A / D converter failure detection device, power supply device provided with A / D converter failure detection device, and A / D converter failure detection method

Abstract

The A / D converter failure detection device is provided with a second IC that is provided with: a second A / D converter that converts a second analog value detected by a second reference terminal for acquiring a second analog value of a reference signal into a second digital signal at a second resolution; and a second communication terminal connected to the first communication terminal for communication. The first IC is capable of transmitting, from the first communication terminal to the second communication terminal, a first digital signal obtained by A / D converting, by a first A / D converter, a first analog value of a reference signal detected by a first reference terminal at a first resolution. The second IC compares the first digital signal and the second digital signal received through the second communication terminal, and determines that a fault has occurred when the difference between the first digital signal and the second digital signal exceeds a predetermined reference value. The second digital signal is a signal obtained by A / D converting a second analog value of the reference signal detected by the second reference terminal at a second resolution by a second A / D converter.

Description

Technical Field

[0001] This disclosure relates to an A / D converter fault detection device, a power supply device equipped with the A / D converter fault detection device, and a fault detection method for the A / D converter. Background Technology

[0002] Electrical devices equipped with A / D converters are used in various fields. For example, in various fields such as mobile applications, power supply devices that use rechargeable secondary batteries such as lithium-ion secondary batteries to drive electrical devices, and electrical devices equipped with such power supply devices are used (e.g., Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2015-109741 Summary of the Invention

[0006] In electrical equipment equipped with an A / D converter as described above, the A / D converter on the analog front end (AFE) side processes the detected analog values ​​such as current and temperature values ​​into digital signals and sends the digital signals to the IC.

[0007] In such electrical equipment, if the A / D converter malfunctions, normal operation will be impossible. For example, in a charger, where safety is ensured by measuring overcurrent and overtemperature and cutting off when they exceed specified thresholds, it is possible that abnormal conditions cannot be detected.

[0008] Therefore, functional safety seeks to ensure safety even if any component fails. Functional safety typically involves physically configuring two integrated circuits (ICs) to ensure redundancy in operation even if either one fails.

[0009] However, to achieve such redundancy, multiple ICs are required, which increases the hardware size, circuit size, and power consumption, leading to problems such as increased circuit structure complexity.

[0010] One aspect of this disclosure relates to an A / D converter fault detection device comprising a first IC and a second IC. The first IC comprises: a first reference terminal for acquiring a first analog value of a predetermined reference signal; a first A / D converter for converting the first analog value detected by the first reference terminal into a first digital signal at a first resolution; and a first communication terminal for communicating with other devices. The second IC comprises: a second reference terminal for acquiring a second analog value of the reference signal; a second A / D converter for converting the second analog value detected by the second reference terminal into a second digital signal at a second resolution; and a second communication terminal for connecting to the first communication terminal for communication. The first IC is capable of converting the first digital value into a digital signal. A signal is transmitted from the first communication terminal to the second communication terminal. The first digital signal is obtained by performing A / D conversion on the first analog value of the reference signal detected by the first reference terminal at the first resolution using the first A / D converter. The second IC is configured to compare the first digital signal with the second digital signal based on the first digital signal and the second digital signal received by the second communication terminal, and to determine that a fault has occurred if the difference between the first digital signal and the second digital signal exceeds a predetermined reference value. The second digital signal is obtained by performing A / D conversion on the second analog value of the reference signal detected by the second reference terminal at the second resolution using the second A / D converter.

[0011] In addition, another method involves a fault detection method for an A / D converter fault detection device. This A / D converter fault detection device includes a first IC and a second IC. The first IC includes: a first reference terminal connected to a predetermined reference signal; a first A / D converter for converting a first analog value of the reference signal detected by the first reference terminal into a first digital signal at a first resolution; and a first communication terminal for communicating with other devices. The second IC includes: a second reference terminal connected to the reference signal; a second A / D converter for converting a second analog value of the reference signal detected by the second reference terminal into a second digital signal at a second resolution; and a second communication terminal for communicating with the first communication terminal. The fault detection method includes... Next step: The first IC detects the first analog value of the reference signal through the first reference terminal, converts the first analog value into a first digital signal using the first A / D converter at the first resolution, and sends the first digital signal from the first communication terminal to the second communication terminal; the second IC detects the second analog value of the reference signal through the second reference terminal, converts the second analog value into a second digital signal using the second A / D converter at the second resolution; the second IC receives the first digital signal from the first IC through the second communication terminal; the second IC compares the first digital signal with the second digital signal based on the first digital signal and the second digital signal, and determines that a fault has occurred if the difference between the first digital signal and the second digital signal exceeds a predetermined reference value.

