Power supply circuit

摘要

In the case where the duty cycle of the PWM signal exists and the duty cycle of the PWM signal is constant for a certain period, a feedback control circuit is operated intermittently with the duty cycle fixed. Specifically, a power supply circuit includes an A/D converter circuit for forming a digital value based on an analog value obtained by monitoring an output voltage based on a reference voltage, a digital filter circuit for smoothing the digital value, a PWM signal generator circuit for generating a PWM signal based on an output value of the digital filter circuit, and an operation mode control circuit for controlling a circuit operation mode based on the duty cycle of the PWM signal.

主权项

1. A power supply circuit comprising:
an A/D converter circuit for forming a digital value in accordance with an output voltage based on a reference voltage; a digital filter circuit for smoothing the digital value; a PWM signal generator circuit for generating a PWM signal based on an output value of the digital filter circuit; and an operation mode control circuit for controlling a circuit operation mode based on a duty cycle of the PWM signal, wherein the operation mode control circuit comprises a clock gating circuit, and wherein the clock gating circuit is configured to stop supply of a clock signal to the A/D converter circuit and the digital filter circuit in an operation mode where the duty cycle of the PWM signal is fixed to be constant.