Measurement system of transient voltage suppressor diode

Abstract

The embodiment of the utility model provides a measurement system of a transient voltage suppressor (TVS), belongs to the technical field of electronics, and aims to solve the problem of large measurement error of the breakdown voltage VBR of the TVS so as to improve the accuracy of measuring the breakdown voltage VBR of the TVS. The system comprises a control unit; the current measuring unit, the first resistor and the transient voltage suppression diode are connected in series to form a series structure; the current excitation measurement unit is connected in series with the series structure; the first voltage measuring unit is connected with the series structure in parallel; wherein the control unit is used for controlling the current excitation measurement unit, the first voltage measurement unit and the current measurement unit to measure the transient voltage suppression diode.

Description

TECHNICAL FIELD

[0001] The embodiments of the present application belong to the technical field of electronics, and particularly relate to a measurement system of a transient voltage suppression diode. BACKGROUND

[0002] The impedance of a transient voltage suppression (TVS) diode when not broken down can reach more than 100 megaohms, and decreases as the absolute value of the input current increases. During the changing process of the impedance of the TVS tube, since the built-in impedance of the measuring device cannot match all changes of the impedance of the TVS tube, the breakdown voltage VBR of the TVS tube obtained by the test has a large error. For example, a current source can be controlled to set a current of 1 mA and directly input to the TVS tube, and a voltmeter in parallel with the TVS tube is used to measure the voltage across the TVS tube to obtain the breakdown voltage VBR. Although the impedance of the voltmeter in parallel with the TVS tube is large, when the impedance of the TVS is also large, the voltmeter in parallel with the TVS tube will have a significant shunt phenomenon, resulting in a large difference between the current output by the current source and the current flowing through the TVS tube, thereby causing the measured breakdown voltage VBR to be inaccurate, and the accuracy level of the measurement error cannot be confirmed. CONTENT OF THE UTILITY MODEL

[0003] The embodiments of the present application provide a measurement system of a transient voltage suppression diode, which can solve the problem of a large measurement error of the breakdown voltage VBR of the TVS tube, so as to improve the accuracy of measuring the breakdown voltage VBR of the TVS tube.

[0004] To achieve the above object, the embodiments of the present application adopt the following technical solutions:

[0005] In a first aspect, a measurement system of a transient voltage suppression diode is provided. The system comprises:

[0006] a control unit;

[0007] a current measurement unit and a first resistor, the current measurement unit, the first resistor and the transient voltage suppression diode being connected in series to form a series structure;

[0008] a current excitation measurement unit connected in series with the series structure;

[0009] a first voltage measurement unit connected in parallel with the series structure;

[0010] The control unit is configured to control the current excitation measurement unit, the first voltage measurement unit and the current measurement unit to measure the transient voltage suppression diode.

[0011] The control unit is specifically configured to:

[0012] The control current excitation measurement unit provides a first current to the series structure and measures the first current;

[0013] The control first voltage measurement unit measures a first voltage across the second series structure;

[0014] The control current measurement unit measures a second current flowing through the transient voltage suppression diode; and

[0015] The first current, the second current, and the first voltage are used to determine whether the transient voltage suppression diode is broken down.

[0016] Optionally, the breakdown condition of the transient voltage suppression diode comprises that a deviation between the first current and the second current is greater than or equal to a current deviation threshold.

[0017] In one possible design, the current measurement unit comprises:

[0018] a second resistor, the second resistor being in series with the transient voltage suppression diode and the first resistor; and

[0019] a second voltage measurement unit, the second voltage measurement unit being in parallel with the second resistor, the second voltage measurement unit being configured to measure a second voltage across the second resistor;

[0020] The second current is a current flowing through the second resistor.

[0021] Optionally, the breakdown condition further comprises that a deviation between a product of the second resistor and the first current and the second voltage is greater than or equal to a voltage deviation threshold.

[0022] Correspondingly, the reverse breakdown voltage of the transient voltage suppression diode satisfies:

[0023] VBR =V1-I2*R2-I2*R1=V1-V2- I2*R1;

[0024] I2=V2 / R2;

[0025] wherein VBR is the reverse breakdown voltage of the transient voltage suppression diode, V1 is the first voltage, V2 is the second voltage, R1 is the first resistor, R2 is the second resistor, I1 is the first current, and I2 is the second current.

