LED current control

摘要

Parallel light emitting diode channels may be controlled using a pulsed control signal input characterized by an input duty cycle and one or more current sense input signals. Each of the one or more current sense input signals is indicative of a current through a corresponding load channel of one or more load channels. One or more pulsed channel current control signals are provided to one or more corresponding dimming controls correspondingly coupled to the one or more load channels. Each of the dimming controls is configured to provide an output signal to a corresponding ON-OFF switch, each of which is coupled in series with a corresponding the load channels. The channel duty cycle of each channel current control signal is adjusted relative to the input duty cycle in response to the current sense input signals.

主权项

1. A light emitting diode (LED) control system, comprising:
two or more digital dimming controls, each of which is configured to receive a corresponding one of two or more pulsed channel current control signals, wherein each of the two or more pulsed channel current control signals is characterized by a corresponding channel duty cycle, wherein each of the two or more dimming controls is configured to provide an output signal directly coupled to a corresponding one of two or more ON-OFF switches without passing the output signal through a regulator, wherein each of said two or more ON-OFF switches is coupled in series with a corresponding one of a plurality of parallel LED channels; and an average current balance element having circuitry configured to receive a pulsed control signal input characterized by an input duty cycle and two or more current sense input signals, wherein each of the two or more current sense input signals is indicative of a current through a corresponding one of the plurality of parallel LED channels, wherein the circuitry is further configured to provide the two or more pulsed channel current control signals to corresponding ones of the two or more digital dimming controls, wherein the circuitry is additionally configured to adjust the channel duty cycle of each of the two or more pulsed channel current control signals relative to the input duty cycle in response to the two or more current sense input signals.