help----which mirror is the best one to bias telescopic OTA

[saiaoying]

There are three high-swing biases:
why the last one is sensitive to body effect? and the others is less sensitive to body effect?
could anyone help me to solve this problem? i will choose one of these circuit to bias my telescopic OTA. help me please.
thank you for your help.

 

[penghan]

For single nwell MOS technology, the bulk of NMOS transistors must be connected to substrate. Therefore, its source and bulk have different voltage levels.

 

[PaloAlto]

Re: help----which mirror is the best one to bias telescopic

The last of the three choices is probably the best because it is the one that goes better with corner. It has body effect, of course it has, but electronics is always a trade-off. I would go for the third one or if you need to save area, maybe the first.