Anomaly detection system

Abstract

To provide an anomaly detection system that is able to detect the occurrence of anomaly in an LSI provided with an LDO (a low dropout) regulator as a power supply circuit.SOLUTION: There is provided an anomaly detection system including: an LDO regulator; a comparator configured to compare an output voltage of the LDO regulator with a predetermined threshold voltage lower than a final output voltage of the LDO regulator; a result determination unit configured to determine whether there is an anomaly in the LDO regulator, by using a comparison result in the comparator at a timing before a first point in time that a final output voltage in a case where the LDO regulator normally operates is reached and at a timing after the first point in time.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an anomaly detection system. [Background technology]

[0002] One type of regulator known is a stabilized power supply circuit (e.g., a linear regulator) that supplies a stable voltage power supply by utilizing a voltage drop across resistors or semiconductor elements. Among stabilized power supply circuits, a digitally controlled LDO (low dropout) regulator is known, which operates as a linear regulator even with a low input-output potential difference and is digitally controlled (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-201730 Summary of the Invention [Problem to be solved by the invention]

[0004] When an LDO regulator is used as a power supply circuit, an external capacitor is required for the LSI (large-scale integrated circuit). When products incorporating power supply circuits are tested for shipment, connection tests are conducted using actual operation. However, if the continuity between the LSI and the capacitor is cut off after shipment due to peeling solder or cracks on the LSI terminal or capacitor, the LDO will malfunction, causing abnormal oscillation or a drop in output.

[0005] The present disclosure has been made in view of the above points, and aims to provide an anomaly detection system that can detect the occurrence of an anomaly in an LSI that includes an LDO regulator as a power supply circuit. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, there is provided an anomaly detection system including: an LDO (low dropout) regulator; a comparator that compares an output voltage of the LDO regulator with a predetermined threshold voltage that is lower than a final output voltage of the LDO regulator; and a result determination unit that determines whether or not an abnormality exists in the LDO regulator using a comparison result from the comparator at a timing before a first point in time at which the final output voltage is reached when the LDO regulator operates normally and at a timing after the first point in time.

[0007] The result determining unit may determine whether or not there is an abnormality in the LDO regulator a plurality of times, at a timing before a first time point and a timing after the first time point.

[0008] The result determination unit may start determining whether or not there is an abnormality in the LDO regulator after the LDO regulator switches to an operating state.

[0009] The result determining unit may determine the presence or absence of an abnormality in the LDO regulator using a comparison result of the comparator at a timing after a second time point that is after the first time point and at which a test current larger than an actual operating current flows.

[0010] The threshold voltage before the first time point and the threshold voltage after the second time point may be different voltages. [Effects of the Invention]

[0011] According to the present disclosure, it is possible to provide an abnormality detection system that can detect the occurrence of an abnormality in an LSI that includes an LDO regulator as a power supply circuit. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a diagram illustrating a schematic configuration of an anomaly detection system according to a first embodiment. [Figure 2] 3A to 3C are diagrams illustrating timings for determining whether or not an abnormality has occurred by the anomaly detection system according to the first embodiment. [Figure 3] 4 is a flowchart showing the operation of the anomaly detection system according to the first embodiment. [Figure 4] 10 is a diagram illustrating the timing for determining whether or not an abnormality has occurred by the anomaly detection system according to the second embodiment. FIG. [Figure 5] 10 is a flowchart showing the operation of the anomaly detection system according to the second embodiment. [Figure 6] FIG. 10 is a diagram illustrating a schematic configuration of an anomaly detection system according to a third embodiment. [Figure 7] FIG. 11 is a diagram illustrating the timing for determining whether or not an abnormality has occurred by the anomaly detection system according to the third embodiment. [Figure 8] 10 is a flowchart showing the operation of the anomaly detection system according to the third embodiment. [Figure 9] FIG. 10 is a diagram illustrating a schematic configuration of an anomaly detection system according to a fourth embodiment. [Figure 10] FIG. 10 is a diagram illustrating the timing for determining whether or not an abnormality has occurred by the abnormality detection system according to the fourth embodiment. [Figure 11] 10 is a flowchart showing the operation of the anomaly detection system according to the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] An example of an embodiment of the present disclosure will be described below with reference to the drawings. The same reference numerals are used throughout the drawings to designate identical or equivalent components and parts. The dimensional proportions of the drawings are exaggerated for illustrative purposes and may differ from the actual proportions.

