Electronic device, electronic system including electronic device, and abnormality determining method executed by electronic device

Abstract

An electronic device (40) comprises: a control unit (41); output pins (45) that can be connected to an external apparatus (30); a signal generator (47) that is provided in an output circuit (46) connecting the control unit (41) and the output pins (45); input pins (49) that can be connected to the external apparatus (30); an analog to digital converter (50) that is provided in an input circuit (51) connecting the input pins (49) and the control unit (41); and a communication unit (53) that receives, from the external apparatus (30), a command for generating an output signal from the signal generator (47), and transmits the state of a circuit (20) being measured to the external apparatus (30). The circuit (20) being measured is connected between the output pins (45) and the external apparatus (30) or between the input pins (49) and the external apparatus (30).

Description

Electronic device, electronic system including the electronic device, and method for determining abnormality executed by the electronic device

[0001] The present disclosure relates to an electronic device, an electronic system including the electronic device, and a method for determining abnormality executed by the electronic device.

[0002] A printed circuit board on which components are soldered is subjected to in-circuit testing (ICT: In-Circuit Tester) before shipment to detect component differences and connection failures in the circuit under test. However, in ICT, in order to inspect the entire board without omission, a large number of test pads need to be arranged on the board, so the test pads interfere with the wiring pattern. In addition, when a large number of test pads are arranged on the board, the board area increases. In Patent Document 1, in order to reduce the number of test pads, the state of the circuit under test is determined based on the time change of the signal passing through the circuit under test.

[0003] Japanese Patent No. 5623040

[0004] In Patent Document 1, for example, it cannot be applied to the determination of the state of a circuit under test including a plurality of electronic circuits having different characteristics. In addition, in Patent Document 1, the accuracy of determining the state of the circuit under test is low. Therefore, there is a need for an electronic device that can preferably execute operations related to the circuit under test.

[0005] The electronic device according to the first aspect of the present disclosure is an electronic device connected to a circuit under test and measuring the state of the circuit under test, including a control unit, an output pin different from a power supply pin and connectable to an external device, a signal generator provided in an output circuit connecting the control unit and the output pin, an input pin different from the power supply pin and connectable to the external device, an analog-to-digital converter provided in an input circuit connecting the input pin and the control unit, and a communication unit that receives a command for generating an output signal from the signal generator from the external device and transmits the state of the circuit under test to the external device, wherein the circuit under test is connected between the output pin and the external device or between the input pin and the external device.

[0006] With this configuration, information regarding the signal generated by the signal generator can be input to the electronic device from the input pin via the circuit under test and an external device. The signal input from the input pin is converted to a digital signal by an analog-to-digital converter and then input to the control unit. Therefore, the control unit can use the digital signal input from the analog-to-digital converter to obtain a digital signal that reflects the influence of the state of the circuit under test, and thus can suitably perform calculations related to the circuit under test.

[0007] The electronic device of the second aspect is the electronic device of the first aspect in which the output pin is one of a plurality of output pins, the input pin is one of a plurality of input pins, the output circuit has a demultiplexer connecting the plurality of output pins and the signal generator, and the input circuit has a multiplexer connecting the plurality of input pins and the analog-to-digital converter.

[0008] This configuration allows for the acquisition of a digital signal that reflects the influence of the state of the circuit under test, either between one of multiple output pins and an external device, or between one of multiple input pins and an external device.

[0009] The electronic device in the third aspect is the electronic device in the second aspect, wherein the control unit controls the demultiplexer to output a signal from one of the multiple output pins by switching the connection state between the multiple output pins and the signal generator, and controls the multiplexer to input a signal input to one of the multiple input pins to the analog-to-digital converter by switching the connection state between the multiple input pins and the analog-to-digital converter.

[0010] With this configuration, one of several output pins can be selected by the demultiplexer, and one of several input pins can be selected by the multipleplexer. Therefore, the circuit under test can be connected to the signal generator and analog-to-digital converter as needed.

[0011] The electronic device of the fourth aspect is an electronic device of any one of the first to third aspects, wherein the control unit is configured to control the signal generator to generate the output signal from the signal generator, the output signal is input to the input pin via the external device and the circuit under test, and then input to the control unit via the analog-to-digital converter, and the control unit is configured to calculate the frequency response of the circuit under test based on the signal based on the output signal input from the analog-to-digital converter.

[0012] This configuration allows the frequency response of the circuit under test to be obtained. In the fifth aspect of the electronic device, the control unit is configured to determine an abnormality in the circuit under test based on a comparison between the frequency response of the circuit under test and a predetermined value.

[0013] This configuration allows for the appropriate determination of abnormalities in the circuit under test based on its frequency response. The sixth aspect of the electronic device is that, in any one of the first to third aspects of the electronic device, the control unit is configured to determine abnormalities in the circuit under test based on the signal input from the analog-to-digital converter.

