Switching current synthesis circuit for power converter

摘要

A control circuit of a power converter is provided. The control circuit comprises a PWM circuit, a sample circuit, and emulation circuit. The PWM circuit generates a switching signal for switching an inductor and generating a switching current of the inductor in response to a current feedback signal. The sample circuit is coupled to sample a switching current signal into a capacitor during an on time of the switching signal. The emulation circuit generates a discharge current couple to discharge the capacitor during an off time of the switching signal for generating the current feedback signal. The switching current signal is correlated to the switching current of the inductor, and the discharge current is generated in response to an input voltage of the inductor, an output voltage of the power converter, and the on time of the switching signal.

主权项

1. A control circuit of a power converter comprising:
a pulse width modulation (PWM) circuit generating a switching signal for switching an inductor and generating a switching current of the inductor in response to a current feedback signal; a sample circuit coupled to sample a switching current signal into a capacitor during an on time of the switching signal; and an emulation circuit generating a discharge current couple to discharge the capacitor during an off time of the switching signal for generating the current feedback signal; wherein the switching current signal is correlated to the switching current of the inductor, and a discharge current is generated in response to an input voltage of the inductor, an output voltage of the power converter, and the on time of the switching signal.