Understanding the Region of Operation for CMOS Transmission Gate: VDD vs Ground

[pumas]

Hello,
I'm supposed to determine the region of operation of both the n-channel and the p-channel MOSFET'S when the control voltage is at VDD(5V) and both I/O terminals are at VDD. Also I have to figure out the region of operation when the control voltage is at VDD but the I/O terminals are at ground.

I think that in both cases the p-channel and the n-channel will be ON. But I don't understand how the I/O terminals affect the region of operation of the MOSFETs. Can anyone help me?

Thank you

 

[berkeman]

Thread moved to homework forums. Welcome to the PF, pumas, but please be sure to post homework and coursework like this in the appropriate homework forum, and not in the general forums like the EE forum.

To help you with your question, I googled CMOS switch tutorial, and got lots of good hits. Here is a good one from Maxim (they make CMOS switches):

http://www.maxim-ic.com/appnotes.cfm/appnote_number/638

All of the voltages are important in the operation of CMOS switches. Quiz question -- why do you need both an n-channel and a p-channel transistor in each switch?

 

[pumas]

Thanks for your help