[0014] (First embodiment) Fig. 1 is a diagram showing a schematic configuration of an anomaly detection system according to a first embodiment of the present disclosure. The anomaly detection system 10 shown in Fig. 1 is a system that detects the occurrence of an anomaly in which electrical continuity between an LDO regulator 11 and a capacitor C1 is interrupted. The anomaly detection system 10 includes the LDO regulator 11, a reference voltage (VREF) generator 12, a comparator (CMP) 13, a timing generation unit 14, and a result determination unit 15.

[0015] The LDO regulator 11 is a power supply circuit that supplies a voltage, and is activated upon receiving an activation signal from the timing generation unit 14 to start supplying a voltage.

[0016] The reference voltage generator 12 generates a predetermined reference voltage. In this embodiment, the reference voltage generator 12 generates a reference voltage that serves as a first voltage threshold. The first voltage threshold is a voltage value that is lower than the final output voltage of the LDO regulator 11 by a predetermined amount.

[0017] The comparator 13 compares the voltage value of the voltage output by the LDO regulator 11 with the first voltage threshold value generated by the reference voltage generator 12, and outputs the comparison result to the result determination unit 15.

[0018] After a predetermined time has elapsed since the timing generation unit 14 output the activation signal to the LDO regulator 11, the timing generation unit 14 outputs a determination timing signal for the result determination unit 15 to make a determination based on the comparison result output from the comparator 13. In this embodiment, after a predetermined time has elapsed since the timing generation unit 14 output the activation signal to the LDO regulator 11, the timing generation unit 14 outputs a second determination timing signal to the result determination unit 15.

[0019] The result determination unit 15 determines whether or not an abnormality has occurred in which electrical continuity between the LDO regulator 11 and the capacitor C1 has been cut off, based on the comparison result output from the comparator 13, at the timing when the determination timing signal is received from the timing generation unit 14. If an abnormality has occurred in which electrical continuity between the LDO regulator 11 and the capacitor C1 has been cut off, the result determination unit 15 outputs an abnormality detection flag.

[0020] FIG. 2 is a diagram illustrating the timing at which the anomaly detection system 10 determines whether an anomaly has occurred. The horizontal axis of the graph in FIG. 2 represents time, and the vertical axis represents voltage. When the LDO regulator 11 and capacitor C1 are electrically connected, the voltage output by the LDO regulator 11 gradually increases after startup as capacitor C1 is charged, as shown by the solid line in the graph in FIG. 2, and reaches the final output voltage at some point. However, when the LDO regulator 11 and capacitor C1 are not electrically connected, the voltage output by the LDO regulator 11 rapidly increases after startup as capacitor C1 is not charged, as shown by the dashed line in the graph in FIG. 2.

[0021] Therefore, the timing generation unit 14 outputs a judgment timing signal to the result judgment unit 15 twice: once before the final output voltage is reached while the LDO regulator 11 and the capacitor C1 are conductive, and once after the final output voltage is reached.

[0022] When the result determination unit 15 receives the first timing determination signal, it determines that the voltage value of the voltage output by the LDO regulator 11 is normal if it is lower than the first voltage threshold value generated by the reference voltage generator 12, and determines that the voltage value is abnormal if it is higher. When the result determination unit 15 receives the second timing determination signal, it determines that the voltage value of the voltage output by the LDO regulator 11 is normal if it is higher than the first voltage threshold value generated by the reference voltage generator 12, and determines that the voltage value is abnormal if it is lower.

[0023] The anomaly detection system 10 has the configuration shown in FIG. 1 and can determine whether an anomaly has occurred that disconnects the electrical continuity between the LDO regulator 11 and the capacitor C1.

