Test circuit
By designing a test circuit, the short circuit of the DB9 connector signal pin is determined by the level values of the pin connection module and the output module. This solves the problems of low efficiency and high cost of manual testing, realizes automated testing, and improves testing efficiency and reliability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-14
- Publication Date
- 2026-04-07
AI Technical Summary
In the existing technology, short circuit detection of the signal pins of the DB9 connector requires manual inspection, which is inefficient and can easily damage the device chip, increasing testing costs.
Design a test circuit that controls two adjacent signal pins of a conducting connector through a first and second pin connection module, and the output module determines the short circuit condition based on the level value, thereby achieving automated detection.
It improves testing efficiency, reduces testing costs, and avoids the time-consuming nature of manual testing and the risk of chip damage.
Smart Images
Figure CN224095981U_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of circuits, and more particularly to a test circuit. Background Technology
[0002] A connector is a device that connects two active devices to transmit current or signals. The male and female terminals can transmit information or current after contact.
[0003] The DB9 connector is a D-type (9-pin) data interface connector, used as an interface standard for connecting electronic devices (such as computers and peripherals). It is named a D-type data interface connector because its shape resembles the letter D.
[0004] Currently, it is necessary to check whether the signal pins of the DB9 connector are short-circuited. Utility Model Content
[0005] This disclosure provides a short-circuit test method, which can at least facilitate the detection of whether the signal pins of a connector are short-circuited.
[0006] According to some embodiments of this disclosure, one aspect of this disclosure provides a test circuit, including a connector comprising a plurality of signal pins; a first pin connection module having a first output terminal and an input terminal of the first pin connection module electrically connected to all the signal pins for conducting the first output terminal and a first signal pin, wherein the first signal pin is any one of the signal pins; a second pin connection module having a second output terminal and an input terminal of the second pin connection module electrically connected to all the signal pins for conducting the second output terminal and a second signal pin, wherein the second signal pin is adjacent to the first signal pin; and an output module having a third output terminal, the input terminal of the output module being electrically connected to the first output terminal and the second output terminal, wherein the third output terminal is used to output a detection signal, the level value of which is used to characterize whether the first signal pin and the second signal pin are short-circuited.
[0007] In some embodiments, the output module includes: a first voltage divider circuit electrically connected to the first output terminal and outputting a first voltage signal; a second voltage divider circuit electrically connected to the second output terminal and outputting a second voltage signal; and an operational amplifier, wherein a first input terminal of the operational amplifier receives the first voltage signal, a second input terminal receives the second voltage signal, and the detection signal is output based on the difference between the level values of the first voltage signal and the second voltage signal.
[0008] In some embodiments, the first voltage divider circuit includes: a first power supply providing a first voltage; a first voltage divider resistor, one end of which is electrically connected to the first power supply and the first output terminal, and the other end of which is electrically connected to the first input terminal of the operational amplifier, wherein the resistance value of the first voltage divider resistor is greater than the internal resistance value of the first pin connection module.
[0009] In some embodiments, the second voltage divider circuit includes: a second power supply providing a second voltage; a second voltage divider resistor, one end of which is electrically connected to the second power supply and the second output terminal, and the other end of which is electrically connected to the second input terminal of the operational amplifier, wherein the resistance value of the second voltage divider resistor is greater than the internal resistance value of the second pin connection module.
[0010] In some embodiments, the system further includes a first gain circuit, one end of which is electrically connected to a first input terminal of the operational amplifier and the other end of which is electrically connected to an output terminal of the operational amplifier, for amplifying the first voltage signal received at the first input terminal.
[0011] In some embodiments, the first voltage divider circuit includes a first voltage divider resistor and a first power supply, and the first gain circuit includes a first gain resistor, wherein the ratio of the resistance value of the first gain resistor to the resistance value of the first voltage divider resistor is less than 1 and greater than or equal to 1 / 3.