[0026] In another possible design, the current measurement unit is an ammeter, the ammeter being in series with the transient voltage suppression diode and the first resistor, and configured to measure the second current.

[0027] Optionally, the reverse breakdown voltage of the transient voltage suppression diode satisfies:

[0028] VBR=V1-I2*R1;

[0029] wherein, VBR is the reverse breakdown voltage of the transient voltage suppression diode, VI is the first voltage, R1 is the first resistance, I2 is the second current, I2*R1 is the voltage across the first resistance.

[0030] Based on the measuring system of the transient voltage suppression diode provided by the embodiments of the present application, the current excitation measuring unit can provide excitation current (first current) for the TVS tube, and the TVS tube, the first resistance and the current measuring unit are connected in series to form a series structure, the current measuring unit is used to measure the current (second current) flowing through the series structure, that is, the current flowing through the TVS tube, and then the voltage across the first resistance is calculated according to the first current and the first resistance, and the first voltage measuring unit is connected in parallel across the series structure to measure the voltage (first voltage) across the series structure, so that whether the TVS tube is broken down can be determined in an indirect way without shunting the TVS tube, and when it is known that the TVS is broken down, the breakdown voltage VBR of the TVS tube can be measured, which can solve the problem that when the impedance of the TVS tube and the impedance of the voltmeter connected in parallel with the TVS tube are close (such as the same order of magnitude), the shunting effect of the voltmeter is obvious, thereby resulting in that the accuracy of the measured breakdown voltage VBR of the TVS tube is low and the error size cannot be confirmed, and the accuracy of measuring the breakdown voltage VBR of the TVS tube can be greatly improved.

[0031] Optionally, the current measuring unit can include a second resistance connected in series with the TVS tube and the first resistance, and a second voltage measuring unit connected in parallel with the second resistance, that is, the current (second current I2) flowing through the TVS tube can be indirectly measured by measuring the voltage (second voltage) across the second resistance, and then the voltage across the first resistance and the breakdown voltage VBR of the TVS tube (that is, the first voltage-second voltage-voltage across the first resistance) can be calculated.

[0032] Optionally, the current measuring unit can be a current meter connected in series with the TVS tube and the first resistance, which is used to directly measure the current (second current) flowing through the TVS tube, and then the voltage across the first resistance and the breakdown voltage VBR of the TVS tube (that is, the first voltage-voltage across the first resistance, and the voltage division of the current meter is ignored) can be calculated. BRIEF DESCRIPTION OF DRAWINGS

[0033] The accompanying drawings, which are included to provide a further understanding of the present application and are incorporated in and constitute a part of this application, illustrate embodiments of the present application and together with the description serve to explain the present application. In the drawings, the same reference numbers and / or letters indicate the same or similar elements throughout the several views. It will be appreciated that the drawings are not necessarily drawn to scale.

[0034] Figure 1 A structure diagram of a measurement system of a transient voltage suppression diode provided by an embodiment of the present application is shown in the figure.

[0035] Figure 2 A structure diagram of another measurement system of a transient voltage suppression diode provided by an embodiment of the present application is shown in the figure.

[0036] Figure 3 A structure diagram of still another measurement system of a transient voltage suppression diode provided by an embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0037] In order to make the personnel in the technical field better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the figures in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by the person of ordinary skill in the art without making any creative labor should belong to the protection scope of the present application.

[0038] The measurement system of the transient voltage suppression diode provided by the embodiments of the present application will be described in detail below in conjunction with the figures in the embodiments of the present application. Figures 1-3

[0039] Exemplarily, Figure 1 A structure diagram of a measurement system of a transient voltage suppression diode provided by an embodiment of the present application is shown in the figure. As shown in the figure, the system comprises: Figure 1 a control unit;

[0040] a current measurement unit I2 and a first resistor R1, the current measurement unit I2, the first resistor R1 and the transient voltage suppression diode are connected in series to form a series structure;

[0041] a current excitation measurement unit I1 connected in series with the series structure;

[0042] a first voltage measurement unit V1 connected in parallel with the series structure;

[0043]

