Title:
CONTINUOUS TIME FILTER TUNED CIRCUIT AND METHOD
Document Type and Number:
Japanese Patent JPH04282912
Kind Code:
A
Abstract:
PURPOSE: To provide a tuning circuit which tunes such an integrated circuit filter as the continuous-time MOSFET-C filter, etc. CONSTITUTION: The transistor 16 and capacitor 14 of a filter 12 are matched to the transistor M and capacitor CI of a tuning circuit 18. The transistor M exists in the feedback circuit of a switched transistor network 20. The tuning circuit 18 is provided with a comparator circuit 30 and generates a control voltage which changes the small-signal resistance value of the transistor M and the control voltage of a line 26 compensates the variation of the capacitor 14 and transistor 16 and tunes the filter 12. When the frequency of the clock of a line 22 is changed, the effective resistance value of the switched capacitor network 20, the control voltage of the line 26, and the frequency response characteristic of the filter 12 change.
Inventors:
JIYANNIBU MITSUSHIERU
Application Number:
JP24562291A
Publication Date:
October 08, 1992
Filing Date:
September 25, 1991
Export Citation:
Assignee:
NAT SEMICONDUCTOR CORP
International Classes:
H03H11/04; H03H19/00; (IPC1-7): H03H19/00
Attorney, Agent or Firm:
Kazuo Kobashi (1 person outside)
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