CN115060962B - Source meter capable of rapidly switching measuring range and temperature compensation method thereof - Google Patents

Source meter capable of rapidly switching measuring range and temperature compensation method thereof Download PDF

Info

Publication number
CN115060962B
CN115060962B CN202210977775.9A CN202210977775A CN115060962B CN 115060962 B CN115060962 B CN 115060962B CN 202210977775 A CN202210977775 A CN 202210977775A CN 115060962 B CN115060962 B CN 115060962B
Authority
CN
China
Prior art keywords
voltage
resistor
current
temperature
range
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.)
Active
Application number
CN202210977775.9A
Other languages
Chinese (zh)
Other versions
CN115060962A (en
Inventor
廉哲
贺江云
潘朝松
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.)
Suzhou Lianxun Instrument Co ltd
Original Assignee
Stelight Instrument Inc
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 Stelight Instrument Inc filed Critical Stelight Instrument Inc
Priority to CN202210977775.9A priority Critical patent/CN115060962B/en
Publication of CN115060962A publication Critical patent/CN115060962A/en
Application granted granted Critical
Publication of CN115060962B publication Critical patent/CN115060962B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/25—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H5/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal non-electric working conditions with or without subsequent reconnection
    • H02H5/04—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal non-electric working conditions with or without subsequent reconnection responsive to abnormal temperature

Abstract

The source meter capable of rapidly switching the range comprises three sub-current analog-to-digital converters and three sub-voltage analog-to-digital converters, and the three sub-current analog-to-digital converters and the three sub-voltage analog-to-digital converters are respectively connected with a current sampling and range switching module and a voltage sampling and range switching module to achieve rapid switching of the range. In addition, the temperature compensation method of the source meter with the fast switching measuring range comprises the step of correcting the current/voltage value read at the ambient temperature of-30 ℃ to 55 ℃ to the current/voltage value corresponding to 23 ℃ through the temperature correction module. The source meter capable of rapidly switching the measuring range can realize non-switching time delay, and simultaneously detect current/voltage in the whole process, so that detection data is not lost, and the temperature drift phenomenon can be reduced. In addition, the temperature compensation method of the source meter can be used for measurement in a wide temperature range from-30 ℃ to 55 ℃, and meanwhile, the detection precision is improved.