[0044] ​​Apart from the control unit, the other parts of the system can also be called the test circuit. The transient voltage suppressor diode under test can also be called the design under test (DUT), which can be different types of TVS diodes (such as high-voltage diodes and low-voltage diodes). The control unit can be a processor, host, or other device, equipment, or component with control functions. It has a communication connection with the current excitation measurement unit I1, the first voltage measurement unit V1, and the current measurement unit I2 in the test circuit. It is used to execute test programs or instructions corresponding to the type of TVS diode under test and to control the current excitation measurement unit I1, the first voltage measurement unit V1, and the current measurement unit I2 to measure the transient voltage suppressor diode.

[0045] Specifically, the control unit can be used to perform the following steps:

[0046] Step 1: Control the current excitation measurement unit I1 to provide and measure the first current I1 to the series structure.

[0047] Specifically, the control unit can send a command to the current excitation measurement unit I1, instructing it to provide and measure a first current I1 to the series structure. The first current I1 can be one or more. When there are multiple first currents I1, they can be provided to the series structure continuously according to a preset interval, sequence, and step size. The interval can be the time required to complete one measurement, the sequence can be from largest to smallest or smallest to largest, and the step size can be the difference between two adjacent first currents I1. For example, at 1-second intervals, a first current I1 ranging from -100mA to +100mA can be applied to the TVS diode in ascending order of size, with a step size of 0.5mA. The positive or negative sign indicates a change in the direction of the first current I1. Figure 1 If the direction shown is positive, then it is the same as... Figure 1 The opposite direction shown is negative.

[0048] Step 2: Control the first voltage measuring unit V1 to measure the first voltage V1 across the second series structure.

[0049] Specifically, the control unit can send a command to the first voltage measurement unit V1, instructing the first voltage measurement unit V1 to measure the voltage (first voltage V1) across the series structure and report it to the control unit.

[0050] Step 3: Control the current measurement unit I2 to measure the second current I2 flowing through the transient voltage suppression diode.

[0051] Specifically, the control unit can send a command to the current measurement unit I2, instructing the current measurement unit I2 to measure the current flowing through the series structure, that is, the current flowing through the TVS tube (the second current I2), and report it to the control unit.

[0052] Steps 2 and 3 above can be performed simultaneously or sequentially, and this application embodiment does not impose any restrictions.

[0053] Step 4: Determine whether the transient voltage suppression diode has been broken down based on the first current I1, the second current I2, and the first voltage V1.

[0054] Optionally, the breakdown condition of the transient voltage suppressor diode includes: the deviation between the first current I1 and the second current I2 is greater than or equal to the current deviation threshold. Instead of directly judging whether the voltage across the transient voltage suppressor diode reaches the breakdown voltage VBR, the breakdown condition is described by current using the electrical characteristics of the transient voltage suppressor diode.

[0055] Specifically, when the voltage across the transient voltage suppressor diode is below the breakdown voltage VBR, the transient voltage suppressor diode is at high impedance, and the first voltage measurement unit V1 connected in parallel with it is also at high impedance. In this case, the first voltage measurement unit V1 will have a significant shunting effect. At this time, the deviation between the second current I2 and the first current I1 will be relatively large, such as when the deviation is greater than the current deviation threshold.

[0056] As the first current I1 increases, the voltage across the transient voltage suppressor diode also increases. When the voltage across the transient voltage suppressor diode reaches the breakdown voltage VBR, the transient voltage suppressor diode will rapidly change from high impedance to low impedance. The shunting effect of the first voltage measurement unit V1 can be ignored. At this time, the first current I1 is close to the second current. If the deviation between the two is less than or equal to the current deviation threshold, it can be considered that the transient voltage suppressor diode meets the breakdown condition and has been reverse-broken down.

[0057] It should be noted that the first voltage measurement unit V1 can be a voltmeter or other components, devices, or equipment that can be used to measure voltage. The current excitation measurement unit I1 has two functions: signal excitation and current measurement. For example, it can be a current source with current measurement capability, or other components, devices, or equipment with two functions: signal excitation and current measurement. The current measurement unit I2 can be an ammeter, or other components, devices, or equipment that can measure current.

