GB1519831A - Symmetrical circuit arrangement for forming a variable ac resistance - Google Patents

Symmetrical circuit arrangement for forming a variable ac resistance

Info

Publication number
GB1519831A
GB1519831A GB25370/75A GB2537075A GB1519831A GB 1519831 A GB1519831 A GB 1519831A GB 25370/75 A GB25370/75 A GB 25370/75A GB 2537075 A GB2537075 A GB 2537075A GB 1519831 A GB1519831 A GB 1519831A
Authority
GB
United Kingdom
Prior art keywords
region
layer
resistance
variable
june
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.)
Expired
Application number
GB25370/75A
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.)
Philips Electronics UK Ltd
Original Assignee
Philips Electronic and Associated Industries 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 Philips Electronic and Associated Industries Ltd filed Critical Philips Electronic and Associated Industries Ltd
Publication of GB1519831A publication Critical patent/GB1519831A/en
Expired 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
    • H03G1/0035—Circuits characterised by the type of controlling devices operated by a controlling current or voltage signal using continuously variable impedance elements
    • H03G1/0082—Circuits characterised by the type of controlling devices operated by a controlling current or voltage signal using continuously variable impedance elements using bipolar transistor-type devices
    • 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
    • H03G1/0017—Circuits characterised by the type of controlling devices operated by a controlling current or voltage signal the device being at least one of the amplifying solid state elements of the amplifier
    • H03G1/0023—Circuits characterised by the type of controlling devices operated by a controlling current or voltage signal the device being at least one of the amplifying solid state elements of the amplifier in emitter-coupled or cascode amplifiers

Landscapes

  • Bipolar Transistors (AREA)
  • Semiconductor Integrated Circuits (AREA)
  • Bipolar Integrated Circuits (AREA)
  • Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)

Abstract

1519831 Semiconductor devices PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd 13 June 1975 [17 June 1974] 25370/75 Heading H1K [Also in Divisions H3 and H4] A symmetrical circuit providing a variable A.C. resistance between terminals 7, 8, Fig. 2, comprises an elongated PN junction 26 separating regions 23, 25, a current source 20 connected to 25 substantially midway between 7 and 8, and a controllable current sink 30 connected to region 23, whereby as the sink current Ir is increased, increasing portions of junction 26 are turned on from the middle outwardly so that a central portion of region 25 is shunted by part of region 23. Region 23 may have its effective resistance reduced by (a) a further region 27, Fig. 3a, to be used as a collector, (b) shunting by a conducting layer, (c) a low resistance buried layer 23<SP>1</SP>, or (d) geometry providing a long path from 7 to 8 via region 25 and a short path via region 23, Figs. 4a, 4b (not shown). A P-type semiconductor substrate has a diffused N<SP>+</SP> layer 23<SP>1</SP>, covered by an N epitaxial layer 23. Two surface P regions 25, 27 are then formed in 23, to produce a lateral PNP transistor. Shaded areas 32-38 indicate contact openings in an insulating layer; conductive layers 7, 8, 9, 31, 39, Fig. 3b, provide terminals.
GB25370/75A 1974-06-17 1975-06-13 Symmetrical circuit arrangement for forming a variable ac resistance Expired GB1519831A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL7408034.A NL161318C (en) 1974-06-17 1974-06-17 SYMMETRICAL DEVICE FOR FORMING AN ADJUSTABLE AC AC RESISTANCE.

Publications (1)

Publication Number Publication Date
GB1519831A true GB1519831A (en) 1978-08-02

Family

ID=19821555

Family Applications (1)

Application Number Title Priority Date Filing Date
GB25370/75A Expired GB1519831A (en) 1974-06-17 1975-06-13 Symmetrical circuit arrangement for forming a variable ac resistance

Country Status (14)

Country Link
JP (1) JPS5329584B2 (en)
AR (1) AR205571A1 (en)
AU (1) AU499961B2 (en)
BR (1) BR7503768A (en)
CA (1) CA1035468A (en)
DE (2) DE2560093C3 (en)
ES (1) ES438562A1 (en)
FR (1) FR2275070A1 (en)
GB (1) GB1519831A (en)
HK (1) HK48679A (en)
IT (1) IT1036297B (en)
NL (1) NL161318C (en)
SE (1) SE413448B (en)
ZA (1) ZA753735B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4345214A (en) 1980-04-23 1982-08-17 Rca Corporation Variable emitter degeneration gain-controlled amplifier

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS52153651A (en) * 1976-06-17 1977-12-20 Sony Corp Gain changing circuit
US4833422A (en) * 1987-09-24 1989-05-23 Burr-Brown Corporation Programmable gain instrumentation amplifier
DE19713571C1 (en) * 1997-04-02 1998-10-01 Telefunken Microelectron Controlled resistance for semi conductor differencing amplifier

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1320027A (en) 1961-10-19 1963-03-08 Westinghouse Electric Corp Semiconductor potentiometer

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4345214A (en) 1980-04-23 1982-08-17 Rca Corporation Variable emitter degeneration gain-controlled amplifier

Also Published As

Publication number Publication date
ES438562A1 (en) 1977-05-16
AU499961B2 (en) 1979-05-10
BR7503768A (en) 1976-07-06
FR2275070B1 (en) 1980-03-21
DE2526309A1 (en) 1976-01-02
JPS5116885A (en) 1976-02-10
DE2560093B2 (en) 1981-04-23
DE2526309B2 (en) 1979-09-20
DE2526309C3 (en) 1980-06-04
CA1035468A (en) 1978-07-25
NL7408034A (en) 1975-12-19
HK48679A (en) 1979-07-27
DE2560093C3 (en) 1982-01-28
IT1036297B (en) 1979-10-30
AR205571A1 (en) 1976-05-14
NL161318C (en) 1980-01-15
SE413448B (en) 1980-05-27
FR2275070A1 (en) 1976-01-09
ZA753735B (en) 1977-01-26
SE7506779L (en) 1975-12-18
JPS5329584B2 (en) 1978-08-22
AU8214675A (en) 1976-12-23
NL161318B (en) 1979-08-15

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Legal Events

Date Code Title Description
PS Patent sealed
PE20 Patent expired after termination of 20 years

Effective date: 19950612