WO2001078446A1 - Microphone avec selection de gammes - Google Patents

Microphone avec selection de gammes Download PDF

Info

Publication number
WO2001078446A1
WO2001078446A1 PCT/US2001/009475 US0109475W WO0178446A1 WO 2001078446 A1 WO2001078446 A1 WO 2001078446A1 US 0109475 W US0109475 W US 0109475W WO 0178446 A1 WO0178446 A1 WO 0178446A1
Authority
WO
WIPO (PCT)
Prior art keywords
circuit
amplifier
microphone
sensitivity
output
Prior art date
Application number
PCT/US2001/009475
Other languages
English (en)
Inventor
Aart Z. VAN HALTEREN
Adrianus M. Lafort
Original Assignee
Microtronic Nederland B.V.
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 Microtronic Nederland B.V. filed Critical Microtronic Nederland B.V.
Priority to AU2001250970A priority Critical patent/AU2001250970A1/en
Priority to EP01924304A priority patent/EP1192836A4/fr
Publication of WO2001078446A1 publication Critical patent/WO2001078446A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R25/00—Deaf-aid sets, i.e. electro-acoustic or electro-mechanical hearing aids; Electric tinnitus maskers providing an auditory perception
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/02—Casings; Cabinets ; Supports therefor; Mountings therein
    • H04R1/04—Structural association of microphone with electric circuitry therefor
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R19/00—Electrostatic transducers
    • H04R19/01—Electrostatic transducers characterised by the use of electrets
    • H04R19/016—Electrostatic transducers characterised by the use of electrets for microphones
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R3/00—Circuits for transducers, loudspeakers or microphones
    • H04R3/04—Circuits for transducers, loudspeakers or microphones for correcting frequency response
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2225/00—Details of deaf aids covered by H04R25/00, not provided for in any of its subgroups
    • H04R2225/61—Aspects relating to mechanical or electronic switches or control elements, e.g. functioning
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2410/00—Microphones
    • H04R2410/01—Noise reduction using microphones having different directional characteristics

Definitions

  • Miniature electret microphones are usually fitted with an internal buffer amplifier in order to decrease the output impedance to a usable level. Because of the nature of the amplifier, the power supply voltage limits the dynamic range of the output signal. In many battery-operated applications, the supply voltage can be very low.
  • FIG. 1 shows a prior art hearing aid which generally includes a microphone (MIC) 10 which is a transducer for converting incoming sound pressure levels to corresponding electrical signals.
  • a second component is a signal processing device 20 which may include an amplifier to further process the electrical signals.
  • a receiver (REC) or loudspeaker component 30 is a transducer which receives the processed electrical signals and converts them to an acoustic output.
  • FIG. 2 depicts a typical electret microphone transducer or cartridge 10 with a buffer amplifier 12.
  • the signal output terminal 14 is taken at the source electrode of a MOSFET transistor 15 in a source follower configuration, wherein the drain electrode of the MOSFET 15 is coupled to a ground terminal 18 and a source resistor 17 is coupled between a positive voltage supply terminal 16 and the source electrode of the MOSFET 15.
  • the electret microphone cartridge 10 is depicted in equivalent circuit form as a signal/current source 21 and a parallel capacitor 22.
  • the buffer amplifier 12 also uses a pair of bias diodes 24.
  • the typical DC output voltage on terminal 14 is about 0.6 VDC.
  • the commonly used source follower amplifier 20 typically has a maximum output amplitude of 0.2 V at a supply voltage of 0.9 V. With a normal microphone sensitivity of -33 dB re. IV/Pa, the maximum usable sound pressure at the input is about 110 dB SPL. In noisy environments (e.g., in motorized vehicles) this maximum can be too low to maintain linearity. However, input sound levels higher than this maximum will result in overloading the amplifier. Minor overloading of the amplifier will cause distortion of the signal ("clipping"). Severe overloading may force the amplifier into a saturated condition, in which the DC level of the output is either close to the supply voltage or close to zero, and the output signal is very low. Recovery of the normal bias condition after saturation will take some time (e.g., in the order of several seconds).
  • a lower sensitivity microphone can be used in noisy conditions without overload, e.g., a-41 dB sensitivity results in a maximum input level of 118 dB. Such a low sensitivity, however, limits the maximum achievable signal-to-noise ratio.
  • the noise from the buffer amplifier, and also noise from the signal processing adds to the microphone output signal level. If, for example, these noise sources contribute an input equivalent noise of 22 dB SPL at -33 dB sensitivity, the contribution will be 30 dB SPL at -41 dB sensitivity.
  • the present invention improves on the above situation by providing a sensitivity or transduction gain adjustment, such as an attenuator between the electret microphone cartridge 10 and amplifier 12.
  • the attenuator may be controllably varied according to the signal level, for example, to attenuate the signal less, or not at all below a certain signal level.
  • One purpose of the attenuator is to protect the amplifier 20 from overload.
  • FIG. 1 is a functional block diagram of a typical hearing aid
  • FIG. 2 is a circuit schematic of a prior art microphone for a hearing aid
  • FIG. 3 is a circuit schematic of a microphone in accordance with one embodiment of the invention.
  • FIG. 4 is a circuit schematic of a microphone in accordance with another embodiment of the invention.
  • FIG. 5 is a functional block diagram of the microphones of FIGS. 2 and 3;
  • FIG. 6 is a functional block diagram similar to FIG. 4 showing an additional decoder
  • FIG. 7 is a functional block diagram similar to FIG. 5 showing an additional memory component
  • FIG. 8 is a functional block diagram similar to FIG 4 showing an additional level detector
  • FIG. 9 shows a microphone employing circuitry similar to that of FIGS. 3 and 5;
  • FIG. 10 shows further details of the embodiment of FIG. 6;
  • FIG. 11 shows further details of the embodiment of FIG. 7;
  • FIG. 12 shows further details of the embodiment of FIG. 8; and FIG. 13 shows an embodiment of the invention further including an analog-to- digital converter.
  • FIG. 3 depicts a first embodiment of the invention.
  • An attenuator in the form of an impedance such as a capacitor 31 is added to the microphone assembly of FIG. 2.
  • Use of a capacitor as the attenuating impedance is advantageous in that it does not affect the frequency response of the microphone.
  • the capacitor can be switched on and off by s means of an electronic switch 32, which is controlled by the voltage on a control terminal 34.
  • the switchable capacitor having a capacitance on the same order of magnitude as the capacitance of the microphone cartridge and the input capacitance of the buffer (a few pF)
  • the sensitivity (or transduction gain) of the microphone assembly can be decreased by several dBs.
  • the switch 32 includes a second MOSFET having its 0 source electrode coupled to the capacitor 31, its drain electrode coupled to ground, and its gate electrode coupled to the control terminal 34.
  • the capacitor 31 and switch 32 may be incorporated in the buffer amplifier chip 12.
  • FIG. 4 depicts a second embodiment employing an approach different from the source follower-type buffer amplifier of FIGS. 2 and 3.
  • a common source 5 amplifier configuration 12a is used.
  • Terminals 14, 16 and 18 are used for signal output, supply voltage and ground respectively.
  • the MOSFET 15 and a bias (drain) resistor 17a form an inverting amplifier, of which the gain is set by a feedback capacitor 38.
  • the negative feedback can be increased by switching in the capacitor 31.
  • the capacitor 31 can be switched in and out of the circuit by means of an electronic switch o 32a, which is controlled by the voltage on a control terminal 34a.
  • the switch 32a is shown as a MOSFET with a gate electrode coupled to the control terminal 34a and the source-drain path between the output signal terminal and the capacitor 31.
  • FIG. 5 illustrates, in somewhat functional form, the concept of dynamic range switching according to the examples given in FIG. 3 and FIG. 4.
  • the switching of an impedance element such as the capacitor 31 into and out of the circuit can correspondingly vary the overall sensitivity of the assembly, acting as an attenuator or sensitivity adjustment, or as a (transduction) gain control arrangement.
  • the electret cartridge 10 and the buffer amplifier 12 produce an electrical output signal at output terminal 14, in response to the sound pressure level experienced at the microphone 10.
  • the sensitivity control circuitry or arrangement is symbolized at reference numeral 40 in FIG. 4, and is responsive to a control signal on control terminal 34 for selecting the dynamic range or sensitivity of the overall system.
  • a feedback signal 42 shown in phantom line in FIG. 4 may also be employed.
  • FIG. 6 a further variation on the arrangement of FIG. 5, namely, a programmable sensitivity arrangement, is illustrated in functional block form.
  • the sensitivity control circuit 40 is controlled indirectly from the control input 34 by an intervening decoder device 44.
  • the sensitivity or gain control circuit 40 may have more than two settings or values (on/off as in FIGS. 3 and 4) and may be a multiple sensitivity stepped device (for example, eight steps of 3 dB each).
  • the decoder 44 is connected to a control terminal 34 which might be a serial code input terminal for driving the decoder to select a suitable sensitivity or gain setting of the circuit 40, for example, by switching or selecting among a plurality of impedance elements of various values, or by selecting the setting of a variable impedance device.
  • the sensitivity setting is programmable and may be programmed or stored in a non-volatile memory component 46 which is operatively coupled with the decoder 44.
  • the decoder 44 in response to the control input signal at input 34, may enter a value or setting, to be stored in the memory 46, as well as decode a previously stored setting into a signal suitable for achieving this setting in the circuit 40, when desired.
  • FIG. 8 a circuit is shown in which the sensitivity setting at the circuit
  • the circuit 50 detects the signal level at the buffer amplifier output 14 and may produce a switching voltage for switching an impedance element such as a capacitor, similar to the circuits of FIGS. 3 and 4, into and out of the circuit when the output level exceeds or falls below some preselected switching level at which a change in sensitivity or gain is desired.
  • a control signal might be produced for switching the attenuator or capacitor into the circuit when the output exceeds a level corresponding to a 100 dB sound pressure input level, and may be set to remove the attenuator or capacitor from the circuit when the sound level drops below a level corresponding to a 90 dB input sound pressure level.
  • An additional output terminal 52 may be provided for the level detector device 50 for making the signal output of this level detector 50 available for external signal processing. It will be noted that with respect to the embodiments of FIGS. 6 and 7, the control signal input to the decoder might also be derived from an output level detector such as the level detector 50 of FIG. 8, whereby multiple sensitivity or gain levels might be achieved by selecting multiple switching levels from the level detection device 50.
  • FIG. 9 shows a more detailed schematic diagram of a circuit similar to that of FIGS. 3 and 5.
  • the electronic switch 32 for switching the capacitor 31 is driven by a Schmitt-trigger 60. If the input 34 is driven to a low level, the switch 32 is disabled and the sensitivity is in the standard (high) range. If the input is driven to a high level the switch 32 is enabled, thus the capacitor 31 is switched in parallel with the amplifier input and the sensitivity is in the low range.
  • FIG. 10 shows a more detailed diagram of the circuit of FIG. 6.
  • 3 range switching devices with 3, 6 and 12 dB sensitivity steps, 8 sensitivity ranges can be obtained.
  • All switches 32a . . . 32n are driven by a decoder 44.
  • the decoder 44 can have either n parallel inputs 34 for 2 n sensitivity ranges, or one serial input signal.
  • FIG. 11 shows a more detailed diagram of a portion of the circuit of FIG. 7. In
  • FIG. 11 a plurality of capacitors 31a . . . 3 In and switches 32a . . . 32n are used, as in FIG. 10.
  • the decoder 44 for the range switching devices 32a . . . 32n receives its input from a non-volatile memory 46, which may be incorporated in the buffer amplifier chip
  • a serial or parallel interface 72 enables programming of the sensitivity setting in the memory 46.
  • the sensitivity setting can be programmed during manufacturing, in which case a prograrnming input 74 may be omitted, or during operation, i.e., in the field.
  • the advantages of sensitivity programming during manufacturing are the possiblity of producing microphones of different sensitivity classes with one design, and the possibility of accurately calibrating the sensitivity level of the microphone to an exact value. With e.g. 4 range switching devices, with 0.3, 0.6, 1.2 and 2.4 dB sensitivity steps, the microphone sensitivity can be tuned within 0.2 dB with a maximum of 4.5 dB, which feature is very useful for applications where matched microphones are applied.
  • FIG. 12 shows a more detailed diagram of a portion of the circuit of FIG. 8.
  • the buffer amplifier circuit components are symbolized at reference numeral 12a.
  • the output signal of the amplitude detector 50 is proportional to the sound pressure level at the input of the microphone.
  • a low-pass filter (LPF) 80 averages the signal during a certain period ( a few tenths of a second up to a few seconds).
  • the level detection operation is completed by a Schmitt trigger 82, which drives the electronic switch 32, and also the output terminal 52.
  • the circuit is switched to a lower sensitivity level after the average sound pressure exceeds a certain level (eg. lOOdB), and returns to the normal sensitivity level after the average sound pressure drops below a lower level (eg. 90 dB).
  • This arrangement can be extended to use with multiple range switches and automatic switching on multiple levels, as in FIGS. 10 and 11.
  • ADC A-to-D converter
  • ADC integrated A-to-D converter
  • FIG. 13 An ADC (A/D) 90 (see FIG.13) is used, the functions of the amplitude detector 50, low-pass filter 80 and Schmitt trigger 82 can be connected after the ADC and be implemented digitally.
  • the output signal from the Schmitt-trigger 82, and the output stream from the ADC 90 are combined at logic 94 to a single output format at output 52a.
  • the microphone has a built-in A-to-D converter
  • the converter can be integrated on the same IC as the buffer amplifier and range switching devices, or can be on a separate IC.
  • the range switching can be used to prevent the A-to-D converter from overflow on high sound levels, and to increase the resolution of the converter for low sound levels.
  • a factory programmable sensitivity range selection as previously described can also be employed in order to tune the microphone sensitivity for optimal use with an ADC, and store the sensitivity value or setting, or a code prepresenting the value or setting, in a non-volatile memory, so that the ADC input range matches a well-defined sound pressure level.
  • the "on board" ADC can also be combined with the other embodiments shown and described herein.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Neurosurgery (AREA)
  • Otolaryngology (AREA)
  • Circuit For Audible Band Transducer (AREA)

Abstract

L'invention concerne un circuit à sensibilité variable/gain variable destiné à un microphone à électret (10). Ledit circuit comporte un amplificateur (12) et un circuit de sélection de la sensibilité (32) couplé à l'amplificateur tampon (12) pour le réglage du gain de transduction du microphone.
PCT/US2001/009475 2000-04-07 2001-03-23 Microphone avec selection de gammes WO2001078446A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
AU2001250970A AU2001250970A1 (en) 2000-04-07 2001-03-23 Microphone with range switching
EP01924304A EP1192836A4 (fr) 2000-04-07 2001-03-23 Microphone avec selection de gammes

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US54564600A 2000-04-07 2000-04-07
US09/545,646 2000-04-07

Publications (1)

Publication Number Publication Date
WO2001078446A1 true WO2001078446A1 (fr) 2001-10-18

Family

ID=24177024

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2001/009475 WO2001078446A1 (fr) 2000-04-07 2001-03-23 Microphone avec selection de gammes

Country Status (3)

Country Link
EP (1) EP1192836A4 (fr)
AU (1) AU2001250970A1 (fr)
WO (1) WO2001078446A1 (fr)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1408716A3 (fr) * 2002-10-01 2004-05-19 AKG Acoustics GmbH Microphones avec sensibilité égalisée
WO2009127568A1 (fr) * 2008-04-15 2009-10-22 Epcos Ag Ensemble microphone à circuit d'autotest intégré
EP2239843A1 (fr) * 2009-04-08 2010-10-13 Nxp B.V. Transducteur d'adaptation à la sensibilité
EP2304968A2 (fr) * 2008-05-23 2011-04-06 Analog Devices, Inc. Microphone avec plage dynamique large
US8036401B2 (en) 2006-09-26 2011-10-11 Epcos Pte Ltd Calibrated microelectromechanical microphone
US8170237B2 (en) 2005-07-19 2012-05-01 Audioasics A/S Programmable microphone
EP2608569A1 (fr) * 2011-12-22 2013-06-26 ST-Ericsson SA Dispositif de microphone numérique doté d'une plage dynamique étendue
US20130308797A1 (en) * 2009-01-20 2013-11-21 Nokia Corporation Multi-Membrane Microphone for High-Amplitude Audio Capture
US8625809B2 (en) 2009-05-20 2014-01-07 Invensense, Inc. Switchable attenuation circuit for MEMS microphone systems
EP2866472A1 (fr) * 2013-10-22 2015-04-29 Starkey Laboratories, Inc. Expansion de marge d'étage d'entrée pour des dispositifs d'assistance auditive
US9236837B2 (en) * 2011-08-25 2016-01-12 Infineon Technologies Ag System and method for low distortion capacitive signal source amplifier
US9413317B2 (en) 2012-04-16 2016-08-09 Infineon Technologies Ag System and method for high input capacitive signal amplifier
WO2017041822A1 (fr) * 2015-09-07 2017-03-16 Epcos Ag Circuit intégré, ensemble circuit et son procédé de fonctionnement
WO2017144255A1 (fr) * 2016-02-24 2017-08-31 Widex A/S Système de prothèse auditive et procédé de fonctionnement d'un système de prothèse auditive
EP3324649A1 (fr) 2016-11-18 2018-05-23 Sonion Nederland B.V. Transducteur avec une sensibilité élevée
US10027298B2 (en) 2012-08-30 2018-07-17 Infineon Technologies Ag System and method for adjusting the sensitivity of a capacitive signal source
JP2018157577A (ja) * 2018-05-10 2018-10-04 Tdk株式会社 集積回路、回路アセンブリおよびその動作方法
US10243521B2 (en) 2016-11-18 2019-03-26 Sonion Nederland B.V. Circuit for providing a high and a low impedance and a system comprising the circuit
US10327072B2 (en) 2016-11-18 2019-06-18 Sonion Nederland B.V. Phase correcting system and a phase correctable transducer system
US10656006B2 (en) 2016-11-18 2020-05-19 Sonion Nederland B.V. Sensing circuit comprising an amplifying circuit and an amplifying circuit

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4582961A (en) * 1981-11-13 1986-04-15 Aktieselskabet Bruel & Kjar Capacitive transducer
US6084972A (en) * 1996-04-03 2000-07-04 Microtronic Nederland B.V. Integrated microphone/amplifier unit, and amplifier module therefor

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH533408A (de) * 1972-02-02 1973-01-31 Bommer Ag Hörgerät
US4466120A (en) * 1981-06-15 1984-08-14 Walker Equipment Corporation Telephone handset amplifier circuit
US4617555A (en) * 1985-04-17 1986-10-14 Data Distribution Devices, Inc. Receiver for audible alarm
US4888807A (en) * 1989-01-18 1989-12-19 Audio-Technica U.S., Inc. Variable pattern microphone system
US5239579A (en) * 1991-01-04 1993-08-24 Schuh Peter O Adaptive amplifier circuit

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4582961A (en) * 1981-11-13 1986-04-15 Aktieselskabet Bruel & Kjar Capacitive transducer
US6084972A (en) * 1996-04-03 2000-07-04 Microtronic Nederland B.V. Integrated microphone/amplifier unit, and amplifier module therefor

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP1192836A4 *

Cited By (40)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7522737B2 (en) 2002-10-01 2009-04-21 Akg Acoustics Gmbh Microphones with equal sensitivity
EP1408716A3 (fr) * 2002-10-01 2004-05-19 AKG Acoustics GmbH Microphones avec sensibilité égalisée
US8515100B2 (en) 2005-07-19 2013-08-20 Analog Devices, Inc. Programmable microphone
US8447049B2 (en) 2005-07-19 2013-05-21 Audioasics A/S Programmable microphone
US8170237B2 (en) 2005-07-19 2012-05-01 Audioasics A/S Programmable microphone
US8036401B2 (en) 2006-09-26 2011-10-11 Epcos Pte Ltd Calibrated microelectromechanical microphone
US8675895B2 (en) 2008-04-15 2014-03-18 Epcos Pte Ltd Microphone assembly with integrated self-test circuitry
WO2009127568A1 (fr) * 2008-04-15 2009-10-22 Epcos Ag Ensemble microphone à circuit d'autotest intégré
DE112009000702B4 (de) * 2008-04-15 2015-09-10 Epcos Pte Ltd Mikrofonbaugruppe mit integrierter Selbsttestschaltungsanordnung
EP2304968A2 (fr) * 2008-05-23 2011-04-06 Analog Devices, Inc. Microphone avec plage dynamique large
US20130308797A1 (en) * 2009-01-20 2013-11-21 Nokia Corporation Multi-Membrane Microphone for High-Amplitude Audio Capture
EP2239843A1 (fr) * 2009-04-08 2010-10-13 Nxp B.V. Transducteur d'adaptation à la sensibilité
WO2010116326A2 (fr) * 2009-04-08 2010-10-14 Nxp B.V. Transducteur à sensibilité adaptative
WO2010116326A3 (fr) * 2009-04-08 2010-12-02 Nxp B.V. Transducteur à sensibilité adaptative
US8625809B2 (en) 2009-05-20 2014-01-07 Invensense, Inc. Switchable attenuation circuit for MEMS microphone systems
US9357296B2 (en) 2009-05-20 2016-05-31 Invensense, Inc. Switchable attenuation circuit for MEMS microphone systems
US10924069B2 (en) 2011-08-25 2021-02-16 Infineon Technologies Ag System and method for low distortion capacitive signal source amplifier
US10171046B2 (en) 2011-08-25 2019-01-01 Infineon Technologies Ag System and method for low distortion capacitive signal source amplifier
US20190068139A1 (en) * 2011-08-25 2019-02-28 Infineon Technologies Ag System and Method for Low Distortion Capacitive Signal Source Amplifier
US9236837B2 (en) * 2011-08-25 2016-01-12 Infineon Technologies Ag System and method for low distortion capacitive signal source amplifier
EP2608569A1 (fr) * 2011-12-22 2013-06-26 ST-Ericsson SA Dispositif de microphone numérique doté d'une plage dynamique étendue
WO2013092782A1 (fr) * 2011-12-22 2013-06-27 St-Ericsson Sa Dispositif microphone numérique à plage dynamique étendue
US9407224B2 (en) 2011-12-22 2016-08-02 Stmicroelectronics International N.V. Digital microphone device with extended dynamic range
US9722563B2 (en) 2012-04-16 2017-08-01 Infineon Technologies Ag System and method for high input capacitive signal amplifier
US9413317B2 (en) 2012-04-16 2016-08-09 Infineon Technologies Ag System and method for high input capacitive signal amplifier
DE102013216305B4 (de) 2012-08-30 2018-10-18 Infineon Technologies Ag System und Verfahren zum Einstellen der Empfindlichkeit einer kapazitiven Signalquelle
US10027298B2 (en) 2012-08-30 2018-07-17 Infineon Technologies Ag System and method for adjusting the sensitivity of a capacitive signal source
EP2866472A1 (fr) * 2013-10-22 2015-04-29 Starkey Laboratories, Inc. Expansion de marge d'étage d'entrée pour des dispositifs d'assistance auditive
EP3347985B1 (fr) * 2015-09-07 2023-07-19 TDK Corporation Circuit intégré, ensemble circuit et son procédé de fonctionnement
WO2017041822A1 (fr) * 2015-09-07 2017-03-16 Epcos Ag Circuit intégré, ensemble circuit et son procédé de fonctionnement
US10622957B2 (en) 2015-09-07 2020-04-14 Tdk Corporation Integrated circuit, circuit assembly and a method for its operation
US10581397B2 (en) 2015-09-07 2020-03-03 Tdk Corporation Integrated circuit, circuit assembly and a method for its operation
US10455332B2 (en) 2016-02-24 2019-10-22 Widex A/S Hearing aid system and a method of operating a hearing aid system
WO2017144255A1 (fr) * 2016-02-24 2017-08-31 Widex A/S Système de prothèse auditive et procédé de fonctionnement d'un système de prothèse auditive
EP3324649A1 (fr) 2016-11-18 2018-05-23 Sonion Nederland B.V. Transducteur avec une sensibilité élevée
US10327072B2 (en) 2016-11-18 2019-06-18 Sonion Nederland B.V. Phase correcting system and a phase correctable transducer system
US10264361B2 (en) 2016-11-18 2019-04-16 Sonion Nederland B.V. Transducer with a high sensitivity
US10656006B2 (en) 2016-11-18 2020-05-19 Sonion Nederland B.V. Sensing circuit comprising an amplifying circuit and an amplifying circuit
US10243521B2 (en) 2016-11-18 2019-03-26 Sonion Nederland B.V. Circuit for providing a high and a low impedance and a system comprising the circuit
JP2018157577A (ja) * 2018-05-10 2018-10-04 Tdk株式会社 集積回路、回路アセンブリおよびその動作方法

Also Published As

Publication number Publication date
EP1192836A4 (fr) 2008-10-08
EP1192836A1 (fr) 2002-04-03
AU2001250970A1 (en) 2001-10-23

Similar Documents

Publication Publication Date Title
EP1192836A1 (fr) Microphone avec selection de gammes
US9419640B2 (en) Control of a microphone
KR101459831B1 (ko) 저왜곡 용량성 신호 소스 증폭기를 위한 시스템 및 방법
US8515100B2 (en) Programmable microphone
US6633202B2 (en) Precision low jitter oscillator circuit
US5606284A (en) Automatic gain control device for producing constant amplitude output signal
US20130058506A1 (en) Microphone Buffer Circuit With Input Filter
US9161123B2 (en) Control of a microphone
KR20090098721A (ko) 콘덴서 마이크로폰
US9407998B2 (en) Hearing device with analog filtering and associated method
US6049618A (en) Hearing aid having input AGC and output AGC
CN215072331U (zh) 用于传感器组件的电路、集成电路和麦克风传感器组件
EP1331835B1 (fr) Amplificateur à gain numérique programmable
US7688987B2 (en) Electret microphone buffer circuit with significantly enhanced power supply rejection
JP6694168B2 (ja) マイクロフォン用の電子回路及びそのマイクロフォン
JP4542482B2 (ja) 残留ノイズ軽減回路
KR20050106841A (ko) 마이크의 클리핑 방지 장치
JP4395314B2 (ja) トーンコントロール回路
JP2001016322A (ja) 電話機の受信部
JPS62150914A (ja) 増幅器の最小音量設定時のノイズ低減回路装置
KR20060032347A (ko) 정전류 및 정전압원을 이용한 적외선 수신장치

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CR CU CZ DE DK DM DZ EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT TZ UA UG UZ VN YU ZA ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE TR BF BJ CF CG CI CM GA GN GW ML MR NE SN TD TG

WWE Wipo information: entry into national phase

Ref document number: 2001924304

Country of ref document: EP

121 Ep: the epo has been informed by wipo that ep was designated in this application
WWP Wipo information: published in national office

Ref document number: 2001924304

Country of ref document: EP

NENP Non-entry into the national phase

Ref country code: JP