Description

Source meter capable of rapidly switching measuring range and temperature compensation method thereof
Technical Field
The application relates to the technical field of circuit measurement, in particular to a source meter capable of rapidly switching measuring ranges and a temperature compensation method thereof. The source meter capable of rapidly switching the measuring range and the temperature compensation method thereof can improve the detection precision while expanding the application temperature range of the instrument. In addition, switching delay can be avoided, current/voltage can be detected in the whole process, detection data can not be lost, and the temperature drift phenomenon can be reduced.
Background
In recent years, with the rapid development of domestic semiconductor technology, a source measurement unit (source measurement unit) has been sought by more and more enterprises as a core member of a semiconductor device test apparatus. The source measuring unit can simultaneously realize the functions of a programmable constant voltage source and a constant current source, an electronic load and a digital multimeter, namely, the source meter has two functions of measuring and sourcing, namely, a source meter measuring instrument (source service unit) has the functions of adding current and voltage sources on the measuring instrument, can simultaneously and accurately acquire and measure voltage and/or current values, and provides additional flexibility for various low-level measuring applications.
Fig. 1 shows the basic architecture of a prior art source-measurement unit, a device under test, not shown, may be coupled between output terminal 37 and output terminal 38, set points and compliance limits may be provided programmed to controller 30, a control output may be provided by a DAC, feedback from the output stage may be provided to IADC 32 and VADC 33 through respective current sensing element 35 and voltage sensing element 36, current feedback may be taken from the current flowing through shunt resistor R18, and a feedback voltage may be taken between the output terminals, current analog-to-digital converter 32 and voltage analog-to-digital converter 33 may provide readback current and voltage values to controller 30.
Because of the characteristics of the insulator and the conductor, the current range of the semiconductor devices or materials such as the diode, the triode, the photoelectric sensor, the MOSFET and the like is very large, and a fixed measuring range cannot be covered, the source meter is required to have a measuring range switching function, and the measuring range of the source meter can be changed according to the size of a measured signal so as to cover the challenge of an overlarge measuring range. The source meter has the function of voltage range switching, and most products in the market adopt the optical coupler or the analog switch to switch the sampling divider resistor when realizing the voltage range switching. The source meter also has a current range switching function so as to meet the requirements of users on current precision under different current ranges, the switching of current ranges of products on the market at present is detected by using an ADC (analog to digital converter), and then sense lines of detection resistors are switched by an analog switch, but the mode cannot realize lossless switching because switching delay exists in the process of switching the analog switch, so that the current cannot be continuously collected in the period of time.
In addition, in the source meter industry, the standard use environment is 23 ℃ ± 5 ℃, that is, the common source meter can only be used in the normal temperature environment, and if the source meter is applied to the low temperature or high temperature environment of the external field, the drift of the measured current value can affect the measurement result, so that the defects of unstable instrument performance, large measurement error and the like can be caused. The source meter measuring instrument is inevitably applied to extreme environments, such as outdoor environments in northern winter, high-temperature environments for oil exploration and the like.
Meanwhile, if a protection circuit is not arranged in the source measurement unit, when the current/voltage of the tested device exceeds the range of the measuring range of the instrument, the instrument can be damaged.
Disclosure of Invention
In view of this, the present application provides a source meter capable of fast switching measurement range and a temperature compensation method thereof. The source meter capable of rapidly switching the measuring range and the temperature compensation method thereof can improve the detection precision while expanding the application temperature range of the instrument. In addition, the switching delay can be avoided, the current/voltage can be detected in the whole process, the detection data can not be lost, and the temperature drift phenomenon can be reduced.
The technical scheme provided by the application is as follows:
a source meter with fast switching range, comprising: the temperature correction module corrects the change generated by voltage/current detection within the temperature range of-30 ℃ to 55 ℃; the controller is connected with the temperature correction module; the switching power supply module is connected with the controller; the current and voltage sampling and range switching module is respectively connected with the switching power supply module and the controller; the output module is connected with the current and voltage sampling and range switching module;
wherein the temperature correction module comprises: the output of the temperature conversion unit is connected with the controller, and the temperature conversion unit performs temperature correction fitting and writes a correction function into the controller; the output of the temperature sampling unit is respectively connected with the input of the controller and the input of the temperature conversion unit, the temperature sampling unit monitors and samples the peripheral ambient temperature of the instrument and transmits the obtained sampling temperature to the controller, and the controller realizes temperature correction compensation according to the correction function so as to correct the current signal values or the voltage signal values read at different temperatures to the corresponding current signal values or voltage signal values at 23 ℃;
wherein, the current-voltage sampling and range switching module comprises: the current sampling and range switching module is respectively connected with the controller, the switching power supply module and the output module; the input of the current analog-to-digital converter is connected with the current sampling and measuring range switching module, and the output of the current analog-to-digital converter is connected with the controller; the current analog-to-digital converter 142 specifically includes three sub-current analog-to-digital converters connected in parallel, and the three sub-current analog-to-digital converters connected in parallel are respectively connected to the current sampling and range switching module 141 to display the current magnitudes of three gears and implement current range switching;
the voltage sampling and range switching module is connected with the output module; the input of the voltage analog-to-digital converter is connected with the voltage sampling and range switching module, and the output of the voltage analog-to-digital converter is connected with the controller; the voltage analog-to-digital converter 144 specifically includes three sub-voltage analog-to-digital converters connected in parallel, and the three sub-voltage analog-to-digital converters connected in parallel are respectively connected to the voltage sampling and range switching module 143 to display the voltage magnitudes of three gears and implement voltage range switching;
and the over-range protection module is connected in parallel at two ends of the current sampling and range switching module.
The application also provides a temperature compensation method applied to the source meter capable of rapidly switching the measuring range, which comprises the following steps:
s1: the temperature conversion unit performs temperature correction fitting and writes the obtained distribution function of the corrected current signal value or the corrected voltage signal value Z (n) into the controller;
s2: after the temperature sampling unit acquires the sampling temperature, transmitting the sampling temperature data to the controller, acquiring a corrected current signal value or a corrected voltage signal value Z (n) by the controller according to a distribution function of the corrected current signal value or the corrected voltage signal value Z (n), and correcting the current signal values or the voltage signal values read at different temperatures to the corresponding current signal values or voltage signal values at 23 ℃;
wherein, S1 comprises the following steps:
s10: uniformly selecting a plurality of test temperature points T (n) in a full temperature range to be tested, wherein the interval between adjacent temperature points is less than 10 ℃, standing and preserving heat for a preset time at each test temperature point T (n) until the internal and external temperatures of a source meter device are basically balanced, wherein n represents each test temperature point, n is a rational number, and the full temperature range to be tested is-30-55 ℃;
s20: acquiring original current/voltage signals M at different test temperature points T (n) x (n) wherein M x (n) represents an original current signal value when the test temperature point temperature is n ℃ or an original voltage signal value when the test temperature point temperature is n ℃;
s30: the temperature conversion unit calculates a current signal value difference or a voltage signal value difference M according to formula (1) y (n)：
M y (n)=M x (n)-M x (23) （1）；
Wherein M is x (23) The original current signal value when the temperature of the test temperature point is 23 ℃ or the original voltage signal value when the temperature of the test temperature point is 23 ℃; m y (n) is the difference value of the original current signal value when the temperature of the test temperature point is n ℃ and the original current signal value when the temperature of the test temperature point is 23 ℃; or M y (n) is the difference value of the original voltage signal value when the temperature of the test temperature point is n ℃ and the original voltage signal value when the temperature of the test temperature point is 23 ℃;
s40: the temperature conversion unit converts the current signal value difference M y (n) or difference M in voltage signal values y (n) fitting the test temperature point T (n) into a curve of the original current signal value or the original voltage signal value on the tested device changing along with the temperature data, wherein the curve of the original current signal value or the original voltage signal value on the tested device changing along with the temperature data satisfies a formula (2):
M y (n)=aT(n)+b1 （2）；
obtaining a distribution function of the modified current signal values or modified voltage signal values Z (n) according to the formula (2):
Z(n)=M x (23)+M y (n)=M x (23)+aT(n)+b1=aT(n)+b2 （3）；
wherein a is a fitting coefficient, b1 and b2 are constants, and the value range of the fitting coefficient a is 10 -5 -10 -3 ；
S50: the temperature conversion unit writes the distribution function of the corrected current signal value or the corrected voltage signal value Z (n) to the controller.
According to the scheme provided by the application, the source meter capable of rapidly switching the measuring range and the temperature compensation method thereof can improve the detection precision while expanding the application temperature range of the instrument. In addition, switching delay can be avoided, current/voltage can be detected in the whole process, detection data can not be lost, and the temperature drift phenomenon can be reduced.
In order to make the aforementioned objects, features and advantages of the present application more comprehensible, preferred embodiments accompanied with figures are described in detail below.
Drawings
To more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and those skilled in the art can also obtain other related drawings based on the drawings without inventive efforts.
FIG. 1 is a schematic diagram of a source table in the prior art;
FIG. 2 is a schematic diagram of the working principle of a source meter capable of switching the range rapidly according to the present invention;
FIG. 3 is a schematic block diagram of a source meter circuit capable of fast range switching according to the present invention;
