Reverse-polarity protection with back-to-back P-MOSFETs
12 parts
Reverse-polarity protection and an off switch from two P-channel MOSFETs back to back. Q1 (drain toward the input) and Q2 (drain toward the load) share their source; one 47 kΩ pulls the shared gate down and a 12 V zener clamps gate to source.
- V1 48V
- R1 22kΩ
- OK
- REV
- L1 22µH
- Q1 Vt 2V
- Z1 12V
- R2 47kΩ
- kill closed
- Q2 Vt 2V
- C1 10µF
- R3 4.7kΩ