CN217639417U - High-precision analog measurement circuit, high-precision digitizer and automatic test equipment - Google Patents
High-precision analog measurement circuit, high-precision digitizer and automatic test equipment Download PDFInfo
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- CN217639417U CN217639417U CN202221696205.4U CN202221696205U CN217639417U CN 217639417 U CN217639417 U CN 217639417U CN 202221696205 U CN202221696205 U CN 202221696205U CN 217639417 U CN217639417 U CN 217639417U
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Abstract
The utility model provides a high accuracy analog measurement circuit, high accuracy digital instrument and automatic test equipment, include: the signal processing unit, the gain amplification circuit and the output circuit are connected in sequence; the signal processing unit is used for processing the detected signal to obtain a processed detected signal; the gain amplification circuit is used for selecting the measuring gear range and amplifying the processed measured signal according to the selected measuring gear range to obtain the amplified measured signal, the number of the measuring gear ranges is multiple, and the precision of small measuring gear ranges in the multiple measuring gear ranges is high; and the output circuit is used for carrying out output measurement on the amplified measured signal to obtain a measured value of the measured signal. The utility model discloses an among the analog measurement circuit, can realize the high accuracy measurement to little measured signal.
Description
Technical Field
The utility model belongs to the technical field of automatic test equipment's technique and specifically relates to a high accuracy analog measurement circuit, high accuracy digitizer and automatic test equipment are related to.
Background
Automatic Test Equipment (ATE) is a key Equipment for semiconductor package testing, and a Digitizer (DIG) is a hardware component in the ATE.
Currently, the measurement gear of conventional DIG is 10V, and the corresponding accuracy is + - (+ -.) (400uV +0.001% Rdg). The accuracy of the measurement gear is low, and high-accuracy measurement cannot be achieved when a small measured signal is measured.
Therefore, how to realize high-precision measurement of a small measured signal becomes a technical problem which needs to be solved urgently at present.
SUMMERY OF THE UTILITY MODEL
In view of this, the utility model aims at providing a high accuracy analog measurement circuit, high accuracy digitizer and automatic test equipment to alleviate the measuring circuit of current DIG and can't carry out high accuracy measurement's technical problem to little measured signal.
In a first aspect, an embodiment of the present invention provides a high-precision analog measurement circuit, including: the signal processing unit, the gain amplification circuit and the output circuit are connected in sequence;
the signal processing unit is used for processing the detected signal to obtain a processed detected signal;
the gain amplification circuit is used for selecting a measurement gear range and amplifying the processed measured signal according to the selected measurement gear range to obtain an amplified measured signal, wherein the number of the measurement gear ranges is multiple, and the precision of small measurement gear ranges in the multiple measurement gear ranges is high;
and the output circuit is used for carrying out output measurement on the amplified measured signal to obtain a measured value of the measured signal.
Further, the signal processing unit includes: the signal attenuation circuit and the instrument amplifier are connected in sequence;
the signal attenuation circuit is used for attenuating a detected signal with a voltage greater than a preset voltage;
and the instrument amplifier is used for differentially processing the detected signal output by the signal attenuation circuit to obtain the processed detected signal.
Further, the gain amplifying circuit includes: the device comprises an inverse proportional operational amplifier, a gain amplification proportional resistor and an analog switch selection proportional resistor;
the positive phase input end of the inverse proportion operational amplifier is grounded, the negative phase input end of the inverse proportion operational amplifier is connected with one end of the gain amplification proportion resistor, the output end of the inverse proportion operational amplifier is connected with the analog switch selection proportion resistor, and the other end of the gain amplification proportion resistor is connected with the analog switch selection proportion resistor.
Further, the gain amplifying proportional resistor comprises:
a plurality of resistors with different resistances connected with the inverting input end of the inverse proportion operational amplifier;
the analog switch selection proportional resistor comprises:
a plurality of line terminals connected to the plurality of resistors having different resistance values, respectively, and,
and the analog switch is used for connecting the line end, the inverse proportion operational amplifier and the output circuit.
Further, the method also comprises the following steps: a programmable reference source;
the programmable reference source is connected with the signal processing unit in parallel and then is connected with the inverting input end of an inverse proportion operational amplifier in the gain amplification circuit;
the programmable reference source outputs a first preset reference voltage, and the voltage obtained by adding the first preset reference voltage and the measured signal is input to the inverting input end of the inverse proportion operational amplifier, so that small measurement gear measurement is realized, and an initial measurement value is obtained.