FIG. 4 is an internal structural diagram of a temperature sampling unit of the source meter capable of rapidly switching the range according to the present invention;
FIG. 5 is a schematic diagram of an internal circuit of the current sampling and range switching module and the current ADC;
FIG. 6 is a schematic diagram of the internal circuitry of the voltage sampling and range switching module and the voltage ADC;
FIG. 7 is a schematic diagram of an internal circuit of the over-range protection module;
FIG. 8 is a flowchart of a temperature compensation method for a source meter capable of fast range switching according to the present invention;
FIG. 9 is a plot of a current/temperature curve line fit for a source meter of the present invention with an output of 1A range;
FIG. 10 is a line segment fit of a voltage/temperature curve of the source meter provided by the present invention at an output of 60V range.
Reference numerals:
37 38-output terminal; 30 12-a controller; 35-a current sensing element; 36-a voltage sensing element; 32 142-current analog-to-digital converter; 33 144-voltage analog to digital converter; 11-a temperature correction module; 13-a switching power supply module; 14-current voltage sampling and range switching module; 15-an output module; 16-a voltage digital-to-analog converter; 17-a current digital-to-analog converter; 18-display and USB interface unit; 19-an auxiliary controller; 111-temperature sampling unit; 112-a temperature conversion unit; 141-current sampling and range switching module; 143-voltage sampling and range switching module; 145-over-range protection module; 1421 — first current analog-to-digital converter; 1422 — second current analog-to-digital converter; 1423 — third current analog-to-digital converter; 1441 — a first voltage analog-to-digital converter; 1442 — a second voltage analog to digital converter; 1443 — third voltage analog-to-digital converter; 1411-a first sampling circuit; 1412-a second sampling circuit; 1413-a third sampling circuit; 1431 — a first voltage divider circuit; 1432 — a second voltage divider circuit; 1433 — a third voltage divider circuit; 211-a first differential op amp; 212-a second differential op amp; 213-a third differential op amp; 214-a first precision handler; 215-a second precision handler; 216-a third precision handler; 217-fourth differential op amp; 218-a fifth differential op amp; 219-sixth differential op amp.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. The components of the embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present application, presented in the accompanying drawings, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present application without making any creative effort, shall fall within the protection scope of the present application.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures. Meanwhile, in the description of the present application, the terms "first", "second", and the like are used only for distinguishing the description, and are not to be construed as indicating or implying relative importance.
In order to overcome the problems that a current range is very large and a fixed range cannot be covered due to the characteristics of a diode, a triode, a photoelectric sensor, an MOSFET and other semiconductor devices or materials between an insulator and a conductor, a source meter is required to have an automatic range switching function, and the prior art has two common improvement modes. The first is that when the voltage range is switched, an optical coupler or an analog switch is used for switching a sampling divider resistor. Another way is to use an ADC to detect when the current range is switched, and then switch the sense line of each detection resistor through an analog switch.
Two methods adopted in the prior art have the effect of processing the automatic range switching function of the source meter to a certain extent, but cause switching delay for industrial production, cannot continuously acquire current/voltage signals and have certain loss.
In addition, the standard use environment of the source meter in the prior art is 23 ℃ ± 5 ℃, that is, the source meter in the prior art can only be used in a normal temperature environment, and if the source meter is applied to a low-temperature or high-temperature environment of an external field, drift of a measured current value can affect a measurement result, so that defects such as unstable instrument performance and large measurement error can be caused. The source meter measuring instrument is inevitably applied to extreme environments, such as outdoor environments in northern winter, high-temperature environments for oil exploration and the like.
Therefore, the technical scheme of the application is provided for overcoming the defects existing in the automatic range switching function problem of the source meter. The technical solution of the present application will be described in detail below.
Referring to fig. 2 and 3, the source meter capable of switching range rapidly according to the present invention includes: the temperature calibration module 11 can calibrate the variation generated by the voltage/current detection in the temperature range of-30 ℃ to 55 ℃.
And the controller 12 is connected with the temperature correction module 11, and is configured to receive the sampling temperature from the temperature correction module and the fitted distribution function to implement temperature compensation, and control other modules in the source table, where the controller 12 may be an FPGA.
And the switching power supply module 13 is connected with the controller 12, acquires the voltage signal output by the controller 12, generates a corresponding PWM pulse, and simultaneously supplies power to other modules.
And a current-voltage sampling and range switching module 14, which is connected to the switching power supply module 13 and the controller 12, respectively, and performs sampling conversion on the output current value and voltage value and performs current/voltage range switching.
And the output module 15 is connected with the current and voltage sampling and range switching module 14 and is used for outputting current and voltage.
Wherein the temperature correction module 11 comprises: the output of the temperature conversion unit 112 is connected to the controller 12, the temperature conversion unit 112 receives the sampling temperature from the temperature sampling unit 111, fits the temperature and the current/voltage value, and transmits the obtained distribution function to the controller 12 to implement a temperature compensation algorithm, the temperature conversion unit 112 is an auxiliary fitting tool, and in one embodiment, may be any one of Matlab, excel, origin, and Curve Expert.
The temperature correction module 11 further includes: the temperature sampling unit 111, the output of the temperature sampling unit 111 is connected with the controller 12, refer to fig. 4, wherein the temperature sampling unit 111 includes a temperature monitoring chip, the temperature monitoring precision can reach ± 0.1 ℃, the temperature sampling unit 111 can monitor the peripheral ambient temperature of the instrument and transmit the temperature to the controller 12 for temperature compensation and correction, and meanwhile, the temperature monitoring chip has an over-temperature protection function, and when the sampling temperature exceeds-30 ℃ to 55 ℃, on-off control of the controller 12 is realized, and effective control of circuit on-off in the electricity use process is realized. The SDA pin and the SCL pin of the temperature monitoring chip are output pins, and the voltage value of the sampled ambient temperature is output to the controller 12 through the SDA pin and the SCL pin. An O.S. pin of the temperature monitoring chip is an over-temperature protection output pin, and an over-temperature alarm signal is output to the controller 12 through the O.S. pin, so that over-temperature protection is realized.
Wherein, the current-voltage sampling and range switching module 14 includes: the switching module 13 supplies power to the controller 12, the switching power supply module 13 and the output module 15, obtains a current value output by the output module 15, converts the current value into a voltage value, and obtains a control signal of the controller 12 to switch current ranges.
The input of the current analog-to-digital converter 142 is connected to the current sampling and range switching module 141, and the output of the current analog-to-digital converter 142 is connected to the controller 12, and is configured to implement conversion between a digital signal output by the controller 12 and an analog signal output by the current sampling and range switching module 141.
And a voltage sampling and range switching module 143, connected to the output module 15, for acquiring the voltage value on the output module 15 to obtain a voltage signal containing information of the actual voltage value, and performing range switching.
The input of the voltage analog-to-digital converter 144 is connected to the voltage sampling and range switching module 143, and the output of the voltage analog-to-digital converter 144 is connected to the controller, and is configured to implement conversion between the digital signal output by the controller 12 and the analog signal output by the voltage sampling and range switching module 143.
And the over-range protection module 145 is connected to two ends of the current sampling and range switching module 141 in parallel, and performs clamping protection on the circuit of the current sampling and range switching module, so that when the detected equipment exceeds the range of the instrument, the instrument is protected from being damaged.
Referring to fig. 5, in one embodiment, the current sampling and range switching module 141 further includes: a first sampling circuit 1411, a second sampling circuit 1412, and a third sampling circuit 1413. The first sampling circuit 1411 further includes a first resistor R1, a fourth resistor R4, a seventh resistor R7, a first differential amplifier 211, a first zener diode D1, and a second zener diode D2. One end of the first resistor R1 is connected with the output V of the switching power supply module 13 OUT And is connected to the inverting terminal of the first differential op amp 211. The other end of the first resistor R1 is connected to the second sampling circuit 1412 and to the non-inverting terminal of the first differential operational amplifier 211. The fourth resistor R4 is connected between the 1 port and the 8 port of the first differential amplifier 211. The output end of the first differential amplifier 211 is connected to one end of the seventh resistor R7. The other end of the seventh resistor R7 is connected to the anode of the second zener diode D2. The cathode of the second zener diode D2 is connected to the cathode of the first zener diode D1. The anode of the first zener diode D1 is grounded. The current range detected by the first sampling circuit 1411 is 0-1A. The seventh resistor R7, the first zener diode D1, and the second zener diode D2 form a voltage stabilizing circuit, which stabilizes the voltage of the first sampling circuit 1411 within 5V.
The second sampling circuit 1412 further includes a second resistor R2, a fifth resistor R5, an eighth resistor R8, a tenth resistor R10, a first switch Q1, a second switch Q2, a second differential operational amplifier 212, a third voltage regulator diode D3, and a fourth voltage regulator diode D4. One end of the second resistor R2 is connected to the first sampling circuit 1411 and to the inverting terminal of the second differential amplifier 212. The other end of the second resistor R2 is connected to the third sampling circuit 1413 and to the non-inverting terminal of the second differential operational amplifier 212. The fifth resistor R5 is connected between the 1 port and the 8 ports of the second differential op amp 212. The output terminal of the second differential amplifier 212 is connected to one end of the eighth resistor R8. The other end of the eighth resistor R8 is connected to the anode of the fourth zener diode D4. The cathode of the fourth zener diode D4 is connected to the cathode of the third zener diode D3. The anode of the third zener diode D3 is grounded. The drain electrode of the first switch tube Q1 is connected to one end of the second resistor R2. And the source electrode of the first switching tube Q1 is connected with the source electrode of the second switching tube Q2. The drain of the second switch tube Q2 is connected to the other end of the second resistor R2, and one end of the tenth resistor R10 is connected to the gates of the first switch tube Q1 and the second switch tube Q2. The other end of the tenth resistor R10 is connected to the controller 12. The controller 12 controls the on/off of the first switching tube Q1 and the second switching tube Q2, the current range detected by the second sampling circuit 1412 is 0-10mA, wherein the eighth resistor R8, the third zener diode D3 and the fourth zener diode D4 form a voltage stabilizing circuit, which stabilizes the voltage of the second sampling circuit 1412 within 5V.
