DC-DC converter

The invention discloses a DC-DC converter, which comprises an oscillator, an error amplifier, an auxiliary soft starting circuit, a drive circuit and a reference circuit, wherein the reference circuitoutputs first reference voltage to the error amplifier and outputs second reference voltage to the oscillator; the oscillator receives feedback voltage after dividing of output voltage and the secondreference voltage and generates a square wave and a triangular wave, the square wave is output to the error amplifier and the triangular wave is output to the comparator; the error amplifier receivesthe square wave, the feedback voltage and the first reference voltage; the voltage output by the error amplifier is input into the comparator under the control of the auxiliary soft starting circuit;and the comparator outputs the compared level to the drive circuit, input voltage is driven and then the output voltage is output through a BUCK circuit. According to the DC-DC converter, the frequency of the oscillator during