[0012] In some embodiments, the system further includes a second gain circuit, one end of which is electrically connected to the second input terminal of the operational amplifier, and the other end is grounded, for amplifying the second voltage signal received at the second input terminal.
[0013] In some embodiments, the second voltage divider circuit includes a second voltage divider resistor and a second power supply, and the second gain circuit includes a second gain resistor, wherein the ratio of the resistance value of the second gain resistor to the resistance value of the second voltage divider resistor is less than 1 and greater than or equal to 1 / 3.
[0014] In some embodiments, the first pin connection module and / or the second pin connection module includes: a selection chip, the selection chip including: a plurality of access pins, one of the access pins being electrically connected to a signal pin; an enable pin, the enable pin being used to activate the selection chip; an output pin, the output pin of the first pin connection module serving as the first output terminal, and the output pin of the second pin connection module serving as the second output terminal; and a selection pin, the selection pin being used to select the access pin and the output pin being electrically connected.
[0015] In some embodiments, the device further includes a first protection resistor, one end of which is electrically connected to the output terminal of the output module, and the other end of which outputs the detection signal.
[0016] The technical solution provided by this disclosure has at least the following advantages: the first pin connection module and the second pin connection module control the conduction of two adjacent signal pins of the connector. If there is a short circuit between two adjacent signal pins of the connector, the first pin connection module and the second pin connection module will conduct. Similarly, when there is no short circuit between two adjacent signal pins of the connector, the first pin connection module and the second pin connection module will be disconnected. Based on this, the output module outputs a detection signal under different conditions, and determines whether there is a short circuit between two adjacent signal pins of the connector by the level value of the detection signal. The test circuit can replace manual detection, thereby realizing measurement automation and improving test efficiency. Attached Figure Description
[0017] One or more embodiments are illustrated by way of example with corresponding pictures in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the pictures in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this disclosure or the conventional technology, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 A circuit diagram of a test circuit provided in one embodiment of this disclosure;
[0019] Figure 2 Another circuit diagram of a test circuit provided in an embodiment of this disclosure. Detailed Implementation
[0020] Currently, during the wave soldering process in connector manufacturing, solder bridging can occur between signal pins. Since the gap between signal pins cannot be determined by the naked eye, it can easily damage the device chip if power is applied. Therefore, it is necessary to provide a test circuit to detect whether the signal pins of the connector are short-circuited.
[0021] In this embodiment, the first pin connection module and the second pin connection module control the conduction of two adjacent signal pins of the connector. If there is a short circuit between two adjacent signal pins of the connector, the first pin connection module and the second pin connection module will conduct. Similarly, when there is no short circuit between two adjacent signal pins of the connector, the first pin connection module and the second pin connection module will be disconnected. Based on this, the output module outputs a detection signal under different conditions, and determines whether there is a short circuit between two adjacent signal pins of the connector by the level value of the detection signal. The test circuit can replace manual detection, thereby realizing measurement automation and improving test efficiency.
[0022] Terms such as "first" or "second" may be used to describe various components, but these components are not limited by the terms described above. The terms described above are used to distinguish one component from another; for example, without departing from the scope of the concept according to this disclosure, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component.
[0023] Furthermore, "connected / linked" indicates that one component is directly electrically connected to another component or indirectly electrically connected through another component. Unless otherwise explicitly stated in the sentence, the singular form may include the plural form. Additionally, the terms "comprising / including" or "containing / including" as used in this specification indicate the presence or addition of one or more components, steps, operations, and elements. Specific structural or functional descriptions of examples of embodiments of the concepts disclosed in this specification are merely illustrative to describe examples of embodiments of the concepts, and examples of embodiments of the concepts can be implemented in various forms, but these descriptions are not limited to the examples of embodiments described in this specification.
[0024] Based on the concept, various modifications and changes can be applied to examples of embodiments, such that examples of embodiments will be illustrated in the accompanying drawings and described in the specification. However, examples of embodiments based on the concept are not limited to specific embodiments, but include all changes, equivalents, or substitutions included within the spirit and scope of this disclosure.
