AMC1200: Floating function

Takumu Izasawa

Part Number: AMC1200

Hi team

My customer is considering to use AMC1200BDWVR.

They want to know output status for VOUTN/VOUTP with below situation.

・No power supply to VDD1 (High-side): VDD1, VINP, VINN, GND are all floating
・ Power supply only for VDD2 (Low-side): 5V power supply


I'm looking forward your answer!

Thanks

over 5 years ago

0 Tom Hendrick over 5 years ago

TI__Guru**** 176421 points

Hi Izasawa-san,

The outputs of the AMC1200 will be either full scale (+) or full scale (-) in this case. There is no fail-safe state/mechanism in the AMC1200.

0 Kotaro Yamashita over 5 years ago in reply to Tom Hendrick

TI__Intellectual 2340 points

Hi Tom,

I'm Kotaro Yamashita, working with Izasawa-san. I did test on TINA with customer's condition as below. And then, I can see VOUTP = Common mode voltage, VOUTN = GND. Is that same as you expected?

Regards,

Kotaro Yamashita

0 Tom Hendrick over 5 years ago in reply to Kotaro Yamashita

TI__Guru**** 176421 points

Hi Yamashita-san,

I don't know that the AMC1200 TINA model can accurately represent this 'open' condition. There is no way to guarantee what state VOUTp and VOUTn would take with open inputs and no VDD1 supply.

0 Kotaro Yamashita over 5 years ago in reply to Tom Hendrick

TI__Intellectual 2340 points

Hi Tom,

Is that possible to do the test at bench? If so, could you do this, please?

Regards,

Kotaro Yamashita

0 Tom Hendrick over 5 years ago in reply to Kotaro Yamashita

TI__Guru**** 176421 points

Yamashita-san,

The AMC1200 does not have a fail-safe feature to ensure a known-state is provided on VOUTx. The outputs can assume different states on power up in this 'open input/noVDD1' condition.

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AMC1200: Floating function