[0012] According to one aspect of the present disclosure, the A / D converter fault detection device, the power supply device equipped with the A / D converter fault detection device, and the A / D converter fault detection method can perform A / D converter fault detection in a software manner. Attached Figure Description

[0013] Figure 1 This is a block diagram illustrating the A / D converter fault detection device according to Embodiment 1.

[0014] Figure 2 This is a block diagram showing a power supply device with A / D converter fault detection function. Detailed Implementation

[0015] The manner of this disclosure can also be determined through the following structure and features.

[0016] In other embodiments of the A / D converter fault detection device disclosed herein, in any of the above embodiments, the first resolution is different from the second resolution, and the second IC is configured to compare the first digital signal and the second digital signal after standardization according to the first resolution and the second resolution. According to the above structure, fault determination can be performed in software while allowing the coexistence of ICs with A / D converters having different resolutions, based on the ability to compare after resolution standardization.

[0017] In addition, in other embodiments of the present disclosure, the fault detection device for the A / D converter is configured such that, in any of the above embodiments, the second IC is configured to normalize the higher of the first resolution and the second resolution to the lower one.

[0018] Furthermore, in other embodiments of this disclosure, the A / D converter fault detection device is configured such that, in any of the aforementioned embodiments, the first resolution is higher than the second resolution.

[0019] Furthermore, in other embodiments of the present disclosure, the A / D converter fault detection device further includes a reference signal generation unit that generates the specified reference signal.

[0020] Furthermore, in other embodiments of the present disclosure, the fault detection device for the A / D converter is wherein, in any of the above embodiments, the specified reference signal is a specified reference voltage.

[0021] Furthermore, in other embodiments of the present disclosure, the fault detection device for the A / D converter includes, in any of the above embodiments, a reference signal generation unit comprising a voltage conversion circuit that converts the driving voltage used to drive the first IC or the second IC into a predetermined reference voltage whose voltage value is lower than that of the driving voltage.

[0022] Furthermore, in other embodiments of the present disclosure, the A / D converter fault detection device further includes, in any of the above embodiments, the first IC having an analog input terminal for inputting an external analog signal, and the first IC being configured to convert the external analog signal input from the analog input terminal into a digital value using the first A / D converter and transmit the digital value from the first communication terminal to the second communication terminal.

[0023] Furthermore, the power supply device according to other embodiments of this disclosure includes: an A / D converter fault detection device as described in any of the above embodiments; one or more secondary battery cells; and a charging and discharging circuit that charges and discharges the one or more secondary battery cells. The first IC is an analog front-end (AFE) that measures the temperature or current value of the one or more secondary battery cells, and the second IC is a microcontroller (MCU) that manages the power supply device.

[0024] The embodiments of this disclosure will now be described based on the accompanying drawings. However, the embodiments shown below are merely illustrative examples to concretize the technical concept of this disclosure, and this disclosure is not intended to be limited to the following content. Furthermore, this specification does not define the components shown in the claims as components of the embodiments. In particular, the dimensions, materials, shapes, and relative arrangements of the structural components described in the embodiments are not intended to limit the scope of this disclosure unless specifically stated otherwise, but are merely illustrative examples. Additionally, the size and positional relationships of the components shown in the accompanying drawings are sometimes exaggerated for clarity. Furthermore, in the following description, detailed descriptions of components with the same name or reference numerals that denote the same or similar components are appropriately omitted. Moreover, the elements constituting this disclosure can be configured such that multiple elements are constituted using the same component and one component serves as multiple elements; conversely, multiple components can be used to share and implement the function of one component.

[0025] The A / D converter fault detection device disclosed herein is preferably applicable to electrical devices such as chargers equipped with batteries. Such electrical devices can be used as power sources for power-assisted bicycles, electric scooters for delivery, electric handcarts for golf courses, factories, airports, etc., power sources for autonomous mobile robots for delivery, power sources for construction machinery, hybrid vehicles, electric vehicles, etc., or power sources for portable electrical devices such as cordless phones, electric vacuum cleaners, and power tools. Furthermore, in stationary energy storage applications, they can be used as backup power for servers, and as power supply devices for home, business, and factory use. Hereinafter, as one embodiment of this disclosure, a battery pack for power-assisted bicycles will be described.

