JP2010110072A - Power temporary blackout countermeasure circuit and electronic unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power temporary blackout countermeasure circuit which stably supplies necessary large current to a load circuit at the time of power temporary blackout. <P>SOLUTION: A power supply line at the time of power temporary blackout is divided into a first power supply line VSL1 to a first load circuit LD1 which can be operated with low power voltage and a second power supply line VSL2 to a second load circuit LD2 which requires high power voltage. A low voltage-side includes a first charging/discharging capacitor C1, a first switch Q1 controlling connection of an input-side and the first charging/discharging capacitor C1 and a second switch Q2 controlling mutual connection of output-sides of the first charging/discharging capacitor C1 and a regulator REG. A high voltage-side is provided with a second charging/discharging capacitor C2 of a high voltage-side, a boosting step-up converter SUC, the regulator REG outputting stable power voltage to the second load circuit LD2 and a third switch Q3 which usually opens output of the regulator REG and connects it to the second load circuit LD2 at the time of temporary blackout. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a power supply interruption countermeasure circuit and an electronic device. That is, the present invention relates to a power supply circuit and an electronic device having an instantaneous interruption countermeasure function. The present invention can be suitably applied not only to electronic devices that require measures against instantaneous interruption of input power but also to electronic devices that require a backup function such as long-time backup of stored information such as memory. .

  In order to build a system driven by power from the power supply, it is almost always the case that a system is constructed by connecting multiple devices that implement various element functions necessary to realize the system functions. It is indispensable to take minimum measures so that the system itself does not cause malfunction due to any abnormality of a plurality of connected devices. Measures against instantaneous power interruption are one of them, and it is also important to prevent failures such as internal circuit resetting and initialization operations caused by instantaneous power interruption, or the necessity of initial setting work. is there. However, due to restrictions on the system size and the size of each equipment, it has been difficult to continuously operate the entire equipment constituting the system when a power interruption occurs.

  Various proposals have been made to solve this problem. For example, FIG. 6 is a circuit diagram showing a circuit configuration of a conventional power supply instantaneous interruption countermeasure circuit. As described in Japanese Patent Application Laid-Open No. 6-30524 (Patent Document 1) “Power Supply Circuit”, FIG. A basic power supply interruption countermeasure circuit is shown for the circuit configuration in the case of taking a power supply interruption countermeasure using the characteristics.

In the power supply interruption countermeasure circuit of FIG. 6, in the normal time when there is no instantaneous power supply interruption, the input power supply voltage Vin is supplied to the load circuit LD through the Zener diode CR2 as a power supply line to the load circuit LD. The charging / discharging capacitor C3 is charged through the Zener diode CR1. However, when the input power supply voltage Vin is momentarily interrupted, the charge / discharge capacitor C3 starts discharging, and the discharge voltage of the charge / discharge capacitor C3 is supplied to the load circuit LD via the Zener diode CR3.
JP-A-6-30524 (page 4-5)

  However, the power supply interruption countermeasure circuit using the charge / discharge characteristics of the capacitor as shown in FIG. 6 is effective when the current consumption of the load circuit LD is small, but the entire system composed of many devices as the load circuit LD. In general, current consumption increases, and in such a system, a voltage drop occurs during discharge due to the internal resistance of the charge / discharge capacitor C3 itself, and the operation of all the equipment on the load circuit LD side It is difficult to supply sufficient power to guarantee

  Further, as the current consumption increases, the voltage drop increases, and the discharge start voltage and the discharge end voltage of the charge / discharge capacitor C3 as the power supply interruption countermeasure circuit (that is, each component circuit constituting the load circuit LD is normal). The minimum operation guarantee voltage for the operation of the power supply) is reduced, the discharge time is shortened, and it is more difficult to operate the load circuit LD stably during the time from power supply interruption to recovery. turn into.

  The present invention has been made in view of such a problem, and provides a power supply interruption countermeasure circuit and an electronic device that can supply a large current to a load circuit not only in a normal state but also in a power supply interruption. It is intended to provide.

  In order to solve the above-described problems, the power supply interruption countermeasure circuit and the electronic apparatus according to the present invention employ the following characteristic configuration.

  (1) A power supply interruption countermeasure circuit that prevents an instantaneous interruption of the power supply voltage supplied to the load circuit by connecting a charge / discharge capacitor for charging / discharging to the power supply line that supplies the power supply voltage from the input power supply to the load circuit. And a step-up converter for boosting a power supply voltage between the input power supply and the charge / discharge capacitor, and a power supply interruption countermeasure circuit for charging / discharging the charge / discharge capacitor at a high voltage.

  According to the power supply interruption countermeasure circuit and the electronic device of the present invention, the following effects can be obtained.

  First, by using a step-up converter for boosting and charging / discharging the charge / discharge capacitor with a high voltage, the discharge time from the start of discharge to the end of discharge can be extended. It becomes. Thus, it is possible to stably supply a large current to the load circuit not only during normal times but also at the time of instantaneous power interruption. Also, by providing a regulator that outputs a stable voltage between the charge / discharge capacitor that discharges at a high voltage and the load circuit, an excessive power supply voltage exceeding the rated voltage of the load circuit is output in the event of a momentary power interruption. Can be reliably prevented.

  Second, by making the power supply line to the load circuit separate for normal and momentary interruptions, the step-up converter for boosting can be used only for charging the charging / discharging capacitor. Since the current capacity of the DC / DC converter used as a step-up converter can be kept small without being affected by the current consumption of the load circuit, the mounting size can also be reduced. The effect on the mounting side can also be expected.

  Thirdly, the devices used in each equipment on the load circuit side are divided into two groups, one with a relatively low minimum guaranteed operating voltage and one with a relatively low voltage, and power is supplied to each grouped device. By dividing each line as a separate line, it becomes possible to disperse the current consumption and suppress a decrease in supply voltage.

  Fourth, a first switch is inserted between the input power supply and the charge / discharge capacitor on the power supply line from the input power supply to the load circuit, and the second switch is inserted between the charge / discharge capacitor and the load circuit. When the first switch is turned on and the first switch is turned on before the second switch is turned on when recovering from the power interruption, a large amount of inrush current flows from the charge / discharge capacitor. Thus, it is possible to more reliably prevent the occurrence of a situation in which the power supply voltage is greatly lowered and the load circuit cannot be operated. Further, when a separate power supply line including a high voltage charge / discharge capacitor, a step-up converter, and a regulator is provided as a power supply system to the load circuit on the high voltage side, the regulator and the load circuit A third switch is inserted between the first switch and the third switch to the OFF state prior to restarting the power supply from the input power supply or before turning on the first switch and the second switch. Therefore, it is possible to more reliably prevent the occurrence of a situation in which a large amount of inrush current flows from the high-voltage charge / discharge capacitor in front of the regulator, the power supply voltage drops significantly, and the load circuit cannot be operated. Can do.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a power supply interruption countermeasure circuit and an electronic apparatus according to the present invention will be described below with reference to the accompanying drawings. Here, as an electronic device according to the present invention, a mobile phone or a personal digital assistant (PDA: Personal) can be used as long as it is an electronic device that needs to prevent malfunction due to a momentary power interruption or a backup function. It may be a portable small electronic device such as Digital Assistants, or may be a stationary electronic device that processes various types of information, such as a desktop PC (Personal Computer).

(Features of the present invention)
Prior to the description of the embodiments of the present invention, an outline of the features of the present invention will be described first. In the present invention, it is possible to stably supply a large current to the load circuit side not only during normal times but also at the time of instantaneous power interruption by using the following two means. Even in the event of a momentary power interruption, it is possible to supply the power necessary to operate the entire load-side equipment.

  (1) A stable power supply voltage can be obtained by charging a charge / discharge capacitor with a high voltage via a step-up converter for boosting, and inserting a regulator after the charge / discharge capacitor to which the load circuit is connected. To each equipment on the side. This makes it possible to increase the difference between the discharge start voltage and the discharge end voltage of the charge / discharge capacitor, increase the discharge time, and continue the operation of each equipment that makes up the load circuit at the momentary power interruption Can be made. Thus, it is possible to stably supply a large current to the load circuit not only during normal times but also at the time of instantaneous power interruption.

  (2) Regarding devices used in each equipment on the load circuit side, those that require a power supply voltage that is higher than a predetermined threshold value and that can operate with a power supply voltage that is lower than the threshold value. And the power supply lines to each of the divided groups are divided as separate lines. As a result, current consumption is dispersed and voltage drop can be suppressed.

  For example, the power supply interruption countermeasure circuit according to the present invention switches between two external power supplies ("first external power supply VS1" and "second external power supply VS2") as shown in the block diagram of FIG. In this case, regarding the instantaneous interruption of the input power supply voltage that occurs at the time of switching, so that the target equipment on the load circuit LD side can continue normal operation even during switching of the external power supply (during instantaneous power interruption) A stable power supply can be supplied to each component in the target equipment.

  That is, the power supply interruption countermeasure circuit shown in FIG. 1 basically uses the charge / discharge characteristics of the charge / discharge capacitor C2 as in the case of the prior art shown in FIG. Unlike the case, the charge / discharge capacitor C2 is charged with a high voltage by a step-up converter SUC (Step Up Converter) for boosting the power supply voltage, and the regulator REG is applied to each component on the load circuit LD (Load) side. Supplying a stabilized voltage with (Regulator), and further dividing the power supply line into two lines depending on the level of operation guarantee voltage inside each component on the load circuit LD side. Even so, it is possible to suppress the decrease in the supply voltage and to continuously operate each component on the load circuit LD side, that is, the entire equipment.