[0058] The following is combined Figure 2 and Figure 3 The two current measurement units I2 shown in the figure illustrate two specific implementations of the measurement system for transient voltage suppression diodes.

[0059] For example, Figure 2 This is a schematic diagram of a measurement system for another transient voltage suppression diode provided in an embodiment of this application. In one possible design, such as... Figure 2 As shown, the current measurement unit I2 includes:

[0060] The second resistor R2 is connected in series with the transient voltage suppression diode and the first resistor R1; and

[0061] The second voltage measuring unit V2 is connected in parallel with the second resistor R2. The second voltage measuring unit V2 is used to measure the second voltage V2 across the second resistor R2.

[0062] The second current I2 is the current flowing through the second resistor R2.

[0063] In other words, the second current I2 can be measured indirectly.

[0064] Optionally, the breakdown condition further includes: the deviation between the product of the second resistor R2 and the first current I1 and the second voltage V2 is greater than or equal to the voltage deviation threshold.

[0065] Specifically, when the voltage across the transient voltage suppressor diode does not reach the breakdown voltage VBR, the transient voltage suppressor diode is a high impedance, and the first voltage measurement unit V1 connected in parallel with it is also a high impedance. In this case, the first voltage measurement unit V1 will have a significant shunting effect. At this time, the deviation between the second current I2 and the first current I1 will be relatively large, which will lead to a relatively large deviation between the product of the second resistor R2 and the first current I1 and the second voltage V2. If it is greater than the voltage deviation threshold, it indicates that there is no linear relationship between the second voltage V2 and the first current I1.

[0066] As the first current I1 increases, the voltage across the transient voltage suppressor diode also increases. When the voltage across the transient voltage suppressor diode reaches the breakdown voltage VBR, the transient voltage suppressor diode will quickly change from high impedance to low impedance. The shunting effect of the first voltage measurement unit V1 can be ignored. At this time, the first current I1 is close to the second current. If the deviation between the two is less than or equal to the current deviation threshold, the product of the second resistor R2 and the first current I1 will be closer to the second voltage V2. If it is less than or equal to the voltage deviation threshold, it indicates that the relationship between the second voltage V2 and the first current I1 can be considered linear.

[0067] Accordingly, the reverse breakdown voltage of the transient voltage suppressor diode satisfies:

[0068] VBR =V1-I2*R2-I2*R1=V1-V2- I2*R1;

[0069] I² = V² / R²;

[0070] Where VBR is the reverse breakdown voltage of the transient voltage suppressor diode, V1 is the first voltage, V2 is the second voltage, R1 is the first resistor, R2 is the second resistor, I1 is the first current, I2 is the second current, and I2*R1 is the voltage across the first resistor.

[0071] For example, Figure 3 This is a schematic diagram of a measurement system for a transient voltage suppression diode provided in an embodiment of this application. In another possible design, such as... Figure 3 As shown, the current measuring unit I2 is an ammeter, which is connected in series with the transient voltage suppression diode and the first resistor R1 to measure the second current.

[0072] Optionally, the reverse breakdown voltage of the transient voltage suppressor diode satisfies:

[0073] VBR = V1 - I2 * R1;

[0074] Where VBR is the reverse breakdown voltage of the transient voltage suppressor diode, V1 is the first voltage, R1 is the first resistance, I2 is the second current, and I2*R1 is the voltage across the first resistor.

[0075] Based on the transient voltage suppression diode measurement system provided in this application embodiment, the current excitation measurement unit I1 can be controlled to provide an excitation current (first current I1) to the TVS diode, and the TVS diode, first resistor R1, and current measurement unit I2 are connected in series to form a series structure. The current measurement unit I2 is used to measure the current flowing through the series structure, i.e., through the TVS diode (second current I2). Then, the voltage division across the first resistor R1 is calculated based on the first current I1 and the first resistor R1, and the first voltage measurement unit V1 is connected in parallel across the series structure to measure the voltage across the series structure (first voltage). The voltage V1 is used to indirectly determine whether a TVS diode is broken down (breakdown condition) without shunting the current in the TVS diode. When the TVS diode is found to be broken down, the breakdown voltage VBR of the TVS diode is measured. This solves the problem in the prior art where the impedance of the TVS diode and the impedance of the voltmeter connected in parallel with the TVS diode are very close (such as impedances of the same order of magnitude), the shunting effect of the voltmeter is obvious, resulting in low accuracy of the measured breakdown voltage VBR of the TVS diode and the inability to confirm the error magnitude. This can greatly improve the accuracy of measuring the breakdown voltage VBR of the TVS diode.

