WO2019016280A1 - Circuit et procédé permettant de piloter un amplificateur audio - Google Patents

Circuit et procédé permettant de piloter un amplificateur audio Download PDF

Info

Publication number
WO2019016280A1
WO2019016280A1 PCT/EP2018/069533 EP2018069533W WO2019016280A1 WO 2019016280 A1 WO2019016280 A1 WO 2019016280A1 EP 2018069533 W EP2018069533 W EP 2018069533W WO 2019016280 A1 WO2019016280 A1 WO 2019016280A1
Authority
WO
WIPO (PCT)
Prior art keywords
signal
input
circuit
level
audio
Prior art date
Application number
PCT/EP2018/069533
Other languages
English (en)
Inventor
Emmanuel Grand
Original Assignee
Dolphin Integration
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 Dolphin Integration filed Critical Dolphin Integration
Publication of WO2019016280A1 publication Critical patent/WO2019016280A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/181—Low-frequency amplifiers, e.g. audio preamplifiers
    • H03F3/183—Low-frequency amplifiers, e.g. audio preamplifiers with semiconductor devices only
    • H03F3/187—Low-frequency amplifiers, e.g. audio preamplifiers with semiconductor devices only in integrated circuits
    • 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
    • H03F1/02—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation
    • H03F1/0205—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation in transistor amplifiers
    • H03F1/0261—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation in transistor amplifiers with control of the polarisation voltage or current, e.g. gliding Class A
    • H03F1/0266—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation in transistor amplifiers with control of the polarisation voltage or current, e.g. gliding Class A by using a signal derived from the input signal
    • 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
    • H03F1/30—Modifications of amplifiers to reduce influence of variations of temperature or supply voltage or other physical parameters
    • H03F1/305—Modifications of amplifiers to reduce influence of variations of temperature or supply voltage or other physical parameters in case of switching on or off of a power supply
    • 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
    • H03F3/45475—Differential amplifiers with semiconductor devices only characterised by the way of implementation of the active amplifying circuit in the differential amplifier using IC blocks as the active amplifying circuit
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2200/00—Indexing scheme relating to amplifiers
    • H03F2200/03—Indexing scheme relating to amplifiers the amplifier being designed for audio applications
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2200/00—Indexing scheme relating to amplifiers
    • H03F2200/264—An operational amplifier based integrator or transistor based integrator being used in an amplifying circuit
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2200/00—Indexing scheme relating to amplifiers
    • H03F2200/303—Indexing scheme relating to amplifiers the loading circuit of an amplifying stage comprising a diode or diode coupled transistor
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2200/00—Indexing scheme relating to amplifiers
    • H03F2200/372—Noise reduction and elimination in amplifier
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2200/00—Indexing scheme relating to amplifiers
    • H03F2200/471—Indexing scheme relating to amplifiers the voltage being sensed
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2200/00—Indexing scheme relating to amplifiers
    • H03F2200/48—Indexing scheme relating to amplifiers the output of the amplifier being coupled out by a capacitor
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2200/00—Indexing scheme relating to amplifiers
    • H03F2200/99—A diode as rectifier being used as a detecting circuit in an amplifying circuit
    • 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
    • H03F2203/45174—Indexing scheme relating to differential amplifiers the application of the differential amplifier being in an integrator circuit
    • 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
    • H03F2203/45512—Indexing scheme relating to differential amplifiers the FBC comprising one or more capacitors, not being switched capacitors, and being coupled between the LC and the IC
    • 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
    • H03F2203/45528—Indexing scheme relating to differential amplifiers the FBC comprising one or more passive resistors and being coupled between the LC and the IC
    • 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
    • H03F2203/45546—Indexing scheme relating to differential amplifiers the IC comprising one or more capacitors feedback coupled to the IC
    • 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
    • H03F2203/45551—Indexing scheme relating to differential amplifiers the IC comprising one or more switched capacitors
    • 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
    • H03F2203/45594—Indexing scheme relating to differential amplifiers the IC comprising one or more resistors, which are not biasing resistor
    • 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
    • H03F2203/45601—Indexing scheme relating to differential amplifiers the IC comprising one or more passive resistors by feedback
    • 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
    • H03F2203/45631—Indexing scheme relating to differential amplifiers the LC comprising one or more capacitors, e.g. coupling capacitors
    • 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
    • H03F2203/45632—Indexing scheme relating to differential amplifiers the LC comprising one or more capacitors coupled to the LC by feedback
    • 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
    • H03F2203/45654—Indexing scheme relating to differential amplifiers the LC comprising one or more extra diodes not belonging to mirrors
    • 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
    • H03F2203/45698—Indexing scheme relating to differential amplifiers the LC comprising one or more resistors coupled to the LC by feedback (active or passive)
    • 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
    • H03F2203/45701—Indexing scheme relating to differential amplifiers the LC comprising one resistor
    • 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
    • H03F2203/45702—Indexing scheme relating to differential amplifiers the LC comprising two resistors
    • 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
    • H03F2203/45712—Indexing scheme relating to differential amplifiers the LC comprising a capacitor as shunt
    • 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
    • H03F2203/45716—Indexing scheme relating to differential amplifiers the LC comprising a RC-series circuit as shunt, e.g. for stabilisation
    • 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
    • H03F2203/45718—Indexing scheme relating to differential amplifiers the LC comprising a resistor as shunt

