Patent · US Expired

Switched-capacitor filter

US4333064A · kind A · utility

11Cited by
3References
12Claims
0Family size

Assignees

Inventors

Key dates

Filing dateMay 23, 1980
Grant dateJun 1, 1982
Priority date
Expiry dateMay 23, 2000

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03H19/004
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A switched-capacitor filter provided with, at its input stage, a prefilter comprised only of a plurality of additional switched capacitors together with a switched capacitor common to the switched-capacitor filter. The switched capacitor common to the switched-capacitor filter is driven by primary clock pulses having a period T, while the additional switched capacitors are sequentially driven by secondary clock pulse groups. Each of the secondary clock pulse groups has the same period T, and the phases of the second clock pulse groups are shifted by T/2.sup.k, 2T/2.sup.k, 3T/2.sup.k . . . (2.sup.k -1)T/2.sup.k with respect to the first clock pulses (k is a positive integer). The sampled and held signals in the switched capacitors are supplied synchronously to the switched-capacitor filter.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.