Loop Gain of a Pulsed Voltage Converter with Output Voltage Loop and Transistor Current Loop Negative Feedback

The paper compares the loop gain frequency characteristics of a buck converter with two-loop feedback for the output voltage and inductor current against the loop gain frequency characteristics of a buck converter with two-loop feedback for the output voltage and transistor current. The reasons for the discrepancy in the loop gains frequency characteristics of the converters are shown. It is shown that the PWM modulator in the transistor current feedback converter has parametric gain. A linear model of a converter with two-loop feedback for the output voltage and transistor current is presented, the loop gains frequency characteristics of which confirmed the correctness of the model proposed.