JPS55123226A - Switched capacitor filter - Google Patents

Switched capacitor filter

Info

Publication number
JPS55123226A
JPS55123226A JP3072779A JP3072779A JPS55123226A JP S55123226 A JPS55123226 A JP S55123226A JP 3072779 A JP3072779 A JP 3072779A JP 3072779 A JP3072779 A JP 3072779A JP S55123226 A JPS55123226 A JP S55123226A
Authority
JP
Japan
Prior art keywords
voltage
amplifier
filter
capacitors
output
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP3072779A
Other languages
Japanese (ja)
Inventor
Mitsuo Tsunoishi
Seiji Kato
Norio Ueno
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fujitsu Ltd
Original Assignee
Fujitsu Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Fujitsu Ltd filed Critical Fujitsu Ltd
Priority to JP3072779A priority Critical patent/JPS55123226A/en
Publication of JPS55123226A publication Critical patent/JPS55123226A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H19/00—Networks using time-varying elements, e.g. N-path filters
    • H03H19/004—Switched capacitor networks

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Filters That Use Time-Delay Elements (AREA)

Abstract

PURPOSE:To obtain a variable-constant filter block suitable to IC-implementation with good mass-producibility by providing a control part which changes filter characteristics by setting the switching period of each switching element. CONSTITUTION:Switches S and capacitors C constitute switched capacitors S1C1'', S2C1', S5C2''', S3C2'', S4C2', S7C3', and S8C0', and operational amplifiers OP1-OP4, integral capacitors C0-C3 connected across them, and resetting switches S6 and S9 constitute a switched capacitor filter. Amplifier OP1 holds voltage V1' N5C0'/ C0 times input voltage Vi until S9 is shorted. Amplifiers OP2 and OP3 are applied with voltage V1' by way of S1C1' and S3C2'' and output voltage V0 via S2C1' and S2C2' respectively, and amplifier OP3 with the output of OP1 via S5C2''', so that the voltages will be integrated by C1 and C2 respectively. Amplifier OP4 is applied with the output of OP3 and voltage V1' and holds the sum voltage by integraing. Then, control circuit CNT exercises control by setting switching periods of S1-S9 to fixed values, so that a filter widh desired characteristics can be obtained.
JP3072779A 1979-03-16 1979-03-16 Switched capacitor filter Pending JPS55123226A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP3072779A JPS55123226A (en) 1979-03-16 1979-03-16 Switched capacitor filter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP3072779A JPS55123226A (en) 1979-03-16 1979-03-16 Switched capacitor filter

Publications (1)

Publication Number Publication Date
JPS55123226A true JPS55123226A (en) 1980-09-22

Family

ID=12311685

Family Applications (1)

Application Number Title Priority Date Filing Date
JP3072779A Pending JPS55123226A (en) 1979-03-16 1979-03-16 Switched capacitor filter

Country Status (1)

Country Link
JP (1) JPS55123226A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59154929U (en) * 1983-04-01 1984-10-17 パイオニア株式会社 bandpass filter
JPS60126698A (en) * 1983-12-13 1985-07-06 株式会社河合楽器製作所 Electronic musical instrument
JPS62145927A (en) * 1985-12-20 1987-06-30 Hitachi Ltd Data converter
JPS62209913A (en) * 1986-03-10 1987-09-16 Hitachi Ltd Switched capacitor filter
US6509791B2 (en) 2001-05-08 2003-01-21 Fujitsu Limited Switched capacitor filter circuit

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
IEEE JOURNAL OF SOLID-STATE CLRCUITS=1977 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59154929U (en) * 1983-04-01 1984-10-17 パイオニア株式会社 bandpass filter
JPS60126698A (en) * 1983-12-13 1985-07-06 株式会社河合楽器製作所 Electronic musical instrument
JPS62145927A (en) * 1985-12-20 1987-06-30 Hitachi Ltd Data converter
JPS62209913A (en) * 1986-03-10 1987-09-16 Hitachi Ltd Switched capacitor filter
US6509791B2 (en) 2001-05-08 2003-01-21 Fujitsu Limited Switched capacitor filter circuit

Similar Documents

Publication Publication Date Title
JPS55123226A (en) Switched capacitor filter
JPS55159630A (en) Analog switch
JPS5748826A (en) Circuit for converting input pulse duty ratio into analog voltage
JPS57202125A (en) Variable reference voltage generating circuit
JPS57101404A (en) Compensation circuit for nonlinear distortion
JPS57162185A (en) Sample holding circuit
JPS5661868A (en) Contour compensating circuit for picture signal
JPS5472936A (en) Resistance-variable circuit of voltage control type
SU1610558A1 (en) D.c. voltage stabilizer
JPS5690496A (en) Charge input circuit
SU873386A1 (en) Active filter
JPS5783925A (en) Digital-to-analog converter
JPS6453612A (en) Amplifier
JPS577602A (en) Fet amplifying circuit
JPS57107676A (en) Horizontal deflecting circuit device
SU574707A1 (en) A.c.voltage stabilizer
JPS57208718A (en) Control circuit for voltage controlled variable attenuator
JPS55147826A (en) Waveform shaping circuit
JPS6453614A (en) Amplifier
JPS5583321A (en) Filter available for selective variation in frequency characteristic
JPS5761319A (en) Electronic variable resistor
JPS5523609A (en) Two wire type signal conversion amplifier
JPS54161259A (en) Voltage-frequency converter
JPS5772415A (en) Circuir having function of band pass filter and oscillator
JPS5715295A (en) Sample holding circuit