TWI749978B - Multi-channel calibration method - Google Patents

Abstract

The invention discloses a multi-channel calibration method comprising the following steps. A first and a second reference module are connected to two ends of a standard component respectively. The first reference module measures the voltage across the standard component, and the second reference module measures the current of the standard component to calculate a reference impedance value. The first reference module measures the voltage across the standard component, and a first test module measures the current of the standard component to calculate a first impedance value. According to the reference and the first impedance values, a first current correction coefficient is calculated. The first test module measures the voltage across the standard component, and the second reference module measures the current of the standard component to calculate a second impedance value. According to the reference and the second impedance values, a first voltage correction coefficient is calculated.

Description

Multi-channel calibration method

The present invention relates to a calibration method, in particular to a multi-channel calibration method.

In order to cope with the trend that the device under test has multiple pins and more and more complex functions, testing devices have gradually adopted a multi-channel measurement architecture with greater flexibility. For example, in order to support the high parallel test function, the test device can adopt any pin measurement structure. That is to say, no matter how the device under test is connected to the pins of the test device, the test device can obtain the voltage, current, or other electrical parameters of the electronic component through different internal test modules (test channels). In this way, the flexible multi-channel measurement architecture can increase the user's operating convenience and improve the competitiveness of the product.

However, in a multi-channel measurement architecture, each test module may have measurement errors due to internal component deviation, aging, or environmental factors (such as temperature and humidity). Therefore, the test device needs to calibrate the test module before it is possible to measure more accurate and reliable data. In practice, under the aforementioned measurement framework of any pin, since the test device can choose two test modules to be used together, these test modules usually produce a large number of permutations and combinations, which makes the calibration process very time-consuming. For example, if the test device has five test modules, since two of the five test modules can be arbitrarily selected for use, there will be a total of 20 test module permutations and combinations of ₅ P _2. Traditionally, since every arrangement and combination of test modules needs to be calibrated, once the total number of test modules is larger, the time spent in calibration will increase significantly. Therefore, the industry needs a new multi-channel calibration method to reduce the calibration time of the test module under any pin measurement framework.

The present invention provides a multi-channel calibration method, which can be used to calibrate a plurality of test modules, so as to reduce the calibration time of the test modules under any pin measurement structure.

The present invention provides a multi-channel calibration method, which includes the following steps. Connect the first reference module and the second reference module to the two ends of the standard component respectively. The first reference module measures the voltage across the standard component, and the second reference module measures the current flowing through the standard component to calculate the reference impedance value associated with the standard component. Replace the second reference module with the first test module. The first reference module measures the voltage across the standard element, and the first test module measures the current flowing through the standard element, and calculates the correlation with the standard The first impedance value of the component. According to the reference impedance value and the first impedance value, a first current correction coefficient associated with the first test module is calculated. Replace the first reference module with the first test module. The first test module measures the voltage across the standard component, and the second reference module measures the current flowing through the standard component, and calculates the correlation with the standard The second impedance value of the component. According to the reference impedance value and the second impedance value, a first voltage correction coefficient associated with the first test module is calculated.

In some embodiments, the first voltage correction coefficient and the first current correction coefficient can be stored in the first test module. The multi-channel correction method can calculate the reference correction coefficient based on the reference impedance value and the standard impedance value associated with the standard component. Moreover, the multi-channel calibration method may further include the following steps. The first test module and the second test module are respectively connected to the two ends of the component to be tested. The first test module measures the cross-voltage of the device under test, and the second test module measures the current flowing through the device under test to calculate the first impedance value to be tested related to the device under test. According to the first impedance value under test, the first voltage correction coefficient, the second current correction coefficient and the reference correction coefficient, the true impedance value associated with the component under test is calculated. And, respectively connect the second test module and the second reference module to the two ends of the standard component. The second test module measures the cross voltage of the standard element, and the second reference module measures the current flowing through the standard element, so as to calculate the third impedance value associated with the standard element. According to the reference impedance value and the third impedance value, a second current correction coefficient associated with the second test module is calculated.

