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.

CMOS Inverter Simulation using SPICE

Status
Not open for further replies.

ANALA

Member level 1
Joined
Aug 7, 2017
Messages
33
Helped
0
Reputation
0
Reaction score
0
Trophy points
6
Activity points
264
Once i build the inverter circuit and simulate using SPICE tool, i can plot the I-V characteristic...Is there any possibility to change the built in drain current expression..[for eg :instead of Id= 0.5K(vgs-vth)^2 to Id=0.5K(vgs-vth)^3] ?
 

You can write whatever expression you want in spice and evaluate it. That's simple but has no merit, as you are not changing the underlying model of the transistor.
 

You can write whatever expression you want in spice and evaluate it. That's simple but has no merit, as you are not changing the underlying model of the transistor.

Exactly what i want to do..i want the new drain current expression to over rule the underlying model..is it possible to do?
 

The default MOSFET level 1 model with LAMBDA = 0 refers to the intended simple quadratic equation

level1.png

Simulation of real discrete and integrated MOSFET transistors uses more complex models. I don't think that any model ends up with the suggested simplified cubic equation, what's its justification?

You can however make a behavioral voltage controlled current source with exactly this equation. Behavioral modeling syntax is different for SPICE variants, refer to reference manuals.
 

If i m using PSPICE how should i go about arriving at the equation which i have mentioned?i just gave an eg of a cubic expression ...i m just trying to evaluate an arbitrary drain current expression
 

Here's a PSPICE example. Use a VCCS (Voltage Controlled Current Source), a G element (GVALUE) as in this example, and put your equation in its transfer function.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top