[0014] According to this configuration, abnormalities in the circuit under test can be suitably determined by the frequency response of the circuit under test. The electronic device of the seventh aspect is configured such that, in the electronic device of the fourth aspect, the control unit controls the signal generator to generate the output signal from the signal generator based on a command from the external device received by the communication unit, and calculates the frequency response of the circuit under test based on a signal based on the output signal input from the analog-to-digital converter.

[0015] This configuration allows for the appropriate calculation of the frequency response of the circuit under test based on commands from an external device. In the electronic device of the eighth aspect, the control unit is configured to control the communication unit to output the result of determining an abnormality in the circuit under test to the external device.

[0016] According to this configuration, the result of determining whether the circuit under test has an abnormality is output to an external device, so that the user can check the result via the external device. The electronic system of the ninth aspect comprises one of the electronic devices of the first to eighth aspects and the external device.

[0017] With this configuration, a digital signal that reflects the influence of the state of the circuit under test can be obtained using the digital signal input from the analog-to-digital converter, thus enabling suitable calculations related to the circuit under test.

[0018] The tenth abnormality determination method is an abnormality determination method for determining an abnormality in a circuit under test, which is performed by an electronic device connected to the circuit under test, wherein the electronic device comprises a control unit, an output pin which is different from a power supply pin and can be connected to an external device, a signal generator provided in an output circuit connecting the control unit and the output pin, an input pin which is different from the power supply pin and can be connected to the external device, and an analog-to-digital converter provided in an input circuit connecting the input pin and the control unit, wherein the control unit performs a process of controlling the signal generator to generate an output signal from the signal generator, the control unit performs a process of calculating the frequency response of the circuit under test connected between the output pin and the external device, or between the input pin and the external device, based on a signal based on the output signal input from the analog-to-digital converter, and the control unit performs a process of determining an abnormality in the circuit under test based on the frequency response of the circuit under test.

[0019] With this configuration, the control unit can use the digital signal input from the analog-to-digital converter to acquire a digital signal that reflects the influence of the state of the circuit under test, thereby enabling it to suitably perform calculations related to the circuit under test.

[0020] This is a block diagram showing the electrical configuration of the electronic system of the embodiment when the circuit under test is located between the output pin and an external device. This is a circuit diagram showing an example of the circuit under test. This is a block diagram showing the electrical configuration of the electronic system of the embodiment when the circuit under test is located between an external device and an input pin. This is a flowchart of the abnormality determination process of the circuit under test performed by the control unit in Figure 1. This is a graph showing the frequency characteristics when the circuit under test includes a voltage divider circuit and a low-pass filter. This is a graph showing the frequency characteristics when the circuit under test includes a voltage divider circuit and a high-pass filter. This is a graph showing the frequency characteristics when the circuit under test includes a voltage divider circuit, a low-pass filter, and a high-pass filter. This is a block diagram showing the electrical configuration of the electronic system of the first modification example. This is a block diagram showing the electrical configuration of the electronic system of the second modification example. This is a block diagram showing the electrical configuration of the electronic system of the third modification example.

[0021] <Electronic System> An electronic system 10 comprising the electronic device 40 of the embodiment will be described with reference to Figures 1 to 4.

[0022] The electronic system 10 shown in Figure 1 is a system in which an electronic device 40, using an external device 30, determines an abnormality in a circuit under test 20 connected to the electronic device 40. The electronic device 40 is connected to the circuit under test 20. The electronic device 40 measures the state of the circuit under test 20. The electronic system 10 comprises the electronic device 40 and the external device 30. In addition to the electronic device 40 and the external device 30, the electronic system 10 also comprises the circuit under test 20. The electronic device 40 and the circuit under test 20 are installed, for example, in electrical equipment. The circuit under test 20 is a circuit used when using the electrical equipment. The electronic device 40 controls the function of the electrical equipment, for example, via the circuit under test 20. The external device 30 is a device separate from the electrical equipment.

[0023] Each component of the electronic device 40 is mounted, for example, on a single substrate. The circuit under test 20 is arranged, for example, around the electronic device 40. The circuit under test 20 is electrically connectable to the electronic device 40. The circuit under test 20 is mounted on the same substrate as the electronic device 40. The electronic device 40 is configured, for example, as a single semiconductor module. The circuit under test 20 may be mounted on a different substrate from the electronic device 40.

[0024] <Electronic Devices> The electronic device 40 includes a control unit 41. The control unit 41 is configured, for example, to control the functions of an electrical device. The control unit 41 includes, for example, a microcomputer and a memory that stores a program for operating the microcomputer. The control unit 41 may be configured as a circuit including one or more processors that execute various processes according to a computer program (software), one or more dedicated hardware circuits such as an Application Specific Integrated Circuit (ASIC) that executes at least some of the various processes, or a combination thereof. The processor includes a CPU (Central Processing Unit) and memory such as RAM (Random Access Memory) and ROM (Read Only Memory). The memory stores program code or instructions configured to cause the CPU to execute processes. Memory, or computer-readable media, includes any available media that can be accessed by a general-purpose or dedicated computer.