(Example of the present invention)
FIG. 2 is a circuit diagram showing an example of the circuit configuration of the power supply interruption countermeasure circuit according to the present invention. The step-up converter SUC boosts the charge / discharge capacitor C2 at a high voltage, and the charge / discharge capacitor. The circuit configuration in the case where a power supply voltage stabilized by a regulator REG subsequent to C2 is supplied to the load circuit LD side is shown. In normal times when the power supply is not momentarily interrupted, although not shown, the power supply line is not connected via a step-up converter SUC or regulator REG, that is, via a power supply line different from that at the time of instantaneous interruption. Thus, the input power supply voltage Vin may be directly supplied to the load circuit LD.

  In FIG. 2, the Zener diode CR4 is for avoiding discharge to the primary side (input side), and the regulator REG charges and discharges the charge / discharge capacitor C2 at a high voltage, so that the load circuit LD This is a circuit for supplying a stable power supply voltage that does not exceed the power supply rating of the load circuit LD in order to prevent a power supply voltage exceeding the power supply rating from being supplied to the load circuit LD.

  However, with the circuit configuration shown in FIG. 2, the power supply voltage is supplied to the entire load circuit LD through one power supply line, and the current required for the operation of the entire load circuit LD increases. The current capacity required for the step-up converter SUC for use increases, the size of the member increases, and a new problem that mounting on the mounting surface becomes difficult may occur.

  3 is a circuit diagram showing another example of the circuit configuration of the power supply interruption countermeasure circuit according to the present invention, and shows a circuit configuration example that solves a problem that may occur in the power supply interruption countermeasure circuit of FIG. ing.

  In the power supply interruption countermeasure circuit of FIG. 3, first, a third switch Q3 is provided after the regulator REG. Here, the third switch Q3 uses a transistor having a small ON resistance, such as a MOS FET (Metal Oxide Semiconductor Field Effect Transistor), in order to suppress a decrease in the power supply voltage to the second load circuit LD2 as much as possible.

  Further, according to the minimum operation guarantee voltage of the device used for the load circuit LD, the load circuit LD is divided into two load groups, the first load circuit LD1 on the low voltage side and the second load circuit LD2 on the high voltage side, In order to supply power separately to each load group at the time of instantaneous power interruption, the power supply line is divided into a first power supply line VSL1 (Voltage Supply Line 1) on the low voltage side and a second power supply line on the high voltage side. By using two power supply lines VSL2 (Voltage Supply Line 2), it is possible to obtain a circuit configuration in which current consumption is dispersed and a decrease in power supply voltage is suppressed.

  The configuration of the power supply interruption countermeasure circuit of FIG. 3 will be further described as follows. That is, the power supply interruption countermeasure circuit shown in FIG. 3 has a voltage drop detection circuit DET that detects the occurrence of a drop (instantaneous interruption) in the input power supply voltage Vin and the switches Q1, Q2, and Q3 based on the detection result of the voltage drop detection circuit DET. A control signal output circuit OUT for outputting a control signal for controlling ON / OFF is provided, and a first power supply line VSL1 for supplying power to the first load circuit LD1 on the low voltage side is configured. 1 and a second power supply system constituting a second power supply line VSL2 for supplying power to the second load circuit LD2 on the high voltage side.

  Here, the circuit element of the first power supply system constituting the first power supply line VSL1 side on the low voltage side is the first charge / discharge capacitor C1 for instantaneous interruption countermeasure, and the first charge / discharge in the normal state. The output side of the capacitor C1 and the regulator REG are connected to each other, and the input power supply voltage Vin is supplied to both the first load circuit LD1 and the second load circuit LD2, and when an instantaneous interruption occurs, the first charge / discharge capacitor In order to avoid the discharge to the input side, the second switch Q2 for disconnecting the output side connection between C1 and the regulator REG and supplying the discharge voltage of the first charge / discharge capacitor C1 only to the first load circuit LD1 The first switch Q1 is included at least. Here, it is desirable that the first switch Q1 and the second switch Q2 be configured using transistors having low ON resistance, for example, MOS FETs.

  On the other hand, the circuit element of the second power supply system constituting the second power supply line VSL2 side on the high voltage side includes the second charge / discharge capacitor C2 and the second charge / discharge capacitor C2 for measures against instantaneous interruption. In order to charge with high voltage, step-up converter SUC (Step Up Converter) that boosts input power supply voltage Vin exceeds the rated value of second load circuit LD2 due to high-voltage discharge of second charge / discharge capacitor C2. A regulator REG (Regulator) for protecting the second load circuit LD2 from being damaged by applying an excessive power supply voltage. Normally, the output of the regulator REG is disconnected from the second load circuit LD2, and an instantaneous interruption occurs. Sometimes, a third switch Q3 for supplying the output of the regulator REG to the second load circuit LD2 and a Zener diode CR4 for avoiding discharge to the input side are provided. It is configured to include even without. As described above, the third switch Q3 is preferably configured using a transistor having a low ON resistance, for example, a MOS FET.

