CN116909192A - Multichannel analog acquisition circuit - Google Patents
Multichannel analog acquisition circuit Download PDFInfo
- Publication number
- CN116909192A CN116909192A CN202310915981.1A CN202310915981A CN116909192A CN 116909192 A CN116909192 A CN 116909192A CN 202310915981 A CN202310915981 A CN 202310915981A CN 116909192 A CN116909192 A CN 116909192A
- Authority
- CN
- China
- Prior art keywords
- unit
- analog
- microcontroller
- digital converter
- type
- 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.)
- Pending
Links
- 238000006243 chemical reaction Methods 0.000 claims abstract description 20
- 238000004891 communication Methods 0.000 claims description 9
- 238000005070 sampling Methods 0.000 claims description 4
- 239000003990 capacitor Substances 0.000 description 43
- 238000010586 diagram Methods 0.000 description 8
- 230000001360 synchronised effect Effects 0.000 description 4
- 238000004146 energy storage Methods 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000009977 dual effect Effects 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 238000007689 inspection Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 206010063385 Intellectualisation Diseases 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 239000011324 bead Substances 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000003750 conditioning effect Effects 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 230000004807 localization Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B19/00—Programme-control systems
- G05B19/02—Programme-control systems electric
- G05B19/04—Programme control other than numerical control, i.e. in sequence controllers or logic controllers
- G05B19/042—Programme control other than numerical control, i.e. in sequence controllers or logic controllers using digital processors
- G05B19/0423—Input/output
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B2219/00—Program-control systems
- G05B2219/20—Pc systems
- G05B2219/24—Pc safety
- G05B2219/24215—Scada supervisory control and data acquisition
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P90/00—Enabling technologies with a potential contribution to greenhouse gas [GHG] emissions mitigation
- Y02P90/02—Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Automation & Control Theory (AREA)
- Analogue/Digital Conversion (AREA)
Abstract
The invention relates to a multichannel analog quantity acquisition circuit which comprises a standard signal unit, a multichannel analog switch unit, an instrument amplifier unit, an analog-to-digital converter unit and a microcontroller unit, wherein the multichannel analog switch unit comprises two multichannel analog switches, the standard signal unit generates multichannel standard signals and inputs the multichannel standard signals to one multichannel analog switch, multichannel tested signals are input to the other multichannel analog switch, the microcontroller unit respectively controls the multichannel analog switches to input standard signals or tested signals to the instrument amplifier unit, the standard signals or the tested signals amplified by the instrument amplifier unit are output to the analog-to-digital converter unit, and the microcontroller unit controls the analog-to-digital converter unit to perform analog-digital conversion. The invention adopts SE508 type multipath analog switch and SE620 type instrument amplifier, and generates known standard signal through low temperature drift reference source to realize hardware real-time calibration of the system, eliminate error on measuring channel and non-ideal parameter error of device, and realize calibration function.
Description
Technical Field
The invention belongs to the technical field of signal processing, and particularly relates to a multichannel analog acquisition circuit.
Background
Along with the continuous improvement of informatization and intellectualization of equipment, the automatic data acquisition circuit and the multi-channel sensor signal inspection switching circuit in the equipment signal processing board card have wide application requirements on multi-channel analog electronic switches, and particularly strict requirements on the precision, the efficiency and the full-national rate of an acquisition system are provided. The existing data acquisition circuit mainly adopts AD (analog to digital) with an MCU (micro control Unit) or adopts data acquisition board cards of imported manufacturers such as NI, panasonic and the like, an interface needs to be matched with a computer with a special upper computer I card slot, so that only unipolar signals can be processed, the defects of small channel number, limited sampling rate, large full-scale error, low autonomous controllable degree, large volume and the like exist, and the requirements of an equipment system on miniaturization, localization and light weight are difficult to realize.