The third sampling circuit 1413 further includes a third resistor R3, a sixth resistor R6, a ninth resistor R9, an eleventh resistor R11, a third switching tube Q3, a fourth switching tube Q4, a third differential amplifier 213, a fifth zener diode D5, and a sixth zener diode D6. One end of the third resistor R3 is connected to the second sampling circuit 1412 and to the inverting terminal of the third differential operational amplifier 213. The other end of the third resistor R3 is connected to the high level V _ HO and to the non-inverting terminal of the third differential amplifier 213. The sixth resistor R6 is connected between the 1 port and the 8 port of the third differential amplifier 213. The output end of the third differential amplifier 213 is connected to one end of the ninth resistor R9. The other end of the ninth resistor R9 is connected to the anode of the sixth zener diode D6. The cathode of the sixth zener diode D6 is connected to the cathode of the fifth zener diode D5. The anode of the fifth zener diode D5 is grounded. The drain of the third switching tube Q3 is connected to one end of the third resistor R3. And the source electrode of the third switching tube Q3 is connected with the source electrode of the fourth switching tube Q4. The drain electrode of the fourth switch tube Q4 is connected to the other end of the third resistor R3, and one end of the eleventh resistor R11 is connected to the gate electrodes of the third switch tube Q3 and the fourth switch tube Q4. The other end of the eleventh resistor R11 is connected to the controller 12. The controller 12 controls the third switching tube Q3 and the fourth switching tube Q4 to be turned on and off, the current range detected by the third sampling circuit 1413 is 0-100 μ a, wherein the ninth resistor R9, the fifth zener diode D5 and the sixth zener diode D6 form a voltage stabilizing circuit, which stabilizes the voltage of the third sampling circuit 1413 within 5V.
The first sampling circuit 1411, the second sampling circuit 1412 and the third sampling circuit 1413 are connected end to end through the first resistor, the second resistor and the third resistor, and are connected in series between the output end of the switching power supply module 13 and a high level. Wherein the resistance of the first resistor R1 < the resistance of the second resistor R2 < the resistance of the third resistor R3.
The current analog-to-digital converter 142 specifically includes three sub-current analog-to-digital converters connected in parallel, which are respectively a first current analog-to-digital converter 1421 (IADC 1), a second current analog-to-digital converter 1422 (IADC 2), and a third current analog-to-digital converter 1423 (IADC 3) for providing current information of three gears to the controller 12, so that the controller 12 performs analysis processing on the current information.
Wherein, the output of the first sampling circuit 1411 is connected to the input of the first current analog-to-digital converter 1421. The output of the second sampling circuit 1412 is connected to the input of the second current analog-to-digital converter 1422. The output of the third sampling circuit 1413 is connected to the input of the third current analog-to-digital converter 1423.
The first switch tube Q1 to the fourth switch tube Q4 are all MOS tubes, and in one embodiment, may be any one of MOS tubes, relays, and switching devices. The first differential operational amplifier 211, the second differential operational amplifier 212 and the third differential operational amplifier 213 are all instrument differential operational amplifiers, and the specific model is INA128.
In one embodiment, the resistance of the first resistor R1 is 0.5 Ω, the resistance of the second resistor R2 is 50 Ω, the resistance of the third resistor R3 is 5k Ω, the resistances of the seventh resistor R7, the eighth resistor R8, the ninth resistor R9 and the tenth resistor R10 are 1k Ω, the resistance of the eleventh resistor R11 is 10k Ω, the first zener diode D1 to the sixth zener diode D6 are 5.1V zener diodes, and the amplification factors of the first differential amplifier 211 to the third differential amplifier 213 are 10 times.
When the current gear of the device under test is in the range gear of 0-100 μ a, at this time, Q1, Q2, Q3, and Q4 are all turned off, the current will flow through the first resistor R1, the second resistor R2, and the third resistor R3, the first sampling circuit 1411, the second sampling circuit 1412, and the third sampling circuit 1413 operate simultaneously, so the currents of the range gears of 0-1A, 0-10mA, and 0-100 μ a are all detected at any time, and the controller 12 selects to read the output of the third current analog-to-digital converter 1423. When the current range is switched to the range of 0-10mA, the controller 12 controls the third switching tube Q3 and the fourth switching tube Q4 to be turned on, and at this time, the third resistor R3 is short-circuited, so that the currents in the range of 0-1A and 0-10mA are detected at any time, and the controller 12 selects to read the output of the second current analog-to-digital converter 1422. When the current gear is switched to the range gear of 0-1A, the controller 12 controls Q1, Q2, Q3, and Q4 to be all turned on, and at this time, R2 and R3 are both short-circuited, so that only the current of the range gear of 0-1A is detected from time to time, and the controller 12 selects to read the output of the first current analog-to-digital converter 1421. Therefore, when the current range gear is switched to 0-10mA or 0-1A, only the controller is needed to open the MOS of the opposite range gear, and the problems of data loss, current overshoot and the like caused by time delay in the switching process can be avoided.
Referring to fig. 6, in one embodiment, the voltage sampling and range switching module 143 further includes: a first voltage dividing circuit 1431, a second voltage dividing circuit 1432, and a third voltage dividing circuit 1433.
The first voltage dividing circuit 1431 further includes a twelfth resistor R12, a thirteenth resistor R13, a seventeenth resistor R17, a first precision amplifier 214, a fourth differential amplifier 217, a seventh zener diode D7, and an eighth zener diode D8. One end of the twelfth resistor R12 is connected to the low level V _ LO. The other end of the twelfth resistor R12 is connected to one end of the thirteenth resistor R13, and is also connected to the non-inverting end of the first precision operational amplifier 214. The other end of the thirteenth resistor R13 is connected to the high level V _ HO. The output end of the first precision operational amplifier 214 is connected to the inverting end of the fourth differential operational amplifier 217. The non-inverting terminal of the fourth differential amplifier 217 is connected to a high level V _ HO. The output end of the fourth differential amplifier 217 is connected to one end of the seventeenth resistor R17. The other end of the seventeenth resistor R17 is connected to the anode of the seventh zener diode D7. The cathode of the seventh zener diode D7 is connected to the cathode of the eighth zener diode D8. The anode of the eighth zener diode D8 is grounded. The voltage range detected by the first voltage division circuit 1431 is 0-60V voltage range. The seventeenth resistor R17, the seventh zener diode D7 and the eighth zener diode D8 form a voltage stabilizing circuit, which stabilizes the voltage of the first voltage dividing circuit 1431 within 5V.
The second voltage dividing circuit 1432 further includes a fourteenth resistor R14, a fifteenth resistor R15, an eighteenth resistor R18, the second precision amplifier 215, the fifth differential amplifier 218, a ninth zener diode D9, and a tenth zener diode D10. One end of the fourteenth resistor R14 is connected to the low level V _ LO. The other end of the fourteenth resistor R14 is connected to one end of the fifteenth resistor R15, and is also connected to the non-inverting terminal of the second precision op amp 215. The other end of the fifteenth resistor R15 is connected to the high level V _ HO. The output terminal of the second precision op amp 215 is connected to the inverting terminal of the fifth differential op amp 218. The non-inverting terminal of the fifth differential op amp 218 is connected to a high level V _ HO. The output terminal of the fifth differential op amp 218 is connected to one end of the eighteenth resistor R18. The other end of the eighteenth resistor R18 is connected to the anode of the ninth zener diode D9. The cathode of the ninth zener diode D9 is connected to the cathode of the tenth zener diode D10. The anode of the tenth zener diode D10 is grounded. The voltage range detected by the second voltage division circuit 1432 is 0-6V. The eighteenth resistor R18, the ninth zener diode D9, and the tenth zener diode D10 form a voltage stabilizing circuit, which stabilizes the voltage of the second voltage dividing circuit 1432 within 5V.
The third voltage dividing circuit 1433 further includes a sixteenth resistor R16, a nineteenth resistor R19, a twentieth resistor R20, a third precision amplifier 216, a sixth differential amplifier 219, an eleventh zener diode D11, and a twelfth zener diode D12. One end of the sixteenth resistor R16 is connected to the low level V _ LO. The other end of the sixteenth resistor R16 is connected to the non-inverting terminal of the third precision op amp 216. The output terminal of the third precision operational amplifier 216 is connected to the inverting terminal of the sixth differential operational amplifier 219. The non-inverting terminal of the sixth differential operational amplifier 219 is connected to a high level V _ HO. The twentieth resistor R20 is connected between the 1 port and the 5 port of the sixth differential amplifier 219. An output end of the sixth differential amplifier 219 is connected to one end of the nineteenth resistor R19. The other end of the nineteenth resistor R19 is connected to the anode of the eleventh zener diode D11. The cathode of the eleventh zener diode D11 is connected to the cathode of the twelfth zener diode D12. The anode of the twelfth zener diode D12 is grounded. The voltage range detected by the third voltage dividing circuit 1433 is 0-0.6V. The nineteenth resistor R19, the eleventh zener diode D11, and the twelfth zener diode D12 form a voltage stabilizing circuit, which stabilizes the voltage of the third voltage dividing circuit 1433 within 5V.
The voltage analog-to-digital converter 144 specifically includes three sub-voltage analog-to-digital converters connected in parallel, which are respectively a first voltage analog-to-digital converter 1441 (VADC 1), a second voltage analog-to-digital converter 1442 (VADC 2), and a third voltage analog-to-digital converter 1443 (VADC 3) for providing voltage information of three gears to the controller 12, so that the controller 12 performs parsing processing on the voltage information.
Wherein an output of the first voltage dividing circuit 1431 is connected to an input of the first voltage analog-to-digital converter 1441, an output of the second voltage dividing circuit 1432 is connected to an input of the second voltage analog-to-digital converter 1442, and an output of the third voltage dividing circuit 1433 is connected to an input of the third voltage analog-to-digital converter 1443.
The resistance of the thirteenth resistor R13 < the resistance of the twelfth resistor R12 = the resistance of the fourteenth resistor R14 = the resistance of the sixteenth resistor R16 < the resistance of the fifteenth resistor R15. The first precision operational amplifier 214, the second precision operational amplifier 215 and the third precision operational amplifier 216 are all high-precision operational amplifiers with low input capacitance and low offset current, and the specific model is the OPA140. The fourth differential operational amplifier 217, the fifth differential operational amplifier 218 and the sixth differential operational amplifier 219 are all instrument differential operational amplifiers, and the specific model is INA128.
A current detection resistor (not shown) is connected in series between the low level V _ LO and ground GND, and a voltage difference across the current detection resistor does not exceed 0.5V, so that the voltage difference between the low level V _ LO and ground GND is within 0.5V, and the voltage difference between the high level V _ HO and the low level V _ LO is within 60V.
In one embodiment, the resistances of the twelfth resistor R12, the fourteenth resistor R14 and the sixteenth resistor R16 are 100k Ω, the resistance of the thirteenth resistor R13 is 10k Ω, the resistance of the fifteenth resistor R15 is 200k Ω, the resistances of the seventeenth resistor R17 to the nineteenth resistor R19 are all 1k Ω, and the seventh zener diode D7 to the twelfth zener diode D12 are all 5.1V zener diodes.
