BQ76940: Value of dissipation resistors

Hello Cleatus, 

The value of the dissipation resistors are dependent on how much balance current your design needs, and the voltage of the cells.

For example, if a design requires a 100-mA balance current and operates at 4.1V, a 28.7 ohm resistor would provide 143 mA of current, you can then use your duty cycle to calculate average current/power, allowing you to pick a resistor with the appropriate wattage rating.

Thanks,
Caleb

Hey Cleatus,

The amount of current that you can balance depends on the FETs, power resistors, and other components you use on your board. Theoretically there is no limit on balance current. However, with higher currents, heat and design complexity/cost become a big factor.

Check out section four of this document for more details on cell balancing with the BQ76940.
https://www.ti.com/lit/an/slua749a/slua749a.pdf

Thanks,
Caleb