Disclosure of Invention
In order to solve the problems, the invention aims to provide a multichannel analog quantity acquisition circuit, which adopts a differential synchronous switching expansion circuit design formed by a pair of multichannel analog electronic switches, wherein the same-direction end and the opposite-direction end of an instrument amplifier are respectively connected with the output common end of the multichannel analog switches, and the addresses and the chip select ends of the multichannel analog switches are synchronously controlled by a microcontroller, so that the acquisition circuit has the functions of self calibration and programmable gain switching.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
a multichannel analog acquisition circuit is characterized in that: the device comprises a standard signal unit, a multi-channel analog switch unit, an instrument amplifier unit, an analog-to-digital converter unit and a microcontroller unit, wherein the multi-channel analog switch unit comprises two multi-channel analog switches, and the two multi-channel analog switches are connected to form a differential input circuit; the standard signal unit generates multiple paths of standard signals and inputs the standard signals to one of the multiple paths of analog switches, multiple paths of tested signals are input to the other of the multiple paths of analog switches, the microcontroller unit respectively controls the multiple paths of analog switches to input the standard signals or the tested signals to the instrument amplifier unit, the standard signals or the tested signals amplified by the instrument amplifier unit are output to the analog-to-digital converter unit, and the microcontroller unit controls the analog-to-digital converter unit to perform analog-to-digital conversion.
Further, the common output ends of the two multipath analog switches are respectively connected with the same-direction end and the opposite-direction end of the instrument amplifier unit, the output end of the instrument amplifier unit is connected with the analog-to-digital converter unit, and the analog-to-digital converter unit is connected with the microcontroller unit for communication.
Further, the analog-to-digital converter unit is connected with a reference circuit unit, and the reference circuit unit provides an external REF reference for the analog-to-digital converter unit.
Further, the standard signal unit includes a 5V reference source, and the 5V reference source generates 4 standard signals of 10mV, 50mV, 2.5V, and 5V.
Further, the multi-path analog switch is a SE508 type single-pole eight-throw multi-path analog switch.
Further, the instrument amplifier unit comprises an SE620 type instrument amplifier, and the output common end of the SE508 type single-pole eight-throw multi-way analog switch is respectively connected with the same-direction end and the opposite-direction end of the SE620 type instrument amplifier.
Furthermore, the analog-to-digital converter unit is an SE7606 type SAR-ADC analog-to-digital conversion circuit, the microcontroller unit comprises a microcontroller, the SE7606 type SAR-ADC analog-to-digital conversion circuit controls sampling frequency, oversampling, measuring range and parallel communication modes through the microcontroller, and the analog-to-digital conversion result is reported through a serial port of the microcontroller.
Further, the reference circuit unit includes a SE25441 type 2.5V reference source, which provides an external REF reference of 1ppm temperature drift for the analog to digital converter unit.
Further, the microcontroller unit is also connected with a data uploading unit, and the microcontroller unit is converted to an SE3490 type 422 bus of the data uploading unit through an RS422/RS485 serial port and finally transmits the data to an upper computer.
Further, the main control chip of the microcontroller is a SE32F103 type controller; the chip of the RS422/RS485 serial port is a SE3490 type bus transceiver.
By adopting the technical scheme, the invention has the following advantages and effects:
(1) The multichannel analog quantity acquisition circuit adopts the SE508 type multichannel analog switch based on domestic 8-channel integration and the high-precision SE620 type instrument amplifier, the acquisition circuit structure is added with a high-precision low-temperature drift standard calibration reference source to provide a known standard signal circuit, and the known standard signal is used for realizing hardware real-time calibration on a data acquisition circuit formed by the multichannel analog switch, the instrument amplifier, an analog-digital converter and other devices, so that errors on a measurement channel and non-ideal parameter errors of the devices are eliminated, a calibration function is realized, and the analog quantity acquisition precision is improved.
(2) The multichannel analog quantity acquisition circuit disclosed by the invention automatically adapts the gain of the instrument amplifier through the programmable SE508 type multichannel analog switch, and can realize the functions of amplifying, filtering and conditioning the amplitudes of signals with different amplitudes through a programmable gain function.