[0025] It should be understood that when describing an element as "connected" or "linked" to another element, the element may be directly connected or linked to the other element, or it may be connected or linked to the other element via a third element. Conversely, it should be understood that when an element is described as "directly connected to" or "directly linked to" another element, no other element is placed between them. Other expressions describing relationships between components (i.e., "between" and "directly between" or "adjacent to" and "directly adjacent to") need to be interpreted in the same way.
[0026] The terminology used in this specification is for the purpose of describing specific examples of implementations only and is not intended to limit this disclosure. The singular form may include the plural form unless there is an explicit contrary meaning in the context. It should be understood in this specification that the terms "comprising" or "having" indicate the presence of the features, quantities, steps, operations, components, parts, or combinations thereof described in the specification, but do not preclude the possibility of the presence or addition of one or more other features, quantities, steps, operations, components, parts, or combinations thereof.
[0027] Unless otherwise defined, all terms used herein (including technical or scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art. If a term is not clearly defined in a common dictionary in this specification, it shall be interpreted as having the same meaning as in the context of the relevant art, and not as an ideal or overly formal meaning.
[0028] Descriptions of known components and processing techniques may be omitted to avoid unnecessarily obscuring the embodiments of this disclosure.
[0029] Throughout this specification, the same reference numerals refer to the same elements. Therefore, even if a reference numeral is not mentioned or described with reference to one drawing, it may be mentioned or described with reference to another drawing. Furthermore, even if a reference numeral is not shown in one drawing, it may be mentioned or described with reference to another drawing.
[0030] Additionally, the logic level of a signal may be different from or opposite to the logic level described. For example, a signal described as having a logic "high" level may optionally have a logic "low" level, and a signal described as having a logic "low" level may optionally have a logic "high" level.
[0031] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this disclosure to facilitate a better understanding of the disclosure. However, the technical solutions claimed in this disclosure can be implemented even without these technical details and various variations and modifications based on the following embodiments.
[0032] refer to Figure 1 and Figure 2 , Figure 1 A circuit diagram of a test circuit provided in one embodiment of this disclosure. Figure 2 Another circuit diagram of a test circuit provided in one embodiment of this disclosure.
[0033] In some embodiments, the test circuit may include a connector 100, which includes a plurality of signal pins 110.
[0034] The test circuit may further include: a first pin connection module 101, the first pin connection module 101 having a first output terminal 111, the input terminal of the first pin connection module 101 being electrically connected to all signal pins 110, for conducting the first output terminal 111 and the first signal pin, the first signal pin being any one of the signal pins 110.
[0035] The test circuit may further include: a second pin connection module 102, the second pin connection module 102 having a second output terminal 112, the input terminal of the second pin connection module 102 being electrically connected to all signal pins 110 for conducting the second output terminal 112 and the second signal pin, the second signal pin being adjacent to the first signal pin.
[0036] The test circuit may further include: an output module 103, the output module 103 having a third output terminal 113, the input terminal of the output module 103 being electrically connected to the first output terminal 111 and the second output terminal 112, the third output terminal 113 being used to output a detection signal, the level value of the detection signal being used to characterize whether the first signal pin and the second signal pin are short-circuited.
[0037] In this embodiment, the first pin connection module 101 and the second pin connection module 102 control the conduction of two adjacent signal pins 110 of the connector 100. If there is a short circuit between the two adjacent signal pins 110 of the connector 100, the first pin connection module 101 and the second pin connection module 102 will conduct. Similarly, when there is no short circuit between the two adjacent signal pins 110 of the connector 100, the first pin connection module 101 and the second pin connection module 102 will be disconnected. Based on this, the output module 103 outputs a detection signal under different conditions, and determines whether there is a short circuit between the two adjacent signal pins 110 of the connector 100 by the level value of the detection signal. The test circuit can replace manual detection, thereby realizing measurement automation and improving test efficiency.