[0025] The electronic device 40 is equipped with power pins 42 for supplying power from the power supply 11 to the control unit 41. The power supply 11 may be a battery provided in the electrical equipment, or it may be an AC power supply connected to the electrical equipment. If the power supply 11 is an AC power supply, the AC power is converted to DC power and supplied to the control unit 41.

[0026] The electronic device 40 includes output pins 45 distinct from the power pins 42. The output pins 45 are pins for outputting signals to the outside of the electronic device 40. The electronic device 40 may, for example, have multiple output pins 45. Each of the multiple output pins 45 is connected to an electrical circuit. All of the multiple output pins 45 may be connected to different electrical circuits, or two or more of the multiple output pins 45 may be connected to different parts of the same electrical circuit.

[0027] The electronic device 40 includes a signal generator 47. The signal generator 47 is provided in an output circuit 46 that connects the control unit 41 and the output pins 45. The output circuit 46 has a demultiplexer 48. The demultiplexer 48 connects the signal generator 47 to a plurality of output pins 45. The demultiplexer 48 connects one of the plurality of output pins 45 to the signal generator 47.

[0028] The electronic device 40 includes input pins 49 distinct from the power supply pins 42. The input pins 49 are pins for inputting signals to the control unit 41. The electronic device 40 includes a plurality of input pins 49. Each of the plurality of input pins 49 is connected to an electrical circuit. All of the plurality of input pins 49 may be connected to different electrical circuits, or two or more of the plurality of input pins 49 may be connected to different parts of the same electrical circuit.

[0029] The electronic device 40 includes an analog-to-digital converter (ADC) 50. The analog-to-digital converter 50 is provided in an input circuit 51 that connects an input pin 49 to a control unit 41. The input circuit 51 has a multiplexer 52. The multiplexer 52 connects a plurality of input pins 49 to the analog-to-digital converter 50. The multiplexer 52 connects one of the plurality of input pins 49 to the analog-to-digital converter 50. The analog-to-digital converter 50 is used, for example, only for calculating the frequency response of the circuit under test 20. The electronic device 40 does not include any analog-to-digital converters other than the analog-to-digital converter 50 used, for example, for calculating the frequency response of the circuit under test 20.

[0030] The electronic device 40 includes a communication unit 53. The communication unit 53 is configured to be connected to an external device 30 so as to be able to communicate with the external device 30. The communication unit 53 may be configured to communicate with the external device 30 via wired communication, for example. The communication unit 53 may also be configured to communicate with the external device 30 via wireless communication, for example. The communication unit 53 receives commands from the external device 30 to generate an output signal from the signal generator 47. The communication unit 53 transmits the state of the circuit under test 20 to the external device 30.

[0031] The electronic device 40 includes, for example, a bus 54. The bus 54 connects the control unit 41 to the various components of the electronic device 40. The control unit 41 transmits control signals via the bus 54 to the signal generator 47, the demultiplexer 48, the analog-to-digital converter 50, the multiplexer 52, and the communication unit 53. Digital signals are input to the control unit 41 from the analog-to-digital converter 50 via the bus 54. Communication signals are input to the control unit 41 from the communication unit 53 via the bus 54.

[0032] <External Device> The external device 30 is a device for diagnosing abnormalities in the circuit under test 20. The external device 30 includes, for example, a first connection part for connecting to the output pin 45 or the circuit under test 20, and a second connection part for connecting to the input pin 49 or the circuit under test 20. The first connection part and the second connection part are, for example, test probes. The output pin 45 can be connected to the external device 30 by the first connection part of the external device 30. The input pin 49 can be connected to the external device 30 by the second connection part of the external device 30. The first connection part is connected to the second connection part by electrical wiring or the like. For example, the external device 30 is configured to transmit the signal input from the output pin 45 or the circuit under test 20 to the first connection part to the second connection part without processing. In this embodiment, no electronic components such as elements are provided in the electrical wiring between the first connection part and the second connection part.

[0033] <Circuit under test> The circuit under test 20 shown in Figures 1 and 2 is any one of the multiple electrical circuits connected to the multiple input pins 49 and the multiple electrical circuits connected to each of the multiple output pins 45. Figure 2 shows an example of the circuit under test 20, which is a voltage divider circuit having a low-pass characteristic. The circuit under test 20 in Figure 2 includes a first resistor 21, a second resistor 22, and a capacitor 23. The type of circuit under test 20 is not limited. The circuit under test 20 may include only one circuit having a predetermined function, or it may include multiple circuits, each having a predetermined function.

[0034] As shown in Figures 1 and 3, the circuit under test 20 is connected between the output pin 45 and the external device 30, or between the input pin 49 and the external device 30. In Figure 1, the circuit under test 20 is connected between the input pin 49 and the external device 30. In Figure 3, the circuit under test 20 is connected between the output pin 45 and the external device 30.

