TPS53681: Behavior with AVSN open

RUSTY BOUDREAUX

Part Number: TPS53681

Tool/software:

What does the part or output voltage do when AVSN is open?

We have 3x120A, 1x40A running at full power with no issues. AVSP and AVSN connect to FPGA on-die sense points. We have 100 Ohm from AVSP to VOUT in case the FPGA is not populated or AVSP is open due to a bad BGA solder joint.

However, we don't have 100 Ohms from AVSN to ground. What happens when AVSP is tied to VOUT but AVSN is floating open?

Thanks.

11 months ago

0 Nick Zahabizadeh 11 months ago

TI__Expert 5645 points

Hi Rusty,

Thanks for your message. I'll need to give this some thought, I'll have a response within 24 hours.

Kind regards,
Nick Z

+1 Nick Zahabizadeh 11 months ago in reply to Nick Zahabizadeh

TI__Expert 5645 points

Hi Rusty,

If AVSN is left open, the TPS56831 will issue a fault through PMBus, STATUS_MFR_SPECIFIC [6] will flip to 1b if any voltage sense pin is detected to be open at power-up. Included is a snippet of section 7.5.26.8 (80h) STATUS_MFR_SPECIFIC register map on the TPS53681 datasheet:

Kind regards,
Nick Z

0 RUSTY BOUDREAUX 11 months ago in reply to Nick Zahabizadeh

Prodigy 50 points

Hi, Nick. Perfect. Thanks for the quick response. Sorry I missed that in the datasheet :)

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TPS53681: Behavior with AVSN open