Definitions

  • Pop noise is the result of the rapid charging or discharging of this coupling capacitor when the amplifier is activated or deactivated.
  • the input signal of the amplifier is generally provided by a digital to analog converter (DAC) , and one solution that has been proposed for reducing pop noise is to provide a start-up phase during which the DAC is initially controlled to force a low signal at the output of the amplifier, and then to gradually increase the output signal to progressively charge the coupling capacitor without causing a pop noise.
  • the audio signal is then applied once the coupling capacitor has been charged to the common-mode level.
  • DAC digital to analog converter
  • the input circuit is adapted to detect the amplitude of the input audio signal by performing envelope detection.
  • the analog circuit comprises a half-wave rectifier or a full-wave rectifier.
  • Figure 7C schematically illustrates an amplitude detection and filtering circuit of Figure 7A in more detail according to an alternative embodiment
  • Figure 8 schematically illustrates an audio circuit according to a further example embodiment
  • Figure 9 is a graph illustrating an example of signals in the circuit of Figure 8 according to an example embodiment
  • the output node 108 of the amplifier 102 is coupled via a coupling capacitor 112 to the load 104.
  • the coupling capacitor 112 for example has a capacitance in the range 100 to 500 .
  • the capacitance of the coupling capacitor 112 is for example of around 1 . More generally, the value of the capacitance is for example chosen based on the resistance of the load and on the signal bandwidth of the audio signal. In view of the size of the coupling capacitor 112, it is for example mounted off-chip.
  • FIG. 2 is a graph illustrating a possible solution to the problem of pop noise, which involves applying a voltage ramp to slowly charge the coupling capacitor 112, and thereby avoid pop noise when the audio amplifier is activated and before the audio playback starts.
  • a linear ramp is for example applied in order to bring the output voltage VQUT °f the audio amplifier 102 from a low level up to the level VQJ ⁇ , before the audio signal is started.
  • the adder 303 for example adds CM to the signal E[n], and the signal CM_COMP[n] is initially equal to CM.
  • the variable common-mode compensation signal CM_COMP[n] for example reaches a level of zero once the amplitude of the input signal has increased sufficiently.
  • the common-mode level VQ ⁇ ' of the audio output signal VQUT will then reach the common mode voltage VQJ ⁇ .
  • the adder 303 for example subtracts, from the signal E (t) , an analog level cm corresponding to the level of the common-mode voltage VQJ ⁇ prior to the amplifier 702, and generates an analog common mode compensation signal QM cOMp(t)- Furthermore, a DAC 706 is coupled to the output of the delay circuit 306, the DAC 706 converting the digital values x' [n] into an analog signal x' (t) , which is provided to the adder 304 to be added to the voltage VQ ⁇ COMP ⁇ ) ⁇
  • the positive and negative inputs of the differential amplifier 1010 are also coupled to the common mode voltage VQJ ⁇ via respective switches 1018 and 1020.
  • the positive input of the differential amplifier 1010 is further coupled to the negative output 1014 via a capacitor 1022, and the negative input of the amplifier 1010 is further coupled to the positive output 1016 of the amplifier 1010 via a capacitor 1024.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Multimedia (AREA)
  • Amplifiers (AREA)

Abstract

L'invention concerne un circuit amplificateur audio comprenant : un amplificateur audio (308) conçu pour fonctionner à un niveau de tension de mode commun (VCM) et comportant un nœud d'entrée servant à recevoir un signal audio (y[n], VIN) et une sortie (310) pouvant être couplée à une charge (104) par l'intermédiaire d'un condensateur de couplage (112) ; et un circuit d'entrée (301) conçu pour : détecter des niveaux d'amplitude d'un signal audio d'entrée (x[n], x(t)) et générer un signal de compensation de mode commun variable (CM_COMP[n],VCM_COMP) sur la base desdits niveaux d'amplitude détectés ; et ajouter le signal de compensation de mode commun variable (CM_COM[n], VCM_COMP) à une version retardée ((x'[n], x'(t)) du signal audio d'entrée (x[n], x(t)) pour générer le signal audio (y[n], VIN) ayant un niveau de mode commun variable.
PCT/EP2018/069533 2017-07-18 2018-07-18 Circuit et procédé permettant de piloter un amplificateur audio WO2019016280A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR1756799 2017-07-18
FR1756799A FR3069397B1 (fr) 2017-07-18 2017-07-18 Circuit et procede de pilotage d'un amplificateur audio

