mm9z1_638 voltage sensor read big range value

[a852013777]

hi nxp partner

We found we read mm9z1_638's vsensor 0～3 have big range value about 210~187V when we provide 196v which measure by voltage meter on our first version board.

When we place usb multilink on BDM connector,vsensor 0~3 reading  becomes normal about 196~198v.Do you have any suggestions ? Any layout issue on our board?

Br,Mike liang

[TomasVaverka]

Hi Mike,

I do not fully understand your use case and the issue you are facing. Could you please provide us with more details and share your schematic?

The maximum rating of VSENSE pins is:

... and the functional operating range:

Best regards,

Tomas

[a852013777 · Accepted solution]

Hi Tomas

You can see video is  attached file. The reading is senor board's voltage input. It is not mcu side.

HV+(PTB 0), PTB1_HV(PTB 1),PTB2_HV(PTB 2),PTB3_HV(PTB 3),Vsense0_HV(Vsense0),Vsense1_HV(Vsense1),Vsense2_HV(Vsense2).

You will see the voltage fluctuation is from 220~209v when apply 196V to  sensor board's voltage input The tolerance is 5%. our acurracy target is +/1%

How can we reduce the voltage fluction? If you need more deatail schematic and layout , you can give me mail address. My mail address is mike.yh.liang@foxconn.com

Br,

Mike