The first voltage dividing circuit 1431, the second voltage dividing circuit 1432 and the third voltage dividing circuit 1433 are turned on at the same time and detect in real time, the first voltage dividing circuit 1431 divides the voltage entering the same-direction end of the first precision operational amplifier 214 through R13, the second voltage dividing circuit 1432 divides the voltage entering the same-direction end of the second precision operational amplifier 215 through R15, since the third voltage dividing circuit detects a smaller voltage range, it is not necessary to increase a voltage dividing resistor, and it is necessary to connect a gain amplifying resistor between two RG terminals of the sixth differential operational amplifier to amplify the output voltage, and since the resistances of the resistors are different, the controller 12 can automatically select to read the outputs of the first voltage analog-to-digital converter 1441 to the third voltage analog-to-digital converter 1443 according to the device under test, thereby completing the non-delay switching.
Referring to fig. 7, in one embodiment, the over-range protection module includes 145: a thirteenth zener diode D13, a fourteenth zener diode D14, a fifteenth zener diode D15, a sixteenth zener diode D16, a seventeenth zener diode D17, and an eighteenth zener diode D18. Wherein the anode of the thirteenth zener diode D13 is connected to the output V of the switching power supply module 13 OUT . The cathode of the thirteenth zener diode D13 is connected to the anode of the fourteenth zener diode D14. The cathode of the fourteenth zener diode D14 is connected to the anode of the fifteenth zener diode D15. The cathode of the fifteenth zener diode D15 is connected to the high level V _ HO, and the anode of the eighteenth zener diode D18 is connected. The cathode of the eighteenth zener diode D18 is connected to the anode of the seventeenth zener diode D17. The cathode of the seventeenth zener diode D17 is connected to the anode of the sixteenth zener diode D16. The cathode of the sixteenth zener diode D16 is connected to the anode of the thirteenth zener diode D13. If the output is in the range of 0-100 mua, when the current is rapidly increased, the thirteenth to eighteenth voltage stabilizing diodes D13-D18 will be conducted, so as to ensure that the voltage drop across the third resistor R3 will not exceed 1.5V, and protect the instrument from being damaged.
In one embodiment, the conduction voltage drops of the thirteenth through eighteenth zener diodes D13 through D18 are all 0.5V.
Referring to fig. 3, in an embodiment, the source meter capable of fast switching the range further includes: and the display and USB interface unit 18 is used for receiving parameter state configuration information, a target current voltage value and monitoring information from the peripheral equipment.
And the auxiliary controller 19 is connected between the display and USB interface unit 18 and the controller 12, and is configured to convert an input instruction into a digital control instruction signal according to a protocol, transmit information of a representative actual voltage and current value from the controller 12 to the display and USB interface unit 18, and simultaneously solve a precision problem caused by aging and the like of devices in the instrument, so as to implement self calibration, where the controller 12 receives the digital control instruction signal from the auxiliary controller 19, analyzes and resolves a target voltage and current setting value preset by a user, and returns corresponding processing information and data to the display and USB interface unit 18 for display.
The voltage digital-to-analog converter 16 is VDAC in fig. 3, an input of the voltage digital-to-analog converter 16 is connected to the controller 12, and an output of the voltage digital-to-analog converter 16 is connected to the switching power supply module 13 through an oscillation generator, and is configured to convert a digital signal containing voltage setting value information output by the controller 12 into a corresponding analog signal.
The current digital-to-analog converter 17 is an IDAC shown in fig. 3, an input of the current digital-to-analog converter 17 is connected to the controller 12, and an output of the current digital-to-analog converter 17 is connected to the switching power supply module 13 through the oscillation generator, and is configured to convert a digital signal containing current setting value information output by the controller 12 into a corresponding analog signal.
Referring to fig. 8, the present application further provides a temperature compensation method applied to the source meter capable of switching the measurement range rapidly, including the following steps:
s1: the temperature conversion unit 112 performs temperature correction fitting and writes the obtained distribution function of the corrected current signal value or the corrected voltage signal value Z (n) to the controller 12.
S2: after the temperature sampling unit 111 obtains the sampling temperature, the sampling temperature data is transmitted to the controller 12, the controller 12 obtains the corrected current signal value or the corrected voltage signal value Z (n) according to the distribution function of the corrected current signal value or the corrected voltage signal value Z (n), and the current signal values or the voltage signal values read at different temperatures are corrected to the corresponding current signal values or voltage signal values at 23 ℃.
Wherein, S1 comprises the following steps:
s10: uniformly selecting a plurality of test temperature points T (n) in a to-be-tested full-temperature range, wherein the interval between adjacent temperature points is less than 10 ℃, standing and preserving heat for a preset time at each test temperature point T (n) until the internal and external temperatures of a source meter device are basically balanced, wherein n represents each test temperature point, n is a rational number, and the to-be-tested full-temperature range is-30 ℃ to 55 ℃.
S20: acquiring original current/voltage signals M at different test temperature points T (n) x (n) wherein M x (n) represents an original current signal value when the test temperature point temperature is n ℃ or an original voltage signal value when the test temperature point temperature is n ℃.
S30: the temperature conversion unit 112 calculates a current signal value difference or a voltage signal value difference M according to formula (1) y (n)：
M y (n)=M x (n)-M x (23) （1）。
Wherein M is x (23) The original current signal value when the temperature of the test temperature point is 23 ℃ or the original voltage signal value when the temperature of the test temperature point is 23 ℃. M y And (n) is the difference value between the original current signal value when the temperature of the test temperature point is n ℃ and the original current signal value when the temperature of the test temperature point is 23 ℃. Or M y And (n) is the difference value between the original voltage signal value when the temperature of the test temperature point is n ℃ and the original voltage signal value when the temperature of the test temperature point is 23 ℃.
S40: the temperature conversion unit 112 converts the current signal value difference M y (n) or difference M in voltage signal values y (n) fitting the test temperature point T (n) into a curve of the original current signal value or the original voltage signal value on the tested device changing along with the temperature data, wherein the curve of the original current signal value or the original voltage signal value on the tested device changing along with the temperature data satisfies a formula (2):
M y (n)=aT(n)+b1 （2）。
obtaining a distribution function of the modified current signal values or modified voltage signal values Z (n) according to the formula (2):
Z(n)=M x (23)+M y (n)=M x (23)+aT(n)+b1=aT(n)+b2 （3）。
wherein a is a fitting coefficient, b1 and b2 are constants, and the value range of the fitting coefficient a is 10 -5 -10 -3 。
S50: the temperature conversion unit 112 writes the distribution function of the corrected current signal value or the corrected voltage signal value Z (n) to the controller 12.
In one embodiment, the raw current/voltage signal M x (n) and the modified current signal value or the modified voltage signal value Z (n) are obtained by reading the display screen of the display and USB interface unit 18.
In one embodiment, the current of the source meter is used as a calibration object, and the specific implementation method is within the range of 0-1A current measurement range:
TABLE 1 original Current value data and corresponding Difference data obtained over the full temperature range to be measured
T (n): temperature (. Degree.C.) Original current value I x (n) Original current value and I x (23) Difference value of (I) y (n)
-30 1.000534 0.0005300
-20 1.000436 0.0004320
-10 1.000336 0.0003320
0 1.000236 0.0002320
10 1.000135 0.0001310
20 1.000035 0.0000310
23 1.000004 0.0000000
30 0.999945 -0.0000590
40 0.999846 -0.0001580
50 0.999743 -0.0002610
55 0.999691 -0.0003130
Firstly, selecting a plurality of test temperature points, reading an original current value before correction, and calculating the difference value between the original current value and the original current value at 23 ℃, for example, setting the environment temperature to-30 ℃ (T (-30)) corresponding to the read original current value before correction as M x (-30) =1.000534, the difference between the original current value and the original current value at 23 ℃ is M y (-30) =0.0005300, setting the ambient temperature to 20 ℃ (T (20)) corresponding to the read raw current value before correction to M x (20) =1.000035, the difference between the original current value and the original current value at 23 ℃ being M y (20) =0.0000310, and so on, and then the current signal difference data M in the above table is compared y (n) and the test temperature point T (n) are fitted into a relational expression M formed by the current value data on the tested equipment along with the change of the temperature data y (n) = -0.0001T (n) +0.000232, and this fitted curve is shown in fig. 9, whereby the distribution function Z (n) = -0.0001T (n) +1.000236 of the corrected current signal value Z (n) is obtained.
In one embodiment, the voltage of the source meter is used as a calibration object, and the specific implementation method is in the voltage range of 0-60V:
TABLE 2 raw voltage value data and corresponding difference value data obtained in the full temperature range to be measured
T (n): temperature (. Degree.C.) Original voltage value V x (n) Original current value and V x (23) Difference value V of y (n)
-30 60.0542 0.0539
-20 60.0435 0.0432
-10 60.0334 0.0331
0 60.0223 0.0220
10 60.0135 0.0132
20 60.0028 0.0025
23 60.0003 0.0000
30 59.9943 -0.0060
40 59.9831 -0.0172
50 59.9791 -0.0212
55 59.9736 -0.0267
Selecting several test temperature points, reading the original voltage value before correction, and calculating the difference between the original voltage value and the original voltage value at 23 deg.C, such as setting the ambient temperature to-30 deg.C (T (-30)) corresponding to the original voltage value before correction as M x (-30) =60.0542, the difference between the original voltage value and the original voltage value at 23 ℃ is M y (-30) =0.0539, the ambient temperature is set to 20 ℃ (T (20)) corresponding to the read original voltage value before correction is M x (20) =60.0028, the difference between the original voltage value and the original voltage value at 23 ℃ is M y (20) =0.0025, and so on, and then the voltage signal difference data M in the above table is compared y (n) and the test temperature point T (n) are fitted into a relational expression M formed by the voltage value data on the tested device along with the change of the temperature data y (n) = -0.001T (n) +0.0231, which is the fitted curve referred to in fig. 10, whereby the distribution function Z (n) = -0.001T (n) +60.0261 of the corrected voltage signal value Z (n) is obtained.
Therefore, the source meter capable of rapidly switching the measuring range and the temperature compensation method thereof can realize no switching delay, detect current/voltage in the whole process, avoid loss of detection data and reduce the temperature drift phenomenon. In addition, the source meter capable of rapidly switching the measuring range can be used for measurement in a wide temperature range from-30 ℃ to 55 ℃, meanwhile, the detection precision is improved, and the current/voltage values read at different temperatures are all corrected to the corresponding current/voltage values at 23 ℃.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

