CN204214938U - A kind of current-to-voltage convertor with driving function - Google Patents

A kind of current-to-voltage convertor with driving function Download PDF

Info

Publication number
CN204214938U
CN204214938U CN201420751874.6U CN201420751874U CN204214938U CN 204214938 U CN204214938 U CN 204214938U CN 201420751874 U CN201420751874 U CN 201420751874U CN 204214938 U CN204214938 U CN 204214938U
Authority
CN
China
Prior art keywords
amplifier
voltage
current
sensor
switch
Prior art date
Legal status (The legal status 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 status listed.)
Expired - Fee Related
Application number
CN201420751874.6U
Other languages
Chinese (zh)
Inventor
陈敏
李志超
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Guangdong Desai Group Co ltd
Original Assignee
Shenzhen Desay Microelectronic Technology Ltd Co
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 Shenzhen Desay Microelectronic Technology Ltd Co filed Critical Shenzhen Desay Microelectronic Technology Ltd Co
Priority to CN201420751874.6U priority Critical patent/CN204214938U/en
Application granted granted Critical
Publication of CN204214938U publication Critical patent/CN204214938U/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Landscapes

  • Amplifiers (AREA)

Abstract

The utility model provides a kind of current-to-voltage convertor with driving function, and comprise sensor drive driving circuit and current-to-voltage converting circuit, sensor drive driving circuit comprises the first amplifier, the second amplifier and resistance R1, R2.Sensor drive driving circuit can ensure when electrode carrying out redox reaction, voltage difference between contrast electrode RE and working electrode WE is fixed, and according to sensor operating principles loading different from measuring method constant voltage or scanning voltage to sensor electrode.Current-to-voltage converting circuit comprises trans-impedance amplifier, integrator, sampling hold circuit and clock generation circuit, the low current signal that sensor exports can be converted to the voltage signal of more than mV level.Current-to-voltage convertor described in the utility model has the advantage of high linearity, high integration, low noise and low-power consumption, can form sensor together read interface circuit with polytype sensor single-chip integration.