[0038] For connector 100, during wave soldering, adjacent signal pins 110 often experience solder bridging, leading to short circuits. Therefore, during testing, adjacent signal pins 110 are sequentially checked for short circuits. Manual testing is time-consuming and may result in missed detections. Direct chip testing, with repeated testing of the short-circuited connector 100, can cause chip malfunctions and increase testing costs. This embodiment of the present disclosure determines the short circuit status of connector 100's signal pins 110 by analyzing the different voltage values output by the connector 100's signal pins 110 under short-circuit and non-short-circuit conditions. This improves testing efficiency and reliability while reducing testing costs.
[0039] In some embodiments, the first pin connection module 101 may include a selection chip 104, which includes: a plurality of access pins 114, one access pin 114 being electrically connected to a signal pin 110; an enable pin 124 for activating the selection chip 104; an output pin 134, which serves as a first output terminal 111; and a selection pin 144 for selecting the electrical connection between the access pin 114 and the output pin 134.
[0040] For example, connector 100 includes 9 signal pins 110. For selection chip 104, only 8 access pins 114 are needed. For instance, the access pins 114 of the first pin connection module 101 are connected to the first to eighth signal pins 110 of connector 100, and the access pins 114 of the second pin connection module 102 are connected to the second to ninth signal pins 110 of connector 100, thus completing short-circuit detection for all signal pins 110 of connector 100. As for the enable pin 124, it only needs to provide an enable signal when the test circuit is activated. For the output pin 134, there is a connection path between the output pin 134 and each access pin 114. For the first pin connection module 101, when the output pin 134 is selected to connect to the first signal pin 110... Output pin 134 is connected to the first signal pin 110, but disconnected from other signal pins 110. For selection pin 144, when the selection chip 104 includes eight access pins 114, the number of selection pins 144 can be three. The selection pin 144 is configured to connect to which signal pin 110 via binary encoding. For example, when the signal corresponding to selection pin 144 is '000', it indicates that selection pin 144 selects the first signal pin 110 to connect to output pin 134; when the signal corresponding to selection pin 144 is '100', it indicates that selection pin 144 selects the fifth signal pin 110 to connect to output pin 134. '0' indicates that a low-level signal is provided to selection pin 144, and '1' ensures a high-level signal is provided to selection pin 144.
[0041] The selection chip 104 can be used to precisely control which signal pin 110 is electrically connected to the first output terminal 111, thereby improving the accuracy of subsequent detection of whether the signal pin 110 is short-circuited.
[0042] It should be noted that the number of pins of the connector 100 and the correspondence between the access pin 114 and the signal pin 110 are merely illustrative examples for ease of understanding and are not intended to impose specific limitations.
[0043] In some embodiments, the first pin connection module 101 can also be a single-pole multi-throw switch. The single-pole multi-throw switch can also be used to select which signal pin 110 is connected to the first output terminal 111.
[0044] In some embodiments, the second pin connection module 102 may include a selection chip 104, comprising: a plurality of access pins 114, one access pin 114 being electrically connected to a signal pin 110; an enable pin 124 for activating the selection chip 104; an output pin 134, the output pin 134 of the second pin connection module 102 serving as a second output terminal 112; and a selection pin 144 for selecting the electrical connection between the access pin 114 and the output pin 134. By setting the second pin connection module 102 as a selection chip 104, precise control can be achieved over which signal pin 110 the second output terminal 112 is electrically connected to, thereby improving the accuracy of subsequent detection of whether the signal pin 110 is short-circuited.
[0045] It should be noted that when the second pin connection module 102 is the selection chip 104, the corresponding control principle can be referred to the above description of the first pin connection module 101, and will not be repeated here.
[0046] In some embodiments, the second pin connection module 102 can also be a single-pole multi-throw switch. The single-pole multi-throw switch can also be used to select which signal pin 110 is connected to the second output terminal 112.
