Patent ID: 7508180
Filing Date: 2009-03-24
Classification: H02M

Abstract:
1. A switching regulator for fixing a frequency comprising: a power stage, the power stage comprising: an output capacitor coupled to the output inductor with an output voltage across the capacitor; a first reference voltage generator used for generating a first reference voltage; a comparator having a first input end coupled to the output inductor and the output capacitor and a second input end coupled to the first reference voltage generator for receiving the first reference voltage, the comparator used for comparing signals received at the first and second input ends; a constant-time trigger coupled between an output end of the comparator and a control end of the power stage, the constant-time trigger used for controlling turning on and off the first switch and the second switch of the power stage according to a result of the comparator; a frequency-to-voltage converter having an input end coupled to an output end of the constant-time trigger for receiving a frequency of the constant-time trigger and an output end for outputting a voltage generated by the frequency-to-voltage converter, the frequency-to-voltage converter used for converting the frequency received at the input end into voltage; and an error amplifier having a first input end coupled to the output end of the frequency-to-voltage converter, a second input end for receiving a second reference voltage, and an output end coupled to a control end of the constant-time trigger, the error amplifier used for generating a regulation signal to control the constant-time trigger turning on and off the first switch and the second switch of the power stage according to signals received at the first and second input ends of the error amplifier.