TPS54331: start up issues

user5208406

Part Number: TPS54331

Dear sir,

TPS54331 failed to start up under normal temperature and minus 30 degrees, enclosed is our schematic, I am wondering if you have simulate environment to test it?

12V-5V-54331.pdf

over 7 years ago

0 Gavin Wang (Zejing) over 7 years ago

TI__Expert 3480 points

1. Why do you add C961 ?
2. Pls attach your startup waveforms for EN pin. Make sure it can reach EN high level threshold.

0 user5208406 over 7 years ago in reply to Gavin Wang (Zejing)

Prodigy 30 points

1. C961 helps the voltage to stabilize at 12V，then TPS54331 can start working.

2. Waveforms attached, EN pin voltage can balance after 100ms, voltage for EN Pin is 1.56V, it can reach 1.35V high level threshold. ( if TPS54331 doesn't work at this time, EN pin voltage should be 1.56V-4uA*30kΩ=1.44V)

0 user5208406 over 7 years ago in reply to user5208406

Prodigy 30 points

1. C961 helps the voltage to stabilize at 12V，then TPS54331 can start working.

attached" test report" for your reference.

Power management

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TPS54331: start up issues