Reduction of frequency variation for ripple based, constant-on-time DC-DC converters

A circuit for controlling frequency variation for an inductor current ripple based, constant on-time DC-DC converter, the circuit comprising:

• a set/reset (SR) latch;
• a comparator configured to set the SR latch;
• and
• an on-time and frequency variation controller configured to reset the SR latch, wherein the on-time and frequency variation controller includes:
• a comparator having a first input and a second input;
• a capacitor connected to the second input of the comparator and configured to provide a ramp voltage to the comparator;
• a reset switch connected to the second input of the comparator;
• an operational transconductance amplifier (OTA) connected to the second input of the comparator and having a first input and a second input;
• and
• a feedback loop connected between the second input of the comparator and the first input of the OTA and configured to increase the rate at which the ramp voltage increases.