I'm working on project that requires I switch a 12v power supply on the high side of a circuit, using a 3.3v micro controller. To make this work, I'm thinking a can connect a PNP transistor on the 12v high side, and connect the base to the collector of an NPN. Then connecting the base of the NPN to the 3.3v pin on the microcontroller and the emitter to ground. I found this example online:
This leads to my question...I need to create 8 separate switches on this one circuit...Does this PNP to NPN high-side switch still work if I connect multiple in series?? Here is my current schematic...
The LED represent the load for the 12v supply.
In this configuration, does the transistor still work like if there were only one NPN and one PNP...Or does the current get amplified with each NPN/PNP in the series?