BMS IC

[somyaagarwal]

I am using MC33771 IC but faced an issue that Coulomb counter stops functioning as soon as balancing of cells start. After that we have to reset the IC to start again calculating coulomb counter.

[TomasVaverka]

Hello Somya,

We have never encountered this issue before on MC33771. A basic test performed with MC33771B and the Evaluation GUI confirms that there is no influence on CC when activating CB.

I would recommend to double check your SW to make sure you are sending the right commands. You can use a SPI sniffer to record the commands the IC is actually receiving and its response.

Best regards,

Tomas  

[somyaagarwal]

Hello Tomas,

Thanks for your reply.

I am reading the registers $2D, $2E and $2F. after that accumulated the $2E and $2F register readings in 32 bit register then took two's complement of this reading and after converting this reading in to voltage by multipling it with V2RES resolution. Then calculated the final current value by dividing this value by $2D value.

Also tried reseting these registers by giving command ADC_CFG[CC_RST] = 1  but found out that these registers were not reset to 00.

and also  as soon as CBx_CFG[CB_EN] = 1 the register $2D, $2E and $2F becomes 00