| 主权项 |
1. A power supply circuit applicable to provide a voltage to a memory, the power supply circuit comprising:
first and second metal-oxide semiconductor field effect transistors (MOSFETs); first to third resistors; first and second inductors; an electronic switch comprising first to third terminals; and a pulse width modulation (PWM) controller, wherein a voltage pin of the PWM controller is connected to a power source, a first gate pin of the PWM controller is connected to a gate of the first MOSFET, a second gate pin of the PWM controller is connected to a gate of the second MOSFET, a phase pin of the PWM controller is connected to a source of the first MOSFET and a drain of the second MOSFET, a drain of the first MOSFET is connected to the power source through the first inductor, a node between the drain of the second MOSFET and the source of the first MOSFET is connected to an input pin of the PWM controller through the second inductor and the first resistor in that order, the input pin of the PWM controller is also grounded through the second resistor and also connected to a first terminal of the electronic switch through the third resistor, a second terminal of the electronic switch is grounded, a control terminal of the electronic switch is connected to a general purpose input output pin of a motherboard, a node between the second inductor and the first resistor outputs a first voltage or a second voltage to the memory, the first voltage and second voltage are based on the formula: Vout1=0.8*(1+r1/(r3/(r2+r3)), Vout2 =0.8*(1+r1/r2), where Vout1 and Vout2 are respectively the first and second voltages, r1 stands for a resistance of the first resistor, r2 stands for a resistance of the second resistor, r3 stands for a resistance of the third resistor. |
