TPS61176: Output Voltage is not generate

kamlesh patel

Part Number: TPS61176

Dear Sir

we have implement Below Schematic and it is not generate Output of 28v but it generate only 4v.

right now we have tied En Pin with Vin pin. voltage input is 4.0v.we have use 10uf capacitor instead 4.7uf capacitor on C24.

we have connect 9led in series and we have 2 channel which is connect to IFB1 and IFB2.

please guide why voltage is not generate.

over 3 years ago

0 Yuting Shao over 3 years ago

TI__Genius 13001 points

Hi Kamlesh,

I can't view your schematic. Can you reload it by clicking "insert file" button?

BR,

Robin

0 kamlesh patel over 3 years ago in reply to Yuting Shao

Prodigy 120 points

HI Robin

I have attached schematic ,can you review it and help me.

0 Yuting Shao over 3 years ago in reply to kamlesh patel

TI__Genius 13001 points

Hi Kamlesh,

Have you measured the PWM/EN signal after power-up?

BR,

Robin

0 kamlesh patel over 3 years ago in reply to Yuting Shao

Prodigy 120 points

hi Robin

i have measure but voltage is fixed about 4.0v.

Actually right now i have set TPS61176 in non-dimming mode.

you can consider like below:

1) bypass Q4 mosfet (means short source to drain )

2) tied PWM/EN pin with 82k pull-up resistor

3) tied MODE/FAULT pin with 1M resistor to GND.(Pull-down).

Vin :- 4.0v

Vout :- 4.0v

i have not attached any load to circuit.

0 Yuting Shao over 3 years ago in reply to kamlesh patel

TI__Genius 13001 points

Hi Kamlesh,

I see no issue from your schematic. So it's necessary to check every pin voltage. For example, VLDO should be about 3.3V.

Robin

0 kamlesh patel over 3 years ago in reply to Yuting Shao

Prodigy 120 points

Hi robin

Thanks for help to us.

actually we have solve issue.

Kamlesh patel

Power management

Power management forum

TPS61176: Output Voltage is not generate