CN102879648A - Resistance change detection device for thin film resistive gas sensor - Google Patents

Resistance change detection device for thin film resistive gas sensor Download PDF

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Publication number
CN102879648A
CN102879648A CN2012103741586A CN201210374158A CN102879648A CN 102879648 A CN102879648 A CN 102879648A CN 2012103741586 A CN2012103741586 A CN 2012103741586A CN 201210374158 A CN201210374158 A CN 201210374158A CN 102879648 A CN102879648 A CN 102879648A
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China
Prior art keywords
resistance
programmable
gas sensor
external
resistive gas
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CN2012103741586A
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Chinese (zh)
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CN102879648B (en
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秦亚杰
张煜斌
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复旦大学
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Abstract

The invention belongs to the technical field of integrated circuits, in particular to a resistance change detection device for a thin film resistive gas sensor. The detection device comprises an external thin film resistive gas sensor, a programmable current source, a programmable resistance module, a reference voltage source, a low-noise instrument amplifier, a programmable gain amplifier, an analogue-to-digital converter, a built-in temperature sensor, a register, a serial peripheral interface (SPI), an external processor micro control unit (MCU) and an external temperature and humidity sensor. By the detection device, the baseline resistance Rb of the external thin film resistive gas sensor can be tracked and eliminated to accurately measure a resistance change; and in addition, environmental parameters of an environment with the external thin film resistive gas sensor can be detected in real time for the compensation processing of the MCU, and the closed loop control of processing results is formed through the register and the SPI to realize a real-time compensation function.

