questions about sense amplifier

[airboss]

Hi,

I have a question about sense amplifier simulation. I want to know how much gain I get from my sense amplifer. I did AC analysis for an Op design before and I applied the same way I did with the Op to my sense amplifer. In other words, I set Vcm+small signal, Vcm-small signal and then look at the output. However I got a number in the range of negative dB, which is very very small. Actually, the input pairs and the nmos at the bottom end are all in triode region. Can anybody point out any mistakes I've made?

 

[szekit]

it looks to me like this is a comparator (dynamic) more than an amplifier. possibly with hystersis.

 

[cougar168]

what applications will this SA be used for?

 

[mists]

in general, SRAM use this type SA

 

[Fom]

Check DC operating point and you will find out your problem.
But this circuit looks very strange for SRAM sense amplifier.
Usually sense amlifier has positive feedback to the input.
Can you explain where are bit lines connection points.
Another question why you need to know the gain? And get it by AC simulation?
What you will do with this gain? To get this you should put the circuit in correct DC operation point. But with positive feedback it will be not so easy.
The most important parameters of the sense amplifier are offset and speed.

 

[qiushidaren]

For me, it looks like a Decision Circuit (Positive FB) which has been widely used in high speed comparator.

 

[jimway]

Usually SA will introduce the cross coupled load to increase the gain

 

[pasher]

Does it be used in SRAM?