[0047] For output module 103, if the first signal pin and the second signal pin are short-circuited, the detection signal has a first level value; if the first signal pin and the second signal pin are not short-circuited, the detection signal has a second level value. The first level value and the second level value are different.
[0048] In some embodiments, the output module 103 may include: a first voltage divider circuit 123, which is electrically connected to a first output terminal 111 and outputs a first voltage signal; a second voltage divider circuit 133, which is electrically connected to a second output terminal 112 and outputs a second voltage signal; and an operational amplifier 143, which receives the first voltage signal at its first input terminal and the second voltage signal at its second input terminal, and outputs a detection signal based on the difference between the levels of the first voltage signal and the second voltage signal.
[0049] When adjacent signal pins 110 are short-circuited, the first pin connection module 101 can form a loop with the second pin connection module 102, and the first voltage divider circuit 123 and the second voltage divider circuit 133 are divided. When adjacent signal pins 110 are not short-circuited, the first pin connection module 101 and the second pin connection module 102 form an open circuit, and the first voltage divider circuit 123 and the second voltage divider circuit 133 are directly electrically connected to the first input terminal and the second input terminal of the operational amplifier 143. Therefore, whether adjacent signal pins 110 are short-circuited will result in different voltage values provided by the first voltage divider circuit 123 and the second voltage divider circuit 133 to the operational amplifier 143. Therefore, it is possible to determine whether adjacent signal pins 110 are short-circuited based on the level value of the detection signal.
[0050] In some embodiments, the first voltage divider circuit 123 may include: a first power supply VDD_1, which provides a first voltage; a first voltage divider resistor R1, one end of which is electrically connected to the first power supply VDD_1 and the first output terminal 111, and the other end of which is electrically connected to the first input terminal of the operational amplifier 143, wherein the resistance value of the first voltage divider resistor R1 is greater than the internal resistance value of the first pin connection module 101.
[0051] The first power supply VDD_1 constantly provides the first voltage. When the adjacent signal pin 110 is short-circuited, the first voltage divider resistor R1 and the internal resistance of the first pin connection module 101 divide the voltage. Since the resistance of the first voltage divider resistor R1 is greater than the internal resistance of the first pin connection module 101, the voltage value transmitted to the first input terminal of the operational amplifier 143 is reduced. This will reduce the voltage value corresponding to the detection signal. When the voltage value corresponding to the detection signal is reduced, it can be indicated that the adjacent signal pin 110 is short-circuited. When the adjacent signal pin 110 is not short-circuited, the first pin connection module 101 is not connected to the loop of the first voltage divider circuit 123, and the entire voltage value of the first voltage will be input to the first input terminal, so that the voltage value of the detection signal corresponds to the expected voltage value. When the voltage value of the detection signal corresponds to the expected voltage value, it can be indicated that the adjacent signal pin 110 is not short-circuited.
[0052] In some embodiments, the resistance value of the first voltage divider resistor R1 can be much greater than the internal resistance value of the first pin connection module 101. For example, the resistance value of the first voltage divider resistor R1 is more than a thousand times the internal resistance value of the first pin connection module 101. In this way, the first input terminal of the operational amplifier 143 can receive a voltage value of approximately 0V.
[0053] In some embodiments, a first voltage regulator resistor R3 is also included. One end of the first voltage regulator resistor R3 is connected to the first power supply VDD_1, and the other end is electrically connected to the output pin 134 to improve the stability of the output of the first power supply VDD_1.
[0054] In some embodiments, the second voltage divider circuit 133 includes: a second power supply VDD_2, which provides a second voltage; a second voltage divider resistor R2, one end of which is electrically connected to the second power supply VDD_2 and the second output terminal 112, and the other end of which is electrically connected to the second input terminal of the operational amplifier 143, wherein the resistance value of the second voltage divider resistor R2 is greater than the internal resistance value of the second pin connection module 102.
