Multiphase power supply circuit

Abstract

A multiphase power supply circuit comprises a PWM (pulse-width modulation) chip and a plurality of sub-circuits. Each sub-circuit comprises an inductor, a first resistor, a first capacitor, a differential line pair, a second resistor and a second capacitor. The first resistor and the first capacitor in each sub-circuit are serially connected, and then are parallelly connected with the inductor in the sub-circuit. The differential line pair in each sub-circuit comprises a first differential line and a second differential line. The first differential line in each sub-circuit is connected between a joint of the corresponding first resistor and the corresponding first capacitor and a terminal of a current sensor of the PWM chip. One end of the second resistor in each sub-circuit is electrically connected to a joint of the corresponding capacitor and the corresponding inductor, one end of the second resistor in each sub-circuit is serially connected with the corresponding second capacitor while the other end of the second capacitor is ground, the second differential line in each sub-circuit is electrically connected between a joint of the corresponding second resistor and the corresponding second capacitor and another terminal of a current sensor of the PWM chip, and the ratio of capacitances of the second capacitors of the sub-circuits is equal to that of lengths of the corresponding differential line pairs. The circuit can prolong sampling time of the long differential line pairs, and increases sampling accuracy.

Description

technical field [0001] The invention relates to a multi-phase power supply circuit. Background technique [0002] In the existing CPU multi-phase power supply circuit, the PWM chip outputs multi-phase control signals to multiple driver chips, and each driver chip drives a group of MOSEFT tubes, and the MOSEFT tubes drop the 12V voltage to a suitable value for the CPU through an inductor. voltage to power the CPU. The PWM chip samples the voltage of the inductor in each phase in a time period, divides the sampled voltage by the proportional coefficient to obtain the current of each phase, then adds the current of each phase, and divides it by the number of phases to obtain the average current. The PWM chip adjusts the output pulse width according to the obtained average current to adjust the voltage provided to the CPU. The existing way to obtain the voltage is to connect an identical RC circuit in parallel at both ends of the inductor of each phase, and obtain the voltage...

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