Further, the programmable reference source comprises: and the digital-to-analog conversion circuit and the digital-to-analog conversion driving circuit are connected in sequence.
Further, the digital-to-analog conversion driving circuit is an operational amplifier.
Further, the output circuit comprises a filter, an analog-to-digital conversion driving circuit and an analog-to-digital conversion circuit which are connected in sequence.
In a second aspect, the embodiment of the present invention further provides a high-precision digitizer, including: the high-precision analog measurement circuit according to any one of the first aspect, further comprising: a controller;
the controller is connected with the analog switch in the high-precision analog measurement circuit and is used for controlling the analog switch in the gain amplification circuit in the high-precision analog measurement circuit to select the measurement range;
the controller is also connected with an analog-to-digital conversion circuit in the high-precision analog measurement circuit and is also used for calculating the actual measurement value of the measured signal based on the initial measurement value obtained by the high-precision analog measurement circuit so as to obtain the actual measurement value of the measured signal.
The third aspect, the embodiment of the utility model provides an still provide an automatic testing equipment, include: the high-precision digitizer according to the second aspect further comprises: calibrating a circuit;
the calibration circuit is used for calibrating the programmable reference source after being connected with the programmable reference source in the high-precision digitizer.
The embodiment of the utility model provides an in, provide a high accuracy analog measurement circuit, include: the signal processing unit, the gain amplification circuit and the output circuit are connected in sequence; the signal processing unit is used for processing the detected signal to obtain a processed detected signal; the gain amplification circuit is used for selecting the measuring gear range and amplifying the processed measured signal according to the selected measuring gear range to obtain the amplified measured signal, wherein the number of the measuring gear ranges is multiple, and the precision of small measuring gear ranges in the multiple measuring gear ranges is high; and the output circuit is used for carrying out output measurement on the amplified measured signal to obtain a measured value of the measured signal. According to the above description, the utility model discloses an among the high accuracy analog measurement circuit, contain a plurality of measurement gear ranges among the gain amplifier circuit, and the precision of little measurement gear range wherein is high, can realize the high accuracy measurement to little quilt survey signal, the measuring circuit who has alleviated current DIG can't carry out high accuracy measurement's technical problem to little quilt survey signal.
The utility model also provides a high accuracy digitizer, include: the high accuracy analog measurement circuit of any of the above, further comprising: a controller; the controller is connected with the analog switch in the high-precision analog measurement circuit and is used for controlling the analog switch in the gain amplification circuit in the high-precision analog measurement circuit to select the measurement range of the measurement gear; thereby realizing high-precision measurement; the controller is also connected with an analog-to-digital conversion circuit in the high-precision analog measurement circuit and is also used for calculating the actual measurement value of the measured signal based on the initial measurement value obtained by the high-precision analog measurement circuit so as to obtain the actual measurement value of the measured signal.
The utility model also provides an automatic change test equipment, include: above-mentioned high accuracy digitizer still includes: calibrating a circuit; and the calibration circuit is used for calibrating the programmable reference source after being connected with the programmable reference source in the high-precision digitizer, so that the test accuracy of the tested signal is further improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the technical solutions in the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
Fig. 1 is a schematic structural diagram of a high-precision analog measurement circuit provided by an embodiment of the present invention;
fig. 2 is a schematic structural diagram of another high-precision analog measurement circuit provided in an embodiment of the present invention;
fig. 3 is a schematic structural diagram of another high-precision analog measurement circuit provided in an embodiment of the present invention;
fig. 4 is a schematic structural diagram of another high-precision analog measurement circuit provided by an embodiment of the present invention.
An icon: 11-a signal processing unit; 12-a gain amplification circuit; 13-an output circuit; 14-a programmable reference source; 111-a signal attenuation circuit; 112-instrumentation amplifier; 121-inverse proportional operational amplifier; 122-gain amplification proportional resistance; 123-analog switch selection proportional resistance; 131-a filter; 132-analog-to-digital conversion driving circuit; 133-analog to digital conversion circuitry; 141-digital-to-analog conversion circuit; 142-digital-to-analog conversion driving circuit.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
The conventional DIG measurement circuit cannot measure small signals to be measured with high precision.
Based on this, the utility model discloses an among the high accuracy analog measurement circuit, contain a plurality of measurement gear ranges among the gain amplification circuit, and the precision of little measurement gear range wherein is high, can realize the high accuracy measurement to little measured signal.
