LP8860-Q1: LP8860-Q1 B Version channel& Blink

user4370495

Part Number: LP8860-Q1

Dear E2E:

i used LP8860-Q1 B version ,my load is : 4channel led , ten leds for each channel. tatal current is 500ma & Boost Voltage: 32V
But i was a little confused when checking the eeprom version configuration. Does is suitable or not ?

Actually, the sample was finished, Basic function is ok in 25℃ condition. But when i do high-low temperature test ,the TFT back light screen blink all the time when temperature reach 85℃
the schematic as fellow. may i know some advise how to check the circuit. thanks a lot.

over 6 years ago

0 Xianghao Meng over 6 years ago

TI__Prodigy 670 points

Version B has internal temp compensation enabled. When the die temperature reaches 100 degree C, the LP8860 will reduce the current for each LED string. So if ambient temperature is 85 degree C, the LED current will drop. So it could explain why customer see blink issue. I would suggest customer to disable the temperature compensation by writing 00 to INT_TEMP_LIM[1:0] register.

Thank you,

Xianghao

0 user4370495 over 6 years ago in reply to Xianghao Meng

Expert 1155 points

Dear TI:

Thanks a lot for your quick feedback.
LP8860B-Q1 can not output 4 channel 100mA/ch Current in normal condition. But it can be via program the EEPROM Register to achieve the function.
Some misunderstand or not ?
thanks

0 Xianghao Meng over 6 years ago in reply to user4370495

TI__Prodigy 670 points

Yes, you can program the EEPROM to realize 4 OUTPUT and each output 100mA. Please refer to below link for EEPROM programming.

www.ti.com/.../snva797.pdf

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LP8860-Q1: LP8860-Q1 B Version channel& Blink