[0024] FIG. 3 is a flowchart showing the operation of the anomaly detection system according to the first embodiment of the present disclosure.

[0025] In step S101, the timing generation unit 14 outputs a start signal to the LDO regulator 11, thereby starting up the LDO regulator 11.

[0026] Following step S101, in step S102, the timing generation unit 14 waits for a predetermined time.

[0027] Following step S102, in step S103, the timing generation unit 14 outputs a first timing determination signal to the result determination unit 15, which then determines whether the measurement result from the comparator 13 is normal. Specifically, the result determination unit 15 determines whether the voltage value of the voltage output by the LDO regulator 11 is lower than the first voltage threshold value generated by the reference voltage generator 12.

[0028] If it is determined in step S103 that the measurement result from the comparator 13 is normal (step S103; Yes), the timing generating unit 14 waits for a predetermined time in step S104 following step S103.

[0029] Following step S104, in step S105, the timing generation unit 14 outputs a second timing determination signal to the result determination unit 15, causing the result determination unit 15 to determine whether the measurement result from the comparator 13 is normal. Specifically, the result determination unit 15 determines whether the voltage value of the voltage output by the LDO regulator 11 is higher than the first voltage threshold generated by the reference voltage generator 12.

[0030] If the result of the determination in step S105 is that the measurement result by the comparator 13 is normal (step S105; Yes), the abnormality detection system 10 determines that the electrical continuity between the LDO regulator 11 and the capacitor C1 is not cut off, and ends the process. That is, the result determination unit 15 does not output an abnormality detection flag.

[0031] On the other hand, if the result of the judgment in step S103 is that the measurement result by the comparator 13 is abnormal (step S103; No), or if the result of the judgment in step S105 is that the measurement result by the comparator 13 is abnormal (step S105; No), the result judgment unit 15 outputs an abnormality detection flag (step S106).

[0032] The anomaly detection system 10 executes the series of processes shown in FIG. 3, thereby determining whether an anomaly has occurred that disconnects the electrical continuity between the LDO regulator 11 and the capacitor C1.

[0033] (Second embodiment) The configuration of the anomaly detection system according to the second embodiment of the present disclosure is the same as the configuration of the anomaly detection system according to the first embodiment, and therefore a detailed description thereof will be omitted. When an abnormality occurs in which the electrical continuity between the LDO regulator 11 and the capacitor C1 is cut off, the output of the LDO regulator 11 may oscillate.

[0034] FIG. 4 is a diagram illustrating the timing for determining whether or not an anomaly has occurred by the anomaly detection system 10 according to the second embodiment. The horizontal axis of the graph in FIG. 4 represents time, and the vertical axis represents voltage. When the LDO regulator 11 and capacitor C1 are electrically connected, the voltage output by the LDO regulator 11 increases gradually after startup, as indicated by the solid line in the graph in FIG. 4, and reaches the final output voltage at some point. However, when the LDO regulator 11 and capacitor C1 are not electrically connected, the voltage output by the LDO regulator 11 increases rapidly after startup, as indicated by the dashed line in the graph in FIG. 4, and may become unstable and oscillate.

[0035] Therefore, in the anomaly detection system according to the second embodiment, the timing generation unit 14 outputs a timing determination signal to the result determination unit 15 multiple times before the final output voltage is reached while the LDO regulator 11 and capacitor C1 are conductive, and also outputs a timing determination signal to the result determination unit 15 multiple times after the final output voltage is reached while the LDO regulator 11 and capacitor C1 are conductive. The result determination unit 15 can improve its determination accuracy by making determinations multiple times before and after the final output voltage is reached while the LDO regulator 11 and capacitor C1 are conductive.

[0036] FIG. 5 is a flowchart showing the operation of the anomaly detection system according to the second embodiment of the present disclosure.

[0037] In step S111, the timing generation unit 14 outputs a start signal to the LDO regulator 11, thereby starting up the LDO regulator 11.

[0038] Following step S111, in step S112, the timing generation unit 14 waits for a predetermined time.

