Connecting the bulk of a PMOS.. (CMOS complex function)

Thread Starter


Joined May 2, 2008

I have to simulate using SPICE a function AB + BC + AC.. and I have various questions. Regarding the PMOS network.. does the bulk of all of the PMOS transistors be connected to Vdd?

Hopefully, someone can help soon. I have other questions, but I need to get this straight first. Any help is appreciated.


Joined Mar 8, 2010
Yes, PMOS substrate goes to Vdd.

PMOS means P-type channel, which means the substrate is N. The channel is substrate being inverted. The source/drain are P-type.

Remember that a diode is a PN junction, with forward current through P to N.
You need that junction reverse biased, which means putting Vdd on the N-type substrate and hopefully the P-type drain/source will be either Vdd or lower.