(3) The multichannel analog quantity acquisition circuit realizes an analog-to-digital conversion function through a low-temperature drift 16-bit Successive Approximation (SAR) ADC, realizes a channel expansion function based on a time division multiplexing chip selection principle by adopting a SE508 type multichannel analog switch, realizes a data real-time uploading function through a SE3490 type RS422/RS485 bus interface, realizes a high-precision data acquisition system calibration function through a standard signal unit consisting of a SE25441 type 2.5V reference source, can finally realize an analog quantity acquisition system with precision higher than one thousandth and efficiency up to 12000 points per second, and can be applied to automatic inspection equipment and multichannel analog quantity acquisition systems.
Drawings
Fig. 1 is a schematic block diagram of the circuit of the present invention.
Fig. 2 is a circuit diagram of a standard signal cell.
Fig. 3 is a circuit diagram of a multi-channel analog switch cell.
Fig. 4 is a circuit diagram of an instrumentation amplifier cell.
Fig. 5 is a circuit diagram of an analog-to-digital converter unit.
Fig. 6 is a circuit diagram of a reference circuit unit.
Fig. 7 is a circuit diagram of a microcontroller unit.
Fig. 8 is a circuit diagram of a data uploading unit.
The reference numerals are as follows: 1-a standard signal unit; 2-a multi-path analog switch unit; 3-an instrumentation amplifier unit; a 4-analog-to-digital converter unit; a 5-microcontroller unit; a 6-reference circuit unit; 7-a data uploading unit.
Detailed Description
The following detailed description of the embodiments of the present invention will be provided with reference to the accompanying drawings in order to more clearly understand the objects, features and advantages of the present invention. It should be understood that the embodiments shown in the drawings are not intended to limit the scope of the invention, but rather are merely illustrative of the true spirit of the invention.
The invention provides a multichannel analog acquisition circuit, which is characterized in that an SE508 type high-performance multichannel analog switch with low on-resistance, quick opening and closing time, high isolation and the like is selected for expanding an analog acquisition channel; in order to reduce common mode interference, a leading end and a reverse end are connected with a pair of multipath analog electronic switches to form a differential synchronous switching expansion circuit; in order to reduce the error of an acquisition circuit, a SE620 type instrument amplifier with the characteristics of low gain error and low offset voltage is adopted to condition the amplitude of the measured signal and the amplitude of the standard cone signal; in order to realize automatic switching of the measuring range, a SE1204 type make-before-break 4-way analog switch is adopted to realize a self-adaptive function of the measuring range; in order to further improve the acquisition precision of the analog signals, the analog-to-digital conversion adopts a low-temperature drift SE7606 type 8 channel 16-bit analog-to-digital converter; in order to eliminate non-ideal errors of devices in the analog quantity acquisition circuit, a high-precision standard signal is generated by a SE25441 type 2.5V reference source to calibrate the system; in order to realize the data uploading function, an SE3490 type RS422/RS485 bus interface is adopted to communicate with an upper computer.
As shown in fig. 1. The invention provides a multichannel analog quantity acquisition circuit, which comprises a standard signal unit 1, a multichannel analog switch unit 2, an instrument amplifier unit 3, an analog-to-digital converter unit 4 and a microcontroller unit 5, wherein the multichannel analog switch unit 2 comprises two multichannel analog switches, the two multichannel analog switches are connected to form a differential input circuit, the standard signal unit 1 generates a multichannel analog switch to which a multichannel standard signal is input, the multichannel measured signal is input to the other multichannel analog switch, the microcontroller unit 5 respectively controls the corresponding multichannel analog switch to input the standard signal or the measured signal to the instrument amplifier unit 3, the standard signal or the measured signal amplified by the instrument amplifier unit 3 is output to the analog-to-digital converter unit 4, and the microcontroller unit 5 simultaneously controls the analog-to-digital converter unit 4 to perform analog-to-digital conversion on the amplified standard signal or the measured signal.
Specifically, the standard signal unit 1 sends out 10mV, 50mV, 2.5V and 5V direct current standard signals for calibration, wherein the 10mV and 50mV direct current standard signals are used for calibration when testing small amplitude signals, and the 2.5V and 5V direct current standard signals are used for directly testing large signals.