[0039] Following step S112, in step S113, the timing generation unit 14 outputs a timing determination signal n times to the result determination unit 15, causing the result determination unit 15 to determine n times whether the measurement result from the comparator 13 is normal. Specifically, the result determination unit 15 determines n times whether the voltage value of the voltage output by the LDO regulator 11 is lower than the first voltage threshold generated by the reference voltage generator 12.

[0040] If it is determined in step S113 that the n measurement results by the comparator 13 are normal (step S113; Yes), the timing generating unit 14 waits for a predetermined time in step S114 following step S113.

[0041] Following step S114, in step S115, the timing generation unit 14 outputs a timing determination signal n times to the result determination unit 15, causing the result determination unit 15 to determine whether the measurement result from the comparator 13 is normal. Specifically, the result determination unit 15 determines n times whether the voltage value of the voltage output by the LDO regulator 11 is higher than the first voltage threshold generated by the reference voltage generator 12.

[0042] If the result of the determination in step S115 is that the n-time measurement results by the comparator 13 are normal (step S115; Yes), the abnormality detection system 10 determines that the electrical continuity between the LDO regulator 11 and the capacitor C1 is not interrupted, and ends the process. That is, the result determination unit 15 does not output an abnormality detection flag.

[0043] On the other hand, if the result of the judgment in step S113 is that the measurement result in the comparator 13 is abnormal even once (step S113; No), or if the result of the judgment in step S105 is that the measurement result in the comparator 13 is abnormal even once (step S115; No), the result judgment unit 15 outputs an abnormality detection flag (step S116).

[0044] By executing the series of processes shown in FIG. 5, the anomaly detection system 10 can determine with higher accuracy than the first embodiment whether an anomaly has occurred in which electrical continuity between the LDO regulator 11 and the capacitor C1 is interrupted.

[0045] (Third embodiment) In low-power applications such as those using batteries, it is common for an LDO regulator to operate intermittently by switching between a standby state in which the output voltage is lowered to reduce power consumption, and a normal operating state in which the voltage is raised.The anomaly detection system according to the third embodiment determines whether an anomaly has occurred at the timing of switching to the operating state when intermittent operation is performed, switching between the standby state and the operating state.

[0046] Fig. 6 is a diagram showing a schematic configuration of an anomaly detection system according to a third embodiment of the present disclosure. The anomaly detection system 10 shown in Fig. 6 is a system that detects the occurrence of an anomaly in which electrical continuity between LDO regulators 11A and 11B and a capacitor C1 is interrupted. The anomaly detection system 10 includes LDO regulators 11A and 11B, a reference voltage (VREF) generator 12, a comparator (CMP) 13, a timing generation unit 14, and a result determination unit 15.

[0047] The anomaly detection system 10 shown in Fig. 6 differs from the anomaly detection system 10 shown in Fig. 1 in that it includes two LDO regulators. LDO regulators 11A and 11B each perform intermittent operation, switching between a standby state and an operating state. The state switching is performed by an LDO switching signal from the timing generation unit 14.

[0048] FIG. 7 is a diagram illustrating the timing for determining whether or not an anomaly has occurred by the anomaly detection system 10 according to the third embodiment. The horizontal axis of the graph in FIG. 7 represents time, and the vertical axis represents voltage. When the LDO regulators 11A and 11B are in an operating state, and the LDO regulators 11A and 11B are electrically connected to the capacitor C1, the voltages output by the LDO regulators 11A and 11B gradually increase after startup, as indicated by the solid lines in the graph in FIG. 7, and reach their final output voltages at a certain point. However, when the LDO regulators 11A and 11B are not electrically connected to the capacitor C1, the voltages output by the LDO regulators 11A and 11B rapidly increase after startup, as indicated by the dashed lines in the graph in FIG. 7.

