Switched capacitor integration and summing circuits

摘要

A switched capacitor circuit employs a single operational amplifier to implement both an integrator and a summer. One input signal is routed to the input of the operational amplifier through (1) one or more integration branches, and (2) one or more first summing branches. A second input signal is routed to the input of the operational amplifier through one or more second summing branches. Each of the branches includes a capacitor and a number of switches controlled by different clock phases. The switched capacitor circuit may be single-ended or differential. The circuit may be used in an access terminal of a cellular communication system. The access terminal may operate under a code division multiple access (CDMA) communication standard.