AMC3330-Q1: AMC3330 input signal layout suggestion

Zoe Yang

Part Number: AMC3330-Q1
Other Parts Discussed in Thread: AMC3330

Dear team,

My customer is planning to use AMC3330-Q1 as 400Vdc voltage sampling measurement. Do you have any suggestion if customer remove RL12 and directly connect INN to PGND?

over 2 years ago

0 kai klaas69 over 2 years ago

Guru 140200 points

Hi Zoe,

the both resistors RL11 and RL12 are part of the input filter. See section 8.2.2.1 of datasheet. The input filter not only suppresses EMI and noise entering the ciruit from the left but also suppresses the chopping noise leaving the input pins of AMC3330. Because of this, removing RL11 or RL12 is not recommended.

Also, the AMC3330 provides a differential input and works best with a balanced input filter. Omitting RL11 or RL12 can degrade the common mode rejection and common mode transient immunity.

Kai

0 Tom Hendrick over 2 years ago

TI__Guru**** 173636 points

Hi Zoe,

If you are measuring DC voltage and do not need to use the negative Vin aspect of the AMC3330, then yes - you can leave RL12 out of the schematic and just use the positive input portion of the device.

0 Zoe Yang over 1 year ago in reply to kai klaas69

TI__Intellectual 2210 points

Kai, My customer is designing the schematic as attached file. Would you please comment on if resistor value can provide the INP and INN has correct input voltage range? Vin =200V~1000V, Normal=400V.

And for input breakdown voltage, are there need to add a ZVS between INP and INN?

Please also help comment on the external configuration of this circuit.

0 Tom Hendrick over 1 year ago in reply to Zoe Yang

TI__Guru**** 173636 points

Please stick to a single post for this issue:

https://e2e.ti.com/support/amplifiers-group/amplifiers/f/amplifiers-forum/1169177/amc3330-q1-schematic-review-for-amc3330/4400336#4400336

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AMC3330-Q1: AMC3330 input signal layout suggestion