Planning to measure (varying under switching e-bike load) voltage from a battery.
To step down the voltage panning to use a voltage divider and buffer the output to an ADC via an op-amp.
To completely switch off the device when the e-bike controller is off will need to switch off the current through the voltage divider (maybe this is an overkill considering how small the current is (~2mA), the controller's quiescent current is probably greater).
Planning to switch the divider with a PMOS.
How do I calculate the bandwidth of the divider + PMOS?
I suppose I should use Rds_on of the PMOS and Cin and Cout of the PMOS to get an equivalent circuit?
I first thought I would represent the PMOS as Rds_on in parallel with Cgs but I'm looking at PMOS datasheets and they only give Cin and Cout.