CN1061490C - 具有分贝线性输出电压的放大级 - Google Patents

具有分贝线性输出电压的放大级 Download PDF

Info

Publication number
CN1061490C
CN1061490C CN94193276A CN94193276A CN1061490C CN 1061490 C CN1061490 C CN 1061490C CN 94193276 A CN94193276 A CN 94193276A CN 94193276 A CN94193276 A CN 94193276A CN 1061490 C CN1061490 C CN 1061490C
Authority
CN
China
Prior art keywords
voltage
transistor
amplifying stage
vagc
multiplier
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 - Fee Related
Application number
CN94193276A
Other languages
English (en)
Other versions
CN1130448A (zh
Inventor
马丁·里格
萨拜因·罗思
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.)
Deutsche Thomson Brandt GmbH
Original Assignee
Deutsche Thomson Brandt GmbH
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 Deutsche Thomson Brandt GmbH filed Critical Deutsche Thomson Brandt GmbH
Publication of CN1130448A publication Critical patent/CN1130448A/zh
Application granted granted Critical
Publication of CN1061490C publication Critical patent/CN1061490C/zh
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/45—Differential amplifiers
    • H03F3/45071—Differential amplifiers with semiconductor devices only
    • H03F3/45076—Differential amplifiers with semiconductor devices only characterised by the way of implementation of the active amplifying circuit in the differential amplifier
    • H03F3/45179—Differential amplifiers with semiconductor devices only characterised by the way of implementation of the active amplifying circuit in the differential amplifier using MOSFET transistors as the active amplifying circuit
    • H03F3/4521—Complementary long tailed pairs having parallel inputs and being supplied in parallel
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G3/00—Gain control in amplifiers or frequency changers
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/32—Modifications of amplifiers to reduce non-linear distortion
    • H03F1/3211—Modifications of amplifiers to reduce non-linear distortion in differential amplifiers
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/45—Differential amplifiers
    • H03F3/45071—Differential amplifiers with semiconductor devices only
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/45—Differential amplifiers
    • H03F3/45071—Differential amplifiers with semiconductor devices only
    • H03F3/45076—Differential amplifiers with semiconductor devices only characterised by the way of implementation of the active amplifying circuit in the differential amplifier
    • H03F3/4508—Differential amplifiers with semiconductor devices only characterised by the way of implementation of the active amplifying circuit in the differential amplifier using bipolar transistors as the active amplifying circuit
    • H03F3/45085—Long tailed pairs
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/45—Differential amplifiers
    • H03F3/45071—Differential amplifiers with semiconductor devices only
    • H03F3/45076—Differential amplifiers with semiconductor devices only characterised by the way of implementation of the active amplifying circuit in the differential amplifier
    • H03F3/4508—Differential amplifiers with semiconductor devices only characterised by the way of implementation of the active amplifying circuit in the differential amplifier using bipolar transistors as the active amplifying circuit
    • H03F3/45085—Long tailed pairs
    • H03F3/45089—Non-folded cascode stages
    • 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
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G3/00—Gain control in amplifiers or frequency changers
    • H03G3/20—Automatic control
    • H03G3/30—Automatic control in amplifiers having semiconductor devices
    • H03G3/3052—Automatic control in amplifiers having semiconductor devices in bandpass amplifiers (H.F. or I.F.) or in frequency-changers used in a (super)heterodyne receiver
    • H03G3/3063—Automatic control in amplifiers having semiconductor devices in bandpass amplifiers (H.F. or I.F.) or in frequency-changers used in a (super)heterodyne receiver using at least one transistor as controlling device, the transistor being used as a variable impedance device
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2203/00—Indexing scheme relating to amplifiers with only discharge tubes or only semiconductor devices as amplifying elements covered by H03F3/00
    • H03F2203/45—Indexing scheme relating to differential amplifiers
    • H03F2203/45241—Two dif amps realised in MOS or JFET technology, the dif amps being either both of the p-channel type or both of the n-channel type, are coupled in parallel with their gates
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2203/00—Indexing scheme relating to amplifiers with only discharge tubes or only semiconductor devices as amplifying elements covered by H03F3/00
    • H03F2203/45—Indexing scheme relating to differential amplifiers
    • H03F2203/45302—Indexing scheme relating to differential amplifiers the common gate stage of a cascode dif amp being controlled
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2203/00—Indexing scheme relating to amplifiers with only discharge tubes or only semiconductor devices as amplifying elements covered by H03F3/00
    • H03F2203/45—Indexing scheme relating to differential amplifiers
    • H03F2203/45311—Indexing scheme relating to differential amplifiers the common gate stage of a cascode dif amp being implemented by multiple transistors
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2203/00—Indexing scheme relating to amplifiers with only discharge tubes or only semiconductor devices as amplifying elements covered by H03F3/00
    • H03F2203/45—Indexing scheme relating to differential amplifiers
    • H03F2203/45371—Indexing scheme relating to differential amplifiers the AAC comprising parallel coupled multiple transistors at their source and gate and drain or at their base and emitter and collector, e.g. in a cascode dif amp, only those forming the composite common source transistor or the composite common emitter transistor respectively
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2203/00—Indexing scheme relating to amplifiers with only discharge tubes or only semiconductor devices as amplifying elements covered by H03F3/00
    • H03F2203/45—Indexing scheme relating to differential amplifiers
    • H03F2203/45392—Indexing scheme relating to differential amplifiers the AAC comprising resistors in the source circuit of the AAC before the common source coupling

