E. Seevinck et al., ACTIVE-BOOTSTRAPPED GAIN-ENHANCEMENT TECHNIQUE FOR LOW-VOLTAGE CIRCUITS, IEEE transactions on circuits and systems. 2, Analog and digital signal processing, 45(9), 1998, pp. 1250-1254
A gain-enhancement technique based on active bootstrapping is proposed
which ideally increases the low-frequency gain by two gain stages wit
h no speed penalty and without adding to the phase shift. Therefore, h
igh-frequency performance and feedback stability are not compromised.
In practice, the gain enhancement will be limited by nonidealities. Th
e technique is particularly suited for minimum supply voltages since n
o cascodes are used and, although the discussion pertains to CMOS, can
also be applied in bipolar and BiCMOS technologies. A complete analys
is, including the effects of nonidealities, is performed. A generally
applicable design methodology is formulated.