For the convenience of understanding the present embodiment, a high-precision analog measurement circuit disclosed in the embodiments of the present invention is first described in detail.
Fig. 1 is a schematic structural diagram of a high-precision analog measurement circuit according to an embodiment of the present invention, as shown in fig. 1, including: a signal processing unit 11, a gain amplifying circuit 12 and an output circuit 13 which are connected in sequence;
the signal processing unit 11 is configured to process the measured signal to obtain a processed measured signal;
the gain amplification circuit 12 is used for selecting the measuring gear range and amplifying the processed measured signal according to the selected measuring gear range to obtain the amplified measured signal, wherein the number of the measuring gear ranges is multiple, and the precision of small measuring gear ranges in the multiple measuring gear ranges is high;
and the output circuit 13 is used for performing output measurement on the amplified measured signal to obtain a measured value of the measured signal.
In the conventional solution, the measurement gear range included in the gain amplifying circuit 12 is ± 10V, and the corresponding accuracy is ± (400uv + 0.001%. The utility model discloses a measurement gear range and precision that contain in above-mentioned gain amplification circuit 12 mainly include following several kinds: measuring gear range is +/-0.1V, and corresponding precision is +/-1 (10uV +0.001% Rdg); measurement gear range is 0.2V, corresponding accuracy is ± (20uV + 0.001%; the measurement gear range is ± 0.5V, the corresponding accuracy is ± (50uv + 0.001%; the measurement gear range is +/-1V, and the corresponding precision is +/- (+/- (100uV +0.001% Rdg); the measurement gear range is +/-2V, and the corresponding precision is +/- (+/- (200uV +0.001% Rdg); the measurement gear range is ± 5V, the corresponding accuracy is ± (300uv + 0.001%; the measurement gear range is 10V, and the corresponding precision is + -, (400uV + 0.001%.
In the analog measurement circuit, the selection of the measurement range can be realized by controlling the switch of the analog switch through the controller, and the preset range is gated through the analog switch, the filter 131 and the like.
The embodiment of the utility model provides an in, provide a high accuracy analog measurement circuit, include: a signal processing unit 11, a gain amplifying circuit 12 and an output circuit 13 which are connected in sequence; the signal processing unit 11 is configured to process the measured signal to obtain a processed measured signal; the gain amplification circuit 12 is used for selecting the measuring gear range and amplifying the processed measured signal according to the selected measuring gear range to obtain the amplified measured signal, wherein the number of the measuring gear ranges is multiple, and the precision of small measuring gear ranges in the multiple measuring gear ranges is high; and the output circuit 13 is used for performing output measurement on the amplified measured signal to obtain a measured value of the measured signal. According to the above description, the utility model discloses an among the high accuracy analog measurement circuit, contain a plurality of measurement gear ranges among the gain amplifier circuit 12, and the precision of little measurement gear range wherein is high, can realize the high accuracy measurement to little measured signal, the measuring circuit who has alleviated current DIG can't carry out high accuracy measurement's technical problem to little measured signal.
The following describes the structure of the high-precision analog measurement circuit:
in an optional embodiment of the present invention, referring to fig. 2, the signal processing unit 11 includes: a signal attenuation circuit 111 and an instrumentation amplifier 112 connected in sequence;
the input end of the signal attenuation circuit 111 is connected with the chip to be tested and is used for attenuating the signal to be tested with the voltage greater than the preset voltage;
and the instrumentation amplifier 112 is used for differentially processing the measured signal output by the signal attenuation circuit 111 to obtain a processed measured signal.
In above-mentioned analog measurement circuit, above-mentioned predetermined voltage can be 10V voltage, the embodiment of the utility model provides a do not carry out specific restriction to above-mentioned predetermined voltage.
In this embodiment, as shown in fig. 2, the signal attenuation circuit 111 includes two electrical tuning attenuation networks (ATTs), the instrumentation amplifier 112 may be a differential amplifier, one of the electrical tuning attenuation networks is connected to the non-inverting input terminal of the instrumentation amplifier 112, the other electrical tuning attenuation network is connected to the inverting input terminal of the instrumentation amplifier 112, and the output terminal of the instrumentation amplifier 112 may be connected to a resistor and then connected to the inverting input terminal of the inverse proportional operational amplifier 121 of the gain amplifier circuit 12.
