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.

Can I get the output impedance of OPAMP by hspice simulation

Status
Not open for further replies.

incol

Full Member level 2
Joined
Jan 18, 2005
Messages
143
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,296
Activity points
1,077
How to simulate the output impedance?
Thanks!
 

Re: Can I get the output impedance of OPAMP by hspice simula

Hi,
There is nothing to do with code. If you see into the output listing file .ls then you will be probably find out the value of output resistance. Value of input and output resistance will be given probably.
If I am wrong then please let me know. Because I am not in touch of these thing now a days.
Thanks!
 

Re: Can I get the output impedance of OPAMP by hspice simula

I'll attach a very short summery of hspice for you. The colour of the part that you need was changed to red.

Hope it helps!!!
 

Thanks for your post!
 

Re: Can I get the output impedance of OPAMP by hspice simula

Sadegh.j said:
I'll attach a very short summery of hspice for you. The colour of the part that you need was changed to red.

Hope it helps!!!

Hi Sadegh.j,

I have read the file which you attach, form this file, I think it may be use ".print AC Zout(M)" to simulate output impedance, but if that so, I have two questions:
1. I didn't write output node, how does it know which node is the Zout.
2. How to add the AC source, add it to the input? or VCC?

thanks!
 

you need use .net to declarating the input port and output port, as following:

.net output input

the 'output' is the output voltage or output current you want to probe,

the 'input' is the input voltage or current source thate include 'ac='.
 

I think using the output voltage divided by the current is a basic method!
 

you can write some hspice command or calculate the output impedance based on gain and gm.
 

Re: Can I get the output impedance of OPAMP by hspice simula

paladinzlp said:
you can write some hspice command or calculate the output impedance based on gain and gm.

HI, can u give me some examples?

BTB, can i write some command in hspice scripts to do some integration & differentiation???? If i can, show me how to do this,

TIA,
 

use the ".tf" statement to solve the problem
 

Re: Can I get the output impedance of OPAMP by hspice simula

finfoun said:
use the ".tf" statement to solve the problem

Hi, everybody
Thanks for your advice, as to the TF command, i tried to use it and got a zero value, I guess what TF does is that at every DC point, it measures the DC voltage and DC current , and then compute the DC output impedance..
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top