(Description of operation of the embodiment)
Next, an example of the operation of the power supply interruption countermeasure circuit shown in FIG. 3 will be described with reference to FIGS. First, a normal operation without a power interruption will be described with reference to FIG. FIG. 4 is a power supply system diagram showing an example of a normal power supply line for supplying the input power supply voltage Vin to the load circuit side in FIG. 3, and two broken lines indicate the second charge / discharge in the normal state. A charge line CUL (Charge-Up Line) to the capacitor C2 and a common power supply line VSL (Voltage Supply Line) to the first load circuit LD1 and the second load circuit LD2 are shown.

  When the input power supply voltage Vin is normally input without a voltage drop at the normal time, the voltage drop detection circuit DET notifies the control signal output circuit OUT that the input power supply voltage Vin is normal. The control signal output circuit OUT receiving that the input power supply voltage Vin is normal outputs a control signal for turning on the first switch Q1 and the second switch Q2 as the first control signal CONT1, and the first control signal CONT1. 3 is output as a second control signal CONT2.

  As a result, the third switch Q3, which is one of the constituent elements of the second power supply line VSL2 on the high voltage side at the time of the momentary power interruption, is turned off, so that the output of the regulator REG becomes no load, and the step-up The power supply voltage Vo2 boosted by the converter SUC is used only for charging the second charging / discharging capacitor C2, as in the charging line CUL indicated by the broken line.

  Further, since both the first switch Q1 and the second switch Q2, which are constituent elements of the first power supply line VSL1 on the low voltage side at the time of instantaneous power interruption, are turned on, the input power supply voltage Vin is The charging / discharging capacitor C1 is charged, and, as the power supply line VSL shown by a broken line, the power supply voltage Vo1 serves as an operating power supply for the first load circuit LD1 on the low voltage side, and via the second switch Q2. Thus, it serves as an operating power source for the second load circuit LD2 on the high voltage side.

  In other words, each component of the first power supply system constituting the first power supply line VSL1 on the low voltage side at the time of instantaneous power interruption is the first load circuit LD1 on the low voltage side and the high voltage supply circuit LD1 in the normal state. A power supply line VSL for supplying the input power supply voltage Vin to the second load circuit LD2 on the voltage side is configured. On the other hand, among the constituent elements of the second power supply system constituting the second power supply line VSL2 on the high voltage side at the momentary power interruption, the step-up converter SUC and the Zener diode CR4 are normally used. The charging line CUL for charging the second charging / discharging capacitor C2 is configured, and the third switch Q3 is normally in an OFF state to supply the power supply voltage Vo3 output from the regulator REG to the high voltage side. The switching function is performed so as not to be supplied to the second load circuit LD2.

  Next, the operation when a power interruption occurs will be described with reference to FIG. FIG. 5 is a power supply system diagram showing an example of a power supply line that supplies a power supply voltage to the load circuit side in the event of a momentary power interruption in FIG. 3, and two broken lines indicate the first on the low voltage side when a momentary interruption occurs. A first power supply line VSL1 (Voltage Supply Line 1) for supplying a power supply voltage to the load circuit LD1 and a second power supply line VSL2 (Voltage Supply Line 1) for supplying a power supply voltage to the second load circuit LD2 on the high voltage side. Supply Line 2) is shown.

  When the instantaneous interruption of the input power supply voltage Vin occurs, the voltage drop detection circuit DET notifies the control signal output circuit OUT that the instantaneous interruption has occurred. The control signal output circuit OUT that has received the fact that the input power supply voltage Vin has been momentarily interrupted, contrary to the normal case, outputs a control signal for turning off the first switch Q1 and the second switch Q2. The control signal CONT1 is output, and the control signal for turning on the third switch Q3 is output as the second control signal CONT2.

  Here, since the input power supply voltage Vin is cut off, the power supply voltage Vo2 output from the step-up converter SUC for charging the second charge / discharge capacitor C2 also decreases, and the second charge / discharge capacitor C2 starts discharging at a high voltage. As a result, as described above, since the third switch Q3 is in the ON state and the second switch Q2 is in the OFF state, the second charging / discharging capacitor C2 that has started discharging at a high voltage. The discharge voltage becomes the power supply voltage Vo3 stabilized by the regulator REG, and is supplied to the second load circuit LD2 via the second power supply line VSL2 on the high voltage side shown by the broken line.

  Thereafter, in the discharging operation of the second charging / discharging capacitor C2, the discharge voltage gradually decreases with time, and the output power supply voltage Vo3 of the regulator REG, which has decreased accordingly, is reduced to the second voltage on the high voltage side. It is stabilized by the regulator REG until a sufficient voltage cannot be supplied to operate the load circuit LD2 or until the momentary interruption is restored and the third switch Q3 is switched from the ON state to the OFF state. The state in which the power supply voltage Vo3 is supplied to the second load circuit LD2 on the high voltage side via the second power supply line VSL2 on the high voltage side continues.