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Control Of Amplification And Gain Control (AREA)
  • Amplifiers (AREA)
  • Tone Control, Compression And Expansion, Limiting Amplitude (AREA)

Abstract

已知利用乘法器调节放大倍数。相对控制信号线性调节输出信号。本发明目的是设计以dB线性方式控制的乘法放大器。为此，将其数值分布系数导致输出电压dB线性地依赖于控制电压的晶体管连接在乘法器(2)的输入端。本发明尤其适于调整DAB电视机的中频放大器的放大倍数。

Description

具有分贝线性输出电压的放大级
本发明涉及dB线性的放大器，即以dB线性方式控制的乘法放大器。
已知利用乘法器进行增益控制。控制信号加到乘法器的一个输入端，而输入信号加到乘法器的第二输入端。输出信号出现在输出端。
在已知增益控制的情况下，输出信号相应于控制信号线性地输出。若给定1伏的输入信号和在0与10伏之间的控制信号，有可能实现具有0与100之间因子的线性增益特性。亦即，10伏的控制信号产生100的增益因子，5伏的控制信号其增益因子为50。如果用dB(分贝)表示增益因子，则增益因子100对应于40dB的值，增益因子50对应34dB的值。因此线性放大器不适用于dB线性，因为输出信号的变化在控制范围的低端具有大的影响，而在控制范围的高端，受控变量的变化对输出信号不具有多少影响。
在中频(IF)范围内增益因子位于数值1与1000之间。这些增益因子必须关于控制电压均匀分布，由此可实现输出电压与控制信号之间的dB线性。
此外由US-A-5057717和US-A-4004141已知将输出电压变为输入电压的对数函数。
本发明的目的是将受控的乘法放大器设计为dB线性的放大器。借助于本发明的下述特征达到该目的，即将若干晶体管连接到乘法器的输入端，凭借两输入端之间所连接的晶体管数目比值的选取，所述晶体管实现输出电压相对于控制电压的dB线性依赖关系。
按照本发明，为驱动目的将晶体管连接在乘法放大器输入端的上游。这些晶体管等同芯片上的晶体管区域。如果选定乘法器各输入端上游的上游晶体管或晶体管区的数量是相同的，乘法器线性工作。如果选定输入端上游的晶体管或晶体管区的数量是不同的，则在给定晶体管或晶体管区的适当分布率时dB线性化是可能的。
通过控制经由晶体管馈入乘法器输入端的电流，可精确设置dB线性。借助于级数展开式可确定合适的晶体管分布率和适当的电流控制。
利用控制单元，一方面将控制电压转换为电流，另一方面补偿温度效应。控制单元具有确保最小增益为1的恒定部件。
在具有1∶5的晶体管分布率的情况下产生可能的最佳的dB线性化。该电路的优点是以低成本使dB线性化成为可能。
下面参照附图说明本发明，其中：
图1示出了按本发明构成的电路；
图2示出了用图1电路获得的特性曲线；
图3示出了按照本发明构成的电路的改进；以及
图4-11示出按照本发明构成的电路的改进。
图1示出dB线性的乘法器。中频电压UE由电压／电流转换器1转换为电流IE，电压／电流转换器1由晶体管T11、T12和电阻RE形成。由上部乘法器2引出电流IE。在乘法器2的输入端出现直流信号U2。输出电压VC出现在乘法器2的输出端。直流电压U1出现在晶体管T1、T2、T3、T4、T5、T6的基极。直流信号U2作为电流Ia，Ib的函数改变其值。控制单元3将控制电压VAGC转换为电流Ia和Ib。晶体管T1依据控制单元3引出电流Ia。晶体管T2、T3、T4、T5、T6依据控制单元3引出电流Ib。由控制单元3按控制电压VAGC的函数控制电流Ia、Ib。电流Ia和Ib是相互补偿的，亦即当一个电流增加时，另一电流下降。控制单元3具有一恒定部分Iconst，借助于该部分产生最小增益1。直流信号U2取决于电流Ia、Ib，通过切换电流IE的方式驱动乘法器，并产生电流I1或电流I2。Ia与Ib之比等于I1与I2之比。电流I1影响电阻RC两端的电压降并通过电压VC提供放大的信号。电流I2不影响电阻RC两端的电压降，并经电压VC减小放大的信号。由此，以这样的方式控制信号分布，即使作为中频电压UE和控制电压VAGC函数的输出电压VC的dB线性成为可能。