[0049] Furthermore, when the LDO regulators 11A and 11B enter a standby state, and there is electrical continuity between the LDO regulators 11A and 11B and the capacitor C1, the voltages output by the LDO regulators 11A and 11B decrease gradually after startup, as shown by the solid lines in the graph of Figure 7. However, when there is no electrical continuity between the LDO regulators 11A and 11B and the capacitor C1, the voltages output by the LDO regulators 11A and 11B decrease rapidly after startup, as shown by the dashed lines in the graph of Figure 7.

[0050] The anomaly detection system according to the third embodiment determines whether an anomaly has occurred only at the timing of switching to the operating state. By having the configuration shown in Fig. 6, the anomaly detection system 10 can determine whether an anomaly has occurred in which electrical continuity between the LDO regulators 11A, 11B and the capacitor C1 is interrupted at the timing of switching to the operating state when intermittent operation is performed, switching between the standby state and the operating state.

[0051] FIG. 8 is a flowchart showing the operation of the anomaly detection system according to the third embodiment of the present disclosure.

[0052] In step S121, the timing generation unit 14 outputs a start signal to the LDO regulators 11A and 11B, thereby starting up the LDO regulators 11A and 11B and putting them into an operating state.

[0053] Following step S121, in step S122, the timing generation unit 14 waits for a predetermined time.

[0054] Following step S122, in step S123, the timing generation unit 14 outputs a first timing determination signal to the result determination unit 15, which then determines whether the measurement result from the comparator 13 is normal. Specifically, the result determination unit 15 determines whether the voltage values ​​of the voltages output by the LDO regulators 11A and 11B are lower than the first voltage threshold value generated by the reference voltage generator 12.

[0055] If it is determined in step S123 that the measurement result from the comparator 13 is normal (step S123; Yes), the timing generating unit 14 waits for a predetermined time in step S124 following step S123.

[0056] Following step S124, in step S125, the timing generation unit 14 outputs a second timing determination signal to the result determination unit 15, causing the result determination unit 15 to determine whether the measurement result from the comparator 13 is normal. Specifically, the result determination unit 15 determines whether the voltage value of the voltage output from the LDO regulators 11A and 11B is higher than the first voltage threshold generated by the reference voltage generator 12.

[0057] If it is determined in step S125 that the measurement result by the comparator 13 is normal (step S125; Yes), the result determination unit 15 determines that the conduction between the LDO regulators 11A, 11B and the capacitor C1 is not cut off.

[0058] Following step S125, in step S127, the LDO regulators 11A and 11B transition to a standby state. Following step S127, in step S128, it is determined whether the LDO regulators 11A and 11B have transitioned to an operating state. If the LDO regulators 11A and 11B have transitioned to an operating state (step S128; Yes), the process returns to step S121, where the LDO regulators 11A and 11B are started up and enter an operating state. If the LDO regulators 11A and 11B have not transitioned to an operating state (step S128; No), the process waits until the LDO regulators 11A and 11B transition to an operating state.

[0059] On the other hand, if the result of the judgment in step S113 is that the measurement result in the comparator 13 is abnormal (step S123; No), or if the result of the judgment in step S125 is that the measurement result in the comparator 13 is abnormal (step S125; No), the result judgment unit 15 outputs an abnormality detection flag (step S126).

[0060] By executing the series of processes shown in FIG. 8, when intermittent operation is performed in which a standby state and an operating state are switched, the abnormality detection system 10 can determine whether or not an abnormality has occurred in which the conduction between the LDO regulators 11A, 11B and the capacitor C1 is interrupted at the timing of switching to the operating state.

[0061] (Fourth embodiment) Up to this point, an anomaly detection system capable of detecting an anomaly such as a disconnection of electrical continuity between an LDO regulator and a capacitor has been described. In a fourth embodiment of the present disclosure, an anomaly detection system capable of detecting an anomaly such as a failure of an LDO regulator will be described.

[0062] Fig. 9 is a diagram showing a schematic configuration of an anomaly detection system according to a fourth embodiment of the present disclosure. The anomaly detection system 10 shown in Fig. 9 is a system that detects the occurrence of an anomaly, such as a failure of an LDO regulator 11. The anomaly detection system 10 includes the LDO regulator 11, reference voltage (VREF) generators 12A and 12B, comparators (CMP) 13A and 13B, a timing generation unit 14, result determination units 15A and 15B, an internal resistor R1, and a switch SW1.

