FRDM33771 BMS not working properly

[stagiair4]

Hello,

I am using the FRDM33771 together with the battery emulator. 

I want to test cell balancing and measure current for SOC however when I enable the cell balancing I see no difference regarding the voltages and the current measurement seems wrong also. 

When I enable MEAS_ISENSE I can't change the voltage with the emulator and it keeps -157.286 mV.

Do I have to connect an external shunt resistor or is it already inside the emulator.

See the attachment for further information. 

Thank you

[guoweisun]

Hi

How do you operate about enable MEAS_ISENSE?

For the emulator the current sense output voltage can vary from around −150 mV to +150 mV.

This output is not designed to drive a large current since the current sense input from the MC3377x needs
as little as 100 nA. If more than 1 μA is pulled from this output, the voltage may drop by a
few mV.