Description

The resistive gas sensor changes in resistance of thin-film electro pick-up unit
Technical field
The invention belongs to technical field of integrated circuits, be specifically related to the resistive gas sensor changes in resistance of a kind of thin-film electro pick-up unit.
Background technology
In recent years, along with the development of sensor technology, increasing gas sensor is used to the detection of the aspects such as gas concentration, humidity, temperature.The resistive gas sensor of thin-film electro can be realized microminiaturization and not need high-temperature heating to be widely used in the gas sensor detection field because of it.From the angle of electricity, the output of the resistive gas sensor of thin-film electro can equivalence be a resistance R e, and this equivalence resistance R e is comprised of baseline electrical resistance Rb and changes in resistance dR.For the resistive gas sensor of different thin-film electro, the variation range of baseline electrical resistance Rb is very large, its scope probably be ten kilohms to tens megohms, changes in resistance dR is then relevant with the variation of the tested measurement of gas.As a rule, the ratio of changes in resistance dR and baseline electrical resistance Rb is very little.Therefore, for the resistive sensor of different thin-film electro, how detecting accurately the very little changes in resistance dR of variation is a present design difficulty.In addition, baseline electrical resistance Rb can along with the time, the periphery the environmental variances such as humiture variation and change, this will cause measuring accuracy not high, this has just proposed the requirement of real-Time Compensation to whole signal conditioning circuit.
Summary of the invention
The present invention aims to provide a kind of can the measurement accurately changes in resistance, and the pick-up unit of the resistive gas sensor changes in resistance of the thin-film electro that can compensate in real time.
The pick-up unit of the resistive gas sensor changes in resistance of thin-film electro provided by the invention comprises: the resistive gas sensor of external thin-film electro, programmable current source, programmable resistance module, reference voltage source, low noise instrument amplifier IA, programmable gain amplifier PGA, analog to digital converter ADC, built-in temperature sensor, register, SPI interface, external processor MCU, external Temperature Humidity Sensor; Wherein, the resistive gas sensor of external thin-film electro is connected with the programmable resistance module, programmable resistance module and reference voltage source are connected respectively positive input and are connected with negative input with low noise instrument amplifier IA, low noise instrument amplifier IA is connected with programmable gain amplifier PGA, programmable gain amplifier PGA and analog to digital converter ADC are linked in sequence, programmable current source, the programmable resistance module, reference voltage source, low noise instrument amplifier IA, programmable gain amplifier PGA, analog to digital converter ADC, built-in temperature sensor and register respectively connect register and are connected with the SPI interface, the SPI interface be connected processor MCU and connect, external Temperature Humidity Sensor be connected processor MCU and connect.
Among the present invention, described programmable resistance module is comprised of two programmable resistor array R1 and R2.Two electric resistance array R1 and R2 form by 16 * 16 resistance, adopt 8 segmentation decoded modes, and its minimum bit is 15.625K Ω.Fig. 2 shows the implementation of programmable resistor array, when input 8 bit data when decoding, high 4 corresponding to row address, low 4 corresponding to column address, again by respectively the control of each switch in the ranks being realized programming to resistance.
Among the present invention, the equivalent resistance Re of the resistive gas sensor of described external thin-film electro and programmable resistor array R1 and R2 have 8 kinds of integrated modes, be respectively: (1) Re+R1+R2, (2) Re+R1, (3) Re+ (R1 ∥ R2), (4) Re ∥ R1 ∥ R2, (5) (Re+R1) ∥ R2, (6) Re ∥ (R1+R2), (7) Re, (8) reservation pattern.
Among the present invention, the electric current that described programmable current source produces flows through baseline electrical resistance Rb and programmable resistor array R1 and the rear resistance R 3 that produces of R2 combination of the resistive gas sensor of external thin-film electro, the voltage that produces and reference voltage source at the voltage difference V1 of low noise instrument amplifier IA input end generation less than threshold V T, voltage difference V1 is output as DC voltage Vdc through low noise instrument amplifier IA, programmable gain amplifier PGA after amplifying, and this voltage satisfies the requirement of DC voltage biasing; Simultaneously, the electric current that programmable current source produces flows through changes in resistance dR and programmable resistor array R1 and the rear resistance R 4 that produces of R2 combination of the resistive gas sensor of external thin-film electro, the voltage that produces is output as alternating voltage Vac through low noise instrument amplifier IA, programmable gain amplifier PGA after amplifying, and this voltage can be detected by analog to digital converter ADC7.
Among the present invention, the enlargement factor of the equivalent resistance Re of programmable current source size of current, programmable resistor array R1 resistance and R2 resistance, the resistive gas sensor of external thin-film electro and the integrated mode of programmable resistor array R1 and R2, low noise instrument amplifier IA, programmable gain amplifier PGA enlargement factor, analog to digital converter ADC, built-in temperature sensor can communicate or dispose with register, and register can be communicated by letter with external processor MCU by the SPI interface and is configured.
Among the present invention, built-in temperature sensor or external Temperature Humidity Sensor obtain the environment parameter of the resistive gas sensor surrounding environment of external thin-film electro, environment parameter is through after the external processor MCU compensation deals, by realizing the real-Time Compensation function after the SPI interface formation closed-loop control.
The beneficial effect that the present invention has is:
1, by external sheet resistance gas sensor baseline electrical resistance Rb is followed the tracks of the technology of eliminating, realizes changes in resistance ground high-acruracy survey;
2, by behind the environment parameter that detects in real time the resistive gas sensor of external thin-film electro place environment through the MCU compensation deals, realize the real-Time Compensation function after forming closed-loop control by register and SPI interface again.
