pnp transistor switch

Thread Starter


Joined Apr 19, 2012
So I am making a swithcing mechanism where a micro controller will send a ttl signal to a pnp transistor, the supply will be 12 volts. Pretty much I wanted to know if this can be done and even if I put a load on the output the voltage will not drop from the supply? Or is it better to use an npn.


Joined Mar 14, 2008
Does the load need to be grounded?

What is the load current?

A PNP transistor connected to a 12V supply needs a 12V control signal, not TTL.


Joined Apr 24, 2011
Here's one way to do it (from my current project). CVON is a PIC pin output used to turn on a 28V source.

I use a polyfuse to hopefully keep this from dying when driving a bad circuit as this is a test fixture.