[0055] The second power supply VDD_2 constantly provides the second voltage. When the adjacent signal pin 110 is short-circuited, the second voltage divider resistor R2 and the internal resistance of the second pin connection module 102 divide the voltage. Since the resistance of the second voltage divider resistor R2 is greater than the internal resistance of the second pin connection module 102, the voltage value transmitted to the second input terminal of the operational amplifier 143 is reduced. This will reduce the voltage value corresponding to the detection signal. When the voltage value corresponding to the detection signal is reduced, it can be indicated that the adjacent signal pin 110 is short-circuited. When the adjacent signal pin 110 is not short-circuited, the second pin connection module 102 is not connected to the loop of the second voltage divider circuit 133, and the entire voltage value of the second voltage will be input to the second input terminal, so that the voltage value of the detection signal corresponds to the expected voltage value. When the voltage value of the detection signal corresponds to the expected voltage value, it can be indicated that the adjacent signal pin 110 is not short-circuited.
[0056] In some embodiments, the resistance value of the second voltage divider resistor R2 can be much larger than the internal resistance value of the second pin connection module 102. The corresponding principle is the same as described above for the first voltage divider resistor R1, and will not be repeated here.
[0057] In some embodiments, a second voltage-regulating resistor R4 is also included. One end of the second voltage-regulating resistor R4 is connected to the second power supply VDD_2, and the other end is electrically connected to the output pin 134 to improve the stability of the output of the second power supply VDD_2.
[0058] The working process of the output module 103 will be described below with reference to a specific embodiment. It should be noted that the data values used in the following examples are only for the purpose of illustrative purposes and are not specific limitations.
[0059] The first voltage is -1.8V, and the second voltage is +1.8V. The resistance of the first voltage divider resistor R1 is much larger than the internal resistance of the first pin connection module 101, and the resistance of the second voltage divider resistor R2 is much larger than the internal resistance of the second pin connection module 102. When the signal pin 110 connected to the first pin connection module 101 and the second pin connection module 102 is short-circuited, due to the influence of the first and second voltage divider resistors R1 and R2, the voltage provided by the first voltage to the first input terminal is close to 0V, and the voltage provided by the second voltage to the second input terminal is close to 0V. The operational amplifier 143 outputs... The voltage value of the detection signal is close to 0V, which is a low level. Thus, when the detection signal is low, it indicates that the signal pin 110 is short-circuited. When the signal pin 110 connected to the first pin connection module 101 and the second pin connection module 102 is not short-circuited, the bypass of the first pin connection module 101 and the second pin connection module 102 is disconnected and not connected to the circuit, so that the first voltage is fully provided to the first input terminal, and the second voltage is also fully provided to the second input terminal. The voltage value of the detection signal output by the operational amplifier 143 is 3.6V, which is a high level. Thus, when the detection signal is high, it indicates that the signal pin 110 is not short-circuited.
[0060] When one of the signal pins 110 connected to the first pin connection module 101 and the second pin connection module 102 is a ground signal, similarly, when the signal pins 110 connected to the first pin connection module 101 and the second pin connection module 102 are short-circuited, the voltage value of the detection signal output by the operational amplifier 143 is close to 0V. When the signal pins 110 connected to the first pin connection module 101 and the second pin connection module 102 are not short-circuited, since there is a ground signal on the signal pin 110, the first voltage or the second voltage is grounded, and the voltage value of the detection signal output by the operational amplifier 143 is 1.8V, which is also a high-level signal.
[0061] In some embodiments, the operational amplifier 143 is also connected to a power supply to provide a voltage signal for the normal operation of the operational amplifier 143.
[0062] In some embodiments, the system further includes: a first capacitor C1, one end of which is electrically connected to the power supply of the operational amplifier 143, and the other end of which is grounded; and a second capacitor C2, one end of which is electrically connected to the power supply of the operational amplifier 143, and the other end of which is grounded. The first capacitor C1 and the second capacitor C2 are used to filter the signal supplied to the operational amplifier 143 by the power supply, thereby improving the operating stability of the operational amplifier 143.