Description

A kind of current-to-voltage convertor with driving function
Technical field
The utility model relates to current-to-voltage convertor technical field, is a kind of current-to-voltage convertor with driving function.
Background technology
In order to detect the low current signal (nA-μ A magnitude) that multiple electrochemical sensor exports, need the current-to-voltage converting circuit adopting high-gain, high linearity, traditional way adopts operational amplifier to add a feedback resistance to form current-to-voltage convertor, but this way is when detecting small area analysis (nA level), need to adopt the large resistance of more than mega-ohms to realize high-gain, not only take a large amount of silicon area, also need trade off between speed and stability simultaneously.Existing bibliographical information [is consulted: Mikko Saukoski, Lasse Aaltonen, Kari Halonen. Fully Integrated Charge Sensitive Amplifier for Readout of Micromechanical Capacitive Sensors [C], IEEE International Symposium on Circuits and Systems, May 2005 (6): 5377-5380] utilize the long channel MOSFET being operated in linear zone to carry out alternative passive resistance, equivalent resistance is adjusted by the gate voltage controlling this transistor, but the active pull-up linearity that this method is formed can be subject to the impact of circuit state, the drain voltage of long channel MOSFET changes along with the change in voltage after conversion, the active electrical resistance of equivalence is have impact on owing to there is second-order effect, thus limit the range of current that can detect.First to add static bias voltage (carrying out the measurement of timing Amperometric) or scan bias voltage (carrying out cyclic voltammetry measurement) dynamically on electrode during most electrochemical sensor work.In order to required voltage is accurately added on electrode, need corresponding driving circuit, but existing electrochemical sensor sensing circuit launches [to consult: Du Li for testing circuit mostly, electrochemical sensor test circuit design and implimentation, Dalian University of Technology, master thesis, 2009, page 6-page 15], driving circuit is not integrated in system.Therefore, be necessary to design that a kind of linearity is good, interface circuit that low noise and band drive the current-to-voltage convertor of function to read as current output sensor signal.
Utility model content
The purpose of this utility model is to provide a kind of current-to-voltage convertor with driving function, its linearity is good, noise is low, the low current signal that sensor exports can be converted to the voltage signal of more than mV level, give the circuit such as follow-up analog to digital converter and process.The bias voltage that working sensor needs is loaded on working electrode WE, contrast electrode RE and auxiliary electrode AE by driving circuit simultaneously.
To achieve these goals, the technical solution of the utility model is as follows:
With the current-to-voltage convertor driving function, comprising the current-to-voltage converting circuit for receiving process sensor signal, it is characterized in that: also comprise the sensor drive driving circuit 101 for providing constant bias voltage or dynamic scan bias voltage for sensor; When test substance carries out chemical reaction, described sensor drive driving circuit 101 ensures that the voltage difference between Sensor Reference electrode RE and working electrode WE is fixed.
Preferably, described sensor drive driving circuit 101 comprises first amplifier 1, second amplifier 2 and resistance R1, R2; The in-phase input end of described second amplifier 2 is connected with Sensor Reference electrode RE, the inverting input of the second amplifier 2 and output terminal short circuit form unity gain amplifier, and the output terminal of the second amplifier 2 is connected to the inverting input of the first amplifier 1 by resistance R2 simultaneously; Bias voltage VBAS is connected to the inverting input of the first amplifier 1 by resistance R1, and the in-phase input end of the first amplifier 1 connects common mode electrical level, output terminal connecting sensor auxiliary electrode AE; Described second amplifier 2 detects the voltage difference of contrast electrode RE and working electrode WE, this voltage difference is added on auxiliary electrode AE by the feedback control loop that the first amplifier 1 and resistance R1, R2 are formed, thus plays the effect regulating voltage difference between contrast electrode RE and working electrode WE.
Preferably, described current-to-voltage converting circuit comprises two trans-impedance amplifier path 11 sum-product intergrator paths 12 independently worked, and the output current signal of sensor is converted to voltage signal in the future.
Compared with prior art, the utility model has following beneficial effect:
(1) band described in the utility model drives the current-to-voltage convertor of function, can with sensor integration on a substrate, while bias voltage needed for working sensor is provided, the low current signal that sensor exports is converted to the above voltage signal of mV level being easy to detect, can be used as interface chip, for the sensor read-out system of microminaturization.
