Re: Noise in Two-stage Opamp
Thank you , noiseless
I considered your suggestions carefully.
1. I checked the simulation gm was the same as my handcalculation.
Next I checked simulation model , and I found thermal noise model
was different from my hand calculation. I should have considered
not only gm but also gds, gmb.
Consequently, difference between simulation and hand calculation
was smaller.
(OPamp noisepower : simulation 116.6a , hand calculation 78a→100a)
But some difference remains.
2. You mean BSIM3 thermal noise model ? I use modified SPICE2
thermal noise model. So the effective length isn't specified, I think.
3. I think open loop w3db is very small (3-4kHz) too. So settling time
can be 250us !! I did'nt realize... thank you !
And I don't know how I simulate fully-differential opamp with other
than this ppt describing...
If anyone knows about above ideas, suggests me please