Control of the output power of a dc-dc converter upon varying the switching frequency

摘要

The power output of a static DC_DC converter employing a current mode PWM controller is controlled upon the varying of the switching frequency, by detecting the sawtooth signal produced by the local oscillator generating a DC signal with amplitude inversely proportional to the frequency and by alternatively clamping the output voltage of the error amplifier of the PWM controller at a voltage proportional to the amplitude of said DC signal or by offsetting the signal present on the currents sensing resistor by a voltage corresponding to the difference between a constant voltage and said DC signal.