Description of drawings
Fig. 1 is theory diagram of the present invention.
Fig. 2 is the implementation of programmable resistance of the present invention.
Fig. 3 is the synoptic diagram of baseline electrical resistance of the present invention and programmable resistance integrated mode.
Fig. 4 is the synoptic diagram of DC voltage Vdc of the present invention.
Fig. 5 is the synoptic diagram of alternating voltage Vac of the present invention.
Embodiment
The invention will be further described below in conjunction with drawings and Examples:
In Fig. 1, the pick-up unit of the resistive gas sensor changes in resistance of thin-film electro comprises the resistive gas sensor 1 of external thin-film electro, programmable current source 2, programmable resistance module 3, reference voltage source 4, low noise instrument amplifier IA5, programmable gain amplifier PGA6, analog to digital converter ADC7, built-in temperature sensor 8, register 9, SPI interface 10, external processor MCU 11, external Temperature Humidity Sensor 12; The resistive gas sensor 1 of external thin-film electro is connected with programmable resistance module 3, programmable resistance module 3 and reference voltage source 4 are connected respectively positive input and are connected with negative input with low noise instrument amplifier IA5, low noise instrument amplifier IA5 is connected with programmable gain amplifier PGA6, programmable gain amplifier PGA6 and analog to digital converter ADC7 are linked in sequence, programmable current source 2, programmable resistance module 3, reference voltage source 4, low noise instrument amplifier IA5, programmable gain amplifier PGA6, analog to digital converter ADC7, built-in temperature sensor 8 is connected with register respectively and is connected, register 9 is connected connection with the SPI interface, SPI interface 10 be connected processor MCU 11 and connect, external Temperature Humidity Sensor 12 be connected processor MCU 11 and connect.
Programmable current source 2 has 3 kinds of output currents, is respectively 25.6uA, 3.2uA and 0.4uA.
Programmable resistance module 3 is comprised of two programmable resistor array R1 and R2, and two electric resistance arrays form by 16 * 16 resistance, adopts 8 segmentation decoded modes, and its minimum bit is 15.625K Ω.Fig. 2 shows the implementation of programmable resistor array, when input 8 bit data when decoding, high 4 corresponding to row address, low 4 corresponding to column address, again by respectively the control of each switch in the ranks being realized programming to resistance.
The baseline electrical resistance Re of the resistive gas sensor 1 of external thin-film electro and programmable resistor array R1 and R2 have 8 kinds of integrated modes, be respectively: (1) Re+R1+R2, (2) Re+R1, (3) Re+ (R1 ∥ R2), (4) Re ∥ R1 ∥ R2, (5) are ∥ R2 (Re+R1), (6) Re ∥ (R1+R2), (7) Re, (8) reservation pattern.In Fig. 3, S1~S10 is switch, can determine the integrated mode of baseline electrical resistance Rb and programmable resistor array R1 and R2 by the on off state that S1~S10 is set, and is as shown in table 1 below:
The corresponding table with integrated mode of table 1 on off state
The reference voltage of reference voltage source 4 output 1.2V, the enlargement factor of low noise instrument amplifier IA5 is 1 to 128 times, programmable gain amplifier PGA6 enlargement factor is that 10 to 100 times, analog to digital converter ADC are 21 high precision converters.
In Fig. 4, the electric current that programmable current source 2 produces flows through baseline electrical resistance Rb and programmable resistor array R1 and the rear resistance R 3 that produces of R2 combination of the resistive gas sensor 1 of external thin-film electro, less than threshold V T, this threshold V T is less than 50mV at the voltage difference V1 of low noise instrument amplifier IA5 input end generation for the voltage that produces and reference voltage source 4; Voltage difference V1 is output as DC voltage Vdc through low noise instrument amplifier IA5, programmable gain amplifier PGA6 after amplifying, and this voltage satisfies the requirement of DC voltage biasing; Simultaneously, the electric current that programmable current source 2 produces flows through changes in resistance dR and programmable resistor array R1 and the rear resistance R 4 that produces of R2 combination of the resistive gas sensor 1 of external thin-film electro, the voltage that produces is output as alternating voltage Vac through low noise instrument amplifier IA5, programmable gain amplifier PGA6 after amplifying, this voltage can be detected by analog to digital converter ADC7, as shown in Figure 5.
The enlargement factor of the equivalent resistance Re of programmable current source 2 size of current, programmable resistor array R1 resistance and R2 resistance, the resistive gas sensor 1 of external thin-film electro and the integrated mode of programmable resistor array R1 and R2, low noise instrument amplifier IA5, programmable gain amplifier PGA6 enlargement factor, analog to digital converter ADC7, built-in temperature sensor 8 can communicate or dispose with register 9, and register 9 can be communicated by letter with external processor MCU 11 by SPI interface 10 and is configured.
Table 2 baseline electrical resistance Rb follows the tracks of and eliminates the part example
Iref 0.4uA 3.2uA 25.6uA
Rid 3MΩ 375KΩ 46.875KΩ
Rb Range 1~9MΩ 125KΩ~1125KΩ 15.625KΩ~140.625KΩ
The Rb compensation precision 15.625KΩ 15.625KΩ 2KΩ
Max V1 6.25mV 50mV 50mV
The part example of eliminating of following the tracks of for baseline electrical resistance Rb as shown in table 2, in the table, Iref is the electric current that programmable current source 2 produces, and Rid is the ideal value of resistance R 3, and the Rb compensation precision is selected suitable resistance R 1 resistance, the resistance of R2 and the compensation precision after the integrated mode for process.
From the above mentioned, external processor MCU 11 is selected suitably enlargement factor and the programmable gain amplifier PGA6 enlargement factor of programmable current source 2 size of current, resistance R 1 resistance, R2 resistance, integrated mode, low noise instrument amplifier IA5 automatically by SPI interface and register, make the voltage difference V1 of generation less than threshold V T, realize the tracking elimination of baseline electrical resistance Rb, the DC voltage Vdc that produces and alternating voltage Vac send to by register 9 and SPI interface 10 can try to achieve changes in resistance dR after external processor MCU 11 is processed.
Built-in temperature sensor 8 or external Temperature Humidity Sensor 12 obtain the environment parameter of resistive gas sensor 1 surrounding environment of external thin-film electro, environment parameter is through after external processor MCU 11 compensation deals, by realizing the real-Time Compensation function after the 10 formation closed-loop controls of SPI interface.

