I am trying to meet the compliance/min output voltage of a wide swing current mirror so the output current (10uA) is within .1% or +/- .01uA. I am using Cadence and ami06 nFET's to do so. I am always off by .005~.01uA in either direction. I have spent 2 days adjusting the widths, lengths, and conduction parameter, k' but cannot get the output current pinned under .1% of the input current.
I believe tweaking the threshold voltages (and body effect) is the only thing left to try. Currently, I have all of my bulk terminals connected to ground and all of my hand W/L ratio calculations include the body effect. This brings me to the question at hand - When using BSIM3V3, is connecting the bulk terminal of a MOSFET to it's source terminal the same as ignoring the body effect when deciding W/L ratios on paper? If so I plan to recalculate all of my ratios without the body effect and try the simulation again. Thanks for your help.