TW201516611A - Power supply circuit for central processing unit - Google Patents

Abstract

A power supply circuit for central processing unit (CPU) includes a comparing circuit, first to third switch circuits, first and second compensation circuits, a pulse width modulation (PWM) controller, a first power circuit connected to a first output pin of the PWM controller, and a second power circuit connected to a second output pin of the PWM controller. When a motherboard operates normally, the comparing circuit outputs a first control signal to control the first and third switch circuits to be turned on. The second switch circuit is turned off. The first compensation circuit provides a compensation signal to the PWM controller. When the motherboard is powered off, the comparing circuit outputs a second control signal to control the first and third switch circuits to be turned off. The second switch circuit is turned on. The second compensation circuit provides a compensation signal to the PWM controller.

Description

CPU power supply circuit

The present invention relates to a CPU power supply circuit.

At present, the computer motherboard provides a multi-phase power supply circuit, such as a two-phase power supply circuit, to supply voltage to the CPU. However, the multi-phase power supply circuit works under normal working conditions of the computer motherboard, and is in a standby state of the computer motherboard. Only one phase power supply circuit works. Because the power supply circuit that supplies power to the CPU is different when the computer is in different states, this will make the voltage received by the CPU unstable and may cause CPU damage.

In view of this, it is necessary to provide a CPU power supply circuit capable of providing a stable voltage to the CPU to prevent the CPU from being damaged due to voltage instability.

A CPU power supply circuit includes a comparison circuit, a first switch circuit, a second switch circuit, a third switch circuit, a first compensation circuit, a second compensation circuit, a pulse width modulation controller, and a connection a first phase power supply circuit of the first output pin of the pulse width modulation controller and a second phase power supply circuit connected to the second output pin of the pulse width modulation controller, the comparison circuit including first and second resistors and a comparison The non-inverting input terminal of the comparator is connected to a power source through the first resistor, the non-inverting input terminal of the comparator is also grounded through the second resistor, and the inverting input terminal of the comparator is connected to a reference voltage, the comparator The output end is connected to the first and third switch circuits to control the on and off of the first and third switch circuits, the second switch circuit is connected to the third switch circuit, and the third switch circuit controls the second switch circuit The first resistor is a thermistor disposed near the inductor of the second phase power supply circuit; when the computer motherboard is working normally, the first and second phase power supply circuits are all working, The comparator outputs a first control signal to the first and third switch circuits according to the voltage of the non-inverting input terminal, the first and third switch circuits are turned on, and the third switch circuit controls the second switch circuit to be turned off. a compensation circuit provides a compensation signal to the pulse width modulation controller through the first switching circuit, so that the pulse width modulation controller adjusts the pulse signals outputted to the first and second phase power supply circuits to provide a stable voltage to the CPU; when the computer motherboard is in standby, the first phase power supply circuit operates and the second phase power supply circuit does not work, the comparator outputs a second control signal to the first and third switch circuits according to the voltage of the non-inverting input terminal thereof The first and third switch circuits are turned off, and the third switch circuit controls the second switch circuit to be turned on, and the second compensation circuit provides a compensation signal to the pulse width modulation controller through the second switch circuit to enable the pulse The wide modulation controller adjusts the pulse signal output to the first phase power supply circuit to provide a stable voltage to the CPU.

The CPU power supply circuit provides a compensation signal through the first compensation circuit to provide a stable voltage to the CPU when the computer motherboard is in an operating state, and provides a compensation signal through the second compensation circuit to provide stability when the computer motherboard is in a standby state. Voltage is given to the CPU. The CPU power supply circuit provides a stable voltage to the CPU, thereby preventing the CPU from being damaged due to voltage instability.