[0063] In some embodiments, the test circuit may further include a first gain circuit 105, one end of which is electrically connected to the first input terminal of the operational amplifier 143, and the other end of which is electrically connected to the output terminal of the operational amplifier 143, for amplifying the first voltage signal received at the first input terminal. Amplifying the first voltage signal through the first gain circuit 105 can further increase the difference between when the signal pin 110 is short-circuited and when it is not short-circuited, thereby further facilitating the differentiation between whether the signal pin 110 is short-circuited.
[0064] In some embodiments, the first voltage divider circuit 123 includes a first voltage divider resistor R1 and a first power supply VDD_1, and the first gain circuit 105 includes a first gain resistor R5, wherein the ratio of the resistance value of the first gain resistor R5 to the resistance value of the first voltage divider resistor R1 is less than 1 and greater than or equal to 1 / 3. For the first gain resistor R5, the smaller the resistance value of R5, the larger the voltage value of the first voltage signal, making it easier to distinguish whether the signal pin 110 is short-circuited. However, the greater the voltage value of the first voltage signal, the larger the voltage value of the detection signal output by the operational amplifier 143, which may lead to safety hazards. Therefore, setting the ratio of the resistance value of the first gain resistor R5 to the resistance value of the first voltage divider resistor R1 to be less than 1 and greater than or equal to 1 / 3 facilitates the distinction of whether the signal pin 110 is short-circuited while avoiding affecting the reliability of the test circuit.
[0065] In some embodiments, the test circuit may further include a second gain circuit 106, one end of which is electrically connected to the second input terminal of the operational amplifier 143, and the other end is grounded, for amplifying the second voltage signal received at the second input terminal. Amplifying the second voltage signal by the second gain circuit 106 can further increase the difference between when the signal pin 110 is short-circuited and when it is not short-circuited, thereby making it easier to distinguish whether the signal pin 110 is short-circuited.
[0066] In some embodiments, the second voltage divider circuit 133 includes a second voltage divider resistor R2 and a second power supply VDD_2, and the second gain circuit 106 includes a second gain resistor R6, wherein the ratio of the resistance value of the second gain resistor R6 to the resistance value of the second voltage divider resistor R2 is less than 1 and greater than or equal to 1 / 3. For the second gain resistor R6, the smaller the resistance value, the larger the voltage value of the second voltage signal, making it easier to distinguish whether the signal pin 110 is short-circuited. However, the greater the voltage value of the second voltage signal, the larger the voltage value of the detection signal output by the operational amplifier 143, which may lead to safety hazards. Therefore, setting the ratio of the resistance value of the second gain resistor R6 to the resistance value of the second voltage divider resistor R2 to be less than 1 and greater than or equal to 1 / 3 facilitates the distinction of whether the signal pin 110 is short-circuited while avoiding affecting the reliability of the test circuit.
[0067] In some embodiments, the test circuit further includes a first protection resistor R7, one end of which is electrically connected to the output terminal of the output module 103, and the other end outputs a detection signal. Setting the first protection resistor R7 can improve the stability of the detection signal output.
[0068] In some embodiments, the test circuit further includes a second protection resistor R8, one end of which is electrically connected to the other end of the first protection resistor R7, and the other end is grounded. By setting the second protection resistor R8 as a pull-down protection resistor, it is used to protect the circuit at the back end of the test circuit.
[0069] In this embodiment, the first pin connection module 101 and the second pin connection module 102 control the conduction of two adjacent signal pins 110 of the connector 100. If there is a short circuit between the two adjacent signal pins 110 of the connector 100, the first pin connection module 101 and the second pin connection module 102 will conduct. Similarly, when there is no short circuit between the two adjacent signal pins 110 of the connector 100, the first pin connection module 101 and the second pin connection module 102 will be disconnected. Based on this, the output module 103 outputs a detection signal under different conditions, and determines whether there is a short circuit between the two adjacent signal pins 110 of the connector 100 by the level value of the detection signal. The test circuit can replace manual detection, thereby realizing measurement automation and improving test efficiency.
