Buck DC-DC converter with improved accuracy and stability

摘要

A buck switching regulator includes a feedback control circuit including a balanced feedback network including first and second gain circuits configured to generate first and second feedback signals, respectively, indicative of the regulated output voltage; a ripple generation circuit configured to inject a first ripple signal to the first gain circuit and a second ripple signal to the second gain circuit; an operational transconductance amplifier (OTA) configured to receive the second feedback signal and a reference signal and to generate an output signal being coupled to a node in the feedback control circuit; and a comparator configured to receive the first feedback signal and a comparator reference signal and to generate a comparator output signal. The output signal of the OTA is applied to the feedback control circuit to cancel a voltage offset in the regulated output voltage due to the injected ripple signal to the first gain circuit.