A Buck LED Driver with a Novel Average Current Mode Control

Abstract

This paper presents a novel methodology to regulate the output current in CCM/DCM-operated buck converters to be used as post-regulators in LED lamp drivers. With this novel method only the current of the power switch needs to be sensed; regulation is accurate and insensitive to the input and output voltages and to the inductance value, with no need of external correction circuit nor calibration. The buck converter works with constant switching frequency, which enables an optimized inductor design. It is also possible to change the regulation setpoint in a continuous manner for LED lamp analog dimming.