AC side isolation measurement

Hi Qianli,

Thank you for reaching out.

Please refer to the below reference design for device recommendations. I believe this can be implemented on either DC side or AC side but the device would need to be powered by a DC supply to operate.

https://www.ti.com/tool/TIDA-010232

I will also notify the power supply group to review your question and provide any other inputs they may have. Thanks.

Regards,
Koteshwar Rao

thanks for your recommendations.looking forward to the following inputs from you. in the proposed design there seems to be a short circuit between two input pins of AMC3330. please find snapshot pic posted. by the way,what is TPSI2140 in cost

regarding isolation measurement proposal, I have a further question. AMC3330 is used to measure potential of P+/M- to PE, what is the voltage of P/M to PE. so that we can determine string resistor and reference voltage(1.65V is shown in the proposal.) to make sure the voltage value(AD value) given to MCU is all positive not minus due to MCU limit.

regarding isolation measurement proposal, I have a further question. AMC3330 is used to measure potential of P+/M- to PE, what is the voltage of P/M to PE. so that we can determine string resistor and reference voltage(1.65V is shown in the proposal.) to make sure the voltage value(AD value) given to MCU is all positive not minus due to MCU limit

Hi Qianli,

Only one TPS switch is meant to be closed at a time, therefor the same sense resistor can be used to measure the leakage of both lines. 

This excel calculator can help you with sizing the measurement resistor: https://www.ti.com/lit/zip/sbar013

Hi Alexander, the source you have provided is very helpful.but I have no idea how to use it.need a license? how to apply? I need your help.thanks

Hi Alexander, this issue has been solved. in addition, here are some questions for you

question 1:for offset voltage of 1.65V, i still don't confirm that it is suitable to make sure the output voltage(TLV6001) is above 0V as mcu can't detect negative value

question 2: A area highlighted ,if I use negative voltage, the calculator doesn't work. how come?

question 3: B area highlighted, is this AMC3330 output?

question 4:do you have the whole calculation including AMC3330 and TLV600L. i am planning to implement in our application.

thanks for your fast response. I have been thru the document by the link you have provided.

here is a question for you

what is Vcm?1.65V or 2.5V?  I am a little confused. please help double check. thanks

Vcm is 1.65V, mid supply of 3.3V; 2.5V is a typo thank you for pointing that out.