[0035] <Abnormality Determination of the Circuit Under Test> The electronic device 40 connected to the circuit under test 20 executes an abnormality determination method to determine if there is an abnormality in the circuit under test 20. When abnormality determination is performed on the circuit under test 20 connected to the input pin 49 as shown in Figure 1, an external device 30 is connected to the circuit under test 20 and one of the multiple output pins 45 by an operator or the like before the abnormality determination is performed by the electronic device 40. When abnormality determination is performed on the circuit under test 20 connected to the output pin 45 as shown in Figure 3, an external device 30 is connected to the circuit under test 20 and one of the multiple input pins 49 by an operator or the like before the abnormality determination is performed by the electronic device 40. In addition, the external device 30 is connected to the communication unit 53 so that it can communicate with the communication unit 53.

[0036] The control unit 41 performs an abnormality determination based on a command to perform an abnormality determination transmitted from the communication unit 53, for example. Hereinafter, the command to perform an abnormality determination will also be referred to as a determination command. The determination command is transmitted from the external device 30 to the communication unit 53 by, for example, operating an operation unit provided on the external device 30. The determination command includes, for example, information that can identify the circuit under test 20. When the control unit 41 performs an abnormality determination of the circuit under test 20 based on the determination command, it controls the demultiplexer 48 so that one of the multiple output pins 45 is connected to the control unit 41, depending on the circuit under test 20. When the control unit 41 starts an abnormality determination of the circuit under test 20 based on the determination command, it controls the multiplexer 52 so that one of the multiple input pins 49 is connected to the control unit 41, depending on the circuit under test 20.

[0037] The control unit 41 controls the demultiplexer 48 to output a signal from one of the multiple output pins 45 by switching the connection state between the multiple output pins 45 and the signal generator 47. The control unit 41 controls the multipleplexer 52 to input a signal input to one of the multiple input pins 49 to the analog-to-digital converter 50 by switching the connection state between the multiple input pins 49 and the analog-to-digital converter 50.

[0038] The control unit 41 is configured to control the signal generator 47 to generate an output signal from the signal generator 47. Based on a command from the external device 30 received by the communication unit 53, the control unit 41 controls the signal generator 47 to generate an output signal from the signal generator 47. For example, when the communication unit 53 receives a determination command, the control unit 41 controls the demultiplexer 48 and the multiplexer 52 to create a state in which the signal generator 47, one output pin 45, the external device 30, the circuit under test 20, one input pin 49, and the analog-to-digital converter 50 are electrically connected, and then controls the signal generator 47 to generate an output signal from the signal generator 47. The output signal may be a square wave or a sine wave. The output signal is input to the input pin 49 via the external device 30 and the circuit under test 20, and then input to the control unit 41 via the analog-to-digital converter 50.

[0039] The control unit 41 is configured to calculate the frequency response of the circuit under test 20 based on a digital signal, which is a signal based on the output signal input from the analog-to-digital converter 50. The output signal input to the analog-to-digital converter 50 is affected by the state of the circuit under test 20 because it has passed through the circuit under test 20. The output signal input to the analog-to-digital converter 50 is converted from an analog signal to a digital signal by the analog-to-digital converter 50. The control unit 41 calculates the frequency response, for example, by Fourier transform. The control unit 41 is configured to determine an abnormality in the circuit under test 20 based on the signal input from the analog-to-digital converter 50. An abnormality in the circuit under test 20 includes, for example, incorrect parts, defective parts, and poor connections. The control unit 41 is configured to determine an abnormality in the circuit under test 20 based on a comparison of the frequency response of the circuit under test 20 with a predetermined value. The predetermined value corresponds, for example, to a value related to the frequency response obtained when the circuit under test 20 is normal. The predetermined values ​​are, for example, stored in the memory of the control unit 41 for each circuit under test 20. The control unit 41 determines that the state of the circuit under test 20 is normal if the value relating to the frequency response of the circuit under test 20 is within a predetermined range that includes the predetermined value. The control unit 41 determines that the state of the circuit under test 20 is abnormal if the value relating to the frequency response of the circuit under test 20 is outside the predetermined range.

[0040] When the period T of the output signal output by the signal generator 47 is taken as the period T, the control unit 41 obtains the gain and phase of the period T signal by, for example, performing a Fourier transform on the digital signal input from the analog-to-digital converter 50 using a sine wave of period T. If the circuit under test 20 is a voltage divider circuit, the gain is determined by the voltage division ratio. Therefore, the control unit 41 determines whether the circuit under test 20 is in a normal or abnormal state by comparing the calculated gain with a predetermined value which is the expected value of the gain. If the circuit under test 20 is a low-pass filter or a high-pass filter, the gain and phase are determined by the circuit constants that constitute the filter, so the predetermined value may include both the gain and the phase. If the circuit under test 20 includes two or more of the low-pass filter, high-pass filter, and voltage divider circuit, the predetermined value includes both the gain and the phase.

