a little bit out of topic, is it true if you connect amplifier in negative feedback, we can partially ignore the linearity issue?
Btw, folded cascode is certainly better than telescopic cascode in terms of linearity. Also important to bias every cascode in wide-swing configuration in low voltage application.
decreasing gain of opamp should never be of concern if a negative feedback configuration is used. Although distortion increases when signal goes large, in negative feedback, the largest signal is defined by the feedback factor instead of the open loop gain of the opamp. In fact when open loop gain of the opamp is large the overall loopgain of the feedback loop will also be large, then the nonlinearity will be reduced by this overall loopgain. So large gain is preferred in terms of linearity.
safwatonline said:
hello,
linearity increase by decreasing gain, increase the headrom for the signal,using some kind of degeneration(dec. the gain),
i THINK that the folded willl be better than telescopic in linearity (more headromm for the signal)