Monolithic Power Systems, Inc.
Constant-frequency control method with fast transient

Abstract:

A control circuit and method for a voltage converter. The control circuit having a ramp circuit, a reference generating circuit, a comparison circuit and a logic circuit. The ramp circuit generates a ramp signal that decreases from the moment the power switch is turned off and increases from the moment the power switch is turned on. The reference generating circuit generates a reference voltage. The comparison circuit compares the reference voltage with the sum of the feedback voltage and the ramp signal to generate a comparison signal. The logic circuit uses the comparison signal and a clock signal to generate the control signal to control a power switch of the voltage converter.