Method for Driving LED

摘要

Method and means for driving one or more LEDs. The method includes turning a power switch on to provide current through an inductor and the power switch, measuring voltseconds of the LEDs at a cycle time, comparing the measured voltseconds to a reference signal at an end of the cycle time, generating a signed discrete logical signal based on a difference between the measured voltseconds and the reference signal, and generating a control signal using the signed discrete logical signal to regulate a peak current through the power switch by keeping the cycle time voltseconds substantially constant. The reference signal may be proportional to a set average LED voltage.

主权项

1. A system for providing power to one or more light emitting diodes, the system comprising:
a power converter comprising a power switch, wherein the power converter is couplable to the one or more light emitting diodes, and wherein the power converter is configured to operate in a discontinuous current mode having a dual phase cycle comprising an on phase when the switch is closed and an off phase when the switch is open; an input current sensor configured to sense a current level through the power switch; at least one of an output voltage sensor or a output current sensor, wherein the output voltage sensor is configured to sense an output voltage level of a voltage drop across the one or more light emitting diodes and the output current sensor is configured to sense an output current level of a current flowing through the one or more light emitting diodes; and a regulator coupled to the power converter, the input current sensor, and the at least one of the output voltage sensor or the output current sensor, wherein the regulator is configured to:
determine at least one of an integrated output voltage level or an integrated output current level during a switching period;compare the determined integrated output voltage level or the determined integrated output current level to a reference signal; anddetermine a next cycle on-phase time based on the comparison.