TPS63700: TPS63700 output voltage problem at low temperature

HONG YK

Prodigy 95 points

Part Number: TPS63700

Hello

I used with output voltage -13.85V.

Please see attached the circuit.

I got problems output voltage at low temp.

It is working -14V under at around 0 degree.

I hope to keep -13.85V up to -40 degrees.

What are the critical factors affecting temperature?

What should I fix to resolve this problem?

Please help me. Thanks.

over 3 years ago

0 Minqiu Xie over 3 years ago

TI__Mastermind 21565 points

Hi Hong:

The -14 is only 1% lower than 13.85. The Vref of our device is 1%. Considering other component's tolerance, it's hard to keep Vo=-13.85. It's a system challenge, not only TPS63700, but also surrounding components.

May I know what's your application and why you need so precision output voltage?

0 HONG YK over 3 years ago in reply to Minqiu Xie

Prodigy 95 points

Thanks for answer.

I fixed this problem by attaching a load resistor.

However I have still problem.

When the current flow about 100mA, voltagedrop occurs about 0.3V.

(At this time the load resistor is 200ohm under.)

I hope to keep voltage regardless of load resistance.

Thanks.

0 Minqiu Xie over 3 years ago in reply to HONG YK

TI__Mastermind 21565 points

HI Hong:

May you help to catch the waveform of Vin, Vout, SW and FB?

Is it for -40 degrees, or?

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TPS63700: TPS63700 output voltage problem at low temperature