Patent ID: 8723437
Filing Date: 2014-05-13
Classification: H05B

Abstract:
1. An LED dimmer control circuit comprising: a dimmer loop configured to receive a dimmer output signal from a dimmer switch, and to generate a first loop signal representative of the dimmer output signal, the dimmer loop comprising a first filter; a constant current loop configured to receive a sense signal representing a load current through an LED coupled to the dimmer control circuit and a reference signal representing a full load current through the LED, and to generate a second loop signal representative of a comparison of the sense signal and the reference signal, the constant current loop comprising a second filter; and a pulse-width modulation generator configured to generate control signals for the LED based on a smaller of the first loop signal and the second loop signal; wherein the bandwidth of the first filter is set to a first predetermined maximum in response to the second loop signal being smaller than the first loop signal; wherein the bandwidth of the second filter is set to a second predetermined maximum in response to the first loop signal being smaller than the second loop signal.