In an alternative embodiment of the present invention, referring to fig. 1 and 2, the gain amplifier circuit 12 includes: an inverse proportional operational amplifier 121, a gain amplification proportional resistor 122, and an analog switch selection proportional resistor 123;
the non-inverting input terminal of the inverse proportional operational amplifier 121 is grounded, the inverting input terminal of the inverse proportional operational amplifier 121 is connected to one end of the gain amplification proportional resistor 122, the output terminal of the inverse proportional operational amplifier 121 is connected to the analog switch selection proportional resistor 123, and the other end of the gain amplification proportional resistor 122 is connected to the analog switch selection proportional resistor 123.
The gain scaling resistor 122 includes: a plurality of resistors having different resistances connected to the inverting input terminal of the inverse proportional operational amplifier 121;
the analog switch selection proportional resistor 123 includes: a plurality of line terminals connected to the plurality of resistors having different resistance values, respectively,
an analog switch for connecting the line side, the inverse proportional operational amplifier 121 and the output circuit 13.
In this embodiment, a plurality of resistors with different resistances correspond to each of the plurality of line ends one to one, two sides of each line end are respectively connected to contacts to be contacted, an output end of the inverse proportional operational amplifier 121 is connected to a stationary end of the first analog switch, a movable end of the first analog switch is selectively connected to a contact on one side of one of the line ends, a movable end of the second analog switch is connected to a contact on the other side of the line end, and a stationary end of the second analog switch is connected to the output circuit 13, so that communication among one of the plurality of line ends, the inverse proportional operational amplifier 121, and the output circuit 13 can be realized.
In addition, after one line end of the analog switch selection proportional resistor 123 is connected into the circuit through the analog switches on both sides, the resistor with the corresponding resistance value connected with the line end is also connected into the circuit, that is, the selection of the measuring range of the measuring gear is completed. Voltage at the output of the inverse proportional operational amplifier: vo = - (R2/R1) × Vi, where Vo represents the voltage at the output of the inverting proportional operational amplifier, R2 represents the resistance switched into the circuit (the resistance in the gain amplifying proportional resistor 122 in the switching circuit) through the analog switch, R1 represents the resistance between the differential amplifier and the inverting proportional operational amplifier, and Vi represents the voltage at the inverting input of the inverting proportional operational amplifier, and it can be seen that the selection of the measurement range can be achieved by adjusting the resistance value of R2 in the switching circuit.
The gain amplifying circuit 12 is connected to the output circuit 13, and the output circuit 13 performs output measurement on the amplified signal to be measured to obtain a measured value of the signal to be measured.
In an optional embodiment of the present invention, referring to fig. 3, further comprising: a programmable reference source 14;
as shown in fig. 3, the programmable reference source 14 is connected in parallel with the signal processing unit 11 and then connected to the inverting input terminal of the inverse proportional operational amplifier 121 in the gain amplifying circuit 12; the gain amplifier circuit 12 is connected to the output circuit 13.
The programmable reference source 14 outputs a first preset reference voltage, and the voltage obtained by summing the first preset reference voltage and the measured signal output by the signal processing unit 11 is input to the inverting input terminal of the inverse proportional operational amplifier 121, so as to realize the small measurement step measurement and obtain an initial measurement value.
Those skilled in the art can know that the precision of the large measurement gear range in the analog measurement circuit is not as good as that of the small measurement gear range (for example, the precision of the ± 5V measurement gear range is not as good as that of the ± 0.5V measurement gear range), and under the existing conditions, it is difficult to improve the precision of the large measurement gear range; when the voltage regulation rate and the load regulation rate of some power management chips are measured, the change of a measured signal is often very small, and may be only tens of uV, and when a large measurement gear range is directly used for measuring a large measured signal, the resolution and the precision cannot be ensured. Therefore, the programmable reference source 14 outputs the first preset reference voltage and the voltage input design after the summation of the measured signal output by the signal processing unit 11, so that the measurement of a small measurement gear is further realized, and the resolution and the precision of the measured signal are effectively improved.
In an alternative embodiment of the present invention, referring to fig. 3-4, the programmable reference source 14 includes: a digital-to-analog conversion circuit 141 and a digital-to-analog conversion drive circuit 142 connected in sequence. Specifically, the digital-to-analog conversion circuit 141 in the programmable reference source 14 is controlled to output a first preset reference voltage, and the digital-to-analog conversion driving circuit 142 is an operational amplifier.