(2) described sensor drive driving circuit when test substance generation chemical reaction, can be kept the voltage difference between working electrode WE and contrast electrode RE constant, and be loaded on the electrode of sensor by impressed voltage VBAS by this driving circuit.
(3) described current-to-voltage convertor both can detect DC current signal, also can detect ac current signal, selected in above-mentioned two diverting passageways according to the size of electric current to be measured; When detecting AC signal, according to the frequency of measured signal, the frequency dividing ratio of corresponding change clock generation circuit, thus change the integration frequencies of integrator and the sample frequency of sampling hold circuit, just can keep identical over-sampling rate.
(4) described current-to-voltage convertor, is adopted full custom method design, one piece of integrated circuit (IC) chip realizes, is made by standard CMOS CMOS (Complementary Metal Oxide Semiconductor) technology.
(5) current-to-voltage convertor of described band driving force, there are two bars diverting passageways, sensing range is wide, current signal between 1nA to 1mA can be converted to the voltage signal of more than mV level, and can provide during sensor electrode generation chemical reaction and need bias voltage, there is the advantage of high linearity, high integration, low noise and low-power consumption.The interface circuit that sensor signal reads can be formed together with polytype sensor single-chip integration.
Accompanying drawing explanation
Fig. 1 is sensor drive driving circuit described in the utility model and current-to-voltage convertor structured flowchart;
Fig. 2 is the scan characteristic curve map adopting trans-impedance amplifier electric current diverting passageway described in the utility model;
Fig. 3 adopts integrator circuit described in the utility model to the simulation result figure of current output sensor integration;
Fig. 4 is the scan characteristic curve map adopting integrator electric current diverting passageway described in the utility model.
Embodiment
those skilled in the art will recognize that for convenience and below in conjunction with drawings and Examples, the utility model to be described in detail.
As shown in Figure 1, described current-to-voltage convertor is made up of sensor drive driving circuit 101 and current-to-voltage converting circuit, and sensor drive driving circuit 101 comprises the first amplifier 1, second amplifier 2, resistance R1 and resistance R2; Current-to-voltage converting circuit comprises trans-impedance amplifier 102, integrator 103, sampling hold circuit 104 and clock generation circuit 105.Sensor drive driving circuit 101 provides required voltage on contrast electrode RE, working electrode WE and auxiliary electrode AE, and impressed voltage VBAS determines added voltage swing on sensor, and VBAS can be quiescent voltage, also can be dynamic scan voltage.Current-to-voltage converting circuit converts the electric current that working electrode WE flows through to voltage, and select trans-impedance amplifier path 11 or integrator path 12 to change according to size of current, every bar diverting passageway all has the feature of high linearity and low noise.
As shown in Figure 1, no matter working sensor electrode WE receives trans-impedance amplifier path 11 or integrator path 12, its voltage is all identical with common mode electrical level, and the voltage difference of contrast electrode RE and working electrode WE is detected by the second amplifier 2 being connected into unity gain amplifier.Meanwhile, the first amplifier 1 and resistance R1, R2 form feedback control loop, this voltage difference are added on auxiliary electrode AE, thus play the effect of voltage between adjustment contrast electrode RE and working electrode WE.In order to allow working sensor, first want impressed voltage VBAS, the magnitude of voltage that added magnitude of voltage is produced needed for redox reaction by test substance is determined, can be constant voltage, also can be scanning voltage, just then can the output current of detecting sensor.Due to contrast electrode RE not flowing through electric current, so the electric current flowed through on working electrode WE is all from auxiliary electrode AE, so also contribute to keeping the voltage stabilization on contrast electrode RE.
As shown in Figure 1, there are two current signal diverting passageways in current-to-voltage converting circuit: trans-impedance amplifier path 11 is for detecting large direct current or alternating current (1 μ A to 1mA); Integrator path 12 is for detecting little direct current or alternating current (1n A is to 1 μ A).Article two, electric current diverting passageway alternation, the voltage signal after conversion is delivered to the circuit such as subsequent A/D converter and is processed.When trans-impedance amplifier path 11 works, can close integrator path, vice versa, effectively reduces circuit power consumption.1M is adopted in trans-impedance amplifier 102 Ωfollowing resistance does feedback resistance, can meet the demand of electric current between detection 1 μ A to 1mA, also can reduce the thermonoise that resistance is introduced.Clock generation circuit 105 produces not overlapping clock Clk1 and Clk2 of two-phase, all switches all adopt transmission gate to realize, avoid threshold value loss phenomenon when adopting separately NMOS tube or PMOS to make switch, effectively reduce the change of switch