100‧‧‧CPU power supply circuit

10‧‧‧Comparative circuit

20‧‧‧First switch circuit

30‧‧‧Second switch circuit

40‧‧‧ Third switch circuit

50‧‧‧First compensation circuit

60‧‧‧Second compensation circuit

70‧‧‧PWM controller

80‧‧‧First phase power supply circuit

90‧‧‧Second phase power supply circuit

200‧‧‧CPU

R0-R8‧‧‧ resistance

C3-C8‧‧‧ capacitor

U1‧‧‧ comparator

Q1-Q5‧‧‧ Field Effect Transistor

1 is a circuit diagram of a preferred embodiment of a CPU power supply circuit of the present invention.

Referring to FIG. 1, the CPU power supply circuit 100 of the present invention is disposed on a computer motherboard to provide a voltage for a central processing unit (CPU) 200. In this embodiment, a two-phase power supply circuit is taken as an example for description. The preferred embodiment of the CPU power supply circuit 100 includes a comparison circuit 10, a first switch circuit 20, a second switch circuit 30, a third switch circuit 40, a first compensation circuit 50, and a second compensation circuit 60. A pulse width modulation (PWM) controller 70, a first phase power supply circuit 80, and a second phase power supply circuit 90. The comparison circuit 10 is disposed adjacent to the second phase power supply circuit 90.

When the computer motherboard is working normally, that is, the first and second phase power supply circuits 80 and 90 are both working, at this time, the comparison circuit 10 outputs a first control signal to the first and third switch circuits 20 and 40. The first and third switch circuits 20 and 40 are turned on, and the second switch circuit 30 is turned off. The first compensation circuit 50 provides a compensation signal to the PWM controller 70 through the first switch circuit 20 to enable the PWM controller. The pulse signals output to the first and second phase power supply circuits 80 and 90 are adjusted to provide a stable voltage to the CPU 200. When the computer motherboard is in standby, that is, the first phase power supply circuit 80 is in operation and the second phase power supply circuit 90 is inactive, the comparison circuit 10 outputs a second control signal to the first and third switch circuits 20 And the first and third switch circuits 20 and 40 are turned off, the second switch circuit 30 is turned on, and the second compensation circuit 60 provides the PWM controller 70 with a compensation signal through the second switch circuit 30 to enable the PWM. The controller 70 adjusts the pulse signal output to the first phase power supply circuit 80 to provide a stable voltage to the CPU 200. The electronic component connection relationship and the working principle of the first and second phase power supply circuits 80 and 90 are conventional technologies, and are not described herein again.

The comparison circuit 10 includes resistors R1, R2 and a comparator U1. The non-inverting input terminal of the comparator U1 is connected to a power source Vcc through the resistor R1. The non-inverting input terminal of the comparator U1 is also grounded through the resistor R2. The inverting input terminal of the comparator U1 is connected to a reference voltage Vcc1. The power terminal of the device is connected to the power source Vcc, and the ground terminal of the comparator U1 is grounded. The output of the comparator U1 is connected to the first and third switching circuits 20 and 40. In this embodiment, the voltage after the power supply Vcc is divided by the resistors R1 and R2 is slightly lower than the reference voltage Vcc1, that is, the voltage of the non-inverting input terminal of the comparator U1 is slightly smaller than the voltage of the inverting input terminal of the comparator U1.

The first switching circuit 20 includes two electronic switches (N-channel field effect transistors Q1 and Q2 in this embodiment). The gate of the field effect transistor Q1 is connected to the gate of the field effect transistor Q2 and the output end of the comparator U1. The source of the field effect transistor Q1 is connected to the input and output of the PWM controller 70 (input/output) , I/O) pin COMP, the drain of the field effect transistor Q1 is connected to the first compensation circuit 50. The source of the field effect transistor Q2 is connected to the I/O pin Vout of the PWM controller 70, and the drain of the field effect transistor Q2 is connected to the first compensation circuit 50.

The output pin PHASE1 of the PWM controller 70 is connected to the CPU 200 via the first phase power supply circuit 80. The output pin PHASE2 of the PWM controller 70 is connected to the first phase power supply circuit 80 via the second phase power supply circuit 90. The CPU 200.

