Self-oscillating resonant converter-based light emitting diode (LED) driver

摘要

A self-oscillating resonator (SOR) may be used to control current through light emitting diodes (LEDs). The SOR may be started and stopped by a controller coupled to a transistor switch in the SOR. The controller may output a control signal that starts and stops the SOR by coupling a supply voltage or a ground to a base of the transistor switch in the SOR. Additional control over the current output to the LEDs may be gained through a resistive DAC coupled to the SOR and duty cycling the SOR.

主权项

1. An apparatus, comprising:
a self-oscillating resonator coupled to a light output node, the self-oscillating resonator comprising:
a first switch;a second switch coupled to the first switch,wherein an emitter of the first switch is coupled to a base of the second switch; andan oscillating network comprising at least one inductor and at least one capacitor, the oscillating network coupled to the first switch and the second switch, and the oscillating network configured to generate an oscillating voltage signal at the light output node; and a controller coupled to the self-oscillating resonator, wherein the controller is configured:
to start and stop the self-oscillating resonator to regulate a current through a load coupled to the light output node, wherein the controller is coupled to a base of the second switch;to receive a dim data signal; andto time the start and the stop of the self-oscillating resonator to perform duty cycling of the self-oscillating resonator for dimming the load coupled to the light output node based, at least in part, on the received dim data signal.