Claims (9)

1. A source meter capable of fast switching range, comprising:
a temperature correction module (11) for correcting the variation generated by the voltage/current detection in the temperature range of-30 ℃ to 55 ℃;
a controller (12) connected to the temperature correction module (11);
a switching power supply module (13) connected to the controller (12);
a current-voltage sampling and range switching module (14) which performs sampling conversion on the output current value and voltage value and performs current/voltage range switching;
an output module (15) for outputting a current and a voltage;
wherein the current-voltage sampling and range switching module (14) comprises:
a current sampling and range switching module (141) respectively connected with the controller (12), the switching power supply module (13) and the output module (15);
a current analog-to-digital converter (142), an input of the current analog-to-digital converter (142) being connected with the current sampling and range switching module (141), an output of the current analog-to-digital converter (142) being connected with the controller (12); the current analog-to-digital converter (142) specifically comprises three sub-current analog-to-digital converters connected in parallel, and the three sub-current analog-to-digital converters connected in parallel are respectively connected with the current sampling and range switching module (141) to display the current of three gears and realize current range switching;
a voltage sampling and range switching module (143) connected to the output module (15);
a voltage analog-to-digital converter (144), wherein an input of the voltage analog-to-digital converter (144) is connected with the voltage sampling and range switching module (143), and an output of the voltage analog-to-digital converter (144) is connected with the controller (12); the voltage analog-to-digital converter (144) specifically comprises three sub-voltage analog-to-digital converters connected in parallel, and the three sub-voltage analog-to-digital converters connected in parallel are respectively connected with the voltage sampling and range switching module (143) to display the voltage of three gears and realize voltage range switching;
the over-range protection module (145), the over-range protection module (145) is connected in parallel with two ends of the current sampling and range switching module (141);
wherein the temperature correction module (11) comprises:
a temperature conversion unit (112), wherein the output of the temperature conversion unit (112) is connected with the controller (12), and the temperature conversion unit (112) performs temperature correction fitting and writes a correction function into the controller (12); and
temperature sampling unit (111), the output of temperature sampling unit (111) respectively with controller (12) with the input connection of temperature conversion unit (112), temperature sampling unit (111) monitors the instrument peripheral environment temperature and samples and transmit the sampling temperature who obtains controller (12), controller (12) basis correction function realizes the temperature correction compensation to current signal value or the voltage signal value that read under the different temperatures all correct the current signal value or the voltage signal value that correspond when 23 ℃.
2. The source meter of claim 1, wherein the current sampling and range switching module (141) comprises:
a first sampling circuit (1411), a second sampling circuit (1412), and a third sampling circuit (1413);
the first sampling circuit (1411) further comprises a first resistor, a fourth resistor, a seventh resistor, a first differential operational amplifier (211), a first voltage stabilizing diode and a second voltage stabilizing diode; one end of the first resistor is connected with the output of the switching power supply module (13) and the inverting end of the first differential operational amplifier (211); the other end of the first resistor is connected with the second sampling circuit (1412) and the non-inverting end of the first differential operational amplifier (211); the fourth resistor is connected between the port 1 and the port 8 of the first differential operational amplifier (211); the output end of the first differential operational amplifier (211) is connected with one end of the seventh resistor; the other end of the seventh resistor is connected with the anode of the second voltage stabilizing diode; the cathode of the second voltage stabilizing diode is connected with the cathode of the first voltage stabilizing diode; the anode of the first voltage stabilizing diode is grounded; the current range detected by the first sampling circuit (1411) is 0-1A;
the second sampling circuit (1412) further comprises a second resistor, a fifth resistor, an eighth resistor, a tenth resistor, a first switching tube, a second differential operational amplifier (212), a third zener diode and a fourth zener diode; one end of the second resistor is connected with the first sampling circuit (1411) and the inverting end of the second differential operational amplifier (212); the other end of the second resistor is connected with the third sampling circuit (1413) and the non-inverting end of the second differential operational amplifier (212); the fifth resistor is connected between the port 1 and the port 8 of the second differential amplifier (212); the output end of the second differential operational amplifier (212) is connected with one end of the eighth resistor; the other end of the eighth resistor is connected with the anode of the fourth voltage stabilizing diode; the cathode of the fourth voltage stabilizing diode is connected with the cathode of the third voltage stabilizing diode; the anode of the third voltage stabilizing diode is grounded; the drain electrode of the first switching tube is connected to one end of the second resistor; the source electrode of the first switch tube is connected with the source electrode of the second switch tube; the drain electrode of the second switch tube is connected to the other end of the second resistor; meanwhile, one end of the tenth resistor is connected to the grids of the first switching tube and the second switching tube; the other end of the tenth resistor is connected with the controller (12); the controller (12) controls the first switch tube and the second switch tube to be turned on and off, and the current range detected by the second sampling circuit (1412) is 0-10mA;
the third sampling circuit (1413) further comprises a third resistor, a sixth resistor, a ninth resistor, an eleventh resistor, a third switching tube, a fourth switching tube, a third differential amplifier (213), a fifth voltage stabilizing diode and a sixth voltage stabilizing diode; one end of the third resistor is connected with the second sampling circuit (1412) and the inverting end of the third differential amplifier (213); the other end of the third resistor is connected with a high level and the non-inverting end of the third differential operational amplifier (213); the sixth resistor is connected between the port 1 and the port 8 of the third differential amplifier (213); the output end of the third differential operational amplifier (213) is connected with one end of the ninth resistor; the other end of the ninth resistor is connected with the anode of the sixth voltage stabilizing diode; the cathode of the sixth voltage stabilizing diode is connected with the cathode of the fifth voltage stabilizing diode; the anode of the fifth voltage stabilizing diode is grounded; the drain electrode of the third switching tube is connected to one end of the third resistor; the source electrode of the third switching tube is connected with the source electrode of the fourth switching tube; the drain electrode of the fourth switching tube is connected to the other end of the third resistor; meanwhile, one end of the eleventh resistor is connected to the grid electrodes of the third switching tube and the fourth switching tube; the other end of the eleventh resistor is connected with the controller (12); the controller (12) controls the third switching tube and the fourth switching tube to be turned on and turned off, and the current range detected by the third sampling circuit (1413) is 0-100 mu A;
the first sampling circuit (1411), the second sampling circuit (1412) and the third sampling circuit (1413) are connected end to end through the first resistor, the second resistor and the third resistor and are connected in series between the output end of the switching power supply module (13) and a high level;
the three parallel-connected sub-current analog-to-digital converters are a first current analog-to-digital converter (1421), a second current analog-to-digital converter (1422) and a third current analog-to-digital converter (1423), respectively;
wherein an output of the first sampling circuit (1411) is connected to an input of the first current analog-to-digital converter (1421); the output of the second sampling circuit (1412) is connected to the input of the second current analog-to-digital converter (1422); an output of the third sampling circuit (1413) is connected to an input of the third current analog to digital converter (1423).
3. The source meter capable of switching the measurement range rapidly according to claim 2, wherein the resistance value of the first resistor is 0.5 Ω, the resistance value of the second resistor is 50 Ω, the resistance value of the third resistor is 5k Ω, the resistance values of the seventh resistor, the eighth resistor, the ninth resistor and the tenth resistor are 1k Ω, the resistance value of the eleventh resistor is 10k Ω, the first voltage regulator diode to the sixth voltage regulator diode are all 5.1V voltage regulator tubes, and the amplification factors of the first differential amplifier to the third differential amplifier are all 10 times.
4. The source meter of claim 3, wherein the voltage sampling and range switching module (143) comprises:
a first voltage dividing circuit (1431), a second voltage dividing circuit (1432), and a third voltage dividing circuit (1433);
the first voltage division circuit (1431) further comprises a twelfth resistor, a thirteenth resistor, a seventeenth resistor, a first precision operational amplifier (214), a fourth differential operational amplifier (217), a seventh voltage stabilizing diode and an eighth voltage stabilizing diode;