In an alternative embodiment of the present invention, referring to fig. 4, the output circuit 13 includes a filter 131, an analog-to-digital conversion driving circuit 132, and an analog-to-digital conversion circuit 133, which are connected in sequence.
Specifically, the filter 131 may be an anti-aliasing low-pass filter 131, the filter 131 is configured to perform noise suppression processing on the amplified measured signal (or the amplified summed voltage signal) and the image aliasing signal brought by the analog-to-digital sampling to obtain a noise-suppressed measured signal (or the noise-suppressed summed voltage signal), and finally, the noise-suppressed measured signal (the noise-suppressed summed voltage signal) enters the analog-to-digital conversion circuit 133 through the analog-to-digital conversion driving circuit 132 to perform analog-to-digital conversion, so as to finally obtain a measured value (or an initial measured value) of the measured signal.
The high-precision analog measurement circuit of the utility model can integrate the programmable reference source 14 directly in the ATE resource board, and simplify the design of the DUT board of the chip to be measured; and, ATE's resource board itself has the calibration circuit, the utility model discloses a 14 accessible relays that can programme on convenient being connected to the calibration circuit (having the high accuracy universal meter), utilize ATE from the software and the calibration circuit of taking, convenient calibrates reference source 14 able to programme, has guaranteed reference source 14 able to programme's precision and reliability. Of course, the programmable reference source 14 is not limited to be integrated directly into the ATE's resource board, as long as the first predetermined reference voltage stable output can be achieved.
The embodiment of the utility model provides a high accuracy digitizer is still provided, include: the high-precision analog measurement circuit in any of the above embodiments, further comprising: a controller;
the controller is connected with the analog switch in the high-precision analog measurement circuit and is used for controlling the analog switch in the gain amplification circuit in the high-precision analog measurement circuit to select the measurement range of the measurement gear;
the controller is also connected with an analog-to-digital conversion circuit in the high-precision analog measurement circuit and is also used for calculating the actual measurement value of the measured signal based on the initial measurement value obtained by the high-precision analog measurement circuit so as to obtain the actual measurement value of the measured signal.
Specifically, if the high-precision analog measurement circuit does not include the programmable reference source 14, the processed measured signal output by the signal processing unit 11 is input to the inverting input terminal of the inverse proportional operational amplifier 121 of the gain amplification circuit 12, the controller controls the analog switch in the gain amplification circuit 12 in the high-precision analog measurement circuit to select the measurement range, after the appropriate measurement range is selected, the measured signal is amplified by the appropriate inverse proportional operational amplifier 121 of the measurement range, and then enters the filter 131, and the filter 131 further performs noise suppression processing on the amplified measured signal and the image aliasing signal brought by analog-to-digital sampling to obtain a noise-suppressed measured signal, and finally, the noise-suppressed measured signal enters the analog-to-digital conversion circuit 133 through the analog-to-digital conversion driving circuit 132 to perform analog-to-digital conversion, and finally obtains the measured value of the measured signal; if the high-precision analog measurement circuit comprises the programmable reference source 14, after the programmable reference source 14 is calibrated, the programmable reference source 14 outputs a first preset reference voltage, the voltage obtained by adding the first preset reference voltage and the measured signal output by the signal processing unit 11 is input to the inverting input end of the inverse proportional operational amplifier 121 of the gain amplification circuit 12, and the controller controls the analog switch in the gain amplification circuit 12 in the high-precision analog measurement circuit to select the measurement range of the measurement gear; specifically, the gain amplifier circuit 12 is controlled to select a small measurement range, so that the voltage obtained by adding the first preset reference voltage and the measured signal is measured at a small measurement range, and an initial measurement value is obtained (specifically, the voltage obtained by adding the first preset reference voltage and the measured signal is amplified by the inverse proportional operational amplifier 121 of the small measurement range, and then enters the filter 131, and further the added voltage signal obtained by amplifying the filter 131 and the image aliasing signal caused by analog-to-digital sampling are subjected to noise suppression processing, so as to obtain a noise-suppressed added voltage signal, and finally, the noise-suppressed added voltage signal enters the analog-to-digital conversion circuit 133 through the analog-to-digital conversion driving circuit 132 to perform analog-to-digital conversion, and finally obtain an initial measurement value), and further, the output circuit 13 sends the initial measurement value to the controller, and then the controller sums the initial measurement value and the second preset reference voltage, so as to obtain an actual measurement value of the measured signal, where the first preset reference voltage is equal to the second preset reference voltage and has an opposite sign.
