Switched capacitor amplifier circuit operating without serially coupled amplifiers

U.S. Patent Number: 5341050

Abstract: A switched capacitor circuit (10) is responsive to a two phase repetitive clock signal comprised of alternating periods (.phi.1) and (.phi.2). The circuit includes a first input branch including a first amplifier (A) for charging a first capacitance (C1) from a first input signal during period (.phi.2). The circuit further includes a second input branch that includes a second amplifier (B) for charging a second capacitance (CA) from a second input signal during a period (.phi.1A), and for charging a third capacitance (CB) from the second input signal during a period (.phi.1B); wherein (.phi.1A) and (.phi.1B) alternate in occurrence with one another during successive (.phi.1) periods. The circuit further includes switches for coupling the first capacitance and the second capacitance to an input of an output amplifier (C) during (.phi.1B), and for coupling the first capacitance and the third capacitance to the input of the output amplifier during (.phi.1A). The teaching of the invention provides for the interconnection of several switched capacitor branches without requiring that any two series connected amplifiers settle during the same clock phase.

Inventors: Mellissinos; Anthony (Encinitas, CA), Powell; Scott (Carlsbad, CA)

Assignee: Hughes Aircraft Company (Los Angeles, CA)

Application Number: 07/855,985

Issued: 1994-08-23

Expired: 2006-08-23

Classes: 327/355 ; 327/551; 327/91; 330/9

Field of search: 307/490,494,520,353,364 328/151,167,127,165 330/9

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