integrated circuit 48 can be controlled by the single comparison circuit 63. By controlling with one comparator circuit 63, when the current control signal is transmitted to each of the shunt circuits 64 and 65, the output timing of the current control signal can be matched, and the direct current is supplied to the second integrated circuit 48. In addition, it is possible to suppress variations in the timing of diversion. As a result, a stable specified voltage V _IC2 can be applied to the second integrated circuit 48. Further, since the control is performed by one comparison circuit 63, the configuration of the power supply device can be simplified, and the manufacturing cost can be reduced.

  Further, according to the power supply device 41 of the present embodiment, the first shunt circuit 64 serves as a shunt circuit for the first integrated circuit 47 and serves as a supply circuit for the second integrated circuit 48. Therefore, the number of parts can be reduced, the configuration of the power supply device 41 can be simplified, and the manufacturing cost can be reduced. Further, since the first and second integrated circuits 47 and 48 are electrically connected in series, the current value of the direct current flowing through the first shunt circuit 64 is controlled to be applied to the first integrated circuit 47. The first applied voltage V4 can be controlled, and the second applied voltage V5 applied to the second integrated circuit 48 can be controlled.

  Further, according to the power supply device 41 of the present embodiment, it is not necessary to provide the power supply circuit 42 for each of the integrated circuits 47 and 48, and the structure of the power supply device 41 can be simplified. As a result, the manufacturing cost of the power supply device can be reduced.

  Further, according to the power supply device 41 of the present embodiment, the notification element 89 notifies that the supply of direct current from the power supply circuit 42 is stopped. As a result, the user can be notified that a voltage outside the allowable voltage range has been applied to the second integrated circuit 48. Accordingly, for example, it is possible to notify the user that one of the first and second integrated circuits 47 and 48 is disconnected.

According to the power supply device 41 of the present embodiment, the first shunt circuit 64 provides the same effect as the second shunt circuit 65. Thus, the first and second applied voltages V4 and V5 applied to the integrated circuits 47 and 48 can be controlled to the specified voltages V _IC1 and V _IC2 .

  FIG. 2 is a circuit diagram showing a power supply device 41A according to the second embodiment of the present invention. The power supply device 41A according to the second embodiment is similar in configuration to the power supply device 41 according to the first embodiment. Therefore, the power supply device 41A according to the second embodiment will be described with respect to differences from the power supply device 41 according to the first embodiment, and the same components will be denoted by the same reference numerals and description thereof will be omitted. The power supply device 41A is further provided with a power-on sequence control means 101 and the abnormal stop circuit 44 is omitted from the power supply device 41 of the first embodiment. However, the abnormal stop circuit 44 may be provided in the power supply device 41A, and when provided, the configuration is the same as that of the power supply device 41 of the first embodiment.

  The power-on sequence control means 101 includes a first supply stop element 102, a second supply stop element 103, and a power-on order control circuit 104. The first supply stop element 102 is composed of a pnp transistor, and is interposed between the main conductive path second portion 45 b and the first integrated circuit 47. The first supply stop element 102 has an emitter electrically connected to the main conductive path second portion 45 b and a collector electrically connected to the first integrated circuit 47. The second supply stop element 103 is composed of a pnp transistor, and is interposed between the first and second integrated circuits 47 and 48. More specifically, the second supply stop element 103 is interposed between the first detection conductive path 62 and the second integrated circuit 48. The second supply stop element 103 has an emitter electrically connected to the first integrated circuit 47 and a collector electrically connected to the second integrated circuit 48. The first and second supply stop elements 102 and 103 correspond to supply stop means.

  The power-on sequence control circuit 104 operates the power switch of the electronic device 40 including the power supply device 41 to supply power to the first and second integrated circuits 47 and 48 in a predetermined order. When the application voltages V4 and V5 are respectively applied and the power supply switch of the electronic device 40 is operated to stop the power supply, the first and second integrated circuits 47 and 48 are applied to the first and second integrated circuits 47 and 48, respectively, in a predetermined order. This is a circuit for stopping the second applied voltages V4 and V5. In the present embodiment, a voltage is applied to the power-on sequence control circuit 104 in the order of the first integrated circuit 47 and the second integrated circuit 48, and is applied in the order of the first integrated circuit 47 and the second integrated circuit 48. Stop the voltage. However, it is not limited to such an order. The power-on sequence control circuit 102 is electrically connected to the bases of the first and second supply stop elements 102 and 103, respectively.

