METHOD FOR REGULATING AN OUTPUT VOLTAGE

摘要

A method for regulating the output voltage of a power supply. A boost PWM switching converter adjusts the gate drive signals to a switching transistor and a pass transistor so that the power supply has an operating frequency, Fs, based on a comparison between a parameter and a reference. The parameter may be a ratio of an input voltage to an output voltage, a difference between the output voltage and the input voltage, or the value of an input voltage. In accordance with the comparison between the parameter and the reference, the switching control circuit linearly decreases the operating frequency of the power supply. By changing the operating frequency, the output and input voltages of the power regulator may be almost equal to each other when operating with a control signal having a low duty cycle while maintaining a low output voltage ripple and a low inductor current ripple.