S32KのトピックRe: BMS Current Measurement

BMS Current Measurement

Mohit_mcu — Mon, 05 Aug 2024 17:54:29 GMT

I am using NXP RD33771-48VEVM BMS evaluation board. I have a issue with reading the current of pack from shunt resistor present in the board. According to the reference document UM11300, I have used the resolutions for calculating the stack voltage, each cell voltage. I thought that for current measurement same ANx resolution will work. But, unfortunately values are not coming proper.

Please help me with this issue.

Re: BMS Current Measurement

TomasVaverka — Tue, 06 Aug 2024 06:45:23 GMT

Hello Mohit,

As stated in the MC33771 datasheet, the resolution of the current sense register is 0.6uV/LSB.
This results in 6mA/LSB when using a 100uΩ shunt resistor on the RD33771-48VEVM.
Here is the complete explanation and example:

BRs, Tomas

Re: BMS Current Measurement

Mohit_mcu — Tue, 13 Aug 2024 17:29:54 GMT

Yes it resolved my problem.

Thanks.