  Further, the third switch Q3 is turned on, and the operation of supplying the discharge voltage of the second charge / discharge capacitor C2 to the second load circuit LD2 is started, and at the same time, the first switch Q1 and the second switch Since Q2 is switched to the OFF state, the first charge / discharge capacitor C1 on the low voltage side also starts to discharge. The power supply voltage Vo1 from the first charging / discharging capacitor C1 that has started discharging is, as indicated by a broken line, the first power supply dedicated to the low voltage side, which is different from the second power supply line VSL2 on the high voltage side. The voltage is supplied to the second load circuit LD2 through the line VSL1. Since the second switch Q2 is in the OFF state, the power supply voltage Vo1 discharged from the first charge / discharge capacitor C1 is not supplied to the second load circuit LD2 on the high voltage side, and the low voltage side Is used only for the operation of the first load circuit LD1.

  That is, at the time of instantaneous power interruption, the first power supply line VSL1 that supplies the discharge voltage of the first charge / discharge capacitor C1, that is, the power supply voltage Vo1, to the first load circuit LD1 on the low voltage side, and the high voltage side A second power supply line VSL2 for supplying a power supply voltage Vo3 obtained by stabilizing the high discharge voltage of the second charge / discharge capacitor C2 to the second load circuit LD2 by the regulator REG serves as two power supply lines. It is divided and formed separately. Among the components of the first power supply system constituting the first power supply line VSL1 on the low voltage side, the first switch Q1 is in the OFF state at the time of instantaneous power interruption, and the first The charging / discharging capacitor C1 performs a switching function to prevent the discharge voltage from flowing into the input side, and the second switch Q2 is turned off when the power supply is instantaneously interrupted, and the first charging / discharging capacitor C1 It performs a switching function for disconnecting each other from the output side of the regulator REG. Further, in the Zener diode CR4, which is one of the components of the second power supply system that constitutes the second power supply line VSL2 on the high voltage side, the discharge voltage of the second charge / discharge capacitor C2 flows into the input side. It plays a function to avoid that.

  When the input power supply voltage Vin is recovered from the instantaneous interruption, the first switch Q1, the second switch Q2, and the third switch Q3 return to the normal state without the instantaneous interruption. As described above, the power supply line VSL is used to charge the first charging / discharging capacitor C1 with the input power supply voltage Vin, the first load circuit LD1 on the low voltage side, and the second load circuit LD2 on the high voltage side. Power supply to the power supply (power supply voltage Vo1) is restarted, and the charging operation to the second charge / discharge capacitor C2 by the power supply voltage Vo2 output from the step-up converter SUC is restarted using the charging line CUL. .

  Here, during the recovery operation, when the charging operation by the input power supply voltage Vin and the power supply operation to the first and second load circuits LD1 and LD2 are resumed, the discharge amount of the second charge / discharge capacitor C2 is reduced. In many cases, the discharge current suddenly flows into the load circuit at the moment when the input power supply voltage Vin is restored, that is, at the moment when the first switch Q1 and the second switch Q2 are turned on. May decrease and the minimum guaranteed operating voltage of the first load circuit LD1 and the second load circuit LD2 may not be satisfied.

  Therefore, the third switch Q3 for turning on / off the connection state between the second charge / discharge capacitor C2 and the second load circuit LD2 is prior to the restart of the power supply from the input power supply voltage Vin. Switching to the OFF state, that is, the first switch Q1, the first charge / discharge capacitor C1, the first load circuit LD1, and the second switch for connecting the input power supply voltage Vin side to the first charge / discharge capacitor C1. Before switching the second switch Q2 for connecting to the load circuit LD2 to the ON state, the second switch circuit Q2 is switched to the OFF state and adjusted to disconnect the second load circuit LD2 from the second charge / discharge capacitor C2. Has been. The first switch Q1 for connecting the input power supply voltage Vin side to the first charging / discharging capacitor C1 is connected between the first charging / discharging capacitor C1, the first load circuit LD1, and the second load circuit LD2. It is adjusted so as to be switched to the ON state before the second switch Q2 to be connected.

  Note that the power supply interruption countermeasure circuit according to the present invention is not limited to the countermeasure against the instantaneous interruption of the input power supply voltage Vin. For example, it is necessary to back up information stored in a memory or the like for a long time, for example, in various control circuit settings. It can also be applied as a backup circuit or the like in such electronic equipment. In other words, in electronic devices equipped with a backup circuit that backs up the control information set in the control circuit and the memory information stored in the memory, etc., it is possible to prevent malfunctions when there is a momentary power interruption or noise. In order to do so, it is also possible to incorporate a power supply interruption countermeasure circuit as described above into the backup circuit.

(Explanation of effect)
As described above, the power supply interruption countermeasure circuit according to this embodiment has the following effects.

