TPS63700: Failed Vout

Part Number: TPS63700

customer uses the TPS63700 to generate -12V out of 5V in a series project. The -12V is needed to drive LEDs. Now they have some devices which fail in production, the -12V missing or aren't stable. This destroys the LEDS because the LEDs can't controlled and are to high. The design is like in the d/s.

What could be the reason?

Regards, Holger

1 Reply

  • Failures are generally difficult to debug, unless the failing event can be repeated and captured in order to analyze it.

    Looking at your layout, the most important high frequency loop on the output is longer than necessary. This goes against the clear recommendations in the D/S and this app note:

    Chris Glaser

    Texas Instruments