Switched capacitor circuits having level-shifting buffer amplifiers, and associated methods

摘要

Switched capacitor circuits and charge transfer methods include a sampling phase and a transfer phase. Circuits and methods are implemented via a plurality of switches, a set of at least two capacitors, at least one buffer amplifier, and an operational amplifier. In one example, during the sampling phase at least one input voltage is sampled, and during the transfer phase at least a first reference voltage provided by the at least one buffer amplifier is subtracted from the at least one input voltage using the operational amplifier. The same set of at least two capacitors may be used in both the sampling phase and the transfer phase.

主权项

1. A switched capacitor circuit operable in a sampling phase and a transfer phase, the switched capacitor circuit comprising:
a plurality of switches; at least one input capacitor; an integration capacitor; at least one buffer amplifier; and an operational amplifier,wherein:
during the sampling phase, the plurality of switches are configured to couple a first input voltage to the at least one input capacitor and a second input voltage to the integration capacitor; and during the transfer phase, the plurality of switches are configured to couple the at least one input capacitor, the integration capacitor, and the at least one buffer amplifier to the operational amplifier to subtract at least a first reference voltage from a sum voltage based on the first input voltage and the second input voltage so as to provide an output voltage from the operational amplifier, wherein an input of the at least one buffer amplifier is electrically coupled to an input terminal of the operational amplifier during the transfer phase.