The initial measurement value is measured through the small measurement gear, the measured initial measurement value is high in precision, the high-precision initial measurement value obtained through measurement is added with the second preset reference voltage, and then the actual measurement value of the measured signal is high in precision.
The embodiment of the utility model provides an automatic change test equipment is still provided, include: above-mentioned high accuracy digitizer still includes: calibrating a circuit;
the calibration circuit is used for calibrating the programmable reference source after being connected with the programmable reference source in the high-precision digitizer.
The analog measurement circuit of any of the above embodiments is disposed on a resource board of an automated test equipment, so as to further improve reliability of precision of a reference source, and finally improve test precision of a measured signal. Certainly, the measurement device is not limited to be disposed on a resource board, as long as the precision test of the signal to be measured can be achieved, for example, a precision reference source and a peripheral amplifying circuit may be built on a product test adapter board (DUT) outside the resource board of the automatic test equipment, so as to improve the measurement resolution and precision of the large signal to be measured. Compare in the precision reference source of setting up on the DUT board, the analog measurement circuit sets up the test accuracy higher on automatic test equipment's the resource board.
In order to facilitate a deeper understanding of the above structure of the present invention, the above high-precision analog measurement circuit, high-precision digitizer, and automatic test equipment of the present invention are described below by way of a specific example (only the programmable reference source 14 is used as an example for description here):
before the measurement of a large measured signal, the programmable reference source 14 may be calibrated through a calibration line (specifically, the programmable reference source 14 may be calibrated by using a software calibration algorithm), so as to ensure that the programmable reference source 14 reaches the index accuracy, and during actual measurement, the programmable reference source 14 is controlled to output a first preset reference voltage (equal to a second preset reference voltage in magnitude and opposite in sign), so as to add the first preset reference voltage and the measured signal, and the controller controls the gain amplification circuit 12 to select a small measurement range (i.e., controls the analog switch to gate the small measurement range gain amplification proportional resistor 122), so as to measure the voltage obtained by adding the first preset reference voltage and the measured signal in a small measurement range. For example, the measured signal is a voltage signal of about +4.8V, in the conventional analog measurement circuit, it is necessary to control the gain amplifier circuit 12 to select a measurement range of ± 5V, and in the analog measurement circuit of the present invention, in order to improve the measurement accuracy, the programmable reference source 14 can be controlled to output a first preset reference voltage of-4.4V, after the measured signal +4.8V and the first preset reference voltage-4.4V are summed, a voltage signal of +0.4V is obtained, so the gain amplifier circuit 12 is controlled to select a measurement range of ± 0.5V, and an initial measurement value is obtained by measurement, and then the sum of the initial measurement value and the second preset reference voltage +4.4V is used as an actual measurement value of the measured signal (i.e. in the controller, the initial measurement value plus the second preset reference voltage +4.4V is an actual measurement value of the measured signal). The process adopts the measurement of the measurement gear range of +/-0.5V on the measured signal, so that the process improves the measurement precision compared with the measurement of the measurement gear range of +/-5V on the measured signal.
According to the above description, the utility model discloses an automatic test equipment, when carrying out the measurement of little measured signal, can control high accuracy analog measurement circuit's programmable reference source 14 not output voltage signal, does not insert programmable reference source 14 in controlling high accuracy analog measurement circuit promptly, then, selects little measurement gear through the controller of high accuracy digital instrument, carries out high accuracy measurement to little measured signal at little measurement gear through high accuracy analog measurement circuit; when the large measured signal is measured, the programmable reference source 14 of the high-precision analog measurement circuit is calibrated through the calibration circuit of the automatic test equipment, the programmable reference source 14 is controlled to output a first preset reference voltage, then a small measurement gear is selected through the controller of the high-precision digitizer, the voltage obtained by adding the first preset reference voltage and the measured signal is measured through the high-precision analog measurement circuit at the small measurement gear, and an initial measurement value is obtained.
In addition, in the description of the embodiments of the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood as a specific case by those skilled in the art.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
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; although the present invention has been described in detail with reference to the foregoing embodiments, it should 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; such modifications and substitutions do not depart from the spirit and scope of the present invention.
