MOSFET Driver Is Reverse-Battery Protected

Abstract: MOSFET power-switch drivers must be protected from a reverse-battery connection. A small rectifier diode can protect against reversed batteries, but that approach is generally unacceptable for systems in which battery life is crucial. For a 6V battery, the diode's forward voltage drop (0.6V to 0.7V typical) produces a constant power loss of approximately 10%, which increases with dwindling battery voltage. An improvement over single-diode protection is shown.