simple transistor noise calculation and simulation

maria98

Newbie level 5
Joined
Dec 9, 2023
Messages
9
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Activity points
93
Hi,
i am looking for simple noise calculation of the transistor and cross verification through cadence simulation. I went through many equations, derivations, but did not find any simple example, which has a simple transistor with its calculation and verification. If any one know, please share. thanks.
 

Sort by date Sort by votes
Hi,

the way you ask .. lets me assume (that´s all I can do without you giving more details) you did not read or did not understand the documents.

It´s like asking: what´s the easiest way to build a formula 1 car.

There are so much parameters to your question, that a simple answer like "V_noise = n * applied_voltage" is not possible.

The answer surely depends on
* what type of transistor you use, like BJT, MOSFET...
* transistor parameters
* what frequency bandwidth you are interested in
* what output measure you expect like V_pp, I_RMS ...
* circuit, voltages, currents, nodes ....
* and many more...

If there was such a simple answer .... why would one use the difficult ones described in the documents?

Klaus
 

Upvote 0 Downvote
Simple to do with a simulator (Simetrix) :



Regards, Dana.
 

Attachments

  • Noise-in-Transistor-Circuits-P-J-Baxandall.pdf
    2.4 MB · Views: 23
Upvote 0 Downvote
Hi,

the Simetrix results ... Is this uV pp or RMS?
I guess they would differ at least by a factor of 5.

Klaus
 

Upvote 0 Downvote
Here is output noise at collector and device alone noise.




The prior table is accumulated noise over the frequency range simulated. The plot is "per-root-Hertz"


Regards, Dana.
 
Last edited:
Upvote 0 Downvote
What type of noise you talk about ?? Johnsson ? Flicker ? Shot Noise ? Random Walk ? Pop-Corn ? Pink ??
Noise is a huge chapter.
 

Upvote 0 Downvote
Random walk, Pink are external sources unless stipulated in Spice, and I see for BJT
spice has no such parameter for either, just one for flicker. PopCorn not "normally"
speced for a BJT, or for that matter most OpAmps.

In the prior sims the BJT does have a flicker parameter, and I am in process of confirming
Johnson is also evaluated in sim....


Regards, Dana.
 
Upvote 0 Downvote
You must log in or register to reply here.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…