The same direction end and the opposite direction end of the standard signal unit 1 are respectively connected with a pair of multipath analog switches, the addresses and the enabling of the two multipath analog switches are controlled by a microcontroller of the microcontroller unit 5, synchronous actions are performed under the control of the microcontroller unit 5, corresponding channels are automatically switched and selected according to a calibration mode, a standard cone signal or a measured signal is input to the instrument amplifier unit 3, a signal amplified by the instrument amplifier unit 3 is output to the analog-digital converter unit 4 for analog-digital conversion, and the converted signal data is communicated with the microcontroller unit 5 through a parallel port of the analog-digital converter unit 4. The range configuration pin, the oversampling configuration pin, the P/S serial-parallel communication mode and the conversion start pin of the analog-to-digital converter unit 4 are controlled by the I/O port of the microcontroller unit 5.
To further improve the system acquisition accuracy, a reference circuit unit 6 is connected to the outside of the analog-to-digital converter unit 4, and the reference circuit unit 6 mainly generates a 2.5V reference source with 1 ppm/DEG C ultra-low temperature drift to provide an external REF reference for the digital-to-analog converter circuit unit.
Further, in order to realize data uploading, a data uploading unit 7 is connected to the microcontroller unit 5, the data uploading unit 7 is based on an RS422/RS485 serial port standard, and a chip of the RS422/RS485 serial port is a SE3490 type bus transceiver. The microcontroller unit 5 is converted to the SE3490 type 422 bus of the data uploading unit 7 through the RS422/RS485 serial port, and transmits the data to the upper computer.
As shown in fig. 2. The standard signal unit 1 generates 4 paths of standard signals of 10mV, 50mV, 2.5V and 5V and is used for calibrating and calibrating a data acquisition integrated circuit formed by a plurality of analog switches, an instrument amplifier, an analog-to-digital converter and other devices. The standard signal unit 1 comprises a 5V reference source U1, a capacitor C1-capacitor C9 and a voltage dividing resistor R1-voltage dividing resistor R4. The 5V reference source U1 is a domestic SE584 type 5V reference source, and the temperature drift coefficient is 2 ppm/DEG C. The capacitors C1-C9 mainly provide decoupling and energy storage for the standard signal cell 1. The voltage dividing resistor is a high-precision low-temperature-drift metal foil resistor. Pin 2 of the SE584 type 5V reference source is connected with a +15V power supply, pin 4 is connected with a ground end GND, a capacitor C1 and a capacitor C2 are connected in parallel between pin 2 and pin 4, a capacitor C5 is connected in series between pin 8 of the SE584 type 5V reference source and the ground end GND, and a capacitor C3 and a capacitor C4 are connected in parallel between pin 6 and pin 4. One end that electric capacity C4 and ground connection GND are connected in proper order parallel have behind electric capacity C7 output 2.5V direct current standard signal, output 50mV direct current standard signal behind the connection electric capacity C8, output 10mV direct current standard signal behind the connection electric capacity C9, and simultaneously electric capacity C4 both ends are connected with electric capacity C6, and the other end of electric capacity C4 is through output 5V direct current standard signal behind the one end of connecting electric capacity C6.
The resistor R1 is connected in series between two ends of the capacitor C6 and the capacitor C7 which simultaneously output the standard signal, the resistor R3 is connected in series between two ends of the capacitor C7 and the capacitor C8 which simultaneously output the direct current standard signal, and the resistor R4 is connected in series between one end of the capacitor C9 which outputs the direct current standard signal and two ends of the ground end GND. The capacities of the capacitor C1, the capacitor C3, the capacitor C5, the capacitor C6, the capacitor C7, the capacitor C8 and the capacitor C9 are 0.1 mu F, the capacities of the capacitor C2 and the capacitor C4 are 10 mu F, the resistance value of the resistor R1 is 50K, the resistance value of the resistor R2 is 25K, the resistance value of the resistor R3 is 1K, and the resistance value of the resistor R4 is 125R.