[0041] The control unit 41 is configured to control the communication unit 53 so as to output the result of determining whether the circuit under test 20 is abnormal to the external device 30. For example, the control unit 41 is configured to control the communication unit 53 so as to output to the external device 30 whether the state of the circuit under test 20 is normal or abnormal.

[0042] The external device 30 includes, for example, a display unit that indicates whether the state of the circuit under test 20 is abnormal or normal. The external device 30 may also include a notification unit that informs the operator that the state of the circuit under test 20 is abnormal if it is abnormal. The external device 30 may also include a storage unit that stores whether the circuit under test 20 is abnormal or normal.

[0043] Referring to Figure 4, the process by which the control unit 41 determines an abnormality in the circuit under measurement 20 will be described. For example, when the control unit 41 receives an abnormality determination command from the external device 30, it starts processing and proceeds to step S11 of the flowchart shown in Figure 4.

[0044] In step S11, the control unit 41 controls the multiplexer 52 and the demultiplexer 48 to connect to the circuit under measurement 20, and then proceeds to step S12. The multiplexer 52 and the demultiplexer form a state in which the circuit under measurement 20 shown in FIG. 3 is connected between the output pin 45 and the external device 30, or a state in which the circuit under measurement 20 shown in FIG. 1 is connected between the input pin 49 and the external device 30.

[0045] In step S12, the control unit 41 controls the signal generator 47 to output a signal from the signal generator 47, and then proceeds to step S13. In step S13, the control unit 41 calculates the frequency response of the signal input from the analog-to-digital converter 50, and then proceeds to step S14.

[0046] In step S14, the control unit 41 determines whether the frequency response is an abnormal value. If the frequency response is an abnormal value, the control unit 41 proceeds to step S15. In step S15, the control unit 41 transmits the abnormal state from the communication unit 53 to the external device 30 and ends the process.

[0047] If the frequency response is not an abnormal value in step S14, the control unit 41 proceeds to step S16. In step S16, the control unit 41 transmits the normal state from the communication unit 53 to the external device 30 and ends the process.

[0048] The operation of this embodiment will be described. For example, when the output signal generated by the signal generator 47 passes through the circuit under measurement 20, the rise time and the fall time of the output signal passing through the circuit under measurement 20 change according to the state of the circuit under measurement 20. However, in terms of the rise time and the fall time of the output signal, when the circuit under measurement 20 includes a plurality of electric circuits, it is difficult to determine whether an abnormality has occurred and, if an abnormality has occurred, in which of the plurality of electric circuits the abnormality has occurred. Since the control unit 41 of this embodiment determines the abnormality of the circuit under measurement 20 based on the frequency response, even when the circuit under measurement 20 includes a plurality of electric circuits, the abnormal part of the circuit under measurement 20 can be specified.

[0049] Figures 5 to 7 show examples of frequency responses when the circuit under test 20 includes two or more of the following: a low-pass filter, a high-pass filter, and a voltage divider circuit. Figure 5 shows an example of frequency response when the circuit under test 20 consists of a voltage divider circuit and a low-pass filter connected in cascaded order. The solid line L11 shows the relationship between frequency and gain when the voltage divider circuit is in a normal state and the low-pass filter is in a normal state. The dashed line L12 shows the relationship between frequency and gain when the voltage divider circuit is in a normal state and the low-pass filter is in an abnormal state. The dashed line L13 shows the relationship between frequency and gain when the voltage divider circuit is in an abnormal state and the low-pass filter is in a normal state. The broken line L14 shows the relationship between frequency and gain when the voltage divider circuit is in an abnormal state and the low-pass filter is in an abnormal state.

[0050] The linearity when the voltage divider circuit shown by the dashed line L13 and the dashed line L14 is in an abnormal state is the same as the linearity when the voltage divider circuit is in a normal state, shown by the solid line L11 and the double-dotted line L12, but shifted horizontally in the gain axis direction. The linearity when the low-pass filter shown by the double-dotted line L12 and the dashed line L14 is in an abnormal state is the same as the linearity when the low-pass filter is in a normal state, shown by the solid line L11 and the dashed line L13, but with the inflection point shifted in the frequency axis direction. Since the solid line L11, the double-dotted line L12, the dashed line L13, and the dashed line L14 all show different linearities, the control unit 41 can identify which of the voltage divider circuit and the low-pass filter is in an abnormal state, for example, by using the gain at a predetermined frequency and at least one of the frequencies at a predetermined gain.

[0051] Figure 6 shows an example of the frequency response when the circuit under test 20 is a series-connected voltage divider circuit and a high-pass filter. The solid line L21 shows the relationship between frequency and gain when the voltage divider circuit is in a normal state and the high-pass filter is in a normal state. The dashed line L22 shows the relationship between frequency and gain when the voltage divider circuit is in a normal state and the high-pass filter is in an abnormal state. The dashed line L23 shows the relationship between frequency and gain when the voltage divider circuit is in an abnormal state and the high-pass filter is in a normal state. The dashed line L24 shows the relationship between frequency and gain when the voltage divider circuit is in an abnormal state and the high-pass filter is in an abnormal state.