Publications (1)

Publication Number Publication Date
WO2019016280A1 true WO2019016280A1 (fr) 2019-01-24

Family

ID=60955109

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2018/069533 WO2019016280A1 (fr) 2017-07-18 2018-07-18 Circuit et procédé permettant de piloter un amplificateur audio

Country Status (2)

Country Link
FR (1) FR3069397B1 (fr)
WO (1) WO2019016280A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109981053A (zh) * 2017-12-27 2019-07-05 田雪松 用于音频放大器的瞬时噪声抑制方法
TWI703817B (zh) * 2019-09-02 2020-09-01 瑞昱半導體股份有限公司 音訊裝置、具有音訊裝置的電子裝置及其音訊處理方法
TWI749801B (zh) * 2020-10-08 2021-12-11 瑞昱半導體股份有限公司 應用在訊號處理電路中的偏壓補償電路及相關的偏壓補償方法

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7227413B1 (en) * 2004-02-19 2007-06-05 Stmicroelectronics S.A. Audio amplification device with antipop circuitry
US20160065143A1 (en) * 2014-08-26 2016-03-03 Emmanuel Grand Circuit for reducing pop noise

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7227413B1 (en) * 2004-02-19 2007-06-05 Stmicroelectronics S.A. Audio amplification device with antipop circuitry
US20160065143A1 (en) * 2014-08-26 2016-03-03 Emmanuel Grand Circuit for reducing pop noise

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109981053A (zh) * 2017-12-27 2019-07-05 田雪松 用于音频放大器的瞬时噪声抑制方法
TWI703817B (zh) * 2019-09-02 2020-09-01 瑞昱半導體股份有限公司 音訊裝置、具有音訊裝置的電子裝置及其音訊處理方法
US11277105B2 (en) 2019-09-02 2022-03-15 Realtek Semiconductor Corp. Audio device, electronic device having audio device and audio signal processing method
TWI749801B (zh) * 2020-10-08 2021-12-11 瑞昱半導體股份有限公司 應用在訊號處理電路中的偏壓補償電路及相關的偏壓補償方法

Also Published As

Publication number Publication date
FR3069397A1 (fr) 2019-01-25
FR3069397B1 (fr) 2020-12-11

Similar Documents

Publication Publication Date Title
US10924069B2 (en) System and method for low distortion capacitive signal source amplifier
US8416017B2 (en) Circuit and method for reducing noise in class D amplifiers
WO2019016280A1 (fr) Circuit et procédé permettant de piloter un amplificateur audio
EP2127070B1 (fr) Système de traitement de données pour correction d'écrêtage
US20100027813A1 (en) Switching audio amplifier, digital speaking device and audio amplification method
US20070054638A1 (en) Apparatus and method to control audio volume in D class amplifier
GB2610918A (en) Chopped triangular wave PWM quantizer and PWM modulator having quantizer with controllable analog gain
US8194887B2 (en) System and method for dynamic bass frequency control in association with a dynamic low frequency control circuit having compression control
JP2016208361A (ja) オーディオ回路、それを用いた車載用オーディオ装置、オーディオコンポーネント装置、電子機器
US9641134B2 (en) Circuit for reducing pop noise
US7492218B2 (en) Digital amplifier apparatus and method of resetting a digital amplifier apparatus
JP7273484B2 (ja) 信号生成回路
US6788792B1 (en) Device for amplitude adjustment and rectification made with MOS technology
US11205999B2 (en) Amplifier with signal dependent mode operation
US7113031B2 (en) Audio amplifier circuit with suppression of unwanted noise when powered on from standby
JP2011066559A (ja) Ｄ級増幅器
JP5499431B2 (ja) 三角波発生回路
US7816980B2 (en) Audio power amplifier using virtual ground and method of processing signal in the audio power amplifier
JP2001119255A (ja) ピーク検波式ａｇｃ回路
JP5157960B2 (ja) Ｄ級増幅器
CN117098034A (zh) 用于声音信号处理的噪声抑制的设备
JP3438593B2 (ja) 振幅調整装置、振幅圧縮装置および振幅伸長装置
US20050185433A1 (en) Device for amplitude adjustment and rectification made with MOS technology
JPH03175709A (ja) 高周波増幅器の電力制御回路
JP2005217583A (ja) スイッチングアンプ

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 18750110

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 18750110

Country of ref document: EP

Kind code of ref document: A1