Patent ID: 9160229
Filing Date: 2015-10-13
Classification: H02M

Abstract:
1. A DC-DC converter having a converter input and a converter output, comprising: at least one electronic switch; first feedback circuitry controlling a voltage at the converter output by adjusting a switching frequency of the electronic switch; and second feedback circuitry further adjusting the switching frequency toward a target switching frequency utilizing a PWM signal used to control the electronic switch when the switching frequency significantly deviates from the target switching frequency by comparing the PWM signal to a reference, the second circuitry further comprising a pulse generator that determines the time period that the electronic switch is activated, where the time period is variable, the pulse generator further comprising a comparator having a ramp voltage as one input and a modified threshold voltage as a second input, where the modified threshold voltage changes with the switching frequency by a frequency to voltage converter driving a transconductance amplifier to increase the modified threshold voltage to thereby increase on-time of the electronic switch.