As shown in the figure, it is the LTC4006 charge management chip, which is a schematic diagram used to charge 4 lithium batteries in series with 16.8V. The input is 20V.
What is the purpose of Q1 marked in my picture?
Gerald Publicado en January 15, 2021
It should be the driver of the input PFET
Ezequiel Publicado en January 15, 2021
Prevent current from flowing back into the input power supply (when the input power supply voltage is relatively low)
Tyrese Publicado en January 15, 2021
Considering that the pin connected between this MOS and the chip drives the gate of the external input PFET, the function is to prevent backflow.