[0063] The anomaly detection system 10 shown in FIG. 9 differs from the anomaly detection system 10 shown in FIG. 1 in that it has two reference voltage generators, two comparators, two result determination units, and an internal resistor R1 and a switch SW1.

[0064] The reference voltage generators 12A and 12B generate reference voltages of different voltage values. In this embodiment, the voltage value of the reference voltage generated by the reference voltage generator 12A is defined as a first voltage threshold, and the voltage value of the reference voltage generated by the reference voltage generator 12B is defined as a second voltage threshold. The second voltage threshold is higher than the first voltage threshold. Furthermore, both the first voltage threshold and the second voltage threshold are lower than the final output voltage of the LDO regulator 11 in a no-load state.

[0065] The anomaly detection system 10 shown in Fig. 9 performs a diagnostic operation before actual operation, applying a test current, which is a predetermined amount added to the maximum value of the actual operating current, through internal resistor R1 to determine whether the LDO regulator 11 meets the predetermined voltage specifications. This allows the anomaly detection system 10 shown in Fig. 9 to determine whether the circuit, including the LDO regulator, is normal through a self-diagnostic test before actual operation.

[0066] 10 is a diagram illustrating the timing for determining whether or not an abnormality has occurred by the anomaly detection system 10 according to the fourth embodiment. The horizontal axis of the graph shown in FIG. 10 represents time, and the vertical axis represents voltage value. In a diagnostic operation prior to actual operation, the anomaly detection system 10 according to the fourth embodiment measures the voltage value of the LDO regulator 11 twice before the voltage reaches the final output voltage in the no-load state of the LDO regulator 11, and determines whether or not a fault has occurred using a first voltage threshold.

[0067] In the diagnostic operation before actual operation, the abnormality detection system 10 according to the fourth embodiment turns on the switch SW1 and connects the internal resistor R1 to the LDO regulator 11 to reduce the output voltage of the LDO regulator 11 after the final output voltage in a no-load state of the LDO regulator 11 is reached, measures the voltage value of the LDO regulator 11 after the reduction, and determines whether a fault has occurred using the second voltage threshold.

[0068] When the LDO regulator 11 is not faulty, turning on the switch SW1 and connecting the internal resistor R1 to the LDO regulator 11 results in a small drop in the voltage output by the LDO regulator 11, as shown by the solid line in the graph of Fig. 10. However, when the LDO regulator 11 is not faulty, turning on the switch SW1 and connecting the internal resistor R1 to the LDO regulator 11 results in a larger drop in the voltage output by the LDO regulator 11 than when there is no fault, as shown by the dashed line in the graph of Fig. 10. Therefore, by appropriately setting the second voltage threshold, the anomaly detection system 10 according to the fourth embodiment can determine whether the circuit, including the LDO regulator, is normal through a self-diagnostic test before actual operation.

[0069] FIG. 11 is a flowchart showing the operation of the anomaly detection system according to the fourth embodiment of the present disclosure.

[0070] In step S131, the timing generation unit 14 outputs a start signal to the LDO regulator 11, thereby starting up the LDO regulator 11 and entering a diagnostic operation state.

[0071] Following step S131, in step S132, the timing generation unit 14 waits for a predetermined time.

[0072] Following step S132, in step S133, the timing generation unit 14 outputs a first timing determination signal to the result determination unit 15A, which then determines whether the measurement result from the comparator 13A is normal. Specifically, the result determination unit 15A determines whether the voltage value of the voltage output by the LDO regulator 11 is lower than the first voltage threshold value generated by the reference voltage generator 12A.

[0073] If it is determined in step S133 that the measurement result from the comparator 13A is normal (step S133; Yes), the timing generating unit 14 waits for a predetermined time in step S134 following step S133.

