TLC6C5712-Q1: Short-to-supply fault when a channel is turned off

Luca Iannuzzi

Part Number: TLC6C5712-Q1

Hello,

during an long test (around 12h) we detecd some short-to supply fault on the channels that happen when the channel is deactivated.

The fail is not persisted it disappear once the registers are read and cleared.

We tried with and without internal pull-ups to supply by using the registers WRITE_DIS_PULL_UP.

Is that normal? Should we use some precise steps to deactivate a channel?

Thanks for your support.

Luca

over 2 years ago

0 Zhiqian Wu over 2 years ago

TI__Mastermind 21925 points

Hi, Luca

Could you let me check the layout of TLC6C5712?

0 Luca Iannuzzi over 2 years ago in reply to Zhiqian Wu

Prodigy 80 points

Hi Zhiquian,

I'll ask if I can upload here a portion of layout.

Meanwhile, what do you would check on it? Maybe I could answer you

Thanks,

Luca

0 Zhiqian Wu over 2 years ago in reply to Luca Iannuzzi

TI__Mastermind 21925 points

Hi，Lucca

Just one of my suppose, there are some parasitic inductor in the loop. so when channel is deactivated, VLED pin will leads to a higher voltage, which is close to the VSENS, and trigger the fault. Pls add a cap in VLED pin to have a try.

0 Luca Iannuzzi over 2 years ago in reply to Zhiqian Wu

Prodigy 80 points

Hi Zhiqian,

I suppose you mean on OUTx pins, correct?

0 Zhiqian Wu over 2 years ago in reply to Luca Iannuzzi

TI__Mastermind 21925 points

Hi, Lucca

Yes, correct

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TLC6C5712-Q1: Short-to-supply fault when a channel is turned off