TPS61081: TPS61081 Led Driver PWM problem

caglar pasli1

Part Number: TPS61081

Hi,

I am using TPS61081DRCT for 10v/270mA backlight. When the device is turn on, If PWM is full on , it is no problem.

But After the device is turn on, If pwm is changed, TPS61081 and output Inductor is very hot. And Backlight is flicker.

After that, Although PWM is full on, Backlight is not changed.

0 Helen chen over 4 years ago

Dear Sir,

Could you please share your schematic with us for a review. I can't figure out the root cause without the schematic.

0 caglar pasli1 over 4 years ago in reply to Helen chen

Dear Helen,

Schematic is below. PWM frequency is 1khz. L27 inductor part number is VLCF5020T-4R7N1R7-1.

Thanks.

0 Helen chen over 4 years ago in reply to caglar pasli1

Dear Sir,

To get 270mA LED current , you need to increase R76 from 1 ohm to 4.5 ohm.

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