TPS61161A: LED_Backlight_Doesnt_Work

Halid CEYLAN

Part Number: TPS61161A

Hello,

The TPS61161A LED controller we added to our circuit for use in our project doesn't work. Do we have to apply PWM to the CTRL pin? It doesn't work with just ON/OFF?

Our screen backlight is a 10-LED, 2-series LED.

Could you please check the TPS61161A and screen circuits we added and help us?

Best Regards.

Halid.

5 months ago

0 Young Zhao 5 months ago

TI__Genius 14110 points

Could you help capture the Vin, Vout, SW, Control signal here for review ?

0 Halid CEYLAN 5 months ago in reply to Young Zhao

Prodigy 65 points

Hi Mr. Young

First of all, thank you for your support.

Where did you want me to measure Vout? I don't want to take measurements from the wrong point.

Best Regards.

Halid.

0 Young Zhao 5 months ago in reply to Halid CEYLAN

TI__Genius 14110 points

is the Vout point

0 Halid CEYLAN 5 months ago in reply to Young Zhao

Prodigy 65 points

Hi Mr. Young,

I added capture scope measurements and test setup image.

CH1=Vout

CH2=SW

CH3=Vin=5V

CH4=CNTRL=3,3V pins.

It's interesting that the integrated circuit doesn't respond at all.

When I opened the case, I wrote the number of LEDs as 10. It was supposed to be 8 LEDs in 2 series, total 16 leds. Sorry.

Best Regards.

Halid.

0 Halid CEYLAN 5 months ago in reply to Young Zhao

Prodigy 65 points

Hi Mr. Young,

I solve the issue. I think, the problem cause by soldering.

What do you recommend we put the Rset resistor for 40mA?

Thank you for support and help.

With regards.

Halid.

0 Young Zhao 5 months ago in reply to Halid CEYLAN

TI__Genius 14110 points

5ohm could work here

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TPS61161A: LED_Backlight_Doesnt_Work