conduction resistance in whole operating voltage range simultaneously, first switch 21, the 3rd switch 23, the 5th switch 25, the 7th switch 26 are controlled by clock Clk2, and second switch 22, the 4th switch 24, the 6th switch 26, the 8th switch 28 are controlled by clock Clk1.Integrator 103 is connected with the first switch 21 that clock Clk2 controls, is connected with the second switch 22 that clock Clk1 controls between integrator path 12 input end and the inverting input of the second amplifier 4 between integrator path 12 input end and common mode electrical level, its role is to when the first switch 21 that clock Clk2 controls closes, input current can be released common mode electrical level, integrator 103 resets simultaneously, the inverting input of the second amplifier 4 is connected with output, because void is short, magnitude of voltage is identical with in-phase input end magnitude of voltage, is common mode electrical level.When the second switch 22 that clock Clk1 controls closes, input current flows through integrating capacitor C itgrcarry out integration.Sampling hold circuit 104 comprises the 3rd amplifier 5, electric capacity C1, electric capacity C2, and sampling hold circuit 104 sum-product intergrator 103 adopts the clock signal with frequency homophase, is carried out by integral voltage delivering to output after sampling keeps.
1. trans-impedance amplifier path
In current signal diverting passageway 1, the gain of trans-impedance amplifier 102 is determined by the variable resistor R being connected across the first amplifier 3 inverting input and output terminal, and output voltage and input current relation are as shown in 1 formula:
(1)
If detect small area analysis (below μ A level) with trans-impedance amplifier 102, need to adopt larger variable resistor (M Ωmore than level), like this by taking a large amount of silicon area, introducing the thermonoise of larger resistance generation, also need trade off between speed and stability simultaneously, reduce circuit reliability.So in the utility model, employing trans-impedance amplifier 102 detects the AC/DC electric current in 1 μ A to 1mA scope, and now variable resistor R only need from 1K Ωto 1M Ωchange.As can be seen from 1 formula, output voltage and input current I inlinear with variable resistor R.
2. integrator path
Integrator 103, sampling hold circuit 104 and clock generation circuit 105 is comprised in integrator path.When working sensor electrode WE sum-product intergrator path input is connected, the output current of sensor is converted to voltage signal by integrator 103.As shown in Figure 1, integrator path adopts two-phase non-overlapping clock Clk1 and Clk2, when clock Clk2 is high, the first switch 21 that Clk2 controls and the 3rd switch 23 close, integrator resets, and the output terminal of the second amplifier 4 is connected with inverting input, and output end voltage is identical with in-phase input end voltage with anti-phase input terminal voltage, be common mode electrical level, now input current does not flow into integrating capacitor C itgrbut flow to common mode electrical level.When clock Clk1 is high, the second switch 22 that Clk1 controls closes, and input current flows through integrating capacitor C itgrcharge, integrator is in integrating state.When Clk1 from high to low saltus step when, the output voltage of integrator is as shown in 2 formulas:
(2)
It is wherein the frequency of clock Clk1.As can be seen from 2 formulas, integral voltage and input current I inbe directly proportional, with integrating capacitor C itgrwith Clk1 clock frequency be inversely proportional to.When detecting small area analysis, integration capacitor value can be reduced and reduce clock frequency.
This integral voltage is undertaken sampling and keeping by sampling hold circuit 104, then exports.When clock Clk1 is high, sampling hold circuit is sampled, the voltage follow integrator 103 output voltage V1 at electric capacity C1 two ends; When clock Clk2 is high, sampling hold circuit is in Holdover mode, and final output voltage is as shown in 3 formulas:
(3)
Get C 1=C 2, then the voltage kept is equal with integral voltage.This diverting passageway have employed Correlated Double Sampling, effectively reduces the KT/C noise that feedback capacity is introduced.
As can be seen from formula (1), (2) and (3) formula, the gain of current-to-voltage convertor is by C itgr, determine with R, when same gear, output voltage and input current linear proportional relation.
Fig. 2 shows when current output sensor scans from 100 μ A-1mA with 5 μ A step-lengths, trans-impedance amplifier electric current diverting passageway of the present utility model is adopted to carry out the simulation result changed, can find out that output voltage reduces with the increase of input current, the linearity is good.When Fig. 3 is the electric current of input 1nA-100nA, adopt integrator of the present utility model to carry out the simulation result of integration, as shown in the figure, when fixing integral time, integral voltage is with the increase monotone decreasing of input current.Fig. 4 is for adopting integrator electric current diverting passageway of the present utility model to current output sensor from 1nA-100nA(0.5nA step-length) Output rusults that scans, find out that output voltage increases monotone decreasing with input current from figure, there is good linearity.

