Questions about mismatch of pmos/nmos

[yen]

mismatch question

Dear all,
I have some question about mismatch question.
1.Why is a larger mismatch of pmos device for Vτ?
2.Which (pmos or nmos)is thermal noise larger ?
3.What is the threshold adjust implant?
4.What are Avτ and Aβ?
thanks very much.

 

[sunking]

mismatch question

reference to "the art of analog layout "

 

[safwatonline]

Re: mismatch question

3- it is a doping stage "ion implantation" to adjust the threshold voltage , it depends on the process and it may involve doping NMOS, PMOS or both , this can be done by one or more type of dopants "this all depend on foundry".

 

[eldo]

mismatch question

1.Why is a larger mismatch of pmos device for Vτ?
I guess it is because of the lower mobility of hole.

2.Which (pmos or nmos)is thermal noise larger ?
There are no difference between PMOS and NMOS regarding thermal noise.

3.What is the threshold adjust implant?
4.What are Avτ and Aβ?
They are two parameters to estimate the mismatch.