Hybrid-control current driver for dimming and color mixing in display and illumination systems

摘要

A control/driver circuit produces variable current output for a lighting system providing improved dimming and color-mixing capability by allowing digital modulation control in addition to analog control over a range of illumination intensities. The circuit and method described is preferably adapted to higher current applications such as LED lighting systems using high-power LEDs. The output current of the circuit varies in proportion to the voltage level of an analog control signal, and additionally in proportion to the relative duty cycle of a digital pulsed control input.