Claims (11)

1. the current-to-voltage convertor with driving function, comprising the current-to-voltage converting circuit for receiving process sensor signal, it is characterized in that: also comprise the sensor drive driving circuit (101) for providing constant bias voltage or dynamic scan bias voltage for sensor; When test substance carries out chemical reaction, described sensor drive driving circuit (101) ensures that the voltage difference between Sensor Reference electrode RE and working electrode WE is fixed.
2. band drives the current-to-voltage convertor of function according to claim 1, it is characterized in that: described sensor drive driving circuit (101) comprises the first amplifier (1), the second amplifier (2) and resistance R1, R2; The in-phase input end of described second amplifier (2) is connected with Sensor Reference electrode RE, the inverting input of the second amplifier (2) and output terminal short circuit form unity gain amplifier, and the output terminal of the second amplifier (2) is connected to the inverting input of the first amplifier (1) by resistance R2 simultaneously; Bias voltage VBAS is connected to the inverting input of the first amplifier (1) by resistance R1, and the in-phase input end of the first amplifier (1) connects common mode electrical level, output terminal connecting sensor auxiliary electrode AE; Described second amplifier (2) detects the voltage difference of contrast electrode RE and working electrode WE, this voltage difference is added on auxiliary electrode AE by the feedback control loop that the first amplifier (1) and resistance R1, R2 are formed, thus plays the effect regulating voltage difference between contrast electrode RE and working electrode WE.
3. band drives the current-to-voltage convertor of function according to claim 1, it is characterized in that: described current-to-voltage converting circuit comprises two trans-impedance amplifier path (11) sum-product intergrator paths (12) independently worked, the output current signal of sensor is converted to voltage signal in the future.
4. band drives the current-to-voltage convertor of function according to claim 3, it is characterized in that: described trans-impedance amplifier path (11) comprises the first amplifier (3) and variable resistor R; The in-phase input end of described amplifier connects common mode electrical level, and inverting input is connected with sensor, and variable resistor R is connected across inverting input and the output terminal of amplifier.
5. band according to claim 4 drives the current-to-voltage convertor of function, it is characterized in that: described variable resistor R variation range is 1K Ωto 1M Ω.
6. band drives the current-to-voltage convertor of function according to claim 3, it is characterized in that: described integrator path comprises integrator (103), sampling hold circuit (104) and clock generation circuit (105), after the output current of sensor is converted to integral voltage by integrator (103), then carry out sampling maintenance by sampling hold circuit (104); Each phase clock that integrator (103) and sampling hold circuit (104) need is produced after the reference clock signal scaling down processing that the external world inputs by clock generation circuit (105).
7. band drives the current-to-voltage convertor of function according to claim 6, it is characterized in that: described clock generation circuit (105) produces two-phase non-overlapping clock.
8. band drives the current-to-voltage convertor of function according to claim 6, it is characterized in that: described integrator (103) comprises the first switch (21), second switch (22), the 3rd switch (23) and the second amplifier (4), integrating capacitor C itgr; Sensor signal is connected to the inverting input of the second amplifier (4) by the first switch (21) that clock signal C lk2 controls, second switch (22) one end connecting sensor input signal end that Clk1 controls, one end connects common mode electrical level, and the second amplifier (4) in-phase input end is connected with common mode electrical level; Second amplifier (4) cross-over connection integrating capacitor C between inverting input and output terminal itgrwith the 3rd switch (23) that clock Clk2 controls.
9. band drives the current-to-voltage convertor of function according to claim 6, it is characterized in that: described sampling hold circuit comprises the 4th switch (24), the 5th switch (25), the 6th switch (26), the 7th switch (27), the 8th switch (28), electric capacity C1, electric capacity C2, the 3rd amplifier (5); The 4th switch (24) that integrator (103) output end signal is controlled by clock Clk1 successively, electric capacity C1, the inverting input of the 7th switch (27) access the 3rd amplifier (5) controlled by clock Clk2; Electric capacity C1 two ends are respectively by being subject to the 5th switch (25) of clock Clk2 control, being connected with common mode electrical level by the 6th switch (26) of clock Clk1 control; The 8th switch (28) that electric capacity C2 and clock Clk1 controls is in parallel, is connected across inverting input and the output terminal of the 3rd amplifier (5), and the in-phase input end of the 3rd amplifier (5) is connected with common mode electrical level simultaneously.
10. band drives the current-to-voltage convertor of function according to claim 9, it is characterized in that: described electric capacity C1, C2 capacitance is identical.
11. are with the current-to-voltage convertor driving function according to claim 9, it is characterized in that: the first to the 8th switch all adopts transmission gate to realize.
CN201420751874.6U 2014-12-04 2014-12-04 A kind of current-to-voltage convertor with driving function Expired - Fee Related CN204214938U (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201420751874.6U CN204214938U (en) 2014-12-04 2014-12-04 A kind of current-to-voltage convertor with driving function

