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.

[SOLVED] MOSFET potential divider output theoretical estimation.

Status
Not open for further replies.

transcendent

Newbie level 4
Joined
Jan 23, 2011
Messages
7
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,361
Having some trouble here. I have simulated a mosfet potential divider in HSPICE given some simplified MOSFET parameters for pmos and nmos. The widths have been prechosen, as is Vdd and Vss.

Key parameters known:
Vdd = 5V
Vss = -5V
Kn = 50u Vt = 0.9
Kp = 18u Vt = -0.6

Current is unknown.
Vgs is unknown
As said: width and length are indeed known.
**broken link removed**

This is essentially the circuit (c). Except that it isn't ground at the bottom. Instead Vss = -5V.

So I ran through spice, which can indeed give simulated Vout (Vref) and the current going through both mosfets and Vgs values.

I can't figure out for the life of me how to extract Vref with the parameters given however.

Id = beta (Vgs - Vt)^2
beta = K/2(W/L)

Tried equating current: beta1 (Vgs1 - Vt1)^2 = beta2 (Vgs2 - Vt2)^2
Still left with unknown Vgs.

Also note, the place i got that diagram says:
**broken link removed**

However, I can't work out how this is derived (including Vss instead of ground)
 
Last edited:

oh how you shame me :p

Thankful as well however =)

Many thanks. This put me back on track.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top