In some embodiments, the multi-channel calibration method may further include the following steps. The first test module and the second test module are respectively connected to the two ends of the component to be tested. The second test module measures the cross-voltage of the device under test, and the first test module measures the current flowing through the device under test, so as to calculate the second impedance value to be tested associated with the device under test. According to the second impedance value to be measured, the first current correction coefficient, the second voltage correction coefficient and the reference correction coefficient, the true impedance value associated with the component to be tested is calculated. And, respectively connect the second reference module and the second test module to the two ends of the standard component. The second reference module measures the voltage across the standard element, and the second test module measures the current flowing through the standard element, so as to calculate the fourth impedance value associated with the standard element. According to the reference impedance value and the fourth impedance value, a second voltage correction coefficient associated with the second test module is calculated.

In summary, the multi-channel calibration method provided by the present invention can be used to calibrate multiple test modules. Among them, the present invention first uses two of the test modules as reference modules, and then measures the errors of other test modules relative to the reference module, thereby reducing the calibration time of the test modules under the measurement framework of any pin.

The features, objectives and functions of the present invention will be further disclosed below. However, the following are only examples of the present invention, and should not be used to limit the scope of the present invention, that is, all equivalent changes and modifications made in accordance with the scope of the patent application of the present invention will still be the essence of the present invention. Without departing from the spirit and scope of the present invention, it should be regarded as a further implementation aspect of the present invention.

Please refer to FIG. 1. FIG. 1 is a schematic circuit diagram of a testing device according to an embodiment of the present invention. As shown in Figure 1, the multi-channel calibration method of the present invention can be applied to a test device with multiple test modules (or called test channels). The test device can be a measurement architecture using any pins, and any two tests The modules can be the same. First, in this embodiment, two test modules are selected from a plurality of test modules, and one of the test modules is defined as the first reference module 10 and the other test module is the second reference module 12. For example, the first reference module 10 and the second reference module 12 may be the first and second test modules, respectively, although the embodiment is not limited thereto. In addition, the first reference module 10 and the second reference module 12 are respectively connected to two ends of a standard component 20. For example, the first reference module 10 is connected to the first end 200 of the standard component 20, and the second reference module 12 is The second end 202 of the standard component 20 is connected.

The first reference module 10 and the second reference module 12 can be used to measure component characteristics such as voltage, current, and impedance of the same standard component 20. This embodiment does not particularly limit the hardware components corresponding to the first reference module 10 and the second reference module 12, for example, the first reference module 10 and the second reference module 12 may be two independent test cards. And the first reference module 10 and the second reference module 12 can be set in the same testing device (not shown). Alternatively, the first reference module 10 and the second reference module 12 may each be an independent device, and are electrically connected to the same standard component 20 respectively. In addition, this embodiment does not limit the types of the standard components 20. As long as the standard components 20 need to use the first reference module 10 and the second reference module 12 to measure the characteristics of the components such as voltage, current, and impedance, they all belong to the present invention. The scope of the standard component 20 referred to in the embodiment. The internal components of the first reference module 10 and the second reference module 12 are respectively described below.

The first reference module 10 may include a voltage sensing unit 100, a current sensing unit 102, and a measurement circuit 104. The voltage sensing unit 100 and the current sensing unit 102 may be electrically connected to the first terminal 200 of the standard element 20, In addition, the measurement circuit 104 can be electrically connected to the voltage sensing unit 100 and the current sensing unit 102. Here, although the example in FIG. 1 shows that the first reference module 10 includes a power supply 106 and the power supply 106 is also electrically connected to the first end 200 of the standard component 20, the power supply 106 is not a necessary component in practice. For example, the power supply 106 may also be provided outside the first reference module 10, for example, it may be an external power supply. In other words, as long as the power supply 106 can supply power to the standard component 20 from the first terminal 200, it conforms to the scope of the power supply 106 in this embodiment.

Similarly, the second reference module 12 may include a voltage sensing unit 120, a current sensing unit 122, and a measurement circuit 124. The voltage sensing unit 120 and the current sensing unit 122 may be electrically connected to the second part of the standard component 20. The terminal 202 and the measurement circuit 124 can be electrically connected to the voltage sensing unit 120 and the current sensing unit 122. Like the power supply 106, the power supply 126 can also be provided outside the second reference module 12, for example, it can also be an external power supply. For the convenience of description, this embodiment assumes that the first reference module 10 and the second reference module 12 include a power supply 106 and a power supply 126. In addition, although FIG. 1 uses two signal input and output terminals as an example, it is not used to limit the number of signal input and output terminals of the standard component 20. In practice, the standard component 20 may also include more signal input and output terminals, and the first terminal 200 and the second terminal 202 may only be two of the signal input and output terminals.

