TPS65131EVM-839: Problems with EVAL-Kit TPS65131EVM outputs

Stani Bell Ngoufack Tchoufack89

Intellectual 1970 points

Part Number: TPS65131EVM-839
Other Parts Discussed in Thread: TPS65131

Hello,

my customer is currently evaluating the TPS65131 using the TPS65131EVM-839 and is facing some problems.

He adapted the resistors of the resistor divider as shown in the table below:

But instead of the Voltages shown above, he received:

VOutP: 7,3V

VOutN: -6,3V

Could you please help explain and propose a fix to this issue?

Also the VOutN does not start every time; could the error be on the TPS65131 chip itself?

Best regards,

Stani

over 4 years ago

0 Grant Falkenburg over 4 years ago

TI__Intellectual 1965 points

Hi Stani,

Thanks for your question. Let me contact the expert for this part. You can expect a response by 12/13/19.

Best,

Grant

0 Liaqat Khan over 4 years ago

TI__Mastermind 18550 points

Hi Stani,

I don't see how the customer can get these voltages with the resistors used. Only thing I can think of is either wrong resistor values or bad TPS65131 chip. Feed-forward capacitors C6 and C9 on the EVM need to adjusted slightly using equations 11 and 12 in the datasheet when upper feedback resistor (1000K) is changed but even without adjusting these capacitor, I would not expect the output like what customer is seeing. So I would suspect resistor values or bad chip.

Kind Regards,

Liaqat

0 Stani Bell Ngoufack Tchoufack89 over 4 years ago in reply to Liaqat Khan

TI__Intellectual 1970 points

Hi Liaqat,

thank you for your feedback.

Regards,

Stani

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TPS65131EVM-839: Problems with EVAL-Kit TPS65131EVM outputs