one end of the twelfth resistor is connected with a low level; the other end of the twelfth resistor is connected with one end of the thirteenth resistor and is also connected with the non-inverting end of the first precision operational amplifier (214); the other end of the thirteenth resistor is connected with a high level; the output end of the first precision operational amplifier (214) is connected with the inverting end of the fourth differential operational amplifier (217); the non-phase end of the fourth differential operational amplifier (217) is connected with a high level; the output end of the fourth differential operational amplifier (217) is connected with one end of the seventeenth resistor; the other end of the seventeenth resistor is connected with an anode of the seventh voltage stabilizing diode; the cathode of the seventh voltage stabilizing diode is connected with the cathode of the eighth voltage stabilizing diode; the anode of the eighth voltage stabilizing diode is grounded; the voltage range detected by the first voltage division circuit (1431) is 0-60V voltage range;
the second voltage division circuit (1432) further comprises a fourteenth resistor, a fifteenth resistor, an eighteenth resistor, a second precision operational amplifier (215), a fifth differential operational amplifier (218), a ninth voltage regulator diode and a tenth voltage regulator diode;
one end of the fourteenth resistor is connected with a low level; the other end of the fourteenth resistor is connected with one end of a fifteenth resistor and is simultaneously connected with the non-inverting end of the second precision operational amplifier (215); the other end of the fifteenth resistor is connected with a high level; the output end of the second precision operational amplifier (215) is connected with the inverting end of the fifth differential operational amplifier (218); the non-inverting terminal of the fifth differential operational amplifier (218) is connected with a high level; the output end of the fifth differential operational amplifier (218) is connected with one end of the eighteenth resistor; the other end of the eighteenth resistor is connected with the anode of the ninth voltage stabilizing diode; the cathode of the ninth voltage stabilizing diode is connected with the cathode of the tenth voltage stabilizing diode; the anode of the tenth zener diode is grounded; the voltage range detected by the second voltage division circuit (1432) is 0-6V;
the third voltage division circuit (1433) further comprises a sixteenth resistor, a nineteenth resistor, a twentieth resistor, a third precision operational amplifier (216), a sixth differential operational amplifier (219), an eleventh voltage stabilizing diode and a twelfth voltage stabilizing diode;
one end of the sixteenth resistor is connected with a low level; the other end of the sixteenth resistor is connected with the non-inverting end of the third precision operational amplifier (216); the output end of the third precision operational amplifier (216) is connected with the inverting end of the sixth differential operational amplifier (219); the non-inverting terminal of the sixth differential operational amplifier (219) is connected with a high level; the twentieth resistor is connected between the 1 port and the 5 port of the sixth differential op-amp (219); the output end of the sixth differential operational amplifier (219) is connected with one end of the nineteenth resistor; the other end of the nineteenth resistor is connected with the anode of the eleventh voltage stabilizing diode; the cathode of the eleventh voltage stabilizing diode is connected with the cathode of the twelfth voltage stabilizing diode; the anode of the twelfth voltage stabilizing diode is grounded; the voltage range detected by the third voltage division circuit (1433) is 0-0.6V;
the three parallel-connected sub-voltage analog-to-digital converters are a first voltage analog-to-digital converter (1441), a second voltage analog-to-digital converter (1442) and a third voltage analog-to-digital converter (1443), respectively;
wherein an output of the first voltage divider circuit (1431) is connected with an input of the first voltage analog-to-digital converter (1441); the output of the second voltage divider circuit (1432) is connected to the input of the second voltage analog-to-digital converter (1442); the output of the third voltage division circuit (1433) is connected to the input of the third voltage analog to digital converter (1443).
5. The source meter capable of switching the range rapidly according to claim 4, wherein the resistance values of the twelfth resistor, the fourteenth resistor and the sixteenth resistor are all 100k Ω, the resistance value of the thirteenth resistor is 10k Ω, the resistance value of the fifteenth resistor is 200k Ω, the resistance values of the seventeenth resistor to the nineteenth resistor are all 1k Ω, and the resistance values of the seventh zener diode to the twelfth zener diode are all 5.1V stabilivolt.
6. The source meter capable of switching range quickly as set forth in claim 5, wherein said over-range protection module (145) comprises: a thirteenth zener diode, a fourteenth zener diode, a fifteenth zener diode, a sixteenth zener diode, a seventeenth zener diode, and an eighteenth zener diode;
wherein the anode of the thirteenth zener diode is connected to the output of the switching power supply module (13); the cathode of the thirteenth voltage stabilizing diode is connected with the anode of the fourteenth voltage stabilizing diode; the cathode of the fourteenth voltage stabilizing diode is connected with the anode of the fifteenth voltage stabilizing diode; the cathode of the fifteenth voltage-stabilizing diode is connected with a high level and is simultaneously connected with the anode of the eighteenth voltage-stabilizing diode; the cathode of the eighteenth voltage-stabilizing diode is connected with the anode of the seventeenth voltage-stabilizing diode; cathode connection of the seventeenth zener diode an anode of the sixteenth zener diode; and the cathode of the sixteenth voltage stabilizing diode is connected with the anode of the thirteenth voltage stabilizing diode.
7. The source meter capable of switching range rapidly as claimed in claim 6,
and the conduction voltage drop from the thirteenth voltage stabilizing diode to the eighteenth voltage stabilizing diode is 0.5V.
8. The source meter capable of switching range rapidly as claimed in claim 7, further comprising:
a display and USB interface unit (18);
an auxiliary controller (19) connected between the display and USB interface unit (18) and the controller (12);
the input of the voltage digital-to-analog converter (16) is connected with the controller (12), and the output of the voltage digital-to-analog converter (16) is connected with the switching power supply module (13) through an oscillation generator;
the input of the current digital-to-analog converter (17) is connected with the controller (12), and the output of the current digital-to-analog converter (17) is connected with the switching power supply module (13) through the oscillation generator.
9. A temperature compensation method applied to the source meter capable of fast switching range as claimed in any one of claims 1 to 8, characterized by comprising the steps of:
s1: the temperature conversion unit (112) performs temperature correction fitting and writes the obtained distribution function of the corrected current signal value or the corrected voltage signal value Z (n) into the controller (12);
s2: after the temperature sampling unit (111) acquires the sampling temperature, transmitting the data of the sampling temperature to the controller (12), acquiring the corrected current signal value or the corrected voltage signal value Z (n) by the controller (12) according to a distribution function of the corrected current signal value or the corrected voltage signal value Z (n), and correcting the current signal values or the voltage signal values read at different temperatures to the corresponding current signal values or voltage signal values at 23 ℃;
wherein, S1 includes the following steps:
s10: uniformly selecting a plurality of test temperature points T (n) in a full temperature range to be tested, wherein the interval between adjacent temperature points is less than 10 ℃, standing and preserving heat for preset time at each test temperature point T (n) until the internal and external temperatures of a source meter device are balanced, wherein n represents each test temperature point, n is a rational number, and the full temperature range to be tested is-30-55 ℃;
s20: at different test temperature points T (n), acquiring an original current/voltage signal M x (n) wherein M x (n) represents an original current signal value when the test temperature point temperature is n ℃ or an original voltage signal value when the test temperature point temperature is n ℃;
s30: the temperature conversion unit (112) calculates a current signal value difference or a voltage signal value difference M according to formula (1) y (n)：
M y (n)=M x (n)-M x (23) （1）；
Wherein M is x (23) The original current signal value when the temperature of the test temperature point is 23 ℃ or the original voltage signal value when the temperature of the test temperature point is 23 ℃; m y (n) is the difference value of the original current signal value when the temperature of the test temperature point is n ℃ and the original current signal value when the temperature of the test temperature point is 23 ℃; or M y (n) is the temperature of the test temperature point n DEG CThe difference value of the original voltage signal value and the original voltage signal value when the temperature of the test temperature point is 23 ℃;
s40: the temperature conversion unit (112) converts the current signal value difference M y (n) or difference M in voltage signal values y (n) fitting the test temperature point T (n) into a curve of the original current signal value or the original voltage signal value on the tested device changing along with the temperature data, wherein the curve of the original current signal value or the original voltage signal value on the tested device changing along with the temperature data satisfies a formula (2):
M y (n)=aT(n)+b1 （2）；
obtaining a distribution function of the modified current signal values or modified voltage signal values Z (n) according to the formula (2):
Z(n)=M x (23)+M y (n)=M x (23)+aT(n)+b1=aT(n)+b2 （3）；
wherein a is a fitting coefficient, b1 and b2 are constants, and the value range of the fitting coefficient a is 10 -5 -10 -3 ；
S50: the temperature conversion unit (112) writes the distribution function of the modified current signal values or modified voltage signal values Z (n) to the controller (12).
CN202210977775.9A 2022-08-16 2022-08-16 Source meter capable of rapidly switching measuring range and temperature compensation method thereof Active CN115060962B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210977775.9A CN115060962B (en) 2022-08-16 2022-08-16 Source meter capable of rapidly switching measuring range and temperature compensation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210977775.9A CN115060962B (en) 2022-08-16 2022-08-16 Source meter capable of rapidly switching measuring range and temperature compensation method thereof

