I am working on OTA ( OP amp) noise analysis and optimisation and would like to know how to typically start. I mean from where ? Anybody tried this before ?
razavi or allen si a good point to start. than move on to cadence tutorials on noise simulations. allthough for runing noise analyses in cadence you don't really need a tutorial.
good luck!
I also want to use SPECTRE of Cadence to simulate noise, and I find there is noise analysis in SPECTRE, but I really wonder how to use it.
For instance, how to apply the input of the OPA? Use a "pin" or a normal voltage source or a "port"?
What's more, how about the output of the OPA?
I have read the tutoral, but I still don't kown how to do.
I really need your help.
Thanks.
I did the noise analysis using cadence and found some wierd results. How come, my results are showing that pmos is producing more flicker noise and less thermal noise compaired to nmos. I was expecting exactly opposite..? Anybody has got any idea ?
SMIC – Semiconductor Manufacturing International Corporation
Instances used – p18, n18
Size of Each Transistor L = 1um; W = 100 um.
Results for CMOs Inverter Circuit at 200 Hz in untis of nV/ sqrt(Hz) -
I think this is correct? For higher frequencies, the flicker noise is negligible and the noise of the transistor is dominated by thermal noise. So for most circuits, the pmos noise IS lower