SLUSFN3 July 2024 BQ25820
PRODUCTION DATA
The battery regulation voltage is programmed using a resistor divider to the FB pin. The default internal voltage reference is 1.536V, and can be changed via the VFB_REG register bits. The top of the resistor divider is selected to be 249 kΩ.
RTOP = 249 kΩ
The bottom resistor can be calculated as:
where
RFB_BOT = 36.5 kΩ.
Choosing the nearest 0.1% resistor value, gives RFB_BOT = 36.5 kΩ, for a nominal charge voltage of 12 V. Further fine-tuning of the regulation voltage can be achieved by changing the internal feedback reference.
It is recommended to use 0.1% accurate resistors to maximize the charge voltage accuracy.