I am trying to understand the documentation for the diode model, but I could not find how to set the forward voltage value.
Can someone help me simulate silicon diode that has a forward voltage of approximately 0.7 volts?
Electronic – How to set forward voltage for a diode model in NGSpice
ngspice
Related Solutions
This link here has some info. If your trying to translate models
First make sure they are an equivalent model.
- Design a simple test spice file that will test the model with a voltage source.
- Test the model that you want to use in a different spice package so you know what the correct result is
- Test the SW model and 'play around' with it until you get the same result.
It will take some work, but somebody's got to do it.
How do I simulate a circuit containing a Mosfet, and transform the values in the datasheet of the mosfet into ngspice.
First of all pick a MOSFET from within your sim that is already present and supported. Try this out to make sure everything seems to work.
Second, double-click (or whatever mechanism is needed) to open that MOSFET part so you can inspect the parameters. Can you edit them - you should be able to do this.
Thirdly, forget about trying to convert data sheet values to spice parameters - just go look for the model of the device you want to use and change the values by editing them. Sometimes models are written down in data sheets but, more often than not you have to dig around.
Some sims will allow you to paste the whole ascii model text into a special area and this will overwrite the model parameters contained in the device you chose. I don't use ngspice so I can only guess at this bit and what facilities it has.
The spice model for the STN2NF10 is found on this page: -
*****************************************************
* Model Generated by STmicroelectronics *
* All Rights Reserved *
* Commercial Use or Resale Restricted *
*****************************************************
* CREATION DATES: 21-04-2006 *
* *
* POWER MOSFET Model (level 3) *
* *
* EXTERNAL PINS DESCRIPTION: *
* *
* PIN 1 -> Drain *
* PIN 2 -> Gate *
* PIN 3 -> Source *
* *
* ****C**** *
* ********************** *
* *************************************** *
* PARAMETER MODELS EXTRACTED FROM MEASURED DATA *
* <<<<<<<<<<<>>>>>>>>>>> *
* *************************************** *
* THIS MODEL CAN BE USED AT TEMPERATURE: 25 °C *
* *
*****************************************************
* MODELLING FOR STN2NF10
.SUBCKT STN2NF10 1 2 3
LG 2 4 7.5E-09
LS 12 3 7.5E-09
LD 6 1 4.5E-09
RG 4 5 4.001
RS 9 12 0.325E-02
RD 7 6 0.142
RJ 8 7 0.445E-03
CGS 5 9 0.419E-09
CGD 7 10 0.467E-09
CK 11 7 0.307E-10
DGD 11 7 DGD
DBS 12 6 DBS
DBD 9 7 DBD
MOS 13 5 9 9 MOS L=1u W=1u
E1 10 5 101 0 1
E2 11 5 102 0 1
E3 8 13 POLY(2) 6 8 6 12 0 0 0 0 0.321
G1 0 100 7 5 1u
D1 100 101 DID
D2 102 100 DID
R1 101 0 1MEG
R2 102 0 1MEG
.ENDS STN2NF10
.MODEL MOS NMOS
+ LEVEL = 3
+ VTO = 4.184
+ PHI = 0.827
+ IS = 0.1E-12
+ JS = 0
+ THETA = 0.995
+ KP = 15.084
+ ETA = 0.199E-02
.MODEL DGD D
+ IS = 0.1E-12
+ CJO = 0.171E-10
+ VJ = 0.754
+ M = 0.367
.MODEL DBD D
+ IS = 0.1E-12
+ CJO = 0.202E-10
+ VJ = 0.755
+ M = 0.335
.MODEL DBS D
+ IS = 0.1E-12
+ BV = 117
+ N = 1
+ TT = 0.699E-07
+ RS = 0.505E-02
.MODEL DID D
+ IS = 0.01E-12
+ RS = 0
+ BV = 127
* END OF MODELLING
Best Answer
You do not simply "set" the forward voltage. The forward voltage is determined by a combination of model parameters. Here's a model I found for the 1N4148 which is a commonly used Silicon diode:
If you use these parameters with the standard PSPICE diode model you should get (I did not check it for you, so no guarantees) a diode with a forward voltage of around 0.7 V at "normal" forward operation (a couple of mA of current flowing).