Claims (10)
1. A high accuracy analog measurement circuit, comprising: the signal processing unit, the gain amplification circuit and the output circuit are connected in sequence;
the signal processing unit is used for processing the detected signal to obtain a processed detected signal;
the gain amplification circuit is used for selecting the measuring gear range and amplifying the processed measured signal according to the selected measuring gear range to obtain the amplified measured signal, wherein the number of the measuring gear ranges is multiple, and the precision of small measuring gear ranges in the multiple measuring gear ranges is high;
and the output circuit is used for carrying out output measurement on the amplified measured signal to obtain a measured value of the measured signal.
2. The high accuracy analog measurement circuit of claim 1, wherein the signal processing unit comprises: the signal attenuation circuit and the instrument amplifier are connected in sequence;
the signal attenuation circuit is used for attenuating a detected signal with a voltage greater than a preset voltage;
and the instrument amplifier is used for differentially processing the detected signal output by the signal attenuation circuit to obtain the processed detected signal.
3. The high accuracy analog measurement circuit of claim 1, wherein the gain amplification circuit comprises: the device comprises an inverse proportional operational amplifier, a gain amplification proportional resistor and an analog switch selection proportional resistor;
the positive phase input end of the inverse proportion operational amplifier is grounded, the negative phase input end of the inverse proportion operational amplifier is connected with one end of the gain amplification proportion resistor, the output end of the inverse proportion operational amplifier is connected with the analog switch selection proportion resistor, and the other end of the gain amplification proportion resistor is connected with the analog switch selection proportion resistor.
4. A high accuracy analog measurement circuit according to claim 3,
the gain amplification proportional resistor comprises:
a plurality of resistors with different resistances connected to the inverting input terminal of the inverse proportional operational amplifier;
the analog switch selection proportional resistor comprises:
a plurality of line terminals connected to the plurality of resistors having different resistance values, respectively,
and the analog switch is used for connecting the line end, the inverse proportion operational amplifier and the output circuit.
5. The high accuracy analog measurement circuit of any of claims 1-4, further comprising: a programmable reference source;
the programmable reference source is connected with the signal processing unit in parallel and then is connected with the inverting input end of an inverting proportional operational amplifier in the gain amplification circuit;
the programmable reference source outputs a first preset reference voltage, and the voltage obtained by adding the first preset reference voltage and the measured signal is input to the inverting input end of the inverse proportion operational amplifier, so that small measurement gear measurement is realized, and an initial measurement value is obtained.
6. The high accuracy analog measurement circuit of claim 5 wherein the programmable reference source comprises: and the digital-to-analog conversion circuit and the digital-to-analog conversion driving circuit are connected in sequence.
7. The high accuracy analog measurement circuit of claim 6 wherein the digital to analog conversion driver circuit is an operational amplifier.
8. The high-precision analog measurement circuit according to any one of claims 1 to 4, wherein the output circuit comprises a filter, an analog-to-digital conversion driving circuit and an analog-to-digital conversion circuit which are connected in sequence.
9. A high-precision digitizer, comprising: the high accuracy analog measurement circuit of any of the above claims 1-8, further comprising: a controller;
the controller is connected with the analog switch in the high-precision analog measurement circuit and is used for controlling the analog switch in the gain amplification circuit in the high-precision analog measurement circuit to select the measurement range;
the controller is also connected with an analog-to-digital conversion circuit in the high-precision analog measurement circuit and is also used for calculating the actual measurement value of the measured signal based on the initial measurement value obtained by the high-precision analog measurement circuit so as to obtain the actual measurement value of the measured signal.
10. An automated test equipment, comprising: the high precision digitizer as described in claim 9, further comprising: calibrating a circuit;
the calibration circuit is used for calibrating the programmable reference source after being connected with the programmable reference source in the high-precision digitizer.
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| CN202221696205.4U CN217639417U (en) | 2022-06-30 | 2022-06-30 | High-precision analog measurement circuit, high-precision digitizer and automatic test equipment |
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| CN202221696205.4U CN217639417U (en) | 2022-06-30 | 2022-06-30 | High-precision analog measurement circuit, high-precision digitizer and automatic test equipment |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN116909192A (en) * | 2023-07-25 | 2023-10-20 | 陕西省电子技术研究所有限公司 | Multichannel analog acquisition circuit |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN116909192A (en) * | 2023-07-25 | 2023-10-20 | 陕西省电子技术研究所有限公司 | Multichannel analog acquisition circuit |
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