Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

About CMOS signal path

Status
Not open for further replies.
Advark

Advark

Member level 3
Joined
Feb 22, 2008
Messages
66
Helped
1
Reputation
2
Reaction score
0
Trophy points
1,286
Location
POA, Brazil-RS
Activity points
1,684
How differente can be the operation of a circuit that the signal path consist only of NMOS transistor than a traditinal CMOS signal path.

I mean the frequency response of the circuit, i know that NMOS gm and carrier mobility it's three or four times than PMOS, but someone can give me a more detail explanation
 

for a certain bias current and to have a certain
(vgs-vt) PMOS transistor width should be more than
3 times NMOS that causes 3 times more parasitic
capacitance
 

Advark said:
How differente can be the operation of a circuit that the signal path consist only of NMOS transistor than a traditinal CMOS signal path.

I mean the frequency response of the circuit, i know that NMOS gm and carrier mobility it's three or four times than PMOS, but someone can give me a more detail explanation
Click to expand...

If you mean the high frenquency circuit, the parasitic is important. But, for low frequency circuit, the difference is small. And some time CMOS have larger linearity than only NMOS, so we like to use CMOS.

Besides, PMOS is better for noise and matching. So it will be important if you care noise performance.
 

Perhaps you could explain me this extract :

The signal path consists of NMOS transistors only, whose carrier mobility and gm in submicron technologies are three to four time that PMOS devices. Therefore, the circuit can operate at a higher frequency than those built on a CMOS signal path.

This extract was taken from the paper in :
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top