ZHCSJ63 December 2018 TLV1805
PRODUCTION DATA.
There is a minimum amount of reverse current that is needed to trip the comparator. To detect this reverse current, a voltage must be dropped across the MOSFET (VMEAS).
When the MOSFET is off, VGS will be in the -600mV to -1V range due to the forward voltage drop (VF) of the MOSFET body diode. Response to this large voltage will be immediate.
However, with the MOSFET "on" (conducting), the current required to create the trip voltage will be much greater. The trip voltage drop required across the MOSFET RDS(ON) will be the comparator offset voltage plus half of the hysteresis.
The maximum offset voltage of the TLV1805 is 5mV with a typical hysteresis of 14mV. The trip voltage can be calculated from:
The actual current trip point will depend on the MOSFET RDS(ON) and VGS drive level. Assuming the MOSFET has a 22 mΩ on resistance, the trip current is found from: