TWI459174B - 低雜訊電壓參考電路 - Google Patents

低雜訊電壓參考電路 Download PDF

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Publication number
TWI459174B
TWI459174B TW097105467A TW97105467A TWI459174B TW I459174 B TWI459174 B TW I459174B TW 097105467 A TW097105467 A TW 097105467A TW 97105467 A TW97105467 A TW 97105467A TW I459174 B TWI459174 B TW I459174B
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TW
Taiwan
Prior art keywords
transistor
transistors
circuit
voltage
amplifier
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TW097105467A
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English (en)
Chinese (zh)
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TW200848972A (en
Inventor
Stefan Marinca
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Analog Devices Inc
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Publication of TW200848972A publication Critical patent/TW200848972A/zh
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    • GPHYSICS
    • G05CONTROLLING; REGULATING
    • G05FSYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
    • G05F3/00Non-retroactive systems for regulating electric variables by using an uncontrolled element, or an uncontrolled combination of elements, such element or such combination having self-regulating properties
    • G05F3/02Regulating voltage or current
    • G05F3/08Regulating voltage or current wherein the variable is DC
    • G05F3/10Regulating voltage or current wherein the variable is DC using uncontrolled devices with non-linear characteristics
    • G05F3/16Regulating voltage or current wherein the variable is DC using uncontrolled devices with non-linear characteristics being semiconductor devices
    • G05F3/20Regulating voltage or current wherein the variable is DC using uncontrolled devices with non-linear characteristics being semiconductor devices using diode- transistor combinations
    • G05F3/30Regulators using the difference between the base-emitter voltages of two bipolar transistors operating at different current densities

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  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Physics & Mathematics (AREA)
  • Power Engineering (AREA)
  • Nonlinear Science (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Automation & Control Theory (AREA)
  • Amplifiers (AREA)
  • Control Of Electrical Variables (AREA)
TW097105467A 2007-03-13 2008-02-15 低雜訊電壓參考電路 TWI459174B (zh)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US11/717,516 US7714563B2 (en) 2007-03-13 2007-03-13 Low noise voltage reference circuit

Publications (2)

Publication Number Publication Date
TW200848972A TW200848972A (en) 2008-12-16
TWI459174B true TWI459174B (zh) 2014-11-01

Family

ID=39315489

Family Applications (1)

Application Number Title Priority Date Filing Date
TW097105467A TWI459174B (zh) 2007-03-13 2008-02-15 低雜訊電壓參考電路

Country Status (6)

Country Link
US (1) US7714563B2 (enExample)
EP (1) EP2118718B1 (enExample)
JP (1) JP5563312B2 (enExample)
CN (1) CN101657775B (enExample)
TW (1) TWI459174B (enExample)
WO (1) WO2008110410A1 (enExample)

Families Citing this family (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7543253B2 (en) * 2003-10-07 2009-06-02 Analog Devices, Inc. Method and apparatus for compensating for temperature drift in semiconductor processes and circuitry
US7576598B2 (en) * 2006-09-25 2009-08-18 Analog Devices, Inc. Bandgap voltage reference and method for providing same
US8102201B2 (en) 2006-09-25 2012-01-24 Analog Devices, Inc. Reference circuit and method for providing a reference
US7714563B2 (en) 2007-03-13 2010-05-11 Analog Devices, Inc. Low noise voltage reference circuit
US20080265860A1 (en) * 2007-04-30 2008-10-30 Analog Devices, Inc. Low voltage bandgap reference source
US7605578B2 (en) 2007-07-23 2009-10-20 Analog Devices, Inc. Low noise bandgap voltage reference
US7598799B2 (en) * 2007-12-21 2009-10-06 Analog Devices, Inc. Bandgap voltage reference circuit
US7612606B2 (en) * 2007-12-21 2009-11-03 Analog Devices, Inc. Low voltage current and voltage generator
US7902912B2 (en) * 2008-03-25 2011-03-08 Analog Devices, Inc. Bias current generator
US7880533B2 (en) * 2008-03-25 2011-02-01 Analog Devices, Inc. Bandgap voltage reference circuit
US7750728B2 (en) * 2008-03-25 2010-07-06 Analog Devices, Inc. Reference voltage circuit
IT1394636B1 (it) 2009-06-23 2012-07-05 St Microelectronics Rousset Circuito di generazione di un segnale di riferimento per un convertitore a/d di un trasduttore acustico microelettromeccanico e relativo metodo
TWI456493B (zh) * 2010-12-29 2014-10-11 Silicon Motion Inc 除法方法及除法裝置
KR101404583B1 (ko) 2013-01-22 2014-06-27 (주) 쿨파워테크놀러지 노이즈에 강한 밴드갭 기준전압 발생회로
US9448579B2 (en) * 2013-12-20 2016-09-20 Analog Devices Global Low drift voltage reference
EP2905672A1 (en) * 2014-02-11 2015-08-12 Dialog Semiconductor GmbH An apparatus and method for a modified brokaw bandgap reference circuit for improved low voltage power supply
US20160091916A1 (en) * 2014-09-30 2016-03-31 Taiwan Semiconductor Manufacturing Company, Ltd. Bandgap Circuits and Related Method
CN105204564A (zh) * 2015-10-30 2015-12-30 无锡纳讯微电子有限公司 一种低温度系数基准源电路
CN105978628B (zh) * 2016-06-13 2018-04-24 青岛海信宽带多媒体技术有限公司 一种光模块
US9727074B1 (en) 2016-06-13 2017-08-08 Semiconductor Components Industries, Llc Bandgap reference circuit and method therefor
US10353414B2 (en) * 2017-04-07 2019-07-16 Texas Instruments Incorporated Bandgap reference circuit with inverted bandgap pairs
IT201700117023A1 (it) * 2017-10-17 2019-04-17 St Microelectronics Srl Circuito di riferimento bandgap, dispositivo e procedimento corrispondenti
US10528070B2 (en) 2018-05-02 2020-01-07 Analog Devices Global Unlimited Company Power-cycling voltage reference
US10409312B1 (en) 2018-07-19 2019-09-10 Analog Devices Global Unlimited Company Low power duty-cycled reference
JP7769636B2 (ja) * 2020-05-07 2025-11-13 テキサス インスツルメンツ インコーポレイテッド ノイズ低減のため入力増幅器を有するバンドギャップ基準
CN114252160B (zh) * 2020-09-22 2024-03-22 无锡华润上华科技有限公司 模数转换器及热电堆阵列

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4059793A (en) * 1976-08-16 1977-11-22 Rca Corporation Semiconductor circuits for generating reference potentials with predictable temperature coefficients
US5563504A (en) * 1994-05-09 1996-10-08 Analog Devices, Inc. Switching bandgap voltage reference
US20040124822A1 (en) * 2002-12-27 2004-07-01 Stefan Marinca Bandgap voltage reference circuit with high power supply rejection ratio (PSRR) and curvature correction
US6765431B1 (en) * 2002-10-15 2004-07-20 Maxim Integrated Products, Inc. Low noise bandgap references
TW200609704A (en) * 2004-06-30 2006-03-16 Analog Devices Inc A proportional to absolute temperature voltage circuit
TW200639609A (en) * 2005-05-10 2006-11-16 Univ Nat Chunghsing Band-gap reference voltage circuit
US7342390B2 (en) * 2006-05-01 2008-03-11 Fujitsu Limited Reference voltage generation circuit

Family Cites Families (95)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4399398A (en) * 1981-06-30 1983-08-16 Rca Corporation Voltage reference circuit with feedback circuit
US4475103A (en) * 1982-02-26 1984-10-02 Analog Devices Incorporated Integrated-circuit thermocouple signal conditioner
US4603291A (en) * 1984-06-26 1986-07-29 Linear Technology Corporation Nonlinearity correction circuit for bandgap reference
US4714872A (en) * 1986-07-10 1987-12-22 Tektronix, Inc. Voltage reference for transistor constant-current source
JP2543872B2 (ja) * 1986-08-13 1996-10-16 株式会社東芝 増幅回路
US4808908A (en) * 1988-02-16 1989-02-28 Analog Devices, Inc. Curvature correction of bipolar bandgap references
US4939442A (en) * 1989-03-30 1990-07-03 Texas Instruments Incorporated Bandgap voltage reference and method with further temperature correction
US5053640A (en) * 1989-10-25 1991-10-01 Silicon General, Inc. Bandgap voltage reference circuit
JPH03185506A (ja) * 1989-12-14 1991-08-13 Toyota Motor Corp 安定化定電圧回路
JPH04167010A (ja) 1990-10-31 1992-06-15 Olympus Optical Co Ltd 電流源回路
IT1245688B (it) 1991-04-24 1994-10-13 Sgs Thomson Microelectronics Struttura di compensazione in temperatura della corrente inversa di saturazione in transistori bipolari
JPH0561558A (ja) * 1991-08-30 1993-03-12 Sharp Corp 基準電圧発生回路
JP3141486B2 (ja) * 1992-01-27 2001-03-05 ソニー株式会社 半導体装置
US5352973A (en) * 1993-01-13 1994-10-04 Analog Devices, Inc. Temperature compensation bandgap voltage reference and method
US5325045A (en) * 1993-02-17 1994-06-28 Exar Corporation Low voltage CMOS bandgap with new trimming and curvature correction methods
US5424628A (en) * 1993-04-30 1995-06-13 Texas Instruments Incorporated Bandgap reference with compensation via current squaring
US5512817A (en) * 1993-12-29 1996-04-30 At&T Corp. Bandgap voltage reference generator
US5646518A (en) * 1994-11-18 1997-07-08 Lucent Technologies Inc. PTAT current source
US5821807A (en) * 1996-05-28 1998-10-13 Analog Devices, Inc. Low-power differential reference voltage generator
US5828329A (en) * 1996-12-05 1998-10-27 3Com Corporation Adjustable temperature coefficient current reference
US5933045A (en) * 1997-02-10 1999-08-03 Analog Devices, Inc. Ratio correction circuit and method for comparison of proportional to absolute temperature signals to bandgap-based signals
US5952873A (en) * 1997-04-07 1999-09-14 Texas Instruments Incorporated Low voltage, current-mode, piecewise-linear curvature corrected bandgap reference
US5982201A (en) * 1998-01-13 1999-11-09 Analog Devices, Inc. Low voltage current mirror and CTAT current source and method
US6356161B1 (en) * 1998-03-19 2002-03-12 Microchip Technology Inc. Calibration techniques for a precision relaxation oscillator integrated circuit with temperature compensation
US6002293A (en) * 1998-03-24 1999-12-14 Analog Devices, Inc. High transconductance voltage reference cell
US6163178A (en) * 1998-12-28 2000-12-19 Rambus Incorporated Impedance controlled output driver
US6157245A (en) * 1999-03-29 2000-12-05 Texas Instruments Incorporated Exact curvature-correcting method for bandgap circuits
US6225796B1 (en) * 1999-06-23 2001-05-01 Texas Instruments Incorporated Zero temperature coefficient bandgap reference circuit and method
US6075354A (en) * 1999-08-03 2000-06-13 National Semiconductor Corporation Precision voltage reference circuit with temperature compensation
US6218822B1 (en) * 1999-10-13 2001-04-17 National Semiconductor Corporation CMOS voltage reference with post-assembly curvature trim
US6329804B1 (en) * 1999-10-13 2001-12-11 National Semiconductor Corporation Slope and level trim DAC for voltage reference
US6489787B1 (en) * 2000-01-11 2002-12-03 Bacharach, Inc. Gas detection circuit
US6529066B1 (en) * 2000-02-28 2003-03-04 National Semiconductor Corporation Low voltage band gap circuit and method
US6329868B1 (en) * 2000-05-11 2001-12-11 Maxim Integrated Products, Inc. Circuit for compensating curvature and temperature function of a bipolar transistor
KR100347349B1 (ko) * 2000-05-23 2002-12-26 삼성전자 주식회사 마이크로파워 저항-캐패시터 발진기
US6426669B1 (en) * 2000-08-18 2002-07-30 National Semiconductor Corporation Low voltage bandgap reference circuit
US6483372B1 (en) * 2000-09-13 2002-11-19 Analog Devices, Inc. Low temperature coefficient voltage output circuit and method
US6255807B1 (en) * 2000-10-18 2001-07-03 Texas Instruments Tucson Corporation Bandgap reference curvature compensation circuit
US6531857B2 (en) * 2000-11-09 2003-03-11 Agere Systems, Inc. Low voltage bandgap reference circuit
US6362612B1 (en) * 2001-01-23 2002-03-26 Larry L. Harris Bandgap voltage reference circuit
US6373330B1 (en) * 2001-01-29 2002-04-16 National Semiconductor Corporation Bandgap circuit
US6501256B1 (en) * 2001-06-29 2002-12-31 Intel Corporation Trimmable bandgap voltage reference
US6489835B1 (en) * 2001-08-28 2002-12-03 Lattice Semiconductor Corporation Low voltage bandgap reference circuit
DE10157292A1 (de) * 2001-11-22 2003-06-05 Infineon Technologies Ag Temperaturstabilisierter Oszillator-Schaltkreis
US6549072B1 (en) * 2002-01-16 2003-04-15 Medtronic, Inc. Operational amplifier having improved input offset performance
US6590372B1 (en) * 2002-02-19 2003-07-08 Texas Advanced Optoelectronic Solutions, Inc. Method and integrated circuit for bandgap trimming
US6614209B1 (en) * 2002-04-29 2003-09-02 Ami Semiconductor, Inc. Multi stage circuits for providing a bandgap voltage reference less dependent on or independent of a resistor ratio
US6642699B1 (en) 2002-04-29 2003-11-04 Ami Semiconductor, Inc. Bandgap voltage reference using differential pairs to perform temperature curvature compensation
JP4167010B2 (ja) 2002-06-18 2008-10-15 株式会社日本マイクロニクス 表示用基板の処理装置
US6737849B2 (en) * 2002-06-19 2004-05-18 International Business Machines Corporation Constant current source having a controlled temperature coefficient