下面描述与乘法器2输入端有关的相同类型晶体管的分布率NT的作用。基极与发射极之间的电压降控制晶体管T1到T6的电流分布。在相同分布率的情况下，所有电流同等分布。也就是说Ia与Ib之比等于I1与I2之比。这是控制电流高频分布的通常直流分布，在该情况下分布率为1∶1。给定诸如1∶5的不同选择的分布率，电流Ib的较少部分电流流过并联连接的5个晶体管中的每个晶体管，且电压降将按一定规则下降。将根据二极管特性Ic=Is *exp ( U BE U Temp ) 来拟定该规则，产生公式UBE=UTemp *ln ( I C I s ) 。在这种情况下，Is表示二极管的反向饱和电流。显然基／射极电压按电流比的自然对数函数变化。因此反向饱和电流取决于晶体管的数目并在晶体管T2至T6之间均匀分布。由晶体管T2到T6产生反向饱和电流Is，于是基／射极比率以因子5下降。对应所选比率1∶5产生电压U1-U2= [ ln ( I a 5 * I b ) * U Temp ] ·             因此，
所选比率以对数用入该公式中。比率1∶5亦即T1∶T2、T3、T4、T5、T6确保输出端的dB线性。
图2示出了要求的曲线轮廓。输出电压VC[dB]表示为控制电压VAGC[V]的函数。曲线轮廓a表示相对于给定所选分布率NT=1∶5的控制电压VAGC的dB线性轮廓。曲线轮廓b表示给定所选分布率NT=1∶3的近似线性曲线轮廓。很明显用所选分布率NT=1∶5得到dB线性。
图3示出了改进的电路，与图1相比的替换存在于控制单元3的连接方式中。控制单元3包含晶体管T13、T14、T15、T16、T17、T18，电阻器R1、R2、R3、R4、R5、R6，参考电压源UTef和恒流源Iconst。控制单元3将控制电压VAGC转换为电流Ia和Ib。不同分布率导致归因于不同电流的温度响应，该温度响应需加以补偿。在这种电路配置的情况下，重新调节电路Ia、Ib，这样增益随温度变化保持恒定。
图4示出具有均衡发射极面积的可控放大器。该放大器包含三个耦合的差分放大器n1、n2、nc。诸晶体管的发射极面积是不同的。在中间的差分放大器nc具有发射极面积nc*Ae，其中nc是整数，Ae是发射极面积单位(例如5μm*5μm)。两个靠外的差分放大器n1、n2分别具有发射极面积n1*Ae，n2*Ae和n2*Ae、n1*Ae。差分放大器的控制电流为Ia、Ib和Ic。集电极电流Ic为
电压增益Av=Va／Ve为 Av = di cl dx * R k
导数 dAv dx 是增益线性的量度。因此增益Av取决于该调制。如果Ia=Ib，则 dAv dx = 2 R k [ i c * e x ( l l + e x ) 2 + io 2 e x + 4 e 2 x + 2 e 3 x i + 4 e x + 6 e 2 x + 4 e 3 x + e 4 x ]
其中ia=ib=io
线性放大器设计的目的是获得电压增益Av=常数的最大可能的调制x。利用数学优选法，现在可确定Ia、Ib、Ic、n1、n2和nc，以此达到该目的。
图5曲线a表示包含中部差分放大器nc的放大器的电压增益Av(x)的轮廓。曲线b表示仅包含两个外侧差分放大器n1的放大器。曲线C表示包含所有3个差分放大器n1、n2、nc的放大器。按照曲线C的解决办法表示在整个调制范围内明显改进的线性。对应不同方案、曲线a、b和c，表1中列出了1％的容许改进的调制限制。表1
    电路／曲线     失真因子k≤1％的调制限制
    nc    ／an1    ／bn1，n2，nc／c理想     x≤0．2x≤1．0x≤1．8X→∞
新方案、曲线C显示出与已知方案、曲线a和b相比几乎双倍的调制范围。
图6示出当借助于VT发生器控制电流与温度成比例增加时具有依赖于温度的增益的电路。
图7示出另一示范实施例。该放大器包含四个放大器，这四个放大器链式联接并单片式集成。失真因子k≤1％的最大容许输入电压Vin是60 mvpp。增益可从0dB变化到60dB。该放大器的噪声电压电平为5nV／v。该放大器的带宽大于120 MHz。
图8示出调制范围的倍增。通过将m个二极管插入差分放大器的发射极路径中将调制范围增加m倍。
图9示出增加带宽的电路。借助于共射共基放大电路，可使寄生集电极／基片电容Cs变得无效，由此增加带宽。
图10示出依赖于输入电压的增益。通过适当选择差分放大器n1、n2、nc、ia、ib和ic可获得可能的任何所需形状的增益曲线。调换集电极线路可产生其它变型。
图11示出另一差分放大器10。通过增加另一差分放大器10可扩展其中放大器为线性的调制范围。