Take a practical example, the power supply 106 of the first reference module 10 can supply power to the first end 200 of the standard component 20, the first reference module 10 measures the voltage across the standard component 20, and the second reference module Group 12 measures the current of the standard component 20. In detail, the voltage sensing unit 100 in the first reference module 10 can be used to measure the cross voltage of the standard element 20, and transmit data corresponding to the cross voltage of the standard element 20 to the measuring circuit 104, and the measuring circuit 104 104 is converted to obtain the first voltage value. In addition, the current sensing unit 122 in the second reference module 12 is used to measure the current flowing through the standard component 20, and send data corresponding to the current flowing through the standard component 20 to the measuring circuit 124, and the measuring circuit 124 converts to obtain the first current value. In an example, the common ground terminal (not shown) of the first reference module 10 and the second reference module 12 can be connected together, so that the voltage sensing unit 100 can obtain the standard through the first terminal 200 and the common ground terminal. The voltage across the element 20. In addition, the current sensing unit 122 can measure the current flowing through the standard element 20 in a resistance series connection or current coupling manner. Since there are many methods for measuring current, this embodiment is not particularly limited.

In order to simplify the test conditions, the power supply 106 and the power supply 126 can be set to not work at the same time, that is, the power supply 126 can be turned off when the power supply 106 is working. At this time, if the first voltage value converted by the measuring circuit 104 is expressed as V ₁₂ , and the first current value converted by the measuring circuit 124 is expressed as I ₁₂ , the reference impedance value Z _{12 of} the standard component 20 can be expressed as It is the following formula (1): Z ₁₂ = V ₁₂ / I ₁₂ (1)

In an example, the reference impedance value Z ₁₂ can be calculated by the processor of the test device or an external computer, and this embodiment is not limited herein. In addition, since the first voltage value V ₁₂ is obtained through the measurement circuit 104 and also includes the error of the measurement circuit 104 itself, the first voltage value V ₁₂ is not the actual cross voltage of the standard component 20. Similarly, since the first current value I ₁₂ is also obtained through the measuring circuit 124, it also includes the error of the measuring circuit 124 itself, so the first current value I ₁₂ is not actually the current flowing through the standard component 20. However, this embodiment does not care about _{the error between the first voltage value V 12} and the first current value I ₁₂ , and the reason will be explained later. In addition, since the standard element 20 is a calibrated element, the standard element 20 should have a known impedance value, which is referred to herein as the standard impedance value Z _{std of the} standard element 20 in this embodiment. In other words, because of temperature differences, humidity differences, aging differences, internal component errors, etc. between different circuits, the reference impedance value Z ₁₂ may actually not be equal to the standard impedance value Z _{std of the} standard component 20. Here, the relational expression between the reference impedance value Z ₁₂ and the standard impedance value Z _std can be expressed by the following formula (2): Z _std = Z ₁₂ × K ₁₂ (2)

K ₁₂ is the reference correction coefficient between the reference _{impedance value Z 12} and the standard impedance value Z _std obtained when the first reference module 10 is used to measure the voltage and the second reference module 12 is used to measure the current. Those with ordinary knowledge in the relevant technology can understand that if the first reference module 10 is used to measure current and the second reference module 12 is used to measure voltage, the obtained reference impedance value may be different from the reference impedance value. Z ₁₂ , so the reference correction coefficient may also be different from the reference correction coefficient K ₁₂ .

