JAJSC31E February 2014 – May 2018 TPS92630-Q1
PRODUCTION DATA.
This device operates a thermal shutdown (TSD) circuit as a protection from overheating. For continuous normal operation, the junction temperature should not exceed the thermal-shutdown trip point. If the junction temperature exceeds the thermal-shutdown trip point, the output turns off. When the junction temperature falls below the thermal-shutdown trip point, the output turns on again.
Calculate the power dissipated by the device according to the following formula:
where:
PT = Total power dissipation of the device
nx = Number of LEDs for channel x
V(LEDx) = Voltage drop across one LED for channel x
Vref = Reference voltage, typically 1.222 V
I(LEDx) = Average LED current for channel x
After determining the power dissipated by the device, calculate the junction temperature from the ambient temperature and the device thermal impedance.