The present invention comprises switched capacitor amplifiers including
positive feedback on semiconductor devices, wafers, and systems
incorporating same and methods for amplifying signals using positive
feedback, while maintaining a stable gain and producing an improved
signal-to-noise ratio. One embodiment includes a switched capacitor
amplifier comprising a CMOS amplifier, a feed-in switched capacitor, and
a feedback switched capacitor. The feed-in switched capacitor couples an
input signal to the non-inverting input of the CMOS amplifier. Similarly,
the feedback switched capacitor couples the amplifier output to the
non-inverting input to create a positive feedback loop. A capacitance of
the feedback switched capacitor relative to a capacitance of the feed-in
switched capacitor comprises a feedback proportion. This feedback
proportion may be configured to maintain a stable gain of the switched
capacitor amplifier and increase a signal-to-noise ratio of the switched
capacitor amplifier, even with the switched capacitor amplifier in a
positive feedback arrangement.