Next, the multi-channel calibration method of this embodiment will calibrate all test modules one after another. It is worth noting that all test modules are calibrated in sequence rather than at the same time. Please refer to FIG. 1 and FIG. 2A together. FIG. 2A is a schematic circuit diagram of calibrating a test module according to the circuit of FIG. 1. As shown in the figure, the aforementioned second reference module 12 is first replaced with the first test module 30, that is, the first reference module 10 is connected to the first end 200 of the standard component 20, and the first test module 30 is connected to the standard The second end 202 of the element 20. The first test module 30 may be m test modules arranged in number. As mentioned above, since each test module can be the same, the internal components of the first test module 30 will not be repeated in this embodiment. When calibrating the first test module 30, the first reference module 10 can measure the voltage across the standard element 20, and the first test module 30 can measure the current flowing through the standard element 20. As mentioned above, in this embodiment, the voltage value measured by the first reference module 10 is expressed as V _1m , and the current value measured by the first test module 30 is expressed as I _1m , then the value of the standard component 20 can be calculated An impedance value (first impedance value) Z _1m can be expressed as the following formula (3): Z _1m = V _1m / I _1m (3)

Furthermore, since the voltage value V _1m and the voltage value V ₁₂ measured by the first reference module 10 should be the same, this embodiment can also continue to derive the correlation from the above equations (1) and (3) _{The first current correction coefficient K Im} in the first test module 30 is as follows: (4), (5) and (6): Z ₁₂ × I ₁₂ = V ₁₂ = V _1m = Z _1m × I _1m (4) I ₁₂ = I _1m × K _Im (5) K _Im = Z _1m / Z ₁₂ (6)

The first current correction coefficient K _Im is the error between the first test module 30 and the second reference module 12 when measuring current. In other words, if the current measured by the first test module 30 is corrected by the first current correction coefficient K _Im , it should be equal to the current measured by the second reference module 12. And as can be seen from the above formula (6), the first current correction coefficient K _Im can be calculated from the reference impedance value Z ₁₂ and the first impedance value Z _1m that have been obtained.

Similarly, this embodiment will replace the aforementioned first reference module 10 with the first test module 30, that is, the first test module 30 is connected to the first end 200 of the standard component 20, and the second reference module 12 is connected to The second end 202 of the standard element 20. Then, when calibrating the first test module 30, the first test module 30 can measure the voltage across the standard element 20, and the second reference module 12 can measure the current flowing through the standard element 20. In this embodiment, the voltage value measured by the first test module 30 is expressed as V _m2 , and the current value measured by the second reference module 12 is expressed as I _m2 , and then another value about the standard component 20 can be calculated The impedance value (second impedance value) Z _m2 can be expressed as the following formula (7): Z _m2 = V _m2 / I _m2 (7)

Furthermore, since the current value I _m2 and the current value I ₁₂ are measured by the second reference module 12, in this embodiment, the above formula (1) and formula (7) can be used to continue to derive the correlation with the first The first voltage correction coefficient K _{Vm of} a test module 30, such as the following formula (8), formula (9) and formula (10): V ₁₂ / Z ₁₂ = I ₁₂ = I _m2 = V _m2 / Z _m2 (8 ) V ₁₂ = V _m2 × K _Vm (9) K _Vm = Z ₁₂ / Z _m2 (10)

The first voltage correction coefficient K _Vm is the error between the first test module 30 and the first reference module 10 when measuring the voltage. In other words, if the voltage measured by the first test module 30 is corrected by the first voltage correction coefficient K _Vm , it should be equal to the voltage measured by the first reference module 10. And as can be seen from the above formula (10), the first voltage correction coefficient K _Vm can be calculated from the reference impedance value Z ₁₂ and the second impedance value Z _m2 that have been obtained.

In order to explain that after the multi-channel calibration method of the present invention, all the test modules can correctly measure the component under test with unknown impedance value. This embodiment demonstrates the calibration of a group of test modules. Please refer to FIG. 2A and FIG. 2B together. FIG. 2B is a schematic circuit diagram of calibrating another test module according to the circuit of FIG. 1. As shown in the figure, the aforementioned second reference module 12 is first replaced with a second test module 32, that is, the first reference module 10 is connected to the first end 200 of the standard component 20, and the second test module 32 is connected to the standard The second end 202 of the element 20. The second test module 32 may be arranged in n test modules. At this time, the same thing as the aforementioned calibrating the first test module 30 is that the second current calibration coefficient K _In can also be calculated in this embodiment. Similarly, the second current correction coefficient K _In indicates that if the current measured by the second test module 32 is corrected with the second current correction coefficient K _In , it should be equal to the current measured by the second reference module 12 .