The second switching circuit 30 includes two electronic switches (N-channel field effect transistors Q3 and Q4 in this embodiment). The gate of the field effect transistor Q3 is connected to the gate of the field effect transistor Q4 and the third switch circuit 40. The source of the field effect transistor Q3 is connected to the I/O pin COMP of the PWM controller 70. The drain of the field effect transistor Q3 is connected to the second compensation circuit 60. The source of the field effect transistor Q4 is coupled to the I/O pin Vout of the PWM controller 70, and the drain of the field effect transistor Q4 is coupled to the second compensation circuit 60.

The third switching circuit 40 includes an electronic switch (in the present embodiment, an N-channel field effect transistor Q5) and a resistor R0. The gate of the field effect transistor Q5 is connected to the output end of the comparator U1, the source of the field effect transistor Q5 is grounded, and the drain of the field effect transistor Q3 is connected to the gate of the field effect transistors Q3 and Q4 and connected via the resistor R0. This voltage source is VCC.

The first compensation circuit 50 includes resistors R3-R5 and capacitors C3-C5. The first end of the capacitor C3 is connected to the drain of the field effect transistor Q1, and the second end of the capacitor C3 is connected to the drain of the field effect transistor Q2 via the resistors R3 and R4 and the capacitor C5. The capacitor C4 The first end is connected to the drain of the field effect transistor Q1, and the second end of the capacitor C4 is connected to the node between the resistors R3 and R4. The first end of the resistor R5 is connected to the drain of the field effect transistor Q2, and the second end of the resistor R5 is connected to the node between the resistors R3 and R4. The feedback pin FB of the PWM controller 70 is connected to a node between the resistors R3 and R4.

The second compensation circuit 60 includes resistors R6-R8 and capacitors C6-C8. The first end of the capacitor C6 is connected to the drain of the field effect transistor Q3, and the second end of the capacitor C6 is connected to the drain of the field effect transistor Q4 via the resistors R6 and R7 and the capacitor C8. The capacitor C7 The first end is connected to the drain of the field effect transistor Q3, and the second end of the capacitor C7 is connected to the node between the resistors R6 and R7. The first end of the resistor R8 is connected to the drain of the field effect transistor Q4, and the second end of the resistor R8 is connected to the node between the resistors R6 and R7. The feedback pin FB of the PWM controller 70 is connected to a node between the resistors R6 and R7.

In the present embodiment, the resistor R1 is a negative temperature coefficient thermistor, and when the temperature of the resistor R1 increases, the resistance value of the resistor R1 becomes small. At the time of wiring, the resistor R1 is provided in the vicinity of the inductance in the second phase power supply circuit 90. In addition, in the present embodiment, the resistance values of the resistors R6-R8 are different from the resistance values of the resistors R3-R5, and the capacitance values of the capacitors C6-C8 are different from the capacitance values of the capacitors C3-C5, so that the first The compensation signals outputted to the PWM controller 70 by the second compensation circuits 50 and 60 are different.

In use, when the computer motherboard is working normally, the first and second phase power supply circuits 80 and 90 are both operated, and the inductance in the second phase power supply circuit 90 works and generates heat. The second phase power supply circuit 90 is located. The temperature of the resistor R1 near the inductor becomes higher, and the resistance value becomes smaller, so that the voltage of the non-inverting input terminal of the comparator U1 is greater than the voltage of the inverting input terminal of the comparator U1, and the comparator U1 outputs a high level signal, the field The effect transistors Q1, Q2 and Q5 are turned on, and the field effect transistors Q3 and Q4 receive a low level signal from the drain of the field effect transistor Q5 and are turned off. At this time, the first compensation circuit 50 transmits the field effect electricity. The crystals Q1 and Q2 provide a compensation signal for the PWM controller 70, so that the PWM controller 70 adjusts the task cycle of the pulse signals output to the first and second phase power supply circuits 80 and 90 according to the received compensation signal, and transmits Controlling alternate turn-on or turn-off of the two field effect transistors in the first and second phase power supply circuits 80 and 90 to charge and discharge the inductors in the first and second phase power supply circuits 80 and 90, thereby providing stability Voltage to the CPU 200