  First, as shown in FIG. 2, by using a step-up converter SUC for boosting, the charge / discharge capacitor C2 is charged / discharged at a high voltage, thereby extending the discharge time from the start of discharge to the end of discharge. It becomes possible to do. Thus, it is possible to stably supply a large current to the load circuit LD not only at the normal time but also at the time of instantaneous power interruption. In addition, by providing a regulator REG that outputs a stable voltage between the charge / discharge capacitor C2 that charges and discharges at a high voltage and the load circuit LD, an excessive voltage exceeding the rated voltage of the load circuit LD can be obtained in the event of a momentary power interruption. It is possible to reliably prevent the power supply voltage from being output.

  Second, the step-up converter SUC for boosting is used only for charging the charging / discharging capacitor C2 by making the power supply line to the load circuit LD a separate line for normal and momentary interruptions. Since the current capacity of the DC / DC converter (DC / DC Converter) used as the step-up converter SUC can be kept small without being affected by the current consumption of the load circuit LD, the mounting size can also be reduced. It can be made smaller, and an effect on the mounting surface can also be expected.

  Thirdly, as shown in FIG. 3, the first load circuit LD1 having a relatively low minimum guaranteed operating voltage and the second load circuit having a relatively high value are used for the devices used in the respective equipment on the load circuit LD side. By dividing into two groups LD2 and dividing the power supply line to each of the divided groups into a first power supply line VSL1 on the low voltage side and a power supply line VSL2 on the high voltage side. Thus, it is possible to disperse the current consumption, and to suppress a decrease in supply voltage.

  Fourth, on the power supply line VSL from the input power supply voltage Vin to the first and second load circuits LD1 and LD2, the first switch Q1 is interposed between the input power supply voltage Vin and the first charge / discharge capacitor C1. Is inserted, and the second switch Q2 is inserted between the first charge / discharge capacitor C1 and the second load circuit LD2 on the high voltage side, and the second charge / discharge capacitor is charged / discharged at a high voltage. When the third switch Q3 is inserted between the regulator REG at the subsequent stage of C2 and the second load circuit LD2 to recover from the instantaneous power interruption, prior to restarting the power supply from the input power supply voltage Vin, or Before turning on the first switch Q1 and the second switch Q2, by switching the third switch Q3 to the OFF state, a large amount of inrush current flows from the second charge / discharge capacitor C2, Source voltage drops significantly, it is possible to the second load circuit LD2 are more reliably prevent the occurrence of not operate situation. Furthermore, by switching the first switch Q1 to the ON state before turning on the second switch Q2, a large amount of inrush current flows from the first charge / discharge capacitor C1, and the power supply voltage is greatly reduced. Thus, it is possible to more reliably prevent the occurrence of a situation where the first and second load circuits LD1 and LD2 cannot operate.

  That is, in the circuit configuration shown in FIG. 2, on the power supply line VSL from the input power supply voltage Vin to the load circuit LD, the first switch Q1 is used as a preceding switch between the input power supply voltage Vin and the charge / discharge capacitor C2. Is inserted, and the second switch Q2 is inserted as a subsequent switch between the charge / discharge capacitor C2 and the load circuit LD, and the second switch Q2 of the subsequent switch is turned on when recovering from an instantaneous power interruption. By switching the first switch Q1 of the previous stage switch to the ON state, a large amount of inrush current flows from the charge / discharge capacitor C2, the power supply voltage is greatly reduced, and the load circuit LD can operate. Occurrence of a situation that disappears can be prevented more reliably.

  Further, as shown in FIG. 3, at least the first switch Q1, the second switch Q2, and the first charge / discharge capacitor C1 are provided to supply power to the first load circuit LD1 on the low voltage side. Separately from the first power supply line VSL1, at least a second charge / discharge capacitor C2, a step-up converter SUC, and a regulator REG for high voltage are provided as a power supply system to the second load circuit LD2 on the high voltage side. When the provided second power supply line VSL2 is provided, a third switch Q3 is inserted between the regulator REG and the second load circuit LD2, and prior to restarting the power supply from the input power supply voltage Vin, Alternatively, before turning on the first switch Q1 and the second switch Q2, the third switch Q3 is switched to the OFF state, thereby regulating. It is even more certain that a large amount of inrush current will flow from the high-voltage second charge / discharge capacitor C2 in the previous stage of the REG, the power supply voltage will drop significantly, and the second load circuit LD2 cannot operate. Can be prevented.