As shown in fig. 3. The multi-path analog switch unit 2 comprises a multi-path analog switch U2 and a multi-path analog switch U3, and the multi-path analog switch U2 and the multi-path analog switch U3 are preferably SE508 type single-pole eight-throw multi-path analog switches. The interfaces of each multipath analog switch comprise a +15V power supply interface, -15V power supply interface, an address control interface A0, an address control interface A1, an address control interface A2 and a chip selection enable EN control interface, wherein the address control interface A0, the address control interface A1, the address control interface A2 and the chip selection enable EN control interface are controlled by the microcontroller unit 5.
The SE508 type single-pole eight-throw multi-path analog switch is an 8-path break-before-make integrated switch, has faster on and off time and lower on resistance, and adopts +15V and-15V dual power supplies to supply power to the multi-path analog switch in order to reduce switching noise and on resistance of the switch. Two SE508 single pole eight throw multi-way analog switches form a common terminal of the differential input circuit, which is connected to the common and opposite terminals of the instrumentation amplifier unit 3, respectively. The address and enable terminals of the two SE508 type multiplexing analog switches are controlled by the microcontroller of the microcontroller unit 5. The switching speed of the switch can be controlled and regulated by software. The address control interface A0, the address control interface A1, the address control interface A2 and the chip selection enable EN control interface are connected to the I/O port of the microcontroller to carry out synchronous control, so that two SE508 type single-pole eight-throw multi-path analog switches of a double-path can synchronously act.
As shown in fig. 4. The instrument amplifier unit 3 comprises an SE620 type instrument amplifier U5, an SE1024 type program-controlled range change-over switch U6, a precision resistor RG, a low-pass filter RA and a low-pass filter CA.
The precision resistor RG comprises a 10 multiplication beneficial resistor R5, a 100 multiplication beneficial resistor R6 and a 1000-time gain resistor R7, wherein the resistance value of the gain resistor R5 is 4.94kΩ, the resistance value of the gain resistor R6 is 494 Ω, and the resistance value of the gain resistor R7 is 49.4 Ω.
The SE620 type instrumentation amplifier U5 is mainly based on an SE620 type operational amplifier, has lower offset voltage and offset current, and can set the gain to 1-10000 through a precision resistor RG connected across a pin 1 and a pin 8 of the SE620 type instrumentation amplifier U5. Pin S1 of SE1024 type program controlled range switch U6 is connected in series with gain resistor R5, pin S2 is connected in series with gain resistor R6, and pin S3 is connected in series with gain resistor R7. Pin 12 and pin 3 of SE1024 type program controlled range change-over switch U6 connect +15V and-15V dual power respectively, SE620 type instrument amplifier U5 and SE508 type single-pole eight-throw multipath analog switch share a power supply.
In order to automatically switch to a proper range according to the magnitude of the detected signal amplitude under the initializing gain, a 4-way analog switch of a SE1024 type program-controlled range switch U6 is adopted to carry out program-controlled switching on a gain resistor RG, when an electronic switch of a SE620 type instrument amplifier U5 is switched to S1, the amplification factor is 1000 times, the switching to S2 is 100 times, the switching to S3 is 10 times, and the switching to S4 is 1 time.
As shown in fig. 5. The analog-to-digital converter unit 4 comprises an SE7606 type analog-to-digital converter U8, the SE7606 type analog-to-digital converter U8 is an SE7606 type SAR-ADC analog-to-digital conversion circuit, and the SE7606 type SAR-to-ADC analog-to-digital conversion circuit mainly comprises an analog input filter circuit, a range selection port, a reference voltage selection port, an oversampling setting port, a reference circuit port and a parallel data interface. The SE7606 SAR-ADC analog-to-digital conversion circuit comprises 8 paths of analog input channels V1 to V8, parallel communication interfaces DB0 to DB15, a reference filter capacitor REF, a range control pin R/S, a serial-parallel communication mode selection pin P/S, a conversion control pin CONVST, a BUSY detection pin BUSY, an internal bootstrap circuit filter capacitor RCAP, an oversampling configuration pin OS0, a pin OS1, a pin OS2, a 5V analog power supply pin AVCC and a 3.3V direct current power supply pin VDRIVE. The SE7606 SAR-ADC analog-to-digital conversion circuit controls sampling frequency, oversampling, measuring range and parallel communication mode through a microcontroller U9 of the microcontroller unit 5, and the result of analog-to-digital conversion is reported through a serial port of the microcontroller U9.