[0026] [Implementation Method 1]

[0027] exist Figures 1-2 The figure shows an A / D converter fault detection device 100 according to Embodiment 1 of this disclosure. In these figures, Figure 1 A block diagram is shown illustrating the A / D converter fault detection device 100 according to Embodiment 1. Figure 2A block diagram is shown illustrating a power supply unit 1000 with A / D converter fault detection functionality. The A / D converter fault detection unit 100 shown in these figures is incorporated into electrical equipment such as chargers and power supply units. For example, in... Figure 2 The power supply unit 1000 shown includes a battery pack incorporated into the charging / discharging circuit 3 and is used in an electrical device that is driven. The power supply unit 1000 can be configured to be detached from or integrated with the electrical device. To measure values ​​such as battery voltage, battery temperature, and the temperature of electronic components such as switching elements, the power supply unit 1000 detects analog signals at an analog front-end (AFE), converts these analog signals into digital signals, and processes them using a microcontroller (MCU). The power supply unit includes an A / D converter for this A / D conversion. If the A / D converter malfunctions, correct operation cannot be guaranteed; therefore, for functional safety, an A / D converter fault detection function is required to detect A / D converter failures.

[0028] For example, in a charger, to protect the battery from overcharging, an additional IC that monitors overcharging is added to achieve redundancy. Figure 2 In this circuit, the second protection circuit 7 is equivalent to the third protection circuit. However, the mechanism for protecting the battery from over-discharge or overheating beyond a specified temperature is not redundant. If additional monitoring ICs are added to address these redundancy issues, the hardware structure becomes larger and more complex, increasing costs.

[0029] In contrast, in the A / D converter fault detection device 100 according to Embodiment 1, considering the case where each IC has an A / D converter, fault detection can be performed by comparing the results obtained by performing A / D conversion on the same reference signal using the A / D conversion functions of different ICs. With this structure, even without adding a new IC, the fault determination function of the A / D converter can be implemented in software using the existing structure, thus achieving the advantage of improving functional safety at a low cost. Hereinafter, based on... Figure 1 Let me elaborate.

[0030] Figure 1 The A / D converter fault detection device 100 shown includes a first IC 10, a second IC 20, and a reference signal generation unit 30.

[0031] (First IC 10)

[0032] The first IC 10 includes a first A / D converter 11, a first control unit 12, and a first communication unit 13. The first control unit 12 is connected to the first A / D converter 11 and the first communication unit 13 to control their operation. Additionally, the first IC 10 includes an analog input terminal 14, a first reference terminal 15, and a first communication terminal 16 as external connection terminals. The analog input terminal 14 is used to input external analog signals. Figure 1 In this illustration, only one analog input terminal 14 is shown, but the first IC 10 can have multiple analog input terminals. The first reference terminal 15, described later, is also a type of analog input terminal 14. When multiple analog input terminals are provided, the inputs can be switched using a multiplexer or the like. Such a first IC 10 can utilize an analog front-end (AFE). An AFE is an analog circuit that connects signal detection devices such as sensors to digital signal processing devices such as microcomputers.

[0033] The first reference terminal 15 is a terminal used to acquire a first analog value of a specified reference signal. Functionally, it is equivalent to the analog input terminal 14. In other words, one of the plurality of analog input terminals 14 provided by the first IC 10 can be used as the first reference terminal 15. The analog input terminal 14 including the first reference terminal 15 is connected to the input side of the first A / D converter 11.

[0034] (First A / D converter 11)

[0035] The first A / D converter 11 converts an external analog signal input from the analog input terminal 14 into a digital signal at a first resolution, and sends the digital signal to the first control unit 12. The first control unit 12 sends the digital signal from the first communication terminal 16 to the second IC 20. Additionally, the first A / D converter 11 can also convert the first analog value of the reference signal detected by the first reference terminal 15 into a first digital signal at the same first resolution, and send the first digital signal from the first communication terminal 16 to the second IC 20 via the first control unit 12.

[0036] (Reference signal generation unit 30)

[0037] The reference signal generation unit 30 generates a predetermined reference signal. The predetermined reference signal can utilize a reference voltage. Preferably, the driving voltage used to drive the first IC 10 and the second IC 20 is used for generating the reference voltage.