Then, replace the aforementioned first reference module 10 with the second test module 32, that is, the second test module 32 is connected to the first end 200 of the standard component 20, and the second reference module 12 is connected to the standard component 20. The second end 202. Next, the same as the aforementioned calibrating the first test module 30 is that the second voltage calibration coefficient K _Vn can also be calculated in this embodiment. Similarly, the second voltage correction coefficient K _Vn indicates that if the voltage measured by the second test module 32 is corrected by the second voltage correction coefficient K _Vn , it should be equal to the voltage measured by the first reference module 10 . It can be expressed as the following formula (11) and formula (12): I ₁₂ =I _1n × K _In (11) V ₁₂ =V _n2 × K _Vn (12)

The derivation process of equation (11) and equation (12) is as described in equation (5) and equation (9), and will not be repeated here in this embodiment. It is worth mentioning that the first test module 30 can store its own first current correction coefficient K _Im and first voltage correction coefficient K _Vm , and the second test module 32 can store its own second current correction coefficient K _In and The second voltage correction coefficient K _Vn . In addition, after calibrating the first test module 30 and the second test module 32, the first test module 30 and the second test module 32 can be used to measure the component under test of unknown impedance.

Please refer to FIG. 3. FIG. 3 is a schematic diagram of a circuit for measuring the device under test using two test modules according to an embodiment of the present invention. As shown in FIG. 3, the first test module 30 and the second test module 32 may be connected to the component under test 40 in two ways, one of which is that the first test module 30 is connected to the first end 400 of the component under test 40. , The second test module 32 is connected to the second end 402 of the component under test 40. The other is that the second test module 32 is connected to the first end 400 of the component under test 40, and the first test module 30 is connected to the second end 402 of the component under test 40. In this embodiment, the first test module 30 is connected to the first end 400 of the device under test 40, and the second test module 32 is connected to the second end 402 of the device under test 40 as an example.

First, the first test module 30 measures the voltage across the device under test 40, and the second test module 32 measures the current flowing through the device under test 40. In this embodiment, the voltage value measured by the first test module 30 is expressed as V _mn , and the current value measured by the second test module 32 is expressed as I _mn , then an impedance of the component under test 40 can be calculated The value (the first impedance value to be measured) Z _mn can be expressed as the following formula (13): Z _mn = V _mn / I _mn (13)

Since the first impedance value Z _{mn under} test includes the error value of the first test module 30 and the second test module 32, it is not necessarily the true impedance value of the component under test 40. Accordingly, in order to obtain the true impedance value of the component under test 40, the present embodiment _{first corrects the voltage value V mn} measured by the first test module 30 with the first voltage correction coefficient K _Vm . Next, in this embodiment, the current value I _mn measured by the second test module 32 is corrected by the second voltage correction coefficient K _In . Accordingly, assuming that the real impedance value of the component under test 40 is Z _dut , the real impedance value Z _dut can be expressed as the following formula (14): Z _dut = (V _mn × K _Vm ) / (I _mn × K _In ) × K ₁₂ (14)

The product of the aforementioned voltage value V _mn and the first voltage correction coefficient K _Vm means that the first test module 30 measures the voltage of the device under test 40 and converts it into the voltage value that the first reference module 10 should read. The product of the above-mentioned current value I _mn and the second voltage correction coefficient K _In means that the second test module 32 measures the current of the device under test 40 and converts it into the current value that the second reference module 12 should read. In addition, the above formula (14) also has a reference correction coefficient K ₁₂ , because the measurement results of the first reference module 10 and the second reference module 12 still have an error _{with the real impedance value Z dut.} As in the meaning of equation (2), the measured impedance values of the first reference module 10 and the second reference module 12 can be corrected by the reference correction coefficient K ₁₂ to eliminate the first reference module 10 and the second reference module 12 The measurement error.

