Patent ID: 8138734

Claim:
A DC-DC converter, comprising: a switching stage, electrically coupled to receive an input signal at an input port and provide an output signal at an output port; and a control circuit, electrically coupled to provide an accurate current limit for peak current mode for said DC-DC converter, said control circuit operative to provide a peak value of said peak current mode, wherein the control circuit comprises: a current sense block, electrically coupled to sense the current flowing through a high-side switch at said switching stage; a slope compensation block, electrically coupled to receive a CLK signal from an oscillator and a PWM signal which is used to drive switches at said switching stage, and provide a slope compensation signal; a peak detector, electrically coupled to detect the peak value of said slope compensation signal; a clamp circuit, electrically coupled to receive the peak value of said slope compensation signal and a preset limit; a divider, electrically coupled to derive a feedback signal from said output port of said DC-DC converter; an error amplifier, electrically coupled to amplify the difference between said feedback signal and a reference; a comparator, electrically coupled to receive the sum of said slope compensation signal and said sensed current at a first input terminal, and receive the output of said error amplifier at a second input terminal; and a RS latch, electrically coupled to receive said CLK signal at its set terminal, receive the output of said comparator at its reset terminal, and provide said PWM signal to said switching stage.