[0038] The first reference terminal 15 is connected to the reference signal generation unit 30. Through the first reference terminal 15, the first IC 10 acquires a predetermined reference signal as a first analog value. Then, the first analog value is converted into a first digital signal using the first A / D converter 11.

[0039] (Voltage conversion circuit)

[0040] Preferably, the reference signal is set to a conversion voltage value lower than the driving voltage. Therefore, the reference signal generation unit 30 includes a voltage conversion circuit 32 that converts the driving voltage used to drive the first IC 10 or the second IC 20 into a predetermined reference voltage whose voltage value is lower than the driving voltage. For example, the reference voltage is set to 40% to 60% of the driving voltage. This allows the reference signal to be positioned in the middle of the range of the first A / D converter 11 used to detect the driving voltage, enabling voltage measurement that effectively utilizes the resolution of the first A / D converter 11.

[0041] The first communication unit 13 is a component for communicating with the second communication unit 23 of the second IC 20. The first communication terminal 16 of the first communication unit 13 is connected to the second communication terminal 26 of the second communication unit 23 via a communication line 17.

[0042] (Second IC 20)

[0043] On the other hand, the second IC 20 includes a second A / D converter 21, a second control unit 22, and a second communication unit 23. The second control unit 22 is connected to the second A / D converter 21 and the second communication unit 23 to control their operation. Furthermore, the second control unit 22 performs the function of a comparator, as described later. Additionally, the second IC 20 includes a second reference terminal 25 and a second communication terminal 26 as external connection terminals. This second IC 20 can utilize digital signal processing devices such as CPUs, MPUs, ASICs, and microcomputers.

[0044] The second reference terminal 25 is a terminal used to acquire a second analog value of a reference signal. The second reference terminal 25 is connected to the input side of the second A / D converter 21. Additionally, the second reference terminal 25 is connected to the reference signal generation unit 30. Through the second reference terminal 25, the second IC 20 acquires a predetermined reference signal as the second analog value.

[0045] (Second A / D converter 21)

[0046] The second A / D converter 21 converts the second analog value detected by the second reference terminal 25 into a second digital signal at a second resolution, and sends the second digital signal to the second control unit 22.

[0047] The second communication unit 23 is a component for communicating with the first communication unit 13 of the first IC 10. The second communication terminal 26 of the second communication unit 23 is connected to the first communication terminal 16 of the first communication unit 13 via a communication line 17. In the second IC 20, the second communication unit 23 receives a first digital signal transmitted from the first IC 10 via the communication line 17 from the second communication terminal 26. The received first digital signal is then sent from the second communication unit 23 to the second control unit 22.

[0048] The A / D converter fault detection device 100 includes a fault detection function for detecting faults in the first A / D converter 11 and the second A / D converter 21. Here, the second control unit 22 determines the fault. Specifically, the second control unit 22 compares a second digital signal with a first digital signal. The second digital signal is obtained by converting a reference signal detected through the second reference terminal 25 using the second A / D converter 21. The first digital signal is obtained by similarly converting the reference signal using the first A / D converter 11 and receiving it through the second communication unit 23. Normally, the first and second digital signals are values ​​obtained by converting the same reference signal, and therefore should be of the same value except for quantization errors. However, when either the first A / D converter 11 or the second A / D converter 21 malfunctions, incorrect A / D conversion results in a deviation between the first and second digital signals. Therefore, by detecting this deviation, a fault in the A / D conversion function can be detected. Specifically, the second control unit 22 calculates the difference between the first and second digital signals. Thus, the second control unit 22 has the function of a comparator. Preferably, the comparator of the second IC 20 is used. Moreover, if the difference exceeds a predetermined reference value, a fault is determined to have occurred. As a result, it is possible to detect malfunctions of the A / D conversion function of the first IC 10 or the second IC 20 in software without utilizing a hardware structure such as dual A / D converters, thus gaining the advantage of adding functional safety at a low cost.

[0049] (standardization)

[0050] When comparing the first digital signal with the second digital signal, if the first resolution of the first A / D converter 11 is different from the second resolution of the second A / D converter 21, normalization to make the number of bits consistent is performed in advance.

[0051] The first and second digital signals are standardized by converting at least one of them in a manner that makes the number of bits in the first digital signal the same as the number of bits in the second digital signal. In the second IC 20, by comparing the first and second digital signals after standardization according to a first resolution and a second resolution, fault determination can be performed in software while ICs with A / D converters having different resolutions coexist.

