How to measure ICMR by Hspice?

[shaq]

icmr (input common

Dear all,

How to measure ICMR (input common-mode range) by Hspice?

Thanks so much!!!

 

[sunking]

input common mode range hspice

sweep the common mode voltage, make sure all the tr. not in triode, then you can get the icmr.

 

[shaq]

icmr opamp

sweep the common mode voltage, make sure all the tr. not in triode, then you can get the icmr.

Thanks, sunking.

I have another question about my folded-cascode opamp.

If my ICMR is 0.7 to 2.3v, is it possible when common-mode input in that range,

all the MOS are working in saturation region?

 

[manissri]

hspice measure sweep

The other method of calculatin the icmr is
just make the opamp in unity gain configuration sweep the + input of opamp to the supply range and check the output .the part of output is linear will be ur icmr.
u can concern the book of allan holberg for this
regds
manish

 

[shaq]

simulate icmr

The other method of calculatin the icmr is
just make the opamp in unity gain configuration sweep the + input of opamp to the supply range and check the output .the part of output is linear will be ur icmr.
u can concern the book of allan holberg for this
regds
manish

Hey! manissri

Do you mean that structure?

Just sweep vin then measure vout, right?

 

[holddreams]

icmr input common mode range

sweep the common mode voltage, make sure all the tr. not in triode, then you can get the icmr.

Can you draw a configuration about that?

Added after 1 minutes:

The other method of calculatin the icmr is
just make the opamp in unity gain configuration sweep the + input of opamp to the supply range and check the output .the part of output is linear will be ur icmr.
u can concern the book of allan holberg for this
regds
manish

Hey! manissri

Do you mean that structure?

Just sweep vin then measure vout, right?

I used to simulate icmr like this.But the mos transistor of the tail current should be considered.Allen's book has explained it in chapter 6,opamp example.