As shown in fig. 6. The reference circuit unit 6 comprises a high-precision SE25441 type 2.5V reference source U7 and a filter energy storage capacitor C12-capacitor C15. Pin 2 of the 2.5V reference source U7 is connected with a pin of the 3.3V direct current power supply, pin 4 is connected with a ground end GND, pin 6 is connected with a 42 nd external reference pin EXREF of the SE7606 type analog-digital converter U8, a capacitor C12 and a capacitor C13 are connected between pin 2 and pin 4 in parallel, a capacitor C14 and a capacitor C15 are connected between pin 6 and the ground end GND in parallel, the capacity of the capacitor C12 and the capacitor C14 is 0.1 mu F, and the capacity of the capacitor C13 and the capacity of the capacitor C15 are 10 mu F. The temperature drift of the SE25441 type 2.5V reference source U7 is 1 ppm/DEG C, so that an external REF reference can be provided for the SE7606 type analog-digital converter U8 of the analog-digital converter unit 4, and the overall data acquisition accuracy of the circuit is ensured.
As shown in fig. 7. The microcontroller unit 5 comprises a microcontroller U9, an analog power supply VBAT, a digital power supply energy storage type filter capacitor CL1, a filter capacitor CL2, a magnetic bead L2, a reset circuit RST, a reset circuit CST, a reset key RST, a clock circuit CYM, a vibration starting capacitor CX1 and a vibration starting capacitor CX2. The main control chip of the microcontroller U9 is a SE32F103 type controller adopting an ARM core, a crystal oscillator circuit, a reset circuit, a power supply circuit and a parallel communication interface are integrated in the SE32F103 type controller, and the SE32F103 type controller is used as a core control part of a global circuit to control a multi-path analog switch and an analog-to-digital converter and report acquisition results.
As shown in fig. 8. The data uploading unit 7 comprises a SE3490 type bus interface chip U4, a 3.3V direct current power supply, a decoupling capacitor C11, a bleeder resistor R6 and an output terminal KF1. The microcontroller U9 transmits data to the upper computer through the RS422/RS485 serial port to SE3490 type 422 bus.
The pin 1-pin 4 of the SE3490 type bus interface chip U4 is connected with the microcontroller U9 through a serial port, wherein the receiving end of RS485RX is connected with the 52 pin RS485RX/GPIO11 of the microcontroller U9, the transmitting end of RS485TX is connected with the 51 pin RS484TX/GPIO10 of the microcontroller U9, the pin 8 of the SE3490 type bus interface chip U4 is connected with a 3.3V direct current power supply and a decoupling capacitor C11, one end of the decoupling capacitor C11 is connected with a grounding end GNG, the decoupling capacitor C11 is used for filtering the 3.3V direct current power supply, and the decoupling capacitor C11 is 100nF. Pin 5 of SE3490 type bus interface chip U4 is connected with ground GNG, and pin 6 and pin 7 of SE3490 type bus interface chip U4 are connected with two ends of resistor R6 and then connected with output terminal KF1 in series. The bleeder resistor R6 is used for preventing charge accumulation, causing bus transmission error or damaging devices, and the resistance value of the termination resistor R6 is 120Ω.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims (10)
1. A multichannel analog acquisition circuit is characterized in that: the multi-channel analog switch comprises a standard signal unit (1), a multi-channel analog switch unit (2), an instrument amplifier unit (3), an analog-to-digital converter unit (4) and a microcontroller unit (5), wherein the multi-channel analog switch unit (2) comprises two multi-channel analog switches, and the two multi-channel analog switches are connected to form a differential input circuit; the standard signal unit (1) generates a plurality of paths of standard signals and inputs the standard signals to one of the plurality of paths of analog switches, a plurality of paths of tested signals are input to the other plurality of paths of analog switches, the microcontroller unit (5) respectively controls the plurality of paths of analog switches to input the standard signals or the tested signals to the instrument amplifier unit (3), the standard signals or the tested signals amplified by the instrument amplifier unit (3) are output to the analog-to-digital converter unit (4), and the microcontroller unit (5) controls the analog-to-digital converter unit (4) to perform analog-to-digital conversion.
