Thermal de-rating power supply for LED loads

摘要

Embodiments disclosed herein describe the use of a power supply to provide power to an LED load. The power supply provides a present output current to the LED, and receives a temperature signal representing the operating temperature of the LED. A target output current is determined, for instance based on the temperature signal. An output current rate of change is determined, and the power supply adjusts the output current to the LED at the determined rate of change until the output current is substantially equal to the target current.

主权项

1. A power supply comprising:
an analog-to-digital converter (“ADC”) configured to:
receive a temperature signal representing a temperature of a light-emitting diode (“LED”); andgenerate a digital temperature signal based on the received temperature signal; an over-temperature protection (“OTP”) circuit configured to:
receive the digital temperature signal;detect an LED over-temperature condition based on the received digital temperature signal; andselect a target output current for the LED based on the detected LED over-temperature condition; and a driver circuit configured to:
provide an output current to the LED;receive an output current rate of change selected based on the provided output current and the target output current; andadjust the provided output current based on the received output current rate of change until the outputted current is substantially equal to the target output current.