FR2842317B1 (fr) * 2002-07-09 2004-10-01 Atmel Nantes Sa Source de tension de reference, capteur de temperature, detecteur de seuil de temperature, puce et systeme correspondant
AU2003250066A1 (en) 2002-07-16 2004-02-02 Max-Planck-Gesellschaft Zur Forderung Der Wissenschaften E.V. Use of sumo- and ubiquitin-modified pcna for detection and channeling of dna transaction pathways
US6661713B1 (en) * 2002-07-25 2003-12-09 Taiwan Semiconductor Manufacturing Company Bandgap reference circuit
US6791307B2 (en) * 2002-10-04 2004-09-14 Intersil Americas Inc. Non-linear current generator for high-order temperature-compensated references
US6664847B1 (en) * 2002-10-10 2003-12-16 Texas Instruments Incorporated CTAT generator using parasitic PNP device in deep sub-micron CMOS process
US6853238B1 (en) * 2002-10-23 2005-02-08 Analog Devices, Inc. Bandgap reference source
US6836160B2 (en) * 2002-11-19 2004-12-28 Intersil Americas Inc. Modified Brokaw cell-based circuit for generating output current that varies linearly with temperature
US6801095B2 (en) * 2002-11-26 2004-10-05 Agere Systems, Inc. Method, program and system for designing an interconnected multi-stage oscillator
US6798286B2 (en) * 2002-12-02 2004-09-28 Broadcom Corporation Gain control methods and systems in an amplifier assembly
US7260377B2 (en) * 2002-12-02 2007-08-21 Broadcom Corporation Variable-gain low noise amplifier for digital terrestrial applications
US6690228B1 (en) * 2002-12-11 2004-02-10 Texas Instruments Incorporated Bandgap voltage reference insensitive to voltage offset
US6885178B2 (en) * 2002-12-27 2005-04-26 Analog Devices, Inc. CMOS voltage bandgap reference with improved headroom
US6828847B1 (en) * 2003-02-27 2004-12-07 Analog Devices, Inc. Bandgap voltage reference circuit and method for producing a temperature curvature corrected voltage reference
US6894544B2 (en) * 2003-06-02 2005-05-17 Analog Devices, Inc. Brown-out detector
US7088085B2 (en) * 2003-07-03 2006-08-08 Analog-Devices, Inc. CMOS bandgap current and voltage generator
US6958643B2 (en) * 2003-07-16 2005-10-25 Analog Microelectrics, Inc. Folded cascode bandgap reference voltage circuit
US6919753B2 (en) * 2003-08-25 2005-07-19 Texas Instruments Incorporated Temperature independent CMOS reference voltage circuit for low-voltage applications
US7057444B2 (en) * 2003-09-22 2006-06-06 Standard Microsystems Corporation Amplifier with accurate built-in threshold
US7199646B1 (en) * 2003-09-23 2007-04-03 Cypress Semiconductor Corp. High PSRR, high accuracy, low power supply bandgap circuit
US7543253B2 (en) * 2003-10-07 2009-06-02 Analog Devices, Inc. Method and apparatus for compensating for temperature drift in semiconductor processes and circuitry
US7012416B2 (en) * 2003-12-09 2006-03-14 Analog Devices, Inc. Bandgap voltage reference
US7211993B2 (en) * 2004-01-13 2007-05-01 Analog Devices, Inc. Low offset bandgap voltage reference
US7112948B2 (en) * 2004-01-30 2006-09-26 Analog Devices, Inc. Voltage source circuit with selectable temperature independent and temperature dependent voltage outputs
US6987416B2 (en) * 2004-02-17 2006-01-17 Silicon Integrated Systems Corp. Low-voltage curvature-compensated bandgap reference
US7253597B2 (en) * 2004-03-04 2007-08-07 Analog Devices, Inc. Curvature corrected bandgap reference circuit and method
US7248098B1 (en) * 2004-03-24 2007-07-24 National Semiconductor Corporation Curvature corrected bandgap circuit
CN1926491A (zh) * 2004-04-16 2007-03-07 松下电器产业株式会社 基准电压产生电路
TWI228347B (en) * 2004-04-23 2005-02-21 Faraday Tech Corp Bandgap reference circuit
US7224210B2 (en) * 2004-06-25 2007-05-29 Silicon Laboratories Inc. Voltage reference generator circuit subtracting CTAT current from PTAT current
US7193454B1 (en) * 2004-07-08 2007-03-20 Analog Devices, Inc. Method and a circuit for producing a PTAT voltage, and a method and a circuit for producing a bandgap voltage reference
US7116129B2 (en) * 2004-07-20 2006-10-03 Micron Technology, Inc. Temperature-compensated output buffer method and circuit
US7053694B2 (en) * 2004-08-20 2006-05-30 Asahi Kasei Microsystems Co., Ltd. Band-gap circuit with high power supply rejection ratio
US20060152206A1 (en) * 2004-12-23 2006-07-13 Yu Tim W H Method for improving the power supply rejection ratio (PSRR) of low power reference circuits
US7170336B2 (en) * 2005-02-11 2007-01-30 Etron Technology, Inc. Low voltage bandgap reference (BGR) circuit
US7224209B2 (en) * 2005-03-03 2007-05-29 Etron Technology, Inc. Speed-up circuit for initiation of proportional to absolute temperature biasing circuits
JP4681983B2 (ja) * 2005-08-19 2011-05-11 富士通セミコンダクター株式会社 バンドギャップ回路
SG134189A1 (en) * 2006-01-19 2007-08-29 Micron Technology Inc Regulated internal power supply and method
JP2007200233A (ja) * 2006-01-30 2007-08-09 Nec Electronics Corp ダイオードの非直線性を補償した基準電圧回路
US7495505B2 (en) * 2006-07-18 2009-02-24 Faraday Technology Corp. Low supply voltage band-gap reference circuit and negative temperature coefficient current generation unit thereof and method for supplying band-gap reference current
US7411380B2 (en) * 2006-07-21 2008-08-12 Faraday Technology Corp. Non-linearity compensation circuit and bandgap reference circuit using the same
US7472030B2 (en) * 2006-08-04 2008-12-30 National Semiconductor Corporation Dual mode single temperature trimming
US7301321B1 (en) * 2006-09-06 2007-11-27 Faraday Technology Corp. Voltage reference circuit
US7576598B2 (en) * 2006-09-25 2009-08-18 Analog Devices, Inc. Bandgap voltage reference and method for providing same
US7714563B2 (en) 2007-03-13 2010-05-11 Analog Devices, Inc. Low noise voltage reference circuit
US20080265860A1 (en) * 2007-04-30 2008-10-30 Analog Devices, Inc. Low voltage bandgap reference source

