TLV431: Component failure in an undervoltage Lockout scheme

Victor Songore

Part Number: TLV431
Other Parts Discussed in Thread: TLVH431

We use the TLV431 in the undervoltage scheme as advised on an application note. The only difference is our 0V is connected to earth.

We are having products returned from customers for failing to power-up. In our diagnosis we have determined that when we replace the TLV431 the power supply unit is restored completely.

Please advise on what could be causing the failures. Failures are reported within 1 to 18 months of deploying product.

Details of the undervoltage scheme are on

http://www.vicorpower.com/documents/application_notes/UV_OV_APPNote.pdf

over 6 years ago

0 Marcoo Z over 6 years ago

TI__Mastermind 19580 points

Hi Victor,

Can you tell me more about the application. What is the highest voltage seen at the +IN mode?
I have a feeling that the TLV431 is rated up to 6V and you might need a TLVH431 which is rated for higher voltages.

-Marcoo

0 Victor Songore over 6 years ago in reply to Marcoo Z

Prodigy 140 points

Thanks Marcoo.

in our application: +IN=12V, (maximum)

We have set R1 to 680ohms.

Under no load conditions, A good module (giving expected output) measures: about 2.5V below R1. A unit with failed TLV431 measures about 4.7V

0 Marcoo Z over 6 years ago in reply to Victor Songore

TI__Mastermind 19580 points

Hi Victor,

The TLV431 can only function to 6V. any voltage greater can damage the device. I will advice to use a TLVH431. I do not believe you will have issues with the TLVH431.

-Marcoo

0 Victor Songore over 6 years ago in reply to Marcoo Z

Prodigy 140 points

Thank you. Hopefully this resolves our problem.

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TLV431: Component failure in an undervoltage Lockout scheme