Multi-Mode LED Illumination System

摘要

This application discloses a lighting emitting diode (LED) illumination system that operates at least in a boost mode and a bypass mode. The LED illumination system includes a plurality of LEDs and bypass elements. Each bypass element is coupled in parallel with one or more LEDs, and configured to bypass them selectively in the bypass mode. A boost converter is configured to drive the LEDs. The boost converter includes a boost controller that is configured to enable the boost mode in response to a boost enable signal. In the boost mode, the boost controller is electrically coupled to control the boost converter to drive the LEDs by a boosted drive voltage, and in the bypass mode, the boost controller is deactivated to allow the boost converter to drive a subset of the LEDs by a regular drive voltage that is substantially lower than the boosted drive voltage.

主权项

1. A lighting emitting diode (LED) illumination system that operates in a first mode and a second mode, comprising:
a plurality of LEDs that are coupled to form an LED string; and a boost converter configured to generate a drive voltage to drive the plurality of LEDs; wherein in the first mode the boost converter is configured to drive the LED string by a boosted drive voltage, and in the second mode the boost converter is configured to drive a second subset of the plurality of LEDs by a regular drive voltage that is lower than the boosted drive voltage.