  Hereinafter, the operation of the power supply device 41 when the power-on sequence control circuit 104 applies voltages in a predetermined order will be described. When the electronic device 40 including the power supply device 41A is turned on, the power-on sequence control circuit 104 transmits a low-level first supply stop signal to the base of the first supply stop element 102, and the second supply stop element A high-level second supply stop signal is transmitted to the base 103. The first and second supply stop signals are current signals. As a result, the first supply stop element 102 becomes conductive between its emitter and collector, and the second supply stop element 103 becomes non-conductive between its emitter and collector. At this time, the direct current to be supplied to the second integrated circuit 48 flows through the second shunt circuit 65, that is, is commutated to the second shunt circuit 65. As a result, a voltage can be applied only to the first integrated circuit 47.

  Next, the power-on sequence control circuit 104 also transmits a low-level second supply stop signal to the second supply stop element 103. As a result, the second supply stop element 103 becomes conductive between its emitter and collector, and a direct current is supplied to the second integrated circuit 48. In this way, the power-on sequence control circuit 104 operates the first and second integrated circuits 47 and 48 in a predetermined order.

  Next, the operation of the power supply device 41 when the power supply sequence control circuit 104 stops the voltage in a predetermined order will be described. When the electronic device 40 including the power supply device 41 </ b> A is powered off, the power-on sequence control circuit 104 transmits a high-level first supply stop signal to the base of the first supply stop element 102, and the second supply stop element 103. A low-level second supply stop signal is transmitted to the base of. As a result, the first supply stop element 102 becomes nonconductive between its emitter and collector, and the second supply stop element 103 becomes conductive between its emitter and collector. At this time, the second integrated circuit 47 and the main conductive path second portion 45 b are electrically connected by the first shunt circuit 64. As a result, a direct current to be supplied to the first integrated circuit 47 is commutated to the first shunt circuit 65 and flows to the second integrated circuit 48 and the second shunt circuit 65. As a result, the voltage applied to the first integrated circuit 47 can be stopped, and the voltage can be applied only to the second integrated circuit 47.

  Next, the power-on sequence control circuit 104 also transmits a high-level second supply stop signal to the second supply stop element 103. As a result, the second supply stop element 103 becomes non-conductive between the emitter and the collector, the supply of DC current to the second integrated circuit 48 is stopped, and the second applied voltage V5 applied to the second integrated circuit 48. Is stopped. In this manner, the power-on sequence control circuit 104 stops the first and second applied voltages V4 and V5 applied to the first and second integrated circuits 47 and 48 in a predetermined order.

Hereinafter, the effect which power supply device 41A comprised in this way produces is explained. According to the power supply device 41A of the present embodiment, when the supply of DC current to the second integrated circuit 48 is stopped by the second supply stop element 103, the second shunt circuit 65 supplies the second integrated circuit 48 with the direct current. The direct current to be commutated is commutated. Even if the supply of the direct current to the second integrated circuit 65 is stopped even though the first and second integrated circuits 47 and 48 are electrically connected in series, the second shunt circuit 65 is used. The direct current can be supplied to the first integrated circuit 47 by the commutation. Thus, for example, even when the second integrated circuit 48 stops applying the voltage before the first integrated circuit 47, the first integrated circuit 47 can be stably applied with the specified voltage V _IC1 . The first supply stop element 103 and the first shunt circuit 64 have the same effect.

  Further, according to the power supply device 41A of the present embodiment, the same effects as those of the power supply device 41 of the first embodiment are obtained.

FIG. 3 is a circuit diagram showing a power supply device 41B according to the third embodiment of the present invention. The power supply device 41B according to the third embodiment is similar to the power supply device 41 according to the first embodiment. Therefore, the power supply device 41B according to the third embodiment will be described with respect to differences from the power supply device 41 according to the first embodiment, the same components will be denoted by the same reference numerals, and description thereof will be omitted. First, second, and third integrated circuits 47, 48, and 111 are electrically connected in series to the power supply device 41B. The third integrated circuit 111 is interposed between the first integrated circuit 47 and the main conductive path second portion 45b. The third integrated circuit 111 is configured to be operable when a specified voltage V _IC3 is applied. The specified voltage V _IC3 is 5.0 V in the present embodiment. Similarly to the first and second integrated circuits 47 and 48, the third integrated circuit 111 is, for example, a microprocessor and a semiconductor memory. However, the third integrated circuit 111 is not limited to these as long as it is formed by combining a plurality of circuit elements.

