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JPS57211814A - Gain variable amplifier - Google Patents

Gain variable amplifier

Info

Publication number
JPS57211814A
JPS57211814A JP9677781A JP9677781A JPS57211814A JP S57211814 A JPS57211814 A JP S57211814A JP 9677781 A JP9677781 A JP 9677781A JP 9677781 A JP9677781 A JP 9677781A JP S57211814 A JPS57211814 A JP S57211814A
Authority
JP
Japan
Prior art keywords
circuit
differential
controlling
transistors
changed
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
JP9677781A
Other languages
Japanese (ja)
Inventor
Takashi Koga
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.)
Toshiba Corp
Original Assignee
Toshiba Corp
Tokyo Shibaura Electric Co 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 Toshiba Corp, Tokyo Shibaura Electric Co Ltd filed Critical Toshiba Corp
Priority to JP9677781A priority Critical patent/JPS57211814A/en
Publication of JPS57211814A publication Critical patent/JPS57211814A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G1/00—Details of arrangements for controlling amplification
    • H03G1/0005—Circuits characterised by the type of controlling devices operated by a controlling current or voltage signal

Landscapes

  • Control Of Amplification And Gain Control (AREA)

Abstract

PURPOSE:To produce a gain variable amplifier of which frequency characteristic is not changed in accordance with the controlling status and output operating part is extremely stabilized by connecting between emitter electrodes of differential amplifiers through transistors and diodes to change the current ratio. CONSTITUTION:Attenuators R2, R3 of an attenuating circuit 1b in a gain controlling circuit 1 are connected in series to emitter electrodes of differential transistors Q2, Q3 of a differential amplifier 5 and diodes D1, D2 of a diode circuit 1a are connected so as to oppose to the emitter electrodes. A control signal S3 is supplied to the base electrode of a differential controlling circuit 1a, one collector electrode of controlling transistors Q5, Q6 of the differential controlling circuit 1a is connected to an opposite part 8 of the diode circuit 1c and the other collector electrode is connected to an intermediate point 7 of the attanuating circuit 1b. The current of the intermediate point 7 and the opposite point 8 is changed by the control signal S3 in accordance with the operation of the controlling transistors Q5, Q6 and the emitter current of the differential amplifier 5 is changed to control the gain.
JP9677781A 1981-06-24 1981-06-24 Gain variable amplifier Pending JPS57211814A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP9677781A JPS57211814A (en) 1981-06-24 1981-06-24 Gain variable amplifier

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9677781A JPS57211814A (en) 1981-06-24 1981-06-24 Gain variable amplifier

Publications (1)

Publication Number Publication Date
JPS57211814A true JPS57211814A (en) 1982-12-25

Family

ID=14174060

Family Applications (1)

Application Number Title Priority Date Filing Date
JP9677781A Pending JPS57211814A (en) 1981-06-24 1981-06-24 Gain variable amplifier

Country Status (1)

Country Link
JP (1) JPS57211814A (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5441053A (en) * 1977-09-07 1979-03-31 Matsushita Electric Ind Co Ltd Gain control amplifier

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5441053A (en) * 1977-09-07 1979-03-31 Matsushita Electric Ind Co Ltd Gain control amplifier

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