A simple demonstration of a bidirectional or reverse-blocking high side power switch using a back-to-back series connected pair of P channel MOSFETs. In this configuration, both MOSFETs are switched on or off together. When off, the back-to-back connection means that reverse conduction through the body diode of M3 is blocked by the body diode of M2 and vice versa. In this example the series pair of MOSFETs are being used to drive a resistive load with some parallel capacitance. Note that when the gates of M2 and M3 are pulled up to VDD1, the capacitor is not discharged through the body diode of M3 as VDD2 falls nor is it charged through the body diode of M2 as VDD2 rises Note also however, that for this circuit to work properly, VDD1 must be not less than VDD2. Just press CTRL+R to run the simulation. The Diodes Inc. DMP4015SK3 spice subckt model is in the EasyEDA library. To create a simulation using this device, simply place the PMOS_E symbol from the EasyEDA Libs in the left hand Navigation panel, select the symbol in the schematic, press the 'I' key, then change the 'Spice Prefix' from 'M' to 'X' and click OK. Then double click on the 'PMOS_E' name, change it to 'DMP4015SK3' then click back on the schematic canvas. Done! See also: Bidirectional MOSFET Driver for DC switching and Bootstrapped Bidirectional MOSFET Switch Driver in: https://easyeda.com/andyfierman/Misc_simulations-lVd6oGYSa