The power supply device 41B includes two voltage control circuits 43, one of which is one voltage control circuit 43a and the other is the other voltage control circuit 43b. In order to clarify which configuration of each of the voltage control circuits 43a and 43b is described, each configuration of one voltage control circuit 43 is denoted by “a” and the other voltage control circuit. Each component of 43b will be described by adding “b” to the reference numeral. One voltage control circuit 43a detects the second applied voltage V5 applied to the second integrated circuit 48, similarly to the power supply device 41 of the first embodiment, and compares the comparison circuit 63a, the first shunt circuit 64a, and The second applied voltage V5 is controlled to the specified voltage V _IC2 by the second shunt circuit 65a. The collector of the first shunt circuit 64 a is electrically connected between the first integrated circuit 47 and the third integrated circuit 111 via the third detection conductive path 112.

  In the other voltage control circuit 43b, the emitter of the first shunt circuit 64b and one end of the first shunt circuit 64b are electrically connected to the main conductive path second portion 45b through the conductive path 113. One end of the third detection conductive path 112 corresponding to the first detection conductive path 62 of the voltage control circuit 43 is electrically connected between the first integrated circuit 47 and the third integrated circuit 111, and the other end is a comparison circuit. It is electrically connected to the inverting input terminal 63b. The emitters of the first and second shunt circuits 64 b and 65 b are electrically connected to the third detection conductive path 112. The collector of the second shunt circuit 65 b is electrically connected to the first detection conductive path 62.

  In the power supply device 41B, the abnormal stop circuit 44 is omitted. However, the abnormal stop circuit 44 may be provided in the power supply device 41B. In this case, the first integrated circuit 47 and the second integrated circuit 48 determine whether a voltage within each allowable voltage range is applied, and at least one of them. If one voltage is outside the allowable voltage range, the supply of direct current from the power supply circuit 42 to each of the integrated circuits 47, 48, and 111 is stopped.

In the power supply device 41B configured as described above, as with the voltage control circuit 43 included in the power supply device 41 of the first embodiment, the first and second integrated circuits 47, The first applied voltage V4 and the second applied voltage V5 applied to 48 are controlled to the specified voltages V _IC1 and V _IC2 , respectively. Further, the other applied voltage control circuit 43b controls the third applied voltage V11 and the first applied voltage V4 applied to the third and first integrated circuits 111 and 47, respectively, to the specified voltages V _IC3 and V _IC1 .

  Hereinafter, the effect which the power supply device 41B comprised in this way has is demonstrated. According to the power supply device 41B of the present embodiment, even if the plurality of integrated circuits 47, 48, and 111 are electrically connected in series, the same effect as the power supply device 41 of the first embodiment is obtained.

  FIG. 4 is a circuit diagram showing a power supply device 41C according to the fourth embodiment of the present invention. In the power supply devices 41, 41 </ b> A, and 41 </ b> B according to the first to third embodiments, a battery such as a battery capable of supplying a direct current is used as the power supply 46, but is not necessarily limited to the battery. As shown in FIG. 4, in the power supply device 41 </ b> C, a commercial power supply capable of supplying an alternating current is used as the power supply 46, and an AC / DC conversion circuit (AC−) capable of converting between alternating current and direct current between the transistor 49 and the power supply 46. DC converter) 115 is provided. Accordingly, a commercial power supply can be used, and a highly versatile power supply device 41 can be realized.

  In the present embodiment, the abnormality detection circuit 75 and the reset detection circuit 78 are not limited to the logical sum operation circuit, and may be a negative logical sum operation circuit (NOR gate). In addition, the resistor electrically connected to the output terminal of each comparator controls the current value of the signal input to the transistor by changing these resistance values. By using such a resistor, the conduction state of each transistor can be controlled, and the current value of the current flowing between the emitter and the collector can be controlled.