[0070] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the embodiments of this disclosure. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the embodiments of this disclosure; therefore, the scope of protection of the embodiments of this disclosure should be determined by the scope defined in the claims.
Claims
1. A test circuit, characterized in that, include: The connector includes a plurality of signal pins; A first pin connection module has a first output terminal and an input terminal that is electrically connected to all the signal pins to conduct the first output terminal and the first signal pin, wherein the first signal pin is any one of the signal pins. The second pin connection module has a second output terminal and its input terminal is electrically connected to all the signal pins to conduct the second output terminal and the second signal pin, wherein the second signal pin is adjacent to the first signal pin. The output module has a third output terminal. The input terminal of the output module is electrically connected to the first output terminal and the second output terminal. The third output terminal is used to output a detection signal. The level value of the detection signal is used to characterize whether the first signal pin and the second signal pin are short-circuited.
2. The test circuit according to claim 1, characterized in that, The output module includes: A first voltage divider circuit is electrically connected to the first output terminal and outputs a first voltage signal; The second voltage divider circuit is electrically connected to the second output terminal and outputs a second voltage signal; An operational amplifier, wherein a first input terminal receives the first voltage signal, a second input terminal receives the second voltage signal, and outputs the detection signal based on the difference between the level values of the first voltage signal and the second voltage signal.
3. The test circuit according to claim 2, characterized in that, The first voltage divider circuit includes: A first power source, which provides a first voltage; The first voltage divider resistor has one end electrically connected to the first power supply and the first output terminal, and the other end electrically connected to the first input terminal of the operational amplifier. The resistance value of the first voltage divider resistor is greater than the internal resistance value of the first pin connection module.
4. The test circuit according to claim 2, characterized in that, The second voltage divider circuit includes: A second power source, which provides a second voltage; The second voltage divider resistor has one end electrically connected to the second power supply and the second output terminal, and the other end electrically connected to the second input terminal of the operational amplifier. The resistance value of the second voltage divider resistor is greater than the internal resistance value of the second pin connection module.
5. The test circuit according to claim 2, characterized in that, Also includes: A first gain circuit, one end of which is electrically connected to the first input terminal of the operational amplifier, and the other end of which is electrically connected to the output terminal of the operational amplifier, is used to amplify the first voltage signal received at the first input terminal.
6. The test circuit according to claim 5, characterized in that, The first voltage divider circuit includes a first voltage divider resistor and a first power supply, and the first gain circuit includes: The first gain resistor has a resistance value that is less than 1 and greater than or equal to 1 / 3 of the resistance value of the first voltage divider resistor.
7. The test circuit according to claim 2, characterized in that, Also includes: The second gain circuit has one end electrically connected to the second input terminal of the operational amplifier and the other end grounded, and is used to amplify the second voltage signal received by the second input terminal.
8. The test circuit according to claim 7, characterized in that, The second voltage divider circuit includes a second voltage divider resistor and a second power supply, and the second gain circuit includes: The second gain resistor has a resistance value that is less than 1 and greater than or equal to 1 / 3 of the resistance value of the second voltage divider resistor.
9. The test circuit according to claim 1, characterized in that, The first pin connection module and / or the second pin connection module include: The selection chip includes: multiple access pins, one of which is electrically connected to a signal pin; an enable pin for activating the selection chip; an output pin, wherein the first pin is connected to the output pin of the module as the first output terminal, and the second pin is connected to the output pin of the module as the second output terminal; and a selection pin for selecting the connection between the access pin and the output pin.
10. The test circuit according to claim 1, characterized in that, Also includes: A first protective resistor, one end of which is electrically connected to the output terminal of the output module, and the other end outputs the detection signal.