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AMC1200: AMC1200: correct wires for isolated vdd1

Luca Meloni

Intellectual 460 points

Part Number: AMC1200

Hi to all!.

I need to measure a variable voltage (0V -> 600V range) with AMC1200.

I use a fully isolated dc/dc converter for build a 5Vdc for Vdd1-Gnd1.

For correct measurament i need to connect Gnd1 to return of high voltage, or can I leave it unplugged? (sse image)

Best regard, luca

over 7 years ago

0 Tom Hendrick over 7 years ago

TI__Guru**** 176421 points

Hi Luca,

The input common mode operating range of the AMC1200 is limited to VDD1, so you would be violating that specification with the arrangement shown above. You would either need to move your 470 ohm resistor to the bottom of the string, or reference GND1 to pin 3.

0 Luca Meloni over 7 years ago in reply to Tom Hendrick

Intellectual 460 points

Tnx Tom!

Ok,i move the 470ohm resistor on the bottom.

But i need to connect GND1 to HIGH voltage return?

0 Tom Hendrick over 7 years ago in reply to Luca Meloni

TI__Guru**** 176421 points

Hi Luca,

Yes, that will work! GND1 would tie to 600V RTN.

0 Luca Meloni over 7 years ago in reply to Tom Hendrick

Intellectual 460 points

I'm sorry, Tom, I don't understand.
Should I connect or not gnd1 to 600v RTN?

0 Tom Hendrick over 7 years ago in reply to Luca Meloni

TI__Guru**** 176421 points

Hi Luca,

Yes - connect both pins 3 and 4 to 600V RTN.

0 Luca Meloni over 7 years ago in reply to Tom Hendrick

Intellectual 460 points

Thanks so much

0 Tom Hendrick over 7 years ago in reply to Luca Meloni

TI__Guru**** 176421 points

My pleasure Luca, do let us know if there are any additional questions.