2. The multi-channel analog acquisition circuit of claim 1, wherein: the common output ends of the two multipath analog switches are respectively connected with the same-direction end and the opposite-direction end of the instrument amplifier unit (3), the output end of the instrument amplifier unit (3) is connected with the analog-digital converter unit (4), and the analog-digital converter unit (4) is connected with the microcontroller unit (5) for communication.
3. A multi-channel analog acquisition circuit according to claim 1 or 2, wherein: the analog-to-digital converter unit (4) is connected with a reference circuit unit (6), and the reference circuit unit (6) provides an external REF reference for the analog-to-digital converter unit (4).
4. A multi-channel analog acquisition circuit according to claim 3, wherein: the standard signal unit (1) comprises a 5V reference source, and the 5V reference source generates 4 paths of standard signals of 10mV, 50mV, 2.5V and 5V.
5. A multi-channel analog acquisition circuit according to claim 1 or 2, wherein: the multi-path analog switch is a SE508 type single-pole eight-throw multi-path analog switch.
6. The multi-channel analog acquisition circuit of claim 5, wherein: the instrument amplifier unit (3) comprises an SE620 type instrument amplifier, and the output common end of the SE508 type single-pole eight-throw multi-path analog switch is respectively connected with the same-direction end and the opposite-direction end of the SE620 type instrument amplifier.
7. The multi-channel analog acquisition circuit of claim 6, wherein: the analog-to-digital converter unit (4) is an SE7606 type SAR-ADC analog-to-digital conversion circuit, the microcontroller unit (5) comprises a microcontroller, the SE7606 type SAR-ADC analog-to-digital conversion circuit controls sampling frequency, oversampling, measuring range and parallel communication modes through the microcontroller, and the analog-to-digital conversion result is reported through a serial port of the microcontroller.
8. A multi-channel analog acquisition circuit according to claim 3, wherein: the reference circuit unit (6) comprises a SE25441 type 2.5V reference source, which 2.5V reference source provides an external REF reference for the analog to digital converter unit (4) with a 1ppm temperature drift.
9. The multi-channel analog acquisition circuit of claim 7, wherein: the microcontroller unit (5) is also connected with a data uploading unit (7), and the microcontroller unit (5) is converted into an SE3490 type 422 bus of the data uploading unit (7) through an RS422/RS485 serial port and finally transmits data to an upper computer.
10. The multi-channel analog acquisition circuit of claim 9, wherein: the main control chip of the microcontroller is a SE32F103 controller; the chip of the RS422/RS485 serial port is a SE3490 type bus transceiver.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310915981.1A CN116909192A (en) | 2023-07-25 | 2023-07-25 | Multichannel analog acquisition circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310915981.1A CN116909192A (en) | 2023-07-25 | 2023-07-25 | Multichannel analog acquisition circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116909192A true CN116909192A (en) | 2023-10-20 |
Family
ID=88364455
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310915981.1A Pending CN116909192A (en) | 2023-07-25 | 2023-07-25 | Multichannel analog acquisition circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116909192A (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1595311A (en) * | 2004-06-23 | 2005-03-16 | 浙江中控技术股份有限公司 | System and method for calibrating analog signal measuring apparatus automatically |
| CN101344544A (en) * | 2008-06-17 | 2009-01-14 | 同济大学 | Monomer voltage polling module of super capacitor bank |
| CN202331914U (en) * | 2011-11-30 | 2012-07-11 | 东北石油大学秦皇岛分校 | Multichannel analog quantity collection device |
| CN111256862A (en) * | 2020-03-31 | 2020-06-09 | 西安微电子技术研究所 | High-precision self-calibration intelligent temperature acquisition and control circuit |