[0074] Following step S134, in step S135, the timing generation unit 14 outputs a second timing determination signal to the result determination unit 15A, causing the result determination unit 15A to determine whether the measurement result from the comparator 13A is normal. Specifically, the result determination unit 15A determines whether the voltage value of the voltage output by the LDO regulator 11 is higher than the first voltage threshold generated by the reference voltage generator 12A.

[0075] If it is determined in step S135 that the measurement result by the comparator 13A is normal (step S135; Yes), the result determination unit 15A determines that the electrical continuity between the LDO regulator 11 and the capacitor C1 is not cut off.

[0076] On the other hand, if the result of the judgment in step S133 is that the measurement result by the comparator 13A is abnormal (step S133; No), or if the result of the judgment in step S135 is that the measurement result by the comparator 13A is abnormal (step S135; No), the result judgment unit 15A outputs an abnormality detection flag (step S136).

[0077] Following step S135, in step S137, the abnormality detection system 10 turns on the switch SW1 to connect the LDO regulator 11 and the internal resistor R1, thereby turning on the load drive.

[0078] Following step S137, in step S138, the timing generation unit 14 outputs a timing determination signal to the result determination unit 15B, which then determines whether the measurement result from the comparator 13B is normal. Specifically, the result determination unit 15B determines whether the voltage value of the voltage output by the LDO regulator 11 is higher than the second voltage threshold generated by the reference voltage generator 12B.

[0079] If the result of the determination in step S138 is that the measurement result by the comparator 13B is normal (step S138; Yes), the result determination unit 15B determines that there is no failure in the LDO regulator 11. On the other hand, if the result of the determination in step S138 is that the measurement result by the comparator 13B is abnormal (step S138; No), the result determination unit 15B outputs a load abnormality detection flag (step S140).

[0080] By executing the series of processes shown in FIG. 11, the anomaly detection system 10 can determine not only whether an anomaly has occurred in which the electrical continuity between the LDO regulator 11 and the capacitor C1 is cut off, but also whether an anomaly has occurred in which the LDO regulator 11 has failed.

[0081] Although the embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings, the technical scope of the present disclosure is not limited to such examples. The above-described embodiments are illustrative and do not limit the technical scope of the present disclosure. It is clear that a person skilled in the art of the present disclosure can conceive of various modifications or alterations within the scope of the technical idea described in the claims, and it is understood that these modifications or alterations also naturally fall within the technical scope of the present disclosure.

[0082] Furthermore, the effects described in the above embodiments are explanatory or exemplary and are not limited to those described in the above embodiments. In other words, the technology according to the present disclosure may achieve other effects that are obvious to a person skilled in the art of the present disclosure from the description in the above embodiments, in addition to or instead of the effects described in the above embodiments. [Explanation of symbols]

[0083] 10 Anomaly Detection System 11 LDO regulator 12 Reference Voltage Generator 13 Comparator 14 Timing generation unit 15 Result judgment section C1 capacitor

Claims

1. an LDO (low dropout) regulator; a comparator that compares the output voltage of the LDO regulator with a predetermined threshold voltage that is lower than the final output voltage of the LDO regulator; a result determination unit that determines whether or not there is an abnormality in the LDO regulator using a comparison result from the comparator at a timing before a first time point at which the LDO regulator reaches a final output voltage when operating normally and at a timing after the first time point; An anomaly detection system comprising:

2. The anomaly detection system according to claim 1 , wherein the result determination unit determines whether or not an anomaly exists in the LDO regulator a plurality of times, each at a timing before a first point in time and a timing after the first point in time.

3. 2. The anomaly detection system according to claim 1, wherein the result determination unit starts determining whether or not an anomaly exists in the LDO regulator after the LDO regulator switches to an operating state.

4. 2. The anomaly detection system according to claim 1, wherein the result determination unit determines whether or not an abnormality exists in the LDO regulator using a comparison result of the comparator at a timing after a second time point that is after the first time point and at which a test current larger than an actual operating current flows.

5. The anomaly detection system according to claim 4 , wherein the threshold voltage before the first time point and the threshold voltage after the second time point are different voltages.

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