Similarly, the second test module 32 can also be connected to the first end 400 of the component under test 40, and the first test module 30 can be connected to the second end 402 of the component under test 40. In this example, the second test module 32 measures the voltage across the device under test 40, and the first test module 30 measures the current flowing through the device under test 40. In this embodiment, the voltage value measured by the second test module 32 is expressed as V _nm , and the current value measured by the first test module 30 is expressed as I _nm , then an impedance of the component under test 40 can be calculated The value (the second impedance value to be measured) Z _nm can be expressed as the following formula (15): Z _nm = V _nm / I _nm (15)

As mentioned above, since the second impedance value Z _{nm under} test also includes the error value of the first test module 30 and the second test module 32, it is not necessarily the true impedance value of the device under test 40. Accordingly, in order to obtain the real impedance value of the component under test 40, this embodiment also _{corrects the voltage value V nm} measured by the second test module 32 with the second voltage correction coefficient K _Vn . Next, in this embodiment, the current value I _nm measured by the first test module 30 is corrected with the first voltage correction coefficient K _Im . Accordingly, assuming that the true impedance value of the component under test 40 is also Z _dut , the true impedance value Z _dut can be expressed as the following formula (16): Z _dut = (V _nm × K _Vn ) / (I _nm × K _Im ) × K ₁₂ (16)

The product of the aforementioned voltage value V _nm and the second voltage correction coefficient K _Vn means that the second test module 32 measures the voltage of the device under test 40 and converts it into the voltage value that the first reference module 10 should read. The product of the aforementioned current value I _nm and the first voltage correction coefficient K _Im means that the first test module 30 measures the current of the device under test 40 and converts it into the current value that the second reference module 12 should read. It is worth noting that even though the first test module 30 and the second test module 32 are reversely connected in this example, as long as different voltage correction coefficients and voltage correction coefficients are selected, they can still be converted into the first reference module 10 should read The voltage value and the current value that the second reference module 12 should read. Accordingly, the above formula (16) will be multiplied by the same reference correction coefficient K ₁₂ to eliminate the measurement error of the first reference module 10 and the second reference module 12 itself.

Taking a practical example, suppose that the test device has 100 test modules (test channels). Since 2 of the 100 test modules can be arbitrarily selected to measure the component under test, they have common knowledge in the technical field. One can understand that all permutations and combinations of test modules need to be calibrated in advance. Here, all the test module permutations and combinations will have ₁₀₀ P _{2 and} a total of 9900 possibilities, that is, 9900 calibrations have to be completed theoretically. It can be seen that it will be time-consuming to calibrate all the test module permutations and combinations. In contrast, the present invention first selects two test modules as the first reference module and the second reference module. The first reference module and the second reference module only need to measure the standard components once to obtain the reference correction coefficient. Next, the present invention will calibrate the remaining 98 test modules one by one. Since each test module needs to replace the first reference module once and the second reference module once, there should be 196 combinations. It can be seen from the above that, plus the first measurement of the standard component by the first reference module and the second reference module, this embodiment only needs to complete 197 calibrations without exhausting all permutations and combinations. Different from the traditional multi-channel calibration method, the multi-channel calibration method of the present invention is obviously more time-saving and simple.

In order to explain the multi-channel calibration method of the present invention, please refer to FIGS. 1 to 4 together. FIG. 4 is a flowchart of the steps of the multi-channel calibration method according to an embodiment of the present invention. As shown in the figure, in step S50, the present embodiment connects the first reference module 10 and the second reference module 12 to the two ends of the standard component 20 respectively. In step S51, the first reference module 10 measures the voltage across the standard element 20, and the second reference module 12 measures the current flowing through the standard element 20 to calculate the reference impedance associated with the standard element 20 The value Z ₁₂ . In step S52, the second reference module 12 is replaced with the first test module 30, the first reference module 10 measures the voltage across the standard element 20, and the first test module 30 measures the flow through the standard Based on the current of the element 20, the first impedance value Z _1m associated with the standard element 20 is calculated. _{In step S53, the first current correction coefficient K Im} associated with the first test module 30 is calculated according to the reference impedance value Z ₁₂ and the first impedance value Z _1m , as shown in the aforementioned formula (6). In step S54, the first reference module 10 is replaced with the first test module 30, the first test module 30 measures the voltage across the standard element 20, and the second reference module 12 measures the flow through the standard According to the current of the element 20, the second impedance value Z _m2 associated with the standard element 20 is calculated. According to the reference impedance value Z ₁₂ and the second impedance value Z _{m2 , the first voltage correction coefficient K Vm} associated with the first test module 30 is calculated, as described in the aforementioned formula (10). The rest of the details of the multi-channel calibration method described in this embodiment have been described in the previous embodiment, so it will not be repeated here.

