LP8551TLXSLASHNOPB datasheet(19/46 Pages) TI2

19 / 46 page

LP8551

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SNVS673E – APRIL 2010 – REVISED SEPTEMBER 2014

8.3.4.4 Device Thermal Regulation

The LP8551 has an internal temperature sensor which can be used to measure the junction temperature of the

device and protect the device from overheating. During thermal regulation, LED PWM is reduced by 2% of full

scale per °C whenever the temperature threshold is reached. Temperature regulation is enabled automatically

when chip is enabled. 11-bit temperature value can be read from Temp MSB and Temp LSB registers, MSB

should be read first. Temperature limit can be programmed in EEPROM as shown in the following table.

Thermal regulation function does not generate fault signal.

TEMP_LIM[1:0]

OVER-TEMP LIMIT (°C)

OFF

110

120

130

8.3.4.5 Thermal Shutdown

If the LP8551 reaches thermal shutdown temperature (150°C), the LED outputs and boost shut down to protect it

from damage. Also the FAULT pin is pulled down to indicate the fault state. The device activates again when

temperature drops below 130°C degrees.

Fault is cleared by setting EN pin low or by reading the fault register.

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LP8551TLX/NOPB Datasheet(PDF) 19 Page - Texas Instruments