[0076] Optionally, the current measurement unit I2 may include a second resistor R2 connected in series with the TVS tube and the first resistor R1, and a second voltage measurement unit V2 connected in parallel with the second resistor R2. That is, the current flowing through the TVS tube (second current I2) can be indirectly measured by measuring the voltage across the second resistor R2 (second voltage V2), and then the voltage across the first resistor and the breakdown voltage VBR of the TVS tube (i.e., first voltage V1 - second voltage V2 - voltage across the first resistor R1) can be calculated.

[0077] Optionally, the current measuring unit I2 can be an ammeter connected in series with the TVS tube and the first resistor R1, so as to directly measure the current flowing through the TVS tube (the second current I2), and then calculate the voltage across the first resistor and the breakdown voltage VBR of the TVS tube (i.e., the first voltage V1 - the voltage across the first resistor R1, the voltage division of the ammeter is negligible).

[0078] Furthermore, the parameters of various measuring instruments and components in the above-mentioned test circuit can be selected according to the type of TVS tube (such as high voltage tube or low voltage tube). For example, the impedance of the first resistor R1 and the second resistor R2 can be selected according to the type of TVS tube, as well as the range of the measuring instrument. This application embodiment will not elaborate further.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A measurement system for a transient voltage suppression diode, characterized by, The application relates to a device for measuring a breakdown condition of a transient voltage suppression diode, comprising: a control unit; a current measurement unit and a first resistor, the current measurement unit, the first resistor and a transient voltage suppression diode being connected in series to form a series structure; a current excitation measurement unit connected in series with the series structure; a first voltage measurement unit connected in parallel with the series structure; wherein the control unit is configured to control the current excitation measurement unit, the first voltage measurement unit and the current measurement unit to measure the transient voltage suppression diode.

2. The measurement system of claim 1, wherein, The control unit is specifically configured to: control the current excitation measurement unit to provide a first current to the series structure and measure the first current; control the first voltage measurement unit to measure a first voltage across the second series structure; control the current measurement unit to measure a second current flowing through the transient voltage suppression diode; and determine whether the transient voltage suppression diode is broken down according to the first current, the second current and the first voltage. The breakdown condition of the transient voltage suppression diode comprises a deviation between the first current and the second current being greater than or equal to a current deviation threshold.

3. The measurement system of claim 2, wherein, The current measurement unit comprises:

4. The measurement system of claim 3, wherein, a second resistor connected in series with the transient voltage suppression diode and the first resistor; and a second voltage measurement unit connected in parallel with the second resistor, the second voltage measurement unit being configured to measure a second voltage across the second resistor; The second current is a current flowing through the second resistor. The breakdown condition further comprises a deviation between a product of the second resistor and the first current and the second voltage being greater than or equal to a voltage deviation threshold.

5. The measurement system of claim 4, wherein, The reverse breakdown voltage of the transient voltage suppression diode satisfies:

6. The measurement system of claim 5, wherein, VBR = V1 - I2 * R2 - I2 * R1 = V1 - V2 - I2 * R1; I2 = V2 / R2; wherein VBR is the reverse breakdown voltage of the transient voltage suppression diode, V1 is the first voltage, V2 is the second voltage, R1 is the first resistor, R2 is the second resistor, I1 is the first current, I2 is the second current, and I2 * R1 is a voltage across the first resistor. The current measurement unit is an ammeter connected in series with the transient voltage suppression diode and the first resistor, and configured to measure the second current.

7. The measurement system of claim 3, wherein, The reverse breakdown voltage of the transient voltage suppression diode satisfies:

8. The measurement system of claim 7, wherein, VBR = V1 - I2 * R1; wherein VBR is the reverse breakdown voltage of the transient voltage suppression diode, V1 is the first voltage, R1 is the first resistor, I2 is the second current, and I2 * R1 is a voltage across the first resistor. ​

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