[0052] During standardization, it is preferable to combine the higher of the first and second resolutions with the lower one for standardization. This avoids the amplification of quantization errors that occur when converting values ​​obtained from A / D conversion using a lower-resolution A / D converter with a higher-resolution converter, enabling more accurate and stable difference detection.

[0053] It is generally believed that the first A / D converter 11 of the first IC 10, which is composed of an AFE, etc., has a higher resolution and higher bit depth than the second A / D converter 21 of the second IC 20, which is composed of a CPU, etc. That is, the first resolution (e.g., 12 bits) of the first A / D converter 11 is higher than the second resolution (e.g., 10 bits) of the second A / D converter 21, so it is preferable to match the second resolution during normalization.

[0054] (Reference signal)

[0055] Furthermore, the reference signal used for comparison utilizes existing voltages in addition to being prepared separately, thereby achieving functional safety without the need for additional components. Here, the drive voltages used to drive the first IC 10 and the second IC 20 are used as the reference signal. Instead of using the drive voltage itself as the reference signal, a converted voltage obtained by converting the drive voltage to a constant voltage is used as the reference signal. As described above, the reference signal generation unit 30 converts the drive voltage into a converted voltage lower than the drive voltage via the voltage conversion circuit 32. Figure 2 In the example of the power supply device 1000 shown, the reference signal generation unit 30 includes a power supply circuit 31 that converts an externally supplied power supply voltage VP (e.g., DC 12V) into drive voltages VDD1 and VDD2 (e.g., DC 5V) for the first IC 10 and the second IC 20. The first IC 10 is driven by receiving the drive voltage from the VDD1 terminal, and the second IC 20 is driven by receiving the drive voltage from the VDD2 terminal.

[0056] On the other hand, the reference signal generation unit 30 includes a voltage conversion circuit 32 that converts the drive voltage VDD into a lower conversion voltage VL (e.g., DC 3.3V). The output side of the voltage conversion circuit 32 is connected to the first reference terminal 15 of the first IC 10 and the second reference terminal 25 of the second IC 20, respectively. The second control unit 22 compares the values ​​obtained by performing A / D conversion on the conversion voltage VL using the first A / D converter 11 and the second A / D converter 21, respectively. The first A / D converter 11 and the second A / D converter 21 are dynamically configured to maximize the drive voltage VDD (e.g., DC 5V). Therefore, by setting the conversion voltage VL (e.g., DC 3.3V) near its midpoint, even if the A / D converter malfunctions and the digital signal fluctuates, saturation can be avoided and the judgment can be made correctly.

[0057] (Timing of fault diagnosis)

[0058] The timing and frequency of fault detection performed by the second control unit 22 can be arbitrarily set. For example, fault detection can be performed at predetermined times such as when the charger equipped with the A / D converter fault detection device 100 is started, when the power is turned off, or periodically at a predetermined frequency such as every 250ms.

[0059] (Power supply unit 1000)

[0060] As an example of a power supply unit 1000 equipped with an A / D converter fault detection device 100, Figure 2 The power supply device 1000 shown not only supplies power to the driven object by discharging the built-in secondary battery unit 1, but also has a charging function for charging the secondary battery unit 1. The power supply device 1000 includes one or more secondary battery units 1, a charging / discharging circuit 3 for charging and discharging the one or more secondary battery units 1, a fuse 4, a current sensing resistor 5, and an A / D converter fault detection device 100. Here, multiple chargeable and dischargeable secondary battery units 1 are connected in series to form a battery block 2. The charging / discharging circuit 3 has an input / output switch connected in series with the output side of the battery block 2. The input / output switch is a switch that switches on / off during charging and discharging of the battery block 2, and is composed of semiconductor switching elements such as FETs and transistors. Furthermore, when overcharging or over-discharging is detected, the input / output switch is switched off. The fuse 4 is connected in series with the battery block 2 and is melted when the secondary battery unit 1 malfunctions to cut off the current to the battery block 2. The current sensing resistor 5 is a component used to detect the charging / discharging current flowing through the charging / discharging path CL.

[0061] The A / D converter fault detection device 100 includes a first IC 10, a second IC 20, and a reference signal generation unit 30.

