JPS55162614A - Variable low pass filter - Google Patents

Variable low pass filter

Info

Publication number
JPS55162614A
JPS55162614A JP6990779A JP6990779A JPS55162614A JP S55162614 A JPS55162614 A JP S55162614A JP 6990779 A JP6990779 A JP 6990779A JP 6990779 A JP6990779 A JP 6990779A JP S55162614 A JPS55162614 A JP S55162614A
Authority
JP
Japan
Prior art keywords
pass filter
low pass
pll
voltage
state
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.)
Granted
Application number
JP6990779A
Other languages
Japanese (ja)
Other versions
JPS6156893B2 (en
Inventor
Tsutomu Noda
Isao Akitake
Kazuhiko Yamazaki
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.)
Hitachi Ltd
Original Assignee
Hitachi 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 Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP6990779A priority Critical patent/JPS55162614A/en
Publication of JPS55162614A publication Critical patent/JPS55162614A/en
Publication of JPS6156893B2 publication Critical patent/JPS6156893B2/ja
Granted legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H11/00—Networks using active elements
    • H03H11/02—Multiple-port networks
    • H03H11/04—Frequency selective two-port networks
    • H03H11/12—Frequency selective two-port networks using amplifiers with feedback
    • H03H11/1291—Current or voltage controlled filters

Landscapes

  • Filters And Equalizers (AREA)
  • Stabilization Of Oscillater, Synchronisation, Frequency Synthesizers (AREA)

Abstract

PURPOSE:To avoid the variation in the input control voltage of VCO (voltage controlled oscillator), by giving the circuit inserted as a shunt circuit to the resistive element constituting the filter, an infinite resistance value in DC, at the switching of cutoff frequency of a low pass filter. CONSTITUTION:With PLL in asynchronous state, a low voltage is fed to the control input terminal 11 and the transistor 10 is in OFF state. In this case, the impedance existing between the terminals 6 and 7 is very low than the value by the resistor 8 and the cutoff frequency of the low pass filter 3 is very high. Accordingly, the PLL is easily drawn to the synchronous state. With PLL drawn to the synchronous state, a high voltage is given to the terminal 11 to turn on the transistor 10. Then, the characteristics of filter can not almost give effect.
JP6990779A 1979-06-06 1979-06-06 Variable low pass filter Granted JPS55162614A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP6990779A JPS55162614A (en) 1979-06-06 1979-06-06 Variable low pass filter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6990779A JPS55162614A (en) 1979-06-06 1979-06-06 Variable low pass filter

Publications (2)

Publication Number Publication Date
JPS55162614A true JPS55162614A (en) 1980-12-18
JPS6156893B2 JPS6156893B2 (en) 1986-12-04

Family

ID=13416230

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6990779A Granted JPS55162614A (en) 1979-06-06 1979-06-06 Variable low pass filter

Country Status (1)

Country Link
JP (1) JPS55162614A (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10688485B2 (en) 2017-07-18 2020-06-23 Ias, Inc Substrate analysis nozzle and method for analyzing substrate

Also Published As

Publication number Publication date
JPS6156893B2 (en) 1986-12-04

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