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201420751874.6U CN204214938U (en) 2014-12-04 2014-12-04 A kind of current-to-voltage convertor with driving function

Publications (1)

Publication Number Publication Date
CN204214938U true CN204214938U (en) 2015-03-18

Family

ID=52983600

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201420751874.6U Expired - Fee Related CN204214938U (en) 2014-12-04 2014-12-04 A kind of current-to-voltage convertor with driving function

Country Status (1)

Country Link
CN (1) CN204214938U (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104614568A (en) * 2014-12-04 2015-05-13 深圳市德赛微电子技术有限公司 Current-voltage converter with drive function
CN107765075A (en) * 2016-08-16 2018-03-06 中兴通讯股份有限公司 A kind of current signal processing unit

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104614568A (en) * 2014-12-04 2015-05-13 深圳市德赛微电子技术有限公司 Current-voltage converter with drive function
CN107765075A (en) * 2016-08-16 2018-03-06 中兴通讯股份有限公司 A kind of current signal processing unit
CN107765075B (en) * 2016-08-16 2021-08-24 中兴通讯股份有限公司 Current signal processing device

Similar Documents

Publication Publication Date Title
CN103399201B (en) The general detection chip system of a kind of sensor feeble signal
CN104614568A (en) Current-voltage converter with drive function
CN101384882B (en) Physical quantity sensor
CN107436416B (en) Magnetic switch system capable of processing vertical Hall disc signals and signal processing method
CN205175565U (en) Temperature sensor device and sensing system
CN105242734B (en) A kind of high power LD O circuit without external electric capacity
CN103472114B (en) Multichannel ion sensitive field effect transistor (ISFET) sensor readout circuit with compensation function
CN105115606B (en) A kind of twin-stage reading circuit based on relaxor ferroelectric monocrystal pyroelectric detector
CN202094863U (en) Hall switch offset voltage eliminating circuit based on complementary metal-oxide-semiconductor transistor (CMOS) technology
CN104614404A (en) Ion sensitive field effect transistor sensor and reading circuit thereof
CN204214938U (en) A kind of current-to-voltage convertor with driving function
CN103257324A (en) Magnetic sensor device
CN102455727B (en) Current control circuit with rang of 100pA-1muA
CN101256167B (en) Reading circuit of micro-array biosensor
CN203376076U (en) A temperature detection circuit for a permanent magnet synchronous motor for an electric car and a controller of the motor
CN104897943A (en) High-sensitivity low-power current detection circuit
CN101750446A (en) Complementation-metal-oxide semiconductor constant potential rectifier with rapid stability characteristic
CN104597316A (en) Weak current detecting device and method
CN202583289U (en) A single-power-supply electronic circuit used for a passing through high-precision closed loop Hall current sensor
CN204462242U (en) Weak current signal detection device
CN207866381U (en) A kind of temperature sensor based on capacitive digital converter
CN203587243U (en) Temperature acquiring and processing circuit for electric-bag composite dust collector
Li et al. A CMOS analog front-end chip for amperometric electrochemical sensors
Kong et al. A Pseudo-Differential Capacitive MEMS Accelerometer Analog Front-End Design
CN101131375B (en) High-precision amplifying circuit especially for ion sensitive field effect sensor

Legal Events

Date Code Title Description
C14 Grant of patent or utility model
GR01 Patent grant
TR01 Transfer of patent right

Effective date of registration: 20220712

Address after: 516003 23rd floor, Desai building, No. 12 Yunshan West Road, Huizhou City, Guangdong Province

Patentee after: Guangdong Desai Group Co.,Ltd.

Address before: Room 2303, 23 / F, Desai technology building, 9789 Shennan Avenue, Nanshan District, Shenzhen, Guangdong 518057

Patentee before: SHENZHEN DESAY MICROELECTRONIC TECHNOLOGY CO.,LTD.

TR01 Transfer of patent right
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20150318