Multi-bleeder mode control for improved led driver performance
AssigneePower Integrations, Inc.
InventorsPeter VAUGHAN, Ricardo L. J. PREGITZER
Life of this patent
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Abstract
Various examples directed to phase-dimming LED driver input circuitry having multiple bleeder circuits activated by a controller with multi-bleeder mode control are disclosed. In one example, the input circuitry may include multiple bleeder circuits controlled by the controller in an open-loop or closed-loop configuration. The controller may selectively activate or deactivate the multiple bleeder circuits based on the input line voltage, the dimming state, and the type of dimming being implemented to improve performance of the LED driver by preventing or reducing shimmering/blinking and by reducing bleeder loss.
Claims27
A multi-bleeder circuit for a light-emitting diode (LED) driver circuit, the multi-bleeder circuit comprising:
- a first bleeder circuit;
- a second bleeder circuit;
- and
- a controller coupled to receive a line sense signal representative of an input voltage, a bleeder current sense signal representative of a current conducted through the second bleeder circuit, and a return current sense signal representative of a return current from a load, wherein the controller is further coupled to activate and deactivate the first and second bleeder circuits based on the line sense signal, the bleeder current sense signal, and the return current sense signal.
A light-emitting diode (LED) driver circuit comprising:
- an input to be coupled to receive an alternating current (ac) input voltage;
- a Triac dimming circuit coupled to the input to receive the ac input voltage and output a phase-controlled ac input voltage;
- a rectifier coupled to receive the phase-controlled ac input voltage and output a phase-controlled rectified input voltage;
- a power converter coupled to receive the phase-controlled rectified input voltage and output a regulated output signal to a load;
- a first bleeder circuit coupled between the rectifier and the power converter;
- a second bleeder circuit coupled between the rectifier and the power converter;
- and
- a controller coupled to receive a line sense signal representative of a voltage of the phase-controlled rectified input voltage, a bleeder current sense signal representative of a current conducted through the second bleeder circuit, and a return current sense signal representative of a return current from the load, wherein the controller is further coupled to activate and deactivate the first and second bleeder circuits based on the line sense signal, the bleeder current sense signal, and the return current sense signal.
Dependencies are inferred from the claim text.