[0052] The linearity when the voltage divider circuit shown by the dashed line L23 and the dashed line L24 is in an abnormal state is the same as the linearity when the voltage divider circuit is in a normal state, shown by the solid line L21 and the double-dotted line L22, but shifted horizontally in the gain axis direction. The linearity when the high-pass filter shown by the double-dotted line L22 and the dashed line L24 is in an abnormal state is the same as the linearity when the high-pass filter is in a normal state, shown by the solid line L21 and the dashed line L23, but with the inflection point shifted in the frequency axis direction. Since the solid line L21, the double-dotted line L22, the dashed line L23, and the dashed line L24 all show different linearities, the control unit 41 can identify which of the voltage divider circuit and the high-pass filter is in an abnormal state, for example, by using the gain at a predetermined frequency and at least one of the frequencies at a predetermined gain.

[0053] Figure 7 shows an example of the frequency response when the circuit under test 20 is a series of connected voltage divider circuits, a low-pass filter, and a high-pass filter. The solid line L31 shows the relationship between frequency and gain when the voltage divider circuit is in a normal state, the low-pass filter is in a normal state, and the high-pass filter is in a normal state. The dashed line L32 shows the relationship between frequency and gain when the voltage divider circuit is in a normal state, the low-pass filter is in a normal state, and the high-pass filter is in an abnormal state. The dashed line L33 shows the relationship between frequency and gain when the voltage divider circuit is in a normal state, the low-pass filter is in an abnormal state, and the high-pass filter is in a normal state. The dashed line L34 shows the relationship between frequency and gain when the voltage divider circuit is in an abnormal state, the low-pass filter is in a normal state, and the high-pass filter is in a normal state.

[0054] Since the solid line L31, the dashed line L32, the single dashed line L33, and the dashed line L34 all show different linearities, the control unit 41 can, for example, use the gain at a predetermined frequency and at least one of the frequencies at a predetermined gain to determine which of the voltage divider circuit, high-pass filter, and low-pass filter is in an abnormal state.

[0055] The effects of this embodiment will now be explained. (1) The electronic device 40 can receive information about the signal generated by the signal generator 47 from the input pin 49 via the circuit under test 20 and the external device 30. The signal received from the input pin 49 is converted into a digital signal by the analog-to-digital converter 50 and then input to the control unit 41. Therefore, the control unit 41 can obtain a digital signal that reflects the influence of the state of the circuit under test 20 using the digital signal received from the analog-to-digital converter 50, and thus can suitably perform calculations related to the circuit under test 20.

[0056] (2) The electronic device 40 can acquire a digital signal that reflects the influence of the state of the circuit under test 20 connected between one of the multiple output pins 45 and the external device 30, or between one of the multiple input pins 49 and the external device 30.

[0057] (3) The control unit 41 can select one of the multiple output pins 45 by the demultiplexer 48 and one of the multiple input pins 49 by the multipleplexer 52. Therefore, the circuit under test 20 can be connected to the signal generator 47 and the analog-to-digital converter 50 as needed. When using an ICT inspection device to determine abnormalities in multiple electrical circuits, it is necessary to sequentially connect each of the two inspection probes to the test pads corresponding to the electrical circuits to be determined to be abnormal. However, with the electronic system 10, abnormalities in multiple electrical circuits can be easily determined.

[0058] (4) The control unit 41 is configured to calculate the frequency response of the circuit under test 20 based on the signal based on the output signal input from the analog-to-digital converter 50. Therefore, the control unit 41 can obtain the frequency response of the circuit under test 20.

[0059] (5) The control unit 41 can suitably determine if there is an abnormality in the circuit under test 20 based on a comparison of the frequency response of the circuit under test 20 with a predetermined value. (6) The control unit 41 can suitably determine if there is an abnormality in the circuit under test 20 based on the signal input from the analog-to-digital converter 50.

[0060] (7) The control unit 41 controls the signal generator 47 to generate an output signal based on a determination command from the external device 30 received by the communication unit 53, and calculates the frequency response of the circuit under test 20 based on the signal based on the output signal input from the analog-to-digital converter 50. Therefore, the control unit 41 can suitably calculate the frequency response of the circuit under test 20 based on the command from the external device 30.

[0061] (8) The control unit 41 outputs the result of determining an abnormality in the circuit under test 20 to the external device 30, so that the user can confirm the determination result via the external device 30. (9) The electronic system 10 comprises the electronic device 40 and the external device 30. Therefore, the electronic system 10 can use the digital signal input from the analog-to-digital converter 50 to acquire a digital signal that reflects the influence of the state of the circuit under test 20, and thus can suitably perform calculations related to the circuit under test 20.