Claims (6)

1. the pick-up unit of the resistive gas sensor changes in resistance of thin-film electro is characterized in that: comprise the resistive gas sensor of external thin-film electro, programmable current source, programmable resistance module, reference voltage source, low noise instrument amplifier IA, programmable gain amplifier PGA, analog to digital converter ADC, built-in temperature sensor, register, SPI interface, external processor MCU, external Temperature Humidity Sensor; Wherein, the resistive gas sensor of external thin-film electro is connected with the programmable resistance module, programmable resistance module and reference voltage source are connected respectively positive input and are connected with negative input with low noise instrument amplifier IA, low noise instrument amplifier IA is connected with programmable gain amplifier PGA, and programmable gain amplifier PGA and analog to digital converter ADC are linked in sequence; Programmable current source, programmable resistance module, reference voltage source, low noise instrument amplifier IA, programmable gain amplifier PGA, analog to digital converter ADC, built-in temperature sensor and register respectively connect register and are connected with the SPI interface, the SPI interface be connected processor MCU and connect, external Temperature Humidity Sensor be connected processor MCU and connect.
2. the pick-up unit of the resistive gas sensor changes in resistance of thin-film electro according to claim 1, it is characterized in that: described programmable resistance module is comprised of two programmable resistor array R1 and R2, two electric resistance array R1 and R2 form by 16 * 16 resistance, adopt 8 segmentation decoded modes, when the decoding of input 8 bit data, high 4 corresponding to row address, low 4 corresponding to column address, again by respectively the control of each switch in the ranks being realized programming to resistance.
3. the pick-up unit of the resistive gas sensor changes in resistance of thin-film electro according to claim 2, it is characterized in that: the equivalent resistance Re of the resistive gas sensor of described external thin-film electro and programmable resistor array R1 and R2 have 8 kinds of integrated modes, be respectively: (1) Re+R1+R2, (2) Re+R1, (3) Re+ (R1 ∥ R2), (4) Re ∥ R1 ∥ R2, (5) (Re+R1) ∥ R2, (6) Re ∥ (R1+R2), (7) Re, (8) reservation pattern.
4. the pick-up unit of the resistive gas sensor changes in resistance of thin-film electro according to claim 3, it is characterized in that: the electric current that described programmable current source produces flows through baseline electrical resistance Rb and programmable resistor array R1 and the rear resistance R 3 that produces of R2 combination of the resistive gas sensor of external thin-film electro, the voltage that produces and reference voltage source at the voltage difference V1 of low noise instrument amplifier IA input end generation less than threshold V T, voltage difference V1 is through low noise instrument amplifier IA, programmable gain amplifier PGA is output as DC voltage Vdc after amplifying, and this voltage satisfies the requirement of DC voltage biasing; Simultaneously, the electric current that programmable current source produces flows through changes in resistance dR and programmable resistor array R1 and the rear resistance R 4 that produces of R2 combination of the resistive gas sensor of external thin-film electro, the voltage that produces is output as alternating voltage Vac through low noise instrument amplifier IA, programmable gain amplifier PGA after amplifying, and this voltage can be detected by analog to digital converter ADC7.
5. the pick-up unit of the resistive gas sensor changes in resistance of thin-film electro according to claim 4, it is characterized in that: the programmable current source size of current, programmable resistor array R1 resistance and R2 resistance, the equivalent resistance Re of the resistive gas sensor of external thin-film electro and the integrated mode of programmable resistor array R1 and R2, the enlargement factor of low noise instrument amplifier IA, programmable gain amplifier PGA enlargement factor, analog to digital converter ADC, built-in temperature sensor can communicate or dispose with register, and register can be communicated by letter with external processor MCU by the SPI interface and is configured.
6. the pick-up unit of the resistive gas sensor changes in resistance of thin-film electro according to claim 5, it is characterized in that: built-in temperature sensor or external Temperature Humidity Sensor obtain the environment parameter of the resistive gas sensor surrounding environment of external thin-film electro, environment parameter is through after the external processor MCU compensation deals, by realizing the real-Time Compensation function after the SPI interface formation closed-loop control.
CN201210374158.6A 2012-10-07 2012-10-07 Thin film resistive gas sensor changes in resistance pick-up unit Expired - Fee Related CN102879648B (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104597383A (en) * 2014-12-08 2015-05-06 惠州市亿能电子有限公司 Controllable resistance output device, method thereof and application
CN107632044A (en) * 2016-07-18 2018-01-26 意法半导体有限公司 Small gas analyzer
US10557812B2 (en) 2016-12-01 2020-02-11 Stmicroelectronics Pte Ltd Gas sensors
US10890548B2 (en) 2017-11-23 2021-01-12 Industrial Technology Research Institute Resistive gas sensor and gas sensing method therefor

