LED string driver with power factor corrector and current governor

摘要

A solid state lighting controller arranged for use with a single stage power factor correction switched mode power supply, a light emitting diode (LED) string and a current sense element arranged to sense current through the LED string, the solid state lighting controller constituted of: a current governor in series with the LED string exhibiting a governor differential amplifier and a governor electronically controlled switch responsive to the output of the governor differential amplifier, the current governor arranged to limit current flow through the LED string responsive to a current limit reference; and a feedback circuit exhibiting an error amplifier, the feedback circuit arranged to feedback a signal to the power factor correction switched mode power supply controller whose value is a function of the difference between the current through the LED string sensed by the current sense element and a target current signal.