[SOLVED] what's wrong with my PMOS code ??

[romel_emperado]

hi I want to do like this curve using hspice but it whatever I do I cant do something like this..

Image1:
**broken link removed**

this is my code for my PMOS:

Title: PMos daw ni(not sure :) )





*Note the syntax: for the transistor,
*Mxxx drain gate source bulk MODEL_NAME L=x W=x 

mp 0 gate source source pch w=2u l=10u



vgs gate 0  5
vds source 0 5


** sweep both Vds from 0 to 5 volts in increments of .2, and Vgs from 0 to 5 volts in increments of 1
                           
.dc vds 0 5v .5 vgs 0 5 1


.option post

.prot
.lib 'rf018.l' tt
.unprot
.op
.plot i(mp)
.END

and the result of this code is this:


**broken link removed**


why is that the starting point of all the sweeps are in 0?

 

[analogLow]

I think you just need to change your sweets from 0 to negative numbers (e.g. .dc vds 0 -5v -.5).

 

[romel_emperado]

ok I will try

---------- Post added at 14:59 ---------- Previous post was at 14:57 ----------

no it's not.. not a pmos curve..

---------- Post added at 14:59 ---------- Previous post was at 14:59 ----------

any other trick to show the curve?

---------- Post added at 16:15 ---------- Previous post was at 14:59 ----------

the problem is all about the supply thing.. anyway here is the correct code

TItLE: PMOS DAW


.param Supply=1.8

.options post
.global Vdd Gnd
Vdd Vdd Gnd 'Supply'


*** mpmos1 drain gate source bulk L= length W= width
m1 ds gs Vdd Vdd pch L=10u W=20u



* VoltageName Node+ Node- VoltageValue
vds Vdd ds 'Supply'
vgs Vdd gs 'Supply'



*increase Vds from 0 to 1.8v with step of 0.1 increase vgs from 0 to 1.8v with step of 0.5

.DC vds 0 5 .5 vgs 0 5 1
.probe dc i1(m1) 
.lib 'rf018.l' tt

.END

 

[leo_o2]

Please dc sweep vds and use ".alter" to change vgs.
ps. .alter is a hspice command.

 

[romel_emperado]

Please dc sweep vds and use ".alter" to change vgs.
ps. .alter is a hspice command.

I haven't use .alter command

do you have the syntax of it?

---------- Post added at 03:46 ---------- Previous post was at 03:25 ----------

what do you mean by shift? something like this?

**broken link removed**

I used this line to sweep my VGS

.DC vds 0 5 .5 vgs 0 5 1