[0062] (10) When using an ICT inspection device to determine abnormalities in an electrical circuit, it is necessary to provide a test pad for each circuit whose abnormality is to be determined. The electronic device 40 of this embodiment uses the output pins 45 and input pins 49 provided on the electronic device 40 to determine abnormalities in the circuit under test 20, thus contributing to a reduction in the number of test pads. Furthermore, in a virtual electronic device that receives an external signal for inspection, such as an ICT inspection device, it is necessary to synchronize the timing of the signal input from the inspection device with the timing of the frequency response calculation in the virtual electronic device. In the electronic device 40 of this embodiment, a signal generator 47 is provided on the electronic device 40, and the control unit 41 controls the signal generator 47, thus reducing the communication load during abnormality determination. Therefore, the control unit 41 can shorten the time required for abnormality determination. In addition, since the output pins 45 and input pins 49 of the electronic device 40 of this embodiment are connected via an external device 30, the configuration of the electrical equipment can be simplified compared to a configuration in which the wiring for abnormality determination of the circuit under test 20 is provided on the electronic device 40 or the electrical equipment on which the electronic device 40 is provided.

[0063] (11) The analog-to-digital converter 50 is used solely for calculating the frequency response of the circuit under test 20. When an abnormality is detected in the circuit under test 20, the other circuits of the electronic device 40 can be deactivated, thus reducing the number of components required for noise countermeasures of the signal input to the analog-to-digital converter 50. Furthermore, the analog-to-digital converter 50 can be used with low precision within the range in which the frequency response of the circuit under test 20 can be calculated. For this reason, a relatively small analog-to-digital converter 50 can be used for the electronic device 40, thus suppressing the increase in size of the electronic device 40.

[0064] <Examples of Modifications> In addition to the embodiments described above, the electronic devices, electronic systems equipped with the electronic devices, and abnormality detection methods performed by the electronic devices may also be, for example, the modified examples shown below, and combinations of at least two non-contradictory modified examples.

[0065] As shown in Figure 8, the external device 30 may include an amplifier 31 between the first connection and the second connection. The amplifier 31 amplifies the voltage of the output signal input from the output pin 45 and outputs it to the input pin 49. For example, if the circuit under test 20 includes a voltage divider circuit that significantly reduces the voltage, the amplifier 31 can ensure that the voltage of the signal input to the analog-to-digital converter 50 is maintained, thus reducing the accuracy of abnormality detection.

[0066] As shown in Figure 9, the electronic device 40 may include an amplifier 55 provided between the multiplexer 52 and the analog-to-digital converter 50. The amplifier 55 amplifies the voltage of the output signal input to the input pin 49 and outputs it to the analog-to-digital converter 50. For example, if the circuit under test 20 includes a voltage divider circuit that significantly reduces the voltage, the amplifier 55 can ensure that the voltage of the signal input to the analog-to-digital converter 50 is maintained, thus preventing a decrease in the accuracy of abnormality detection.

[0067] As shown in Figure 10, the electronic device 40 may include a low-pass filter 56 provided between the multiplexer 52 and the analog-to-digital converter 50. The low-pass filter 56 removes noise from the output signal input to the input pin 49 and outputs it to the analog-to-digital converter 50. The low-pass filter 56 has a cutoff frequency that is, for example, half the sampling rate of the analog-to-digital converter 50.

[0068] - The electronic device 40 does not need to have a demultiplexer 48. In this modified example, the signal generator 47 is always connected to one output pin 45. In this modified example as well, if an electrical circuit that can be the circuit under test 20 is connected to each of the multiple input pins 49, the control unit 41 can use the multipleplexer 52 to set one of the electrical circuits connected to each of the multiple input pins 49 as the circuit under test 20.

[0069] - The electronic device 40 does not necessarily have to include a multiplexer 52. In this modified example, one input pin 49 is always connected to the analog-to-digital converter 50. In this modified example as well, if an electrical circuit that could be the circuit under test 20 is connected to each of the multiple output pins 45, the control unit 41 can use the demultiplexer 48 to set one of the circuits connected to each of the multiple output pins 45 as the circuit under test 20.

[0070] - The electronic device 40 does not necessarily have to include a demultiplexer 48 and a multiplexer 52. In this modified example, the signal generator 47 is always connected to one output pin 45, and one input pin 49 is always connected to the analog-to-digital converter 50. In this modified example as well, the electrical circuit connected to one output pin 45 and the electrical circuit connected to one input pin 49 can be set as the circuit under test 20.

[0071] The control unit 41 may be configured to initiate abnormality determination of the circuit under test 20 based on a judgment command other than that from the external device 30. In this modified example, for example, the electronic device 40 or the electronic device on which the electronic device 40 is installed is provided with an operating unit for initiating abnormality determination of the circuit under test 20. When the operating unit is operated, the control unit 41 initiates abnormality determination of the circuit under test 20.

