TPS65131: TPS65131 output fail TPS65131 output fail with high frequency sound.

Hi,

I have notified our expert regarding this issue. Please expect a response by 8/21/18.

Thanks,
Aaron

Hello,
Can you please send your schematics? What is the input supply voltage and what is the load current? Is the inductor sized correctly for peak inductor current (Isat)?
Are you using the device in power save mode or regular operating mode?
Once I have answers to these questions, I may be able to figure out what may be causing this issue.
Kind Regards,
Liaqat

Hi, Liaqat：

I need confirm with customer, please wait.

Sure. Let me know once you have information from customer.
Kind Regards,
Liaqat

Hi, Liaqat：

Customer's condition as below

Vin = 5V  

Vpos = 10~15V  Vneg = -10~-15V (adjust with Variable resistance)

Ipos & Ineg = 100mA

schematic & inducter spec as attachment files.

updating some information, add the resistor can't completely solve the problem. About 6 of the 10 boards become to normally. 

Thanks for your help.

TPRH0603-4R7MA to鴻普18.07.25.pdf

PID2_TBoard.pdf

Hello,
Ouput current from boost and inverting converter is small enough that inductor Isat is not an issue.
Once thing I noticed in the schematics is R59 is connected to inverting converter switch node (pins 5&6). it should be connected to pin 4 (VIN). Since we have an RC filter to pin 4, I am thinking that connecting R59 incorrectly may provide a path to bypass this filter internally. Can you blue wire R59 to pin 4 and see how it affects operation? If the problem still continues, can you please measure VPOS, VNEG, boost SW node (pin 1) and inverting converter SW node (pin 6) waveform and send it me? I am not sure but these wave forms may provide a clue.

Kind Regards,
Liaqat

Hi, Liaqat:

I saw EVM's schematic ENP and ENN ware connected via jump to INN too.

Anyway, I will try to modify R59 first.

HI, Liaqat:

Modifying the R59 is not an effective solution.

I will try to get waveform for you.

Hi NObody,

Please provide the waveforms but it would be best if you can arrange to send a board to me so that I can take a look in the lab as I have a feeling that this may come down to actually debugging it on the board. Are you a TI employee? If so you can look me up in the TI directory services under my name Liaqat Khan and e-mail to me directly.

Kind Regards,

Liaqat

Hi, Liaqat:

I am not TI's employee just disty's FAE.

I will try to get PCB and send it to you, but how could I send it for you?

Via local TI FAE?

update:

I already got PCB on hand. please provide how to send the PCB to you.

Hello NObody,
You can send the board to me via local TI FAE/Sales Engineer.
Kind Regards,
Liaqat