Claims (8)

1、具有随控制电压(VAGC)的对数线性变化的增益、因而控制电压(VAGC)变化一定比率对应于增益变化以dB表示的相同比率，并具有受控制电压(VAGC)控制的乘法器的放大级，其特征在于：晶体管(T1、T2、T3、T4、T5、T6)连接在控制电压(VAGC)与乘法器(2)的输入端之间，凭借两输入端之间所连接的晶体管数目比值的选取，所述晶体管实现输出电压(VC)相对于控制电压(VAGC)的dB线性依赖关系。
2、如权利要求1所述的放大级，其特征在于：配备控制单元(3)，用于将控制电压(VAGC)转换为电流(Ia、Ib)。
3、如权利要求2所述的放大级，其特征在于：控制单元(3)以这样的方式重新调节电流(Ia，Ib)，即增益相对温度保持恒定。
4、如权利要求1所述的放大级，其特征在于：乘法器(2)输入端上游的晶体管(T1、T2、T3、T4、T5、T6)的分布率具有例如1∶5的数值。
5、如权利要求1所述的放大级，其特征在于：由芯片上相应晶体管区形成所述晶体管。
6、如权利要求1所述的放大级，其特征在于：当给定恒定电压增益(Av)时，用耦合差分放大器(nc)获得调制范围的增大。
7、如权利要求6所述的放大级，其特征在于：通过将m个二极管插入差分放大器的发射级路径中调制范围增加m倍。
8、如权利要求1所述的放大级，其特征在于：借助于共射共基放大电路增加带宽。
CN94193276A 1993-09-04 1994-08-25 具有分贝线性输出电压的放大级 Expired - Fee Related CN1061490C (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4329896A DE4329896A1 (de) 1993-09-04 1993-09-04 Verstärkerstufe mit einer dB-linearen Ausgangsspannung
DEP4329896.6 1993-09-04