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080298475A1 (en) * 2007-06-04 2008-12-04 Faraday Technology Corp. Circuit and method for baseline wandering compensation
CN101482531A (en) * 2009-01-10 2009-07-15 大连理工大学 Baseline shift adaptive compensation detecting method used for combustible gas detector
CN102639992A (en) * 2009-12-02 2012-08-15 纽约州立大学研究基金会 Gas sensor with compensation for baseline variations

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080298475A1 (en) * 2007-06-04 2008-12-04 Faraday Technology Corp. Circuit and method for baseline wandering compensation
CN101482531A (en) * 2009-01-10 2009-07-15 大连理工大学 Baseline shift adaptive compensation detecting method used for combustible gas detector
CN102639992A (en) * 2009-12-02 2012-08-15 纽约州立大学研究基金会 Gas sensor with compensation for baseline variations

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
A.L.WINTENBERG 等: "A CMOS Variable Gain Amplifier for PHENIX Electronic Calorimeter and RICH Energy Measurements", 《IEEE TRANSACTIONS ON NUCLEAR SCIENCE》 *
S.R.HAHN 等: "A Large Dynamic Range Charge Amplifier ADC for the Fermilab Collider Detector Facillity", 《IEEE TRANSACTIONS ON NUCLEAR SCIENCE》 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104597383A (en) * 2014-12-08 2015-05-06 惠州市亿能电子有限公司 Controllable resistance output device, method thereof and application
CN107632044A (en) * 2016-07-18 2018-01-26 意法半导体有限公司 Small gas analyzer
US10429330B2 (en) 2016-07-18 2019-10-01 Stmicroelectronics Pte Ltd Gas analyzer that detects gases, humidity, and temperature
US10557812B2 (en) 2016-12-01 2020-02-11 Stmicroelectronics Pte Ltd Gas sensors
US10890548B2 (en) 2017-11-23 2021-01-12 Industrial Technology Research Institute Resistive gas sensor and gas sensing method therefor

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Inventor after: Qin Yajie

Inventor after: Zhang Yubin

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