[0072] - The control unit 41 may be configured to store the calculated frequency response of the circuit under test 20 in a memory unit included in the control unit 41. The control unit 41 may also be configured to transmit the calculated frequency response of the circuit under test 20 to an external device 30. In this modified example, the control unit 41 does not need to perform abnormality determination of the circuit under test 20. In this modified example, the external device 30 may perform abnormality determination of the circuit under test 20 based on the frequency response of the circuit under test 20 received by the external device 30.

[0073] ・The embodiments of the electronic device, the electronic system equipped with the electronic device, and the abnormality detection method performed by the electronic device have been described above. It should be understood that various modifications to the form and details are possible without departing from the spirit and scope of the electronic device, the electronic system equipped with the electronic device, and the abnormality detection method performed by the electronic device as described in the claims.

[0074] 10...Electronic system 20...Circuit under test 30...External device 40...Electronic device 41...Control unit 42...Power supply pin 45...Output pin 46...Output circuit 47...Signal generator 48...Demultiplexer 49...Input pin 50...Analog-to-digital converter 51...Input circuit 52...Multiplexer 53...Communication unit

Claims

1. An electronic device (40) connected to a circuit under test (20) for measuring the state of the circuit under test (20), comprising: a control unit (41); an output pin (45) that is different from the power supply pin (42) and can be connected to an external device (30); a signal generator (47) provided in an output circuit (46) connecting the control unit (41) and the output pin (45); an input pin (49) that is different from the power supply pin (42) and can be connected to the external device (30); an analog-to-digital converter (50) provided in an input circuit (51) connecting the input pin (49) and the control unit (41); and a communication unit (53) that receives a command from the external device (30) to generate an output signal from the signal generator (47) and transmits the state of the circuit under test (20) to the external device (30), An electronic device in which the circuit under test (20) is connected between the output pin (45) and the external device (30), or between the input pin (49) and the external device (30).

2. The electronic device according to claim 1, wherein the output pin (45) is one of a plurality of output pins (45), the input pin (49) is one of a plurality of input pins (49), the output circuit has a demultiplexer (48) connecting the plurality of output pins (45) and the signal generator (47), and the input circuit has a multipleplexer (52) connecting the plurality of input pins (49) and the analog-to-digital converter (50).

3. The electronic device according to claim 2, wherein the control unit (41) controls the demultiplexer (48) to output a signal from one of the plurality of output pins (45) by switching the connection state between the plurality of output pins (45) and the signal generator (47), and controls the multiplexer (52) to input a signal input to one of the plurality of input pins (49) to the analog-to-digital converter (50) by switching the connection state between the plurality of input pins (49) and the analog-to-digital converter (50).

4. The electronic device according to any one of claims 1 to 3, wherein the control unit (41) is configured to control the signal generator (47) to generate the output signal from the signal generator (47), the output signal is input to the input pin (49) via the external device (30) and the circuit under test (20), and then input to the control unit (41) via the analog-to-digital converter (50), and the control unit (41) is configured to calculate the frequency response of the circuit under test (20) based on the signal based on the output signal input from the analog-to-digital converter (50).

5. The electronic device according to claim 4, wherein the control unit (41) is configured to determine an abnormality in the circuit under test (20) based on a comparison of the frequency response of the circuit under test (20) with a predetermined value.

6. The electronic device according to any one of claims 1 to 3, wherein the control unit (41) is configured to determine an abnormality in the circuit under test (20) based on a signal input from the analog-to-digital converter (50).

7. The electronic device according to claim 4, wherein the control unit (41) is configured to control the signal generator (47) to generate the output signal from the signal generator (47) based on a command from the external device (30) received by the communication unit, and to calculate the frequency response of the circuit under test (20) based on a signal based on the output signal input from the analog-to-digital converter (50).

8. The electronic device according to claim 5, wherein the control unit (41) is configured to control the communication unit (53) to output the result of determining an abnormality in the circuit under test (20) to the external device (30).

9. An electronic system (10) comprising an electronic device (40) according to any one of claims 1 to 8, and the external device (30).

10. An abnormality determination method for determining an abnormality in a circuit under test (20) performed by an electronic device (40) connected to the circuit under test (20), wherein the electronic device (40) comprises: a control unit (41); an output pin (45) which is different from a power supply pin (42) and can be connected to an external device (30); a signal generator (47) provided in an output circuit (46) connecting the control unit (41) and the output pin (45); an input pin (49) which is different from a power supply pin (42) and can be connected to the external device (30); and an analog-to-digital converter (50) provided in an input circuit (51) connecting the input pin (49) and the control unit (41), wherein the control unit (41) controls the signal generator (47) to generate an output signal from the signal generator (47), An abnormality determination method comprising: a control unit (41) calculating the frequency response of the circuit under test (20) connected between the output pin (45) and the external device (30), or between the input pin (49) and the external device (30), based on a signal based on the output signal input from the analog-to-digital converter (50); and a control unit (41) determining an abnormality of the circuit under test (20) based on the frequency response of the circuit under test (20).

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