  In this embodiment, the plurality of integrated circuits are electrically connected to the ground side in order from the lowest specified voltage, but the order is not necessarily limited to this. In this embodiment, the electronic component is described as an integrated circuit. However, the present invention is not necessarily limited to this. The electronic component may be a circuit element such as a resistor, a capacitor, and a coil, or may be an electronic circuit configured by combining a plurality of circuit elements, and is a component to which a predetermined voltage is to be applied. I just need it. The electronic device 40 is not limited to the ECU, and may be an audio device, a personal computer, an electric appliance such as a microwave oven and a refrigerator, and may be any device provided with a plurality of integrated circuits.

It is a circuit diagram which shows the power supply device 41 which is the 1st Embodiment of this invention. It is a circuit diagram which shows the power supply device 41A of the 2nd Embodiment of this invention. It is a circuit diagram which shows the power supply device 41B of the 3rd Embodiment of this invention. It is a circuit diagram which shows the power supply device 41C of the 4th Embodiment of this invention. It is a circuit diagram of the power supply device 1 of the conventional 1st technique. It is a circuit diagram of the power supply device 21 of the conventional 2nd technique.

Explanation of symbols

40 Electronic Device 41 Power Supply Device 42 Power Supply Circuit 43 Voltage Control Circuit 44 Abnormal Stop Circuit 47 First Integrated Circuit 48 Second Integrated Circuit 49 Transistor 62 First Detection Conductive Path 63 Comparison Circuit 64 First Shunt Circuit 65 Second Shunt Circuit 72 Second 2 detection conductive path 79 stop determination circuit 80 abnormality determination means 102 first supply stop circuit 103 second supply stop circuit 111 third integrated circuit 112 third detection conductive path 115 AC / DC conversion circuit

Claims (8)

A power supply circuit that steps down to a supply voltage and supplies a voltage by a step-down element that consumes power and steps down the voltage, and a power supply in which a plurality of electronic components to which a predetermined specified voltage is to be applied are electrically connected in series Circuit,
Detection means for detecting a voltage applied to one electronic component;
Comparing means for comparing the detected voltage with a specified voltage of the electronic component to be detected;
Voltage control means for controlling the voltage applied to the electronic component to be detected to the specified voltage based on the comparison result of the comparison means,
The voltage control means includes a shunt circuit capable of shunting a direct current supplied to the electronic component to be detected and capable of changing a current value of the shunted direct current based on a comparison result of the comparison means. Power supply. The voltage control means
A DC circuit capable of supplying a DC current to the electronic component to be detected, and further comprising a supply circuit capable of changing the current value of the DC current to be supplied based on the comparison result of the comparison means;
When the comparison means determines that the detected voltage is less than the specified voltage, the current value of the direct current supplied by the supply circuit is increased, the current value of the direct current shunted by the shunt circuit is decreased,
When the comparison means determines that the detected voltage exceeds the specified voltage, the current value of the direct current supplied by the supply circuit is decreased, and the current value of the direct current divided by the shunt circuit is increased. The power supply device according to claim 1. A supply stop means for stopping the supply of direct current to the electronic component to be detected;
The voltage control means, when supply of direct current to the electronic component to be detected is stopped, causes a direct current to be supplied to the electronic component to be detected to be commutated by a shunt circuit. Or the power supply device of 2.   The power supply device according to any one of claims 1 to 3, wherein the power supply circuit has a function of converting an alternating current or a direct current supplied from a power supply into a direct current having a predetermined supply voltage. An abnormality determination that determines whether or not the voltage applied to the electronic component to be detected is not included in the allowable voltage range that can be applied to the electronic component to be verified based on the detection result of the detection means Means,
The power supply apparatus according to any one of claims 1 to 4, further comprising stop means for stopping supply of direct current from the power supply circuit when the abnormality determination means determines that the state is abnormal.   The power supply apparatus according to claim 1, wherein an electronic component having a low impedance is arranged closer to a ground side than an electronic component having a high impedance. The power supply circuit is a series regulator whose step-down element is a transistor.
The comparison means is a comparator,
7. The power supply device according to claim 1, wherein the shunt circuit is a transistor that switches a current value of a direct current to be shunted based on an output signal of the comparator. An electronic apparatus provided with the power supply device described in any one of Claims 1-7.

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