Publications (2)

Publication Number Publication Date
CN1130448A CN1130448A (zh) 1996-09-04
CN1061490C true CN1061490C (zh) 2001-01-31

Family

ID=6496826

Family Applications (1)

Application Number Title Priority Date Filing Date
CN94193276A Expired - Fee Related CN1061490C (zh) 1993-09-04 1994-08-25 具有分贝线性输出电压的放大级

Country Status (10)

Country Link
US (1) US5874857A (zh)
EP (1) EP0716783B1 (zh)
JP (2) JP3986553B2 (zh)
KR (1) KR100319009B1 (zh)
CN (1) CN1061490C (zh)
BR (1) BR9407380A (zh)
DE (2) DE4329896A1 (zh)
ES (1) ES2117290T3 (zh)
MY (1) MY110755A (zh)
WO (1) WO1995007574A1 (zh)

Families Citing this family (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5933771A (en) * 1997-06-20 1999-08-03 Nortel Networks Corporation Low voltage gain controlled mixer
US6049251A (en) * 1998-03-30 2000-04-11 Maxim Integrated Products, Inc. Wide-dynamic-range variable-gain amplifier
US6525609B1 (en) 1998-11-12 2003-02-25 Broadcom Corporation Large gain range, high linearity, low noise MOS VGA
US6985035B1 (en) 1998-11-12 2006-01-10 Broadcom Corporation System and method for linearizing a CMOS differential pair
EP1145430B1 (en) 1998-11-12 2004-09-15 Broadcom Corporation Integrated tuner architecture
US7276970B2 (en) * 1998-11-12 2007-10-02 Broadcom Corporation System and method for linearizing a CMOS differential pair
JP2000232328A (ja) 1999-02-09 2000-08-22 Nec Ic Microcomput Syst Ltd 可変利得増幅器の利得制御回路
US7696823B2 (en) 1999-05-26 2010-04-13 Broadcom Corporation System and method for linearizing a CMOS differential pair
JP4073152B2 (ja) 2000-06-30 2008-04-09 富士通株式会社 利得可変増幅器
JP2002043875A (ja) 2000-07-24 2002-02-08 Nec Corp 可変利得増幅器及びそれを備えた電子機器
US6522200B2 (en) * 2000-12-11 2003-02-18 Texas Instruments Incorporated Process-insensitive, highly-linear constant transconductance circuit
DE10106388C2 (de) * 2001-02-12 2002-12-12 Infineon Technologies Ag Schaltungsanordnung zur Bereitstellung einer exponentiellen Vorverzerrung für einen einstellbaren Verstärker
DE10150476A1 (de) * 2001-10-16 2003-04-17 Thomson Brandt Gmbh Wireless LAN
JP4027102B2 (ja) * 2002-01-31 2007-12-26 キヤノン株式会社 情報処理装置、情報処理方法、及び制御プログラム
US8010073B2 (en) * 2004-01-22 2011-08-30 Broadcom Corporation System and method for adjusting power amplifier output power in linear dB steps
KR100574470B1 (ko) * 2004-06-21 2006-04-27 삼성전자주식회사 전류증폭결합기를 포함하는 선형 혼합기회로
US7262661B2 (en) * 2005-06-27 2007-08-28 Linear Technology Corporation Variable gain amplifier with temperature compensation and gain linearity enhancement
TWI378640B (en) * 2009-10-23 2012-12-01 Sunplus Technology Co Ltd Variable-gain low noise amplifier
WO2011064220A1 (en) 2009-11-24 2011-06-03 Oce-Technologies B. V. Sheet stacking device and method of stacking sheets
CN109417366B (zh) * 2016-06-28 2021-01-29 华为技术有限公司 dB线性可变增益放大器

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4004141A (en) * 1975-08-04 1977-01-18 Curtis Douglas R Linear/logarithmic analog multiplier
US4429416A (en) * 1982-03-26 1984-01-31 National Semiconductor Corporation Multistage cascade/cascode limiting IF amplifier and meter circuit
US5057717A (en) * 1990-02-01 1991-10-15 Nec Corporation Logarithmic amplifier circuit