Publications (2)

Publication Number Publication Date
CN115060962A CN115060962A (en) 2022-09-16
CN115060962B true CN115060962B (en) 2022-12-09

Family

ID=83207953

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210977775.9A Active CN115060962B (en) 2022-08-16 2022-08-16 Source meter capable of rapidly switching measuring range and temperature compensation method thereof

Country Status (1)

Country Link
CN (1) CN115060962B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116106608A (en) * 2023-02-21 2023-05-12 苏州联讯仪器股份有限公司 Test source table and test system

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6170471A (en) * 1984-08-13 1986-04-11 シイーアイ‐エル・インコーポレイテツド Method and device for measuring continuity and resistance ofwiring circuit for blasting
US5953221A (en) * 1996-10-25 1999-09-14 Klockner Moeller Gmbh Circuit breaker or contact system with a multi-range power supply unit and a multi-range power supply unit
CN107976647A (en) * 2018-01-24 2018-05-01 镇江市计量实验工厂 A kind of high-voltage high resistance calibrating instrument intelligence calibrating installation
CN208752486U (en) * 2018-09-17 2019-04-16 西安赛锐特机电测控科技有限公司 Constant current source generating circuit for fluid wall shear stress tester
CN109975616A (en) * 2018-12-29 2019-07-05 浙江机电职业技术学院 A kind of wide-range high-precision resistance meter
CN110907691A (en) * 2019-12-05 2020-03-24 中国人民解放军92942部队 Wide-range direct-current voltage measuring device based on resistance voltage division time-sharing sampling self-calibration
CN211528541U (en) * 2019-11-29 2020-09-18 珠海市运泰利自动化设备有限公司 Resistance measuring circuit of programmable constant current source
CN112816088A (en) * 2021-01-12 2021-05-18 北京微芯区块链与边缘计算研究院 Self-adaptive range switching temperature sensor
CN113067469A (en) * 2021-03-30 2021-07-02 苏州源特半导体科技有限公司 Quick response loop compensation circuit, loop compensation chip and switching power supply
CN113466523A (en) * 2021-07-27 2021-10-01 北京华峰测控技术股份有限公司 Current measuring device and method
CN113824415A (en) * 2021-11-25 2021-12-21 山东汉芯科技有限公司 Intelligent program-controlled high-gain amplifier with temperature compensation
CN114384387A (en) * 2021-12-17 2022-04-22 苏州联讯仪器有限公司 Scalable precision source meter

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6170471A (en) * 1984-08-13 1986-04-11 シイーアイ‐エル・インコーポレイテツド Method and device for measuring continuity and resistance ofwiring circuit for blasting
US5953221A (en) * 1996-10-25 1999-09-14 Klockner Moeller Gmbh Circuit breaker or contact system with a multi-range power supply unit and a multi-range power supply unit
CN107976647A (en) * 2018-01-24 2018-05-01 镇江市计量实验工厂 A kind of high-voltage high resistance calibrating instrument intelligence calibrating installation
CN208752486U (en) * 2018-09-17 2019-04-16 西安赛锐特机电测控科技有限公司 Constant current source generating circuit for fluid wall shear stress tester
CN109975616A (en) * 2018-12-29 2019-07-05 浙江机电职业技术学院 A kind of wide-range high-precision resistance meter
CN211528541U (en) * 2019-11-29 2020-09-18 珠海市运泰利自动化设备有限公司 Resistance measuring circuit of programmable constant current source
CN110907691A (en) * 2019-12-05 2020-03-24 中国人民解放军92942部队 Wide-range direct-current voltage measuring device based on resistance voltage division time-sharing sampling self-calibration
CN112816088A (en) * 2021-01-12 2021-05-18 北京微芯区块链与边缘计算研究院 Self-adaptive range switching temperature sensor
CN113067469A (en) * 2021-03-30 2021-07-02 苏州源特半导体科技有限公司 Quick response loop compensation circuit, loop compensation chip and switching power supply
CN113466523A (en) * 2021-07-27 2021-10-01 北京华峰测控技术股份有限公司 Current measuring device and method
CN113824415A (en) * 2021-11-25 2021-12-21 山东汉芯科技有限公司 Intelligent program-controlled high-gain amplifier with temperature compensation
CN114384387A (en) * 2021-12-17 2022-04-22 苏州联讯仪器有限公司 Scalable precision source meter

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
双极性电压脉冲激励的智能电导率测量仪;赵学亮等;《自动化仪表》;20110120(第01期);第76-79页 *

Also Published As

Publication number Publication date
CN115060962A (en) 2022-09-16

Similar Documents

Publication Publication Date Title
US9413174B2 (en) I-V measurement system for photovoltaic modules
US9935598B2 (en) Differential amplifier design as the preamp of DMM
Nenova et al. Linearization circuit of the thermistor connection
CN115060962B (en) Source meter capable of rapidly switching measuring range and temperature compensation method thereof
CN110161313B (en) High-precision resistance measurement system and method combining differential method and proportional method
EP2873979B1 (en) Active current sensing circuit and measurement device
CN114895231B (en) High-end voltage differential sampling calibration system and method
KR101375363B1 (en) Apparatus for measuring temperature using thermistor
CN214409627U (en) Airborne equipment parameter collector
EP2874310B1 (en) Current sensing circuit
CN102478438A (en) Thermal resistance analog calibration system for signal simulation system
CN103940533A (en) Measurement and control method for engine coolant temperature sensor, and measurement and control system thereof
CN109564139B (en) Sensor device
US20070222651A1 (en) Method and circuit for amplitude compensation in a digital-to-analog converter
CN211085507U (en) Single ADC multichannel temperature monitoring circuit controlled by GPIO
CN113514168B (en) Multi-channel temperature sensor testing device
CN108572273B (en) Low current measuring circuit and measuring method thereof
CN115453609A (en) Pt 100-based high-purity germanium detector protection system
CN203705550U (en) Thermistor tester
CN103439018A (en) Temperature difference detector and detection method
RU2397500C1 (en) Resistance-to-voltage converter
CN112698066A (en) Acquisition and measurement circuit for temperature compensation based on thermistor
CN218587165U (en) ADC correction circuit applied to wide-range current detection
CN220650862U (en) Current calibration circuit for current sense amplifier
RU2549255C1 (en) Digital temperature meter

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
GR01 Patent grant
GR01 Patent grant
CP03 Change of name, title or address

Address after: Building 5, No. 1508, Xiangjiang Road, Suzhou High-tech Zone, Suzhou City, Jiangsu Province 215129

Patentee after: Suzhou Lianxun Instrument Co.,Ltd.

Address before: 215000 Building 5, No. 1508, Xiangjiang Road, high tech Zone, Suzhou, Jiangsu

Patentee before: STELIGHT INSTRUMENT Inc.

CP03 Change of name, title or address