WO2021135296A1 - Circuit de détection de capteur, et appareil électronique - Google Patents

Circuit de détection de capteur, et appareil électronique Download PDF

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Publication number
WO2021135296A1
WO2021135296A1 PCT/CN2020/111275 CN2020111275W WO2021135296A1 WO 2021135296 A1 WO2021135296 A1 WO 2021135296A1 CN 2020111275 W CN2020111275 W CN 2020111275W WO 2021135296 A1 WO2021135296 A1 WO 2021135296A1
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WO
WIPO (PCT)
Prior art keywords
detection circuit
sensor detection
input
digital
delta
Prior art date
Application number
PCT/CN2020/111275
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English (en)
Chinese (zh)
Inventor
李琛
王浩
Original Assignee
无锡华润上华科技有限公司
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Filing date
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Application filed by 无锡华润上华科技有限公司 filed Critical 无锡华润上华科技有限公司
Publication of WO2021135296A1 publication Critical patent/WO2021135296A1/fr

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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
    • H03M1/00—Analogue/digital conversion; Digital/analogue conversion
    • H03M1/66—Digital/analogue converters
    • H03M1/68—Digital/analogue converters with conversions of different sensitivity, i.e. one conversion relating to the more significant digital bits and another conversion to the less significant bits
    • H03M1/687—Segmented, i.e. the more significant bit converter being of the unary decoded type and the less significant bit converter being of the binary weighted type
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
    • H03M1/00—Analogue/digital conversion; Digital/analogue conversion
    • H03M1/66—Digital/analogue converters
    • H03M1/68—Digital/analogue converters with conversions of different sensitivity, i.e. one conversion relating to the more significant digital bits and another conversion to the less significant bits
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
    • H03M3/00—Conversion of analogue values to or from differential modulation

Definitions

  • the present invention relates to the field of detection, in particular to a sensor detection circuit and an electronic device.
  • ASIC Application Specific Integrated Circuit
  • MEMS Microwave Integrated Circuit
  • ADC analog-to-digital converter
  • DSP dedicated digital signal processor
  • the preamplifier requires a larger area and power consumption.
  • the mainstream chopper amplifier also requires additional circuits such as clock circuits and low-pass filters, which further significantly increases the cost of the chip, and it also affects the overall
  • the sensor signal amplification is mainly determined by the preamplifier, and the analog-to-digital converter adopts a fixed conversion range. Therefore, this scheme is suitable for a certain application, but it lacks flexibility in a general-purpose design.
  • the present invention provides a sensor detection circuit.
  • the first aspect of the present invention provides a sensor detection circuit.
  • the sensor detection circuit includes a digital-to-analog converter and digital signal processing between the input and output of the sensor detection circuit.
  • the sensor detection circuit receives a sensor signal at the input terminal, and the sensor signal is output from the output terminal of the sensor detection circuit after sequentially passing through the digital-to-analog converter and the digital signal processor,
  • the digital-to-analog converter includes a delta-sigma modulator, the delta-sigma modulator includes an input stage and a feedback stage, and the input to the delta-sigma modulator is realized by adjusting the ratio of the input stage to the feedback stage Signal amplification control.
  • a sensor detection circuit comprising a digital-to-analog converter and a digital signal processor located between an input terminal and an output terminal of the sensor detection circuit, the sensor detection circuit receiving a sensor at the input terminal Signal, the sensor signal is output from the output terminal of the sensor detection circuit after sequentially passing through the analog-to-digital converter and the digital signal processor, wherein the analog-to-digital converter includes a delta-sigma modulator,
  • the delta-sigma modulator includes an input stage and a feedback stage, and the ratio of the input stage to the feedback stage determines the input dynamic range of the delta-sigma modulator.
  • the second aspect of the present invention provides an electronic device including the aforementioned sensor detection circuit.
  • Figure 1 is a block diagram of the principle of a traditional sensor detection circuit
  • Figure 2 is a block diagram of a sensor detection circuit shown in an embodiment of the present invention.
  • Fig. 3 is a delta-sigma block diagram shown in an embodiment of the present invention.
  • FIG. 4 is a schematic diagram of the principle of offset calibration shown in an embodiment of the present invention.
  • the processing circuit generally uses a pre-amplifier to amplify the original sensor signal and send it to the subsequent analog-to-digital converter for processing.
  • Figure 1 the block diagram of the sensor detection circuit principle is shown in Figure 1.
  • the sensor detection circuit includes an analog input terminal, a digital output terminal, and an analog output terminal.
  • the analog input terminal introduces the analog input signal generated by the sensor into the preamplifier, and the preamplifier can perform different gain adjustments according to the amplitude of the sensor signal.
  • the high-precision analog-to-digital converter is used for analog-to-digital conversion, and then the digital calibration signal processor is used for signal processing. Part of the processed signal is used as a digital output, and the other part is simulated by a high-precision digital-to-analog converter Output.
  • the square frame also includes a reference circuit, an oscillator, and a memory to cooperate with the sensor signal processing.
  • Figure 1 is only an exemplary description of the sensor detection circuit, of which only the preamplifier is a traditional sensor processing circuit.
  • the components included in Figure 1, the other components in Figure 1, such as: high-precision analog-to-digital converters, digital calibration signal processors, reference circuits, oscillators, and memory are only exemplary descriptions, and their inclusion in Figure 1 is only a follow-up comparison. For convenience, it is not admitted that the above-mentioned components are necessarily included in the traditional processing system.
  • a chopped-wave amplifier (CHOPPER) is generally used to achieve pre-amplification, that is, a chopper amplifier is used as a pre-amplifier.
  • this structure requires additional clock and filtering. Circuit.
  • the analog-to-digital converter generally uses a fixed conversion range; in system design, the general analog-to-digital converter sets the optimal conversion range according to the output range of the preamplifier.
  • the traditional sensor detection circuit needs a high-performance preamplifier to amplify the signal, because the output signal of the sensor is generally mv level, which is much smaller than the dynamic input range of the digital-to-analog converter.
  • the high-performance preamplifier amplifies the sensor's original signal before sending it to ADC for conversion.
  • the noise and offset introduced by the preamplifier will seriously affect the quality of the sensor signal.
  • the preamplifier significantly increases the circuit design complexity, as mentioned above In order to meet the requirements of high gain, low noise, and low offset, the preamplifier must adopt a special architecture to achieve it, which increases the difficulty of the design.
  • the preamplifier increases the area and power consumption, it significantly improves the chip Cost.
  • the preamplifier requires a larger area and power consumption.
  • the mainstream chopper amplifier also requires additional circuits such as clock circuits and low-pass filters, which significantly increases the cost of the chip.
  • the sensor signal amplification is mainly determined by the preamplifier. Because the front end of the signal has been amplified, the analog-to-digital converter often uses a fixed conversion range, and the analog-to-digital converter has a fixed range will cause this Sensor detection circuits are often only suitable for certain specific applications, but they lack flexibility in general-purpose designs.
  • the present invention proposes a sensor detection circuit.
  • the sensor detection circuit includes an analog-to-digital converter and a digital signal processor located between the input terminal and the output terminal of the sensor detection circuit.
  • the circuit receives a sensor signal at the input terminal, and the sensor signal is output from the output terminal of the sensor detection circuit after sequentially passing through the analog-to-digital converter and the digital signal processor, and directly through the analog-to-digital converter
  • the sensor's analog small signal is processed, thereby significantly reducing the design difficulty, and at the same time greatly reducing the chip area and power consumption, and it is suitable for most sensor signal processing, improving versatility.
  • the high-precision delta-sigma ADC is used in the sensor detection circuit.
  • the analog small signal can be amplified synchronously during the analog-to-digital conversion process, thereby replacing The amplification effect of the preamplifier.
  • the ADC can directly process the analog small signals of the sensor, thereby significantly reducing the design difficulty, while greatly reducing the chip area and power consumption, and it is suitable for most sensor signal processing, improving versatility.
  • Fig. 2 is a block diagram of a sensor detection circuit shown in an embodiment of the present invention
  • Fig. 3 is shown in an embodiment of the present invention
  • Fig. 4 is a schematic diagram of the principle of offset calibration shown in an embodiment of the present invention.
  • the technical scheme shown in Fig. 2 removes the preamplifier, and the analog small signal is directly sent to the high-precision analog-to-digital converter for processing.
  • the analog-to-digital conversion is performed through a high-precision analog-to-digital converter, and then a digital calibration signal processor is used for signal processing. Part of the processed signal is used as a digital output, and the other part is passed through a high-precision analog-to-digital converter for analog output.
  • the digital calibration signal processor can also be called a digital signal processor.
  • the square frame Inside the square frame, it also includes a reference circuit, an oscillator, and a memory to cooperate with the sensor signal processing.
  • the high-precision analog-to-digital converter shown in Figure 2 has its unique characteristics to cooperate with the sensor detection circuit without a preamplifier to achieve its function.
  • the present invention adopts the simplest low-cascade integrator feedback (CIFB) single-bit quantizer structure to meet the system requirements.
  • CIFB low-cascade integrator feedback
  • Fig. 3 is a delta-sigma block diagram shown in an embodiment of the present invention.
  • the input dynamic range of the modulator can be determined by the ratio of the input stage C1 and the feedback stage C2.
  • the present invention is to amplify and control the small output signal of the sensor by adjusting the ratio of C1 and C2. ,
  • the greater the amplifying effect on the input signal that is to say, the signal of the sensor is amplified by the ratio of C1/C2 in the modulator. Therefore, through The adjustment of the ratio between the input stage and the feedback stage in the modulator can realize the amplification effect of the preamplifier in the system shown in Fig.
  • the - ⁇ modulator can replace the preamplifier's amplifying effect on the output signal of the sensor, which simplifies the setting of the sensor detection circuit.
  • the present invention introduces a low-order (first-order or two-order) integrator.
  • the low-order integrator is connected to the signals of the input stage and the feedback stage, and integrates the signals formed by the input stage and the feedback stage.
  • the signal enters the single-bit quantizer after passing through the low-order integrator.
  • the output level of the single-bit quantizer is provided by the reference source.
  • the reference voltage level determines the normalized voltage range of the modulator.
  • the output reference voltage of the single-bit quantizer in the invention is also adjustable. The greater the difference between the high and low levels, the smaller the input range of the modulator, that is, the greater the amplification effect of the modulator. This adjustment can be matched with the above input stage and feedback The ratio of the stages, that is, the ratio of C1/C2 is carried out together.
  • the output of the single-bit quantizer is a PDM (Pulse Density Modulation) output, and the output signal is also provided to the feedback stage C2.
  • PDM Pulse Density Modulation
  • FIG. 4 is a schematic diagram of the principle of offset calibration shown in an embodiment of the present invention.
  • the present invention also needs to add a corresponding offset calibration circuit before the delta-sigma modulator, and multiple calibration capacitors are connected to the positive and negative ends of the differential input, and the digital switches are connected in series. Connected to the positive and negative reference levels, according to the actual system offset, the switch can be closed by a digital signal to compensate for the input signal offset. The number of switches and capacitors is determined by the system requirements.
  • the positive reference VP and the negative reference VN The level is also adjustable.
  • the offset calibration circuit includes a calibration capacitor and a digital signal control switch, which has an analog positive input IP and an analog negative input IN.
  • the analog positive input IP terminal is connected to more than four capacitors.
  • One end of the calibration capacitor is connected to the analog positive input IP, and the other end is connected to the positive reference VP.
  • a digital switch is provided between each calibration capacitor and the positive reference VP, and the closed state of the digital switch will determine the number of capacitors connected to the positive reference VP.
  • One end of the calibration capacitor is connected to the analog negative input IN, and the other end is connected to the negative reference VN.
  • a digital switch is provided between each calibration capacitor and the negative reference VN, and the closed state of the digital switch will determine the number of capacitors connected to the negative reference VN.
  • the digital switch can compensate for the input signal offset by controlling the number of calibration capacitors connected to the positive reference VP and the negative reference VN.
  • the number of switches and capacitors is determined by the system requirements. Ground, the levels of the positive reference VP and the negative reference VN are also adjustable.
  • the number of switches and capacitors connected to the positive reference VP and the number of switches and capacitors connected to the negative reference VN may be the same or different.
  • the signal after offset calibration can enter the delta-sigma modulator for signal modulation.
  • the frequency of the sensor signal is extremely low (approximately DC), based on low-speed sensor signal applications, so a high oversampling rate can obtain sufficient accuracy, and also greatly reduces the requirements for the digital filter after the delta-sigma modulator.
  • the present invention A first-order Gaussian filter is introduced to filter the signal modulated by the delta-sigma modulator.
  • OSR oversampling ratio
  • the digital filter is exemplarily located inside the digital calibration signal processor shown in FIG. 2.
  • the present invention does not need to provide a complicated preamplifier circuit, which significantly reduces the design difficulty and at the same time significantly reduces the chip area and circuit power consumption.
  • the sensor signal is directly amplified by the analog-to-digital converter.
  • the delta-sigma architecture analog-to-digital converter is adopted.
  • the gain of the analog-to-digital converter can be adjusted, and the input
  • the ratio of the stage capacitor to the feedback stage capacitor is adjustable, and the reference voltage range of the analog-to-digital converter is also adjustable.
  • the gain of the analog-to-digital converter can be easily adjusted, and the digital-to-analog conversion
  • the range of the ADC is variable, which is suitable for a variety of sensors with different signal amplitudes, which increases the versatility of the signal processing circuit.
  • a low-order integrator is used in the delta-sigma modulator.
  • the signal misalignment at the input terminal does not require a complicated correction circuit, and can be compensated and corrected by fine-tuning the capacitance at the input terminal.
  • An embodiment of the present invention provides an electronic device that uses the sensor detection circuit according to the embodiment. Since the sensor detection circuit used has advantages over the prior art, the electronic device also has the advantages of significantly reducing the design difficulty, while greatly reducing the chip area and power consumption, and being suitable for most sensor signal processing, improving versatility, etc. .
  • the electronic device can be any electronic product or device such as a mobile phone, a tablet computer, a notebook computer, a netbook, a game console, a TV, a VCD, a DVD, a navigator, a camera, a camcorder, a voice recorder, MP3, MP4, PSP, etc.

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  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Compression, Expansion, Code Conversion, And Decoders (AREA)

Abstract

La présente invention concerne un circuit de détection de capteur. Le circuit de détection de capteur comprend un convertisseur analogique-numérique et un processeur de signal numérique qui sont situés entre une extrémité d'entrée et une extrémité de sortie du circuit de détection de capteur, le circuit de détection de capteur recevant un signal de capteur à l'extrémité d'entrée, et le signal de capteur passe successivement à travers le convertisseur analogique-numérique et le processeur de signal numérique, et est ensuite émis à partir de l'extrémité de sortie du circuit de détection de capteur ; et le convertisseur analogique-numérique comprend un modulateur delta-sigma, le modulateur delta-sigma comprend un niveau d'entrée et un niveau de rétroaction, et une plage d'entrée dynamique du modulateur delta-sigma est déterminée au moyen du rapport du niveau d'entrée au niveau de rétroaction.
PCT/CN2020/111275 2019-12-30 2020-08-26 Circuit de détection de capteur, et appareil électronique WO2021135296A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201911395853.9A CN113131943B (zh) 2019-12-30 2019-12-30 一种传感器检测电路及电子装置
CN201911395853.9 2019-12-30

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WO2021135296A1 true WO2021135296A1 (fr) 2021-07-08

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106374930A (zh) * 2016-09-28 2017-02-01 东南大学 基于数字域自校正的逐次逼近模数转换器及模数转换方法
CN108199718A (zh) * 2018-03-30 2018-06-22 福州大学 基于Sigma-Delta调制的电容传感器检测方法
CN109086641A (zh) * 2018-09-13 2018-12-25 国网浙江省电力有限公司宁波供电公司 集成无源无线传感器的自适应调谐标签
CN109238516A (zh) * 2018-10-16 2019-01-18 聚辰半导体(上海)有限公司 一种高精度温度传感器校准方法及电路
US20190305794A1 (en) * 2018-04-02 2019-10-03 Texas Instruments Incorporated Suppressing idle tones in a delta-sigma modulator

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102340314A (zh) * 2010-07-28 2012-02-01 中兴通讯股份有限公司 一种∑-δ调制器
CN103308183B (zh) * 2013-05-31 2015-10-14 中国科学院微电子研究所 一种用于传感器的读出电路
CN105356884B (zh) * 2015-11-03 2018-08-17 南京天易合芯电子有限公司 基于Sigma-Delta模数转换器的传感器读出电路

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106374930A (zh) * 2016-09-28 2017-02-01 东南大学 基于数字域自校正的逐次逼近模数转换器及模数转换方法
CN108199718A (zh) * 2018-03-30 2018-06-22 福州大学 基于Sigma-Delta调制的电容传感器检测方法
US20190305794A1 (en) * 2018-04-02 2019-10-03 Texas Instruments Incorporated Suppressing idle tones in a delta-sigma modulator
CN109086641A (zh) * 2018-09-13 2018-12-25 国网浙江省电力有限公司宁波供电公司 集成无源无线传感器的自适应调谐标签
CN109238516A (zh) * 2018-10-16 2019-01-18 聚辰半导体(上海)有限公司 一种高精度温度传感器校准方法及电路

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CN113131943B (zh) 2022-09-23

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