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DD110726A1 (zh) * 1974-04-01 1975-01-05
DE3027071A1 (de) * 1980-07-17 1982-02-11 Philips Patentverwaltung Gmbh, 2000 Hamburg Transistorverstaerker mit zwei emittergekoppelten transisorpaaren
DE3134936A1 (de) * 1981-09-03 1983-03-17 Siemens AG, 1000 Berlin und 8000 München Integrierbare signalverarbeitende halbleiterschaltung
DE3941677A1 (de) * 1989-12-18 1991-06-20 Telefunken Electronic Gmbh Differenzverstaerker
DE4113498C1 (zh) * 1991-04-25 1992-04-30 Deutsche Thomson-Brandt Gmbh, 7730 Villingen-Schwenningen, De
US5589791A (en) * 1995-06-09 1996-12-31 Analog Devices, Inc. Variable gain mixer having improved linearity and lower switching noise

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4004141A (en) * 1975-08-04 1977-01-18 Curtis Douglas R Linear/logarithmic analog multiplier
US4429416A (en) * 1982-03-26 1984-01-31 National Semiconductor Corporation Multistage cascade/cascode limiting IF amplifier and meter circuit
US5057717A (en) * 1990-02-01 1991-10-15 Nec Corporation Logarithmic amplifier circuit

Also Published As

Publication number Publication date
US5874857A (en) 1999-02-23
EP0716783B1 (de) 1998-04-15
JP2007082257A (ja) 2007-03-29
KR100319009B1 (ko) 2002-07-03
EP0716783A1 (de) 1996-06-19
WO1995007574A1 (de) 1995-03-16
DE4329896A1 (de) 1995-03-09
DE59405728D1 (de) 1998-05-20
ES2117290T3 (es) 1998-08-01
JP4291354B2 (ja) 2009-07-08
KR960705400A (ko) 1996-10-09
CN1130448A (zh) 1996-09-04
JP3986553B2 (ja) 2007-10-03
BR9407380A (pt) 1996-07-16
MY110755A (en) 1999-02-27
JPH09502316A (ja) 1997-03-04

Similar Documents

Publication Publication Date Title
CN1061490C (zh) 具有分贝线性输出电压的放大级
KR100461969B1 (ko) Ｃｍｏｓ 공정을 통해 구현된 지수함수 발생기 및 그를이용한 가변이득증폭기
KR100310405B1 (ko) 이득제어증폭기및그제어방법
US6049251A (en) Wide-dynamic-range variable-gain amplifier
CA2318146C (en) Gain control amplifier, variable gain and automatic gain control amplifiers including differential circuit transistors and current splitter
SE9701082L (sv) Variabel flerstegsförstärkningskrets
US6124761A (en) Variable gain amplifier with gain linear with control voltage
CN101394157A (zh) 具有宽增益变化和宽带宽的可变增益放大器
KR19990072771A (ko) 이득가변증폭회로
US5389893A (en) Circuit for a controllable amplifier
US5682119A (en) Variable gain circuit
GB2070359A (en) Variable-gain amplifier stage equipped with field-effect transistors
US5352944A (en) Apparatus and method for producing a temperature-independent current signal in an automatic gain control circuit
US7453307B2 (en) Process independent voltage controlled logarithmic attenuator having a low distortion and method therefor
US6091275A (en) Linear quad variable gain amplifier and method for implementing same
KR860000440B1 (ko) 신호레벨제어회로
US5028882A (en) Multiple output operational amplifier
US3651420A (en) Variable gain direct coupled amplifier
US20030169112A1 (en) Variable gain amplifier with low power consumption
US6864748B2 (en) Differential current amplifier with common mode rejection and high frequency boost
KR100282713B1 (ko) 이동통신단말기의 자동이득제어용 가변이득증폭 회로
ATE251817T1 (de) Elektronische lautstärkesteuerungsschaltung mit gesteuerter ausgangscharakteristik
KR890007296Y1 (ko) 무신호 영역을 갖는 증폭회로
KR940002238Y1 (ko) 자동 이득 제어회로
JPH0695631B2 (ja) ヒステリシスを有する電圧比較回路

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant
C17 Cessation of patent right
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20010131

Termination date: 20120825