| CN112666868A (en) * | 2020-12-23 | 2021-04-16 | 浙江源创建筑智能科技有限公司 | Data acquisition device with self-calibration and self-inspection functions and use method thereof |
| CN113541689A (en) * | 2020-04-17 | 2021-10-22 | 国控精仪（北京）科技有限公司 | Automatic calibration circuit and calibration method for analog acquisition potentiometer-free device |
| CN217639417U (en) * | 2022-06-30 | 2022-10-21 | 杭州长川科技股份有限公司 | High-precision analog measurement circuit, high-precision digitizer and automatic test equipment |
-
2023
- 2023-07-25 CN CN202310915981.1A patent/CN116909192A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1595311A (en) * | 2004-06-23 | 2005-03-16 | 浙江中控技术股份有限公司 | System and method for calibrating analog signal measuring apparatus automatically |
| CN101344544A (en) * | 2008-06-17 | 2009-01-14 | 同济大学 | Monomer voltage polling module of super capacitor bank |
| CN202331914U (en) * | 2011-11-30 | 2012-07-11 | 东北石油大学秦皇岛分校 | Multichannel analog quantity collection device |
| CN111256862A (en) * | 2020-03-31 | 2020-06-09 | 西安微电子技术研究所 | High-precision self-calibration intelligent temperature acquisition and control circuit |
| CN113541689A (en) * | 2020-04-17 | 2021-10-22 | 国控精仪（北京）科技有限公司 | Automatic calibration circuit and calibration method for analog acquisition potentiometer-free device |
| CN112666868A (en) * | 2020-12-23 | 2021-04-16 | 浙江源创建筑智能科技有限公司 | Data acquisition device with self-calibration and self-inspection functions and use method thereof |
| CN217639417U (en) * | 2022-06-30 | 2022-10-21 | 杭州长川科技股份有限公司 | High-precision analog measurement circuit, high-precision digitizer and automatic test equipment |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111965447B (en) | Hardware configurable analog signal comprehensive test system | |
| CN201233288Y (en) | Multipath data acquisition system | |
| CN103177551A (en) | Data collection card having self calibration function and data collection apparatus | |
| CN112332845A (en) | High-precision current frequency conversion circuit | |
| CN114355152A (en) | Multi-channel radio frequency chip testing device and testing method | |
| CN115031896B (en) | Capacitive film vacuum gauge detection device, vacuum gauge and detection method | |
| CN209961315U (en) | Dynamic and static railroad track scale weighing instrument | |
| CN116909192A (en) | Multichannel analog acquisition circuit | |
| US11093081B2 (en) | Detection circuit and electronic device | |
| CN107687905B (en) | Platinum resistance temperature acquisition device | |
| CN107192851A (en) | A kind of charge modulation device accelerometer capacitive detection system | |
| CN103439379A (en) | Reading circuit and reading method based on electrochemical sensor | |
| CN116054826A (en) | Digital low-cost high-precision current frequency conversion system | |
| CN103134979A (en) | Checking circuit for energy storage device terminal voltage | |
| CN203705594U (en) | 10V switch cabinet internal discharge detector based on electromagnetic wave antenna reception array | |
| CN208012758U (en) | A kind of on-line vibration harvester for collecting sensor signal state of testing oneself | |
| CN112269340A (en) | Multi-signal type high-precision acquisition card | |
| CN109617534B (en) | Charge amplifier | |
| CN114095020B (en) | Offset error correction system and method for multichannel analog-to-digital converter | |
| CN112362954B (en) | Micro-current automatic detection system based on pico-ampere-level double-channel amplifier | |
| CN219476018U (en) | Voltage analog acquisition module | |
| CN111189553A (en) | Thermocouple and synchronous acquisition device for multi-order differential signals thereof | |
| CN217034560U (en) | Support signal acquisition board of 4 ways communications | |
| CN103825596B (en) | It is applicable to the programmable switch capacitance integrator of temperature sensor | |
| CN117665381B (en) | Detection circuit, electronic device and method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |