POWER-SUPPLY REJECTION IN DIFFERENTIAL SWITCHED-CAPACITOR FILTERS

Aspects of the design of a fully differential switched-capacitor filter are reported. The principal motivation for using a fully differential configuration is to reduce power supply coupling, so an analysis of some of the mechanisms associated with this effect and the usefulness of some forms of common mode feedback are discussed. Experimental results obtained from a CMOS integrated circuit realization are also included. The circuit achieves 50 db of power supply rejection ratio across the passband.