This high-side, current sensing solution uses a current sense amplifier, a comparator with an integrated reference and a P-channel MOSFET to create an over-current latch circuit. When a load current greater than 200 mA is detected, the circuit disconnects the system from its power source. The comparator output will latch (hold the gate source voltage of the P-channel MOSFET to 0 V) until power to the circuit is cycled, since the comparator drives the gate of the P-channel MOSFET and feeds the signal back into the reference pin of the current sense amplifier.
- Load current Ioc = 200 mA
- System supply typical: Vs = 24 V
- Current sense amp: gain = 20 V/V
- Comparator output status: over current: Voh = Vs
- Normal operation: Vol = Vs - 5 V