The configuration of the preferred embodiment of the present invention has been described above. However, it should be noted that such examples are merely illustrative of the invention and do not limit the invention in any way. Those skilled in the art will readily understand that various modifications and changes can be made according to a specific application without departing from the gist of the present invention. For example, the embodiment of the present invention can be expressed as the following configuration in addition to the configuration (1) in the means for solving the problems.
(2) A power supply voltage that can stably operate without exceeding a rated value of the load circuit by inserting a regulator that outputs a stable voltage between the charge / discharge capacitor and the load circuit. (1) The instantaneous power failure countermeasure circuit for supplying power to the load circuit.
(3) A Zener diode is inserted between the step-up converter and the charge / discharge capacitor to prevent a discharge operation from the charge / discharge capacitor to the input power supply side. ) Power supply interruption countermeasure circuit.
(4) Between the step-up converter and the charge / discharge capacitor, a discharge operation from the charge / discharge capacitor to the input power supply side is prevented, and the step-up converter and the charge / discharge capacitor are connected to each other. A first-stage switch for turning on / off the power supply is inserted, and a second-stage switch for turning on / off the connection between the charge / discharge capacitor and the load circuit is inserted between the charge / discharge capacitor and the load circuit. ) Or (2) power supply interruption countermeasure circuit.
(5) The power supply interruption countermeasure circuit according to (4), wherein when the input power supply is recovered from the instantaneous interruption, the preceding switch is turned on before the latter switch is turned on.
(6) The first load circuit on the low voltage side capable of operating each component constituting the load circuit with a power supply voltage whose minimum operation guaranteed voltage is lower than a predetermined threshold, and the minimum operation guaranteed voltage When the input power supply is momentarily cut off, the power supply voltage is supplied to the first load circuit on the low voltage side when the input power supply is momentarily interrupted. A first power supply system constituting a first power supply line for performing a second power supply line and a second power supply line constituting a second power supply line for supplying a power supply voltage to the second load circuit on the high voltage side The power supply interruption countermeasure circuit according to any one of the above (1) to (5), wherein each component of the power supply interruption countermeasure circuit is divided into two parts with the power supply system.
(7) The components constituting the second power supply system include the second charge / discharge capacitor for high-voltage side instantaneous interruption countermeasures and the second charge / discharge capacitor for charging the second charge / discharge capacitor with a high voltage. The step-up converter inserted between an input power supply and the second charge / discharge capacitor, the second charge / discharge capacitor and the second charge / discharge capacitor for outputting a stable power supply voltage to the second load circuit. In the normal time when there is no instantaneous interruption of the input power supply and the regulator inserted between the load circuit and the load circuit, the output of the regulator is disconnected from the second load circuit, while the input power supply is instantaneously interrupted. The power supply interruption countermeasure circuit according to (6), which is configured to include at least a third switch for connecting the output of the regulator to the second load circuit.
(8) The components constituting the first power supply system include a first charging / discharging capacitor on the low voltage side for instantaneous interruption, and discharging from the first charging / discharging capacitor to the input power source side. And a first switch for turning on / off the connection between the input power source and the first charge / discharge capacitor, and in a normal time when there is no instantaneous interruption of the input power source, The output side of the regulator is connected to each other, and input power is supplied to both the first load circuit and the second load circuit. On the other hand, when an instantaneous interruption of the input power occurs, the first charge / discharge capacitor And a second switch that disconnects the output side connection with the regulator and supplies the discharge voltage of the first charge / discharge capacitor only to the first load circuit (7) Power supply interruption countermeasure circuit of.
(9) When recovering from a momentary interruption of the input power supply, prior to restarting power supply from the input power supply or prior to switching the first switch and the second switch to the ON state (8) The instantaneous power failure countermeasure circuit for switching the third switch to the OFF state.
(10) The power supply interruption countermeasure circuit according to (9), wherein when the input power supply is recovered from the instantaneous interruption, the first switch is turned on before the second switch is turned on. .
(11) In an electronic device provided with a backup circuit that backs up control information of the control circuit and stored information stored in the memory, as a protection mechanism for preventing malfunction at the time of instantaneous power interruption or noise Item 11. An electronic device comprising the backup power supply circuit including the power supply interruption countermeasure circuit according to any one of Items 1 to 10.

It is a block diagram which shows an example of the concept of the circuit structure of the power supply instantaneous interruption countermeasure circuit by this invention. It is a circuit diagram which shows an example of the circuit structure of the power supply instantaneous interruption countermeasure circuit by this invention. It is a circuit diagram which shows the other example of the circuit structure of the power supply instantaneous interruption countermeasure circuit by this invention. FIG. 4 is a power supply system diagram illustrating an example of a normal power supply line that supplies an input power supply voltage to the load circuit side in FIG. 3. FIG. 4 is a power supply system diagram illustrating an example of a power supply line that supplies power to the load circuit side in the event of a momentary power interruption in FIG. 3. It is a circuit diagram which shows the circuit structure of the conventional power supply interruption countermeasure circuit.

Explanation of symbols

C1 first charge / discharge capacitor C2 second charge / discharge capacitor (or charge / discharge capacitor)
C3 charge / discharge capacitor CONT1 first control signal CONT2 second control signal CR1 zener diode CR2 zener diode CR3 zener diode CR4 zener diode CUL charge line DET voltage drop detection circuit LD load circuit LD1 first load circuit LD2 second load Circuit OUT Control signal output circuit Q1 First switch Q2 Second switch Q3 Third switch REG Regulator
SUC Step Up Converter
Vin input power supply voltage VS1 first external power supply VS2 second external power supply VSL power supply line VSL1 first power supply line VSL2 second power supply line

Claims (11)

  In the power supply interruption countermeasure circuit that prevents instantaneous interruption of the power supply voltage supplied to the load circuit by connecting a charge / discharge capacitor for charging / discharging to the power supply line that supplies the power supply voltage from the input power supply to the load circuit, A power supply interruption countermeasure circuit, wherein a step-up converter for boosting a power supply voltage is inserted between an input power supply and the charge / discharge capacitor, and the charge / discharge capacitor is charged / discharged at a high voltage.   A regulator that outputs a stable voltage is inserted between the charge / discharge capacitor and the load circuit, and a power supply voltage that can operate stably without exceeding the rated value of the load circuit is supplied to the load. The power supply interruption countermeasure circuit according to claim 1, wherein the circuit is supplied to the circuit.   The Zener diode for preventing the discharge operation | movement from the said charging / discharging capacitor | condenser to the said input power supply side is inserted between the said step-up converter and the said charging / discharging capacitor | condenser. Power supply interruption countermeasure circuit described in 1.   Between the step-up converter and the charge / discharge capacitor, a discharge operation from the charge / discharge capacitor to the input power supply side is prevented, and the connection between the step-up converter and the charge / discharge capacitor is turned ON / OFF. A pre-stage switch to be turned off is inserted, and a post-stage switch to turn on / off the connection between the charge / discharge capacitor and the load circuit is inserted between the charge / discharge capacitor and the load circuit. Item 3. A circuit for countermeasures against instantaneous power interruption according to item 1 or 2.   5. The power supply interruption countermeasure circuit according to claim 4, wherein when the input power supply is recovered from an instantaneous interruption, the front stage switch is switched to an ON state prior to switching the rear stage switch to an ON state.   Each component constituting the load circuit includes a first load circuit on a low voltage side capable of operating with a power supply voltage whose minimum operation guaranteed voltage is lower than a predetermined threshold, and a minimum operation guaranteed voltage equal to or higher than the threshold. When the input power supply is momentarily interrupted, the power supply voltage is supplied to the first load circuit on the low voltage side when divided into two groups with the second load circuit on the high voltage side that requires a high power supply voltage. A first power supply system constituting a first power supply line, and a second power supply system constituting a second power supply line for supplying a power supply voltage to the second load circuit on the high voltage side The power supply interruption countermeasure circuit according to claim 1, wherein each component of the power supply interruption countermeasure circuit is disposed.   The components constituting the second power supply system include: a second charging / discharging capacitor for countermeasures against instantaneous interruption on a high voltage side; and the input power supply for charging the second charging / discharging capacitor with a high voltage. The step-up converter inserted between the second charge / discharge capacitor and the second charge / discharge capacitor and the second load for outputting a stable power supply voltage to the second load circuit. In the normal time when there is no instantaneous interruption of the input power supply and the regulator inserted between the circuit, the output of the regulator is disconnected from the second load circuit, while when the instantaneous interruption of the input power supply occurs, The power supply interruption countermeasure circuit according to claim 6, comprising at least a third switch for connecting an output of a regulator to the second load circuit.   The components constituting the first power supply system include a first charging / discharging capacitor for low-voltage-side instantaneous interruption countermeasures, and preventing discharge from the first charging / discharging capacitor to the input power supply side. The first switch for turning on / off the connection between the input power source and the first charge / discharge capacitor, and the normal time when there is no instantaneous interruption of the input power source, the first charge / discharge capacitor and the regulator The output sides are connected to each other, and input power is supplied to both the first load circuit and the second load circuit. On the other hand, when an instantaneous interruption of the input power occurs, the first charge / discharge capacitor and the regulator And a second switch that disconnects the connection on the output side and supplies the discharge voltage of the first charge / discharge capacitor only to the first load circuit. Power supply interruption countermeasure circuit of claim 7.   When recovering from an instantaneous interruption of the input power supply, prior to resuming the power supply from the input power supply, or prior to switching the first switch and the second switch to the ON state, The power supply interruption countermeasure circuit according to claim 8, wherein the switch 3 is switched to an OFF state.   10. The power supply instantaneous switch according to claim 9, wherein when the input power supply is recovered from the instantaneous interruption, the first switch is turned on before the second switch is turned on. Disconnection countermeasure circuit.   In an electronic device provided with a backup circuit that backs up control information of a control circuit and storage information stored in a memory, as a protection mechanism for preventing malfunction when a power supply interruption occurs or noise occurs, claims 1 to An electronic apparatus comprising the power supply interruption countermeasure circuit according to any one of 10 in the backup circuit.

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