huber wrote on Mar 3rd, 2006, 1:13pm:Hi Steven-
The Temes paper Paul referenced is a great comprehensive reference for offset removal, but if you want something a little friendlier to read try:
Design techniques for high-speed, high-resolution comparators
Razavi, B.; Wooley, B.A.
Solid-State Circuits, IEEE Journal of
Volume 27, Issue 12, Dec. 1992 Page(s):1916 - 1926
It gives a good review of input vs. output offset storage techinique.
-Dan
Hi Paul and Dan,
Thanks a lot for your inputs on the broad topic I brought up. I will get the paper recommended by Paul. The self-descriptive title seems very interesting.
I've read the paper Dan pointed out. In fact, the IOS and OOS techniques are more attractive since the loops in those cases are not as complicated as other RC feedback loop. "Complicated" means the additive loop-gain caused from the extra RC lowpass filter, which extracts the DC component. However, the OOS and IOS technique may not be suitable to opamp case but good for comparator because the former one has stability issue if additional capacitors are added while the later has a positive feedback in general. So less complex loop or no loop would be preferred in (high gain) Opamps, maybe a better term I am asking is an open-loop autozeroing technique. At least this was I thought when I asked. However, I don't know if there are any systematical analysis out there.
Thanks again,
Steven