When the computer motherboard is in standby, the second phase power supply circuit 90 does not work, that is, the PWM controller 70 only outputs a pulse signal to the first phase power supply circuit 80, and does not output a pulse signal to the second phase power supply circuit 90. The temperature of the inductor in the second phase power supply circuit 90 returns to normal temperature, and the temperature of the resistor R1 located near the second phase power supply circuit 90 also returns to normal temperature, so that the voltage of the non-inverting input terminal of the comparator U1 is smaller than the inverting input of the comparator U1. The output voltage of the comparator outputs a low level signal, and the field effect transistors Q1, Q2 and Q5 are turned off, and the field effect transistors Q3 and Q4 receive a high level signal from the voltage source Vcc to be turned on. At this time, the second compensation circuit 60 provides a compensation signal to the PWM controller 70 through the field effect transistors Q3 and Q4, so that the PWM controller 70 adjusts the output to the first phase power supply circuit 80 according to the received compensation signal. The task of the pulse signal is cycled, and the inductance of the first phase power supply circuit 80 is charged and discharged by controlling the alternate turn-on or turn-off of the two field effect transistors in the first phase power supply circuit 80. A predetermined voltage to the CPU 200, so that the CPU200 work in both or computer motherboard to receive stable standby voltage, voltage instability due CPU200 avoid damage.

The circuit of the present invention has two compensation circuits, and different compensation circuits are used when the computer is in different states. The CPU power supply circuit 100 provides a compensation signal through the first compensation circuit 50 to provide a stable voltage when the computer motherboard is in an active state. The CPU 200 is provided with a compensation signal through the second compensation circuit 60 to provide a stable voltage to the CPU 200 when the computer motherboard is in the standby state. The CPU power supply circuit 100 ensures a stable voltage of the CPU 200 while saving power to prevent the CPU 200 from being damaged due to voltage instability.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiments, and those skilled in the art will be able to make equivalent modifications or variations in accordance with the spirit of the present invention. It should be covered by the following patent application.

no

100‧‧‧CPU power supply circuit

10‧‧‧Comparative circuit

20‧‧‧First switch circuit

30‧‧‧Second switch circuit

40‧‧‧ Third switch circuit

50‧‧‧First compensation circuit

60‧‧‧Second compensation circuit

70‧‧‧PWM controller

80‧‧‧First phase power supply circuit

90‧‧‧Second phase power supply circuit

200‧‧‧CPU

R0-R8‧‧‧ resistance

C3-C8‧‧‧ capacitor

U1‧‧‧ comparator

Q1-Q5‧‧‧ Field Effect Transistor

Claims (10)

A CPU power supply circuit includes a comparison circuit, a first switch circuit, a second switch circuit, a third switch circuit, a first compensation circuit, a second compensation circuit, a pulse width modulation controller, and a connection a first phase power supply circuit of the first output pin of the pulse width modulation controller and a second phase power supply circuit connected to the second output pin of the pulse width modulation controller, the comparison circuit including first and second resistors and a comparison The non-inverting input terminal of the comparator is connected to a power source through the first resistor, the non-inverting input terminal of the comparator is also grounded through the second resistor, and the inverting input terminal of the comparator is connected to a reference voltage, the comparator The output end is connected to the first and third switch circuits to control the on and off of the first and third switch circuits, the second switch circuit is connected to the third switch circuit, and the third switch circuit controls the second switch circuit The first resistor is a thermistor disposed near the inductor of the second phase power supply circuit; when the computer motherboard is working normally, the first and second phase power supply circuits are all working, The comparator outputs a first control signal to the first and third switch circuits according to the voltage of the non-inverting input terminal, the first and third switch circuits are turned on, and the third switch circuit controls the second switch circuit to be turned off. a compensation circuit provides a compensation signal to the pulse width modulation controller through the first switching circuit, so that the pulse width modulation controller adjusts the pulse signals outputted to the first and second phase power supply circuits to provide a stable voltage to the CPU; when the computer motherboard is in standby, the first phase power supply circuit operates and the second phase power supply circuit does not work, the comparator outputs a second control signal to the first and third switch circuits according to the voltage of the non-inverting input terminal thereof The first and third switch circuits are turned off, and the third switch circuit controls the second switch circuit to be turned on, and the second compensation circuit provides a compensation signal to the pulse width modulation controller through the second switch circuit to enable the pulse The wide modulation controller adjusts the pulse signal output to the first phase power supply circuit to provide a stable voltage to the CPU. The CPU power supply circuit of claim 1, wherein the first switch circuit includes first and second electronic switches, and the first end of the first electronic switch is connected to the first end of the second electronic switch and An output end of the comparator, a second end of the first electronic switch is connected to the first input and output pin of the pulse width modulation controller, and a third end of the first electronic switch is connected to the first compensation circuit, the second electronic The second end of the switch is connected to the second input/output pin of the pulse width modulation controller, and the third end of the second electronic switch is connected to the first compensation circuit. The CPU power supply circuit of claim 2, wherein the second switch circuit comprises third and fourth electronic switches, the first end of the third electronic switch being connected to the first end of the fourth electronic switch and the a third switching circuit, a second end of the third electronic switch is connected to the first input and output pin of the pulse width modulation controller, and a third end of the third electronic switch is connected to the second compensation circuit, the fourth electronic switch The second end is connected to the second input/output pin of the pulse width modulation controller, and the third end of the fourth electronic switch is connected to the second compensation circuit. The CPU power supply circuit of claim 3, wherein the third switch circuit comprises a fifth electronic switch and a third resistor, the first end of the fifth electronic switch being connected to the output end of the comparator, The second end of the fifth electronic switch is grounded, and the third end of the fifth electronic switch is connected to the first end of the third and fourth electronic switches and connected to the voltage source via the third resistor. The CPU power supply circuit of claim 4, wherein the first compensation circuit comprises fourth to sixth resistors and third to fifth capacitors, and the first end of the third capacitor is connected to the first electronic switch The third end of the third capacitor is connected to the third end of the second electronic switch via the fourth and fifth resistors, and the first end of the fourth capacitor is connected to the first electronic switch. The third end of the fourth capacitor is connected to the node between the fourth and fifth resistors, and the first end of the sixth resistor is connected to the third end of the second electronic switch, the sixth resistor The second end is connected to the node between the fourth and fifth resistors, and the feedback pin of the pulse width modulation controller is connected to the node between the fourth and fifth resistors. The CPU power supply circuit of claim 5, wherein the second compensation circuit comprises seventh to ninth resistors and sixth to eighth capacitors, and the first end of the sixth capacitor is connected to the third electronic switch a third end, the second end of the sixth capacitor is connected to the third end of the fourth electronic switch via the seventh and eighth resistors, and the first end of the seventh capacitor is connected to the third electron a third end of the switch, the second end of the seventh capacitor is connected to the node between the seventh and eighth resistors, and the first end of the ninth resistor is connected to the third end of the fourth electronic switch, the ninth A second end of the resistor is coupled to the node between the seventh and eighth resistors, and a feedback pin of the pulse width modulation controller is coupled to the node between the seventh and eighth resistors. The CPU power supply circuit of claim 6, wherein the first resistor is a negative temperature coefficient thermistor. The CPU power supply circuit of claim 7, wherein when the motherboard is in a standby state, the voltage of the power source divided by the first resistor and the second resistor is less than the reference voltage. The CPU power supply circuit of claim 8, wherein the resistance values of the seventh to ninth resistors are different from the resistance values of the fourth to sixth resistors, and the capacitance values of the sixth to eighth capacitors The capacitance values of the third to fifth capacitors are different. The CPU power supply circuit of claim 9, wherein the first to fifth electronic switches are N-channel field effect transistors, and the first to third ends of the first to fifth electronic switches are respectively The gate, source and drain of the field effect transistor.