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ADE7953ACPZ differential connection

Category: Hardware
Product Number: ADE7953

Excuse me.
I'm an engineer who uses Analog Devices ICs frequently.
This time, there is something I don't understand about how to use the IC, and I would like to ask a question on this forum.
First of all, is my question posted in the correct place?

I have a question about the ADE7953ACPZ.
I would like to use this IC mainly for zero-cross detection and overcurrent detection of single-phase AC power supplies.

Checking the test circuit in Fig. 35 of the datasheet p16,
IAP-IAN (pin5 - pin6) and IBP-IBN (pin9 - pin10) are used as differential current inputs,
I think that VN (pin11) is not input and is used as a single-ended voltage input between VP (pin12) and AGND.

(1) For my application, can I use IAP-IAN (pin5 - pin6) and IBP-IBN (pin9 - pin10) as differential voltage inputs?

(2) I actually assembled the circuit and checked the operation, but there is a problem.
A voltage of ±2V or more is generated between IAP (pin5) and AGND and between IAN (pin6) and AGND.
(absolute maximum rating ±2V in the datasheet)
Of course, the differential voltage input to IAP-IAN (pin5 - pin6) is floating with respect to the AGND of the IC, so I think it will happen,
Please advise if you have any suggestions for improvement.
(How to make the voltage between AGND and each pin less than ±2V with differential voltage input.
I think it can be improved by making a single-ended connection,
"I want to improve it with a differential connection."

  • (1)  it would be fine to use IAP-IAN (pin5 - pin6) and IBP-IBN (pin9 - pin10) as differential voltage inputs since as a front end they are just measuring a voltage.

    Is there a reason IAN and IBN are tied together? 

    It is possible that modifying the size of the capacitor IXP and GND and IXN and GND could improve the +/- 2V


    David M