Control-to-output transfer function of peak current-mode controlled pulse-width modulated dc–dc buck converter in continuous conduction mode

The control-to-output transfer function is essential for the design of the compensator in the outer-voltage loop as it represents the plant for the outer-voltage loop in the peak current-mode-controlled converters. The control-to-output transfer function for the peak current-mode-controlled pulse-width-modulated (PWM) dc–dc buck converter is derived using power-stage transfer functions and the modulator transfer function in the inner-current loop. Experimental Bode plots are presented to verify the derived transfer function. The required critical path open-loop duty cycle-to-inductor current and duty cycle-to-output voltage transfer functions for a peak current-mode controlled dc–dc PWM buck converter are derived and experimentally verified. The theoretical results were in good agreement with all the measured Bode plots.