I am currently trying to reduce the offset voltage of the circuit attached below to less than +/- 2mV over a 1V to 4V input range.
I have a few constraints for this task:
I can use
nmos
,pmos
andpmos4
but can't usenmos4
as the fabrication process does not support separate bulks for NMOS transistors.I cannot use controlled sources e.g (
vcvs
,vccs
,ccvs
,cccs
) except when calculating VoffsetI can only use one
Vdc
forVdd
and oneVdc
forVin
and use onlyidc
for biasingUse at least 100nA bias current in all transistors
So far I have tried adding cascodes to the circuit to reduce this offset voltage but no luck. I would really appreciate it if someone could point me in the right direction regarding this task. Thank you.
Voltage Follower Circuit: