I was considering using the circuit shown below to measure the battery voltage without having to drain the battery (see original post here). The MCU is an ESP32 and uses 3.3V and needs to measure the battery voltage using a voltage divider to step the voltage down from the 4.2V.
BATT_SENS_EN pin of the MCU turns the mosfet on and the
BATT_SENS pin can read half the voltage applied at
B_OUT+. My question is particularly around the
BATT_SENS_EN pin — this seems like it is pulled up to 4.2V and will most certainly damage the MCU. Are there any techniques to address this issue?
Thanks for any pointers.