In summary, the multi-channel calibration method provided by the present invention can be used to calibrate multiple test modules. Among them, the present invention first uses two of the test modules as reference modules, and then measures the errors of other test modules relative to the reference module, thereby reducing the calibration time of the test modules under the measurement framework of any pin.

10: The first reference module 100: Voltage sensing unit 102: current sensing unit 104: Measuring circuit 106: Power 12: The second reference module 120: Voltage sensing unit 122: current sensing unit 124: measurement circuit 126: Power 20: Standard components 200: first end 202: second end 30: The first test module 32: The second test module 40: component under test 400: first end 402: second end S51~S55: Step flow

FIG. 1 is a schematic circuit diagram of a testing device according to an embodiment of the present invention.

FIG. 2A is a schematic diagram of a circuit for calibrating a test module according to the circuit of FIG. 1.

FIG. 2B is a schematic diagram of a circuit for calibrating another test module according to the circuit of FIG. 1.

FIG. 3 is a schematic diagram of a circuit for measuring the device under test using two test modules according to an embodiment of the present invention.

FIG. 4 is a flowchart of the steps of a multi-channel calibration method according to an embodiment of the present invention.

none

S50~S55: Step flow

Claims (7)

A multi-channel calibration method, including: Respectively connect a first reference module and a second reference module to both ends of a standard component; A first reference module measures the voltage across the standard element, and a second reference module measures the current flowing through the standard element, so as to calculate a reference impedance value associated with the standard element; Replacing the second reference module with a first test module, the first reference module measures the voltage across the standard component, and the first test module measures the current flowing through the standard component, According to which a first impedance value associated with the standard component is calculated; Calculating a first current correction coefficient associated with the first test module according to the reference impedance value and the first impedance value; Replacing the first reference module with the first test module, the first test module measures the voltage across the standard component, and the second reference module measures the current flowing through the standard component, According to which a second impedance value associated with the standard component is calculated; and According to the reference impedance value and the second impedance value, a first voltage correction coefficient associated with the first test module is calculated. The multi-channel calibration method according to claim 1, wherein the first voltage calibration coefficient and the first current calibration coefficient are stored in the first test module. The multi-channel calibration method described in claim 2 further includes: According to the reference impedance value and a standard impedance value associated with the standard component, a reference correction coefficient is calculated. The multi-channel calibration method described in claim 3 further includes: Respectively connect the first test module and a second test module to two ends of a component under test; The first test module measures the voltage across the device under test, and the second test module measures the current flowing through the device under test to calculate a first test module associated with the device under test. Measure the impedance value; and According to the first impedance value to be measured, the first voltage correction coefficient, a second current correction coefficient, and the reference correction coefficient, a true impedance value associated with the device under test is calculated. The multi-channel calibration method described in claim 4 further includes: Respectively connect the second test module and the second reference module to both ends of the standard component; The second test module measures the voltage across the standard element, and the second reference module measures the current flowing through the standard element, so as to calculate a third impedance value associated with the standard element; According to the reference impedance value and the third impedance value, the second current correction coefficient associated with the second test module is calculated. The multi-channel calibration method described in claim 3 further includes: Respectively connect the first test module and a second test module to two ends of a component under test; The second test module measures the voltage across the device under test, and the first test module measures the current flowing through the device under test to calculate a second test module associated with the device under test. Measure the impedance value; and According to the second impedance value to be measured, the first current correction coefficient, a second voltage correction coefficient, and the reference correction coefficient, a true impedance value associated with the device under test is calculated. The multi-channel calibration method described in claim 6, further including: Respectively connect the second reference module and the second test module to both ends of the standard component; The second reference module measures the voltage across the standard element, and the second test module measures the current flowing through the standard element, so as to calculate a fourth impedance value associated with the standard element; According to the reference impedance value and the fourth impedance value, the second voltage correction coefficient associated with the second test module is calculated.

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