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4059793A (en) * 1976-08-16 1977-11-22 Rca Corporation Semiconductor circuits for generating reference potentials with predictable temperature coefficients
US5563504A (en) * 1994-05-09 1996-10-08 Analog Devices, Inc. Switching bandgap voltage reference
US6765431B1 (en) * 2002-10-15 2004-07-20 Maxim Integrated Products, Inc. Low noise bandgap references
US20040124822A1 (en) * 2002-12-27 2004-07-01 Stefan Marinca Bandgap voltage reference circuit with high power supply rejection ratio (PSRR) and curvature correction
TW200609704A (en) * 2004-06-30 2006-03-16 Analog Devices Inc A proportional to absolute temperature voltage circuit
TW200639609A (en) * 2005-05-10 2006-11-16 Univ Nat Chunghsing Band-gap reference voltage circuit
US7342390B2 (en) * 2006-05-01 2008-03-11 Fujitsu Limited Reference voltage generation circuit

Also Published As

Publication number Publication date
JP2010521029A (ja) 2010-06-17
US20080224759A1 (en) 2008-09-18
CN101657775B (zh) 2013-06-12
WO2008110410A1 (en) 2008-09-18
EP2118718A1 (en) 2009-11-18
JP5563312B2 (ja) 2014-07-30
TW200848972A (en) 2008-12-16
EP2118718B1 (en) 2013-03-13
CN101657775A (zh) 2010-02-24
US7714563B2 (en) 2010-05-11

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