[0062] The first IC 10 is an AFE that measures the temperature or current value of one or more secondary battery cells 1. The second IC 20 is a MCU that manages the power supply device 1000. The AFE of the first IC 10 measures the battery voltage, charging / discharging current value, battery temperature, and the temperature of electronic components such as switching elements constituting the charging / discharging circuit 3 of each secondary battery cell 1. Specifically, the first IC 10 uses a current sensing resistor 5 to detect the charging / discharging current flowing through the charging / discharging path CL and sends this current to the second IC 20. Additionally, the first IC 10 detects the voltage of each secondary battery cell 1 and sends this voltage to the second IC 20. Furthermore, the first IC 10 detects the temperature of the secondary battery cell 1 based on the signal from a temperature sensor 6 thermally coupled to the secondary battery cell 1. The analog signals detected by the first IC 10 are converted into digital signals by the first A / D converter 11 and then processed as MPUs of the second IC 20. The second IC 20 detects the voltage of each secondary battery cell 1 that constitutes the battery block 2 and controls the input / output switch 2 to be on / off.

[0063] Additionally, the power supply unit 1000 includes a second protection circuit 7 for monitoring overcharging. When the second protection circuit 7 detects overcharging, the second IC 20 stops charging.

[0064] [Fault Detection Method for A / D Converter Fault Detection Device]

[0065] Here, the fault detection method of the A / D converter fault detection device 100 described above will be explained. First, the first IC 10 detects a first analog value of a reference signal through the first reference terminal 15, converts the first analog value into a first digital signal at a first resolution using the first A / D converter 11, and transmits the first digital signal from the first communication terminal 16 to the second communication terminal 26. On the other hand, the second IC 20 detects a second analog value of the reference signal through the second reference terminal 25, and converts the second analog value into a second digital signal at a second resolution using the second A / D converter 21.

[0066] Then, the second IC 20 receives the first digital signal from the first IC 10 via the second communication terminal 26. Furthermore, the second IC 20 compares the first digital signal with the second digital signal based on the first digital signal and the second digital signal, and determines a fault has occurred if the difference between the first digital signal and the second digital signal exceeds a predetermined reference value. That is, the second IC 20 compares the first digital signal with the second digital signal, and determines that at least one of the A / D converters 11 and 21 has failed if the difference between the first digital signal and the second digital signal exceeds a predetermined reference value. This allows for fault detection of the A / D converters in software. During the comparison, if the first resolution of the first A / D converter 11 differs from the second resolution of the second A / D converter 21, the comparison is performed after standardizing the resolutions.

[0067] The above example illustrates a fault determination method that compares the digital signals obtained from A / D conversion between the first IC 10 and the second IC 20, each equipped with an A / D converter. However, this disclosure is not limited to this structure; fault determination can also be performed by comparing the values ​​obtained from converting the same analog signal into a digital signal between three or more ICs. This method allows for more accurate fault determination. In particular, when the difference between two ICs exceeds a threshold, although a fault can be determined, it is impossible to identify which IC's A / D conversion function has failed. In contrast, when comparing three or more ICs, it is possible to determine that the fault occurred in the IC with the largest difference compared to the others, thus providing the advantage of being able to identify the faulty A / D conversion function.

[0068] In the above examples, the power supply unit 1000 is installed on the electrical equipment being driven to supply power to the equipment. Furthermore, when the remaining capacity of the power supply unit decreases or deteriorates over time, the power supply unit can be replaced and the electrical equipment can continue to be used. However, this disclosure does not limit the power supply unit to a replaceable type that primarily houses a secondary battery unit; it can also be applied to a type where the secondary battery unit is housed within the frame of the electrical equipment. In this disclosure, the power supply unit is sufficient as long as the secondary battery unit is housed within a frame such as a housing; a device that has a secondary battery unit for driving built into the frame of the electrical equipment itself is also called a power supply unit. That is, this disclosure is not limited to replaceable power supply units, but can also be applied to electrical equipment with a built-in secondary battery unit.

[0069] [Industry availability]

[0070] The A / D converter fault detection device, power supply device equipped with the A / D converter fault detection device, and fault detection method disclosed herein are preferably used as power sources for power-assisted bicycles, autonomous mobile robots for delivery, electric trolleys for delivery and golf courses, electric scooters, construction machinery, hybrid vehicles, electric cars, and other vehicles. Furthermore, they can be appropriately used as power sources for portable electrical equipment such as wireless phones, electric vacuum cleaners, and power tools, and in stationary energy storage applications, they can be appropriately used as backup power supplies for servers, and as power supplies for home, business, and factory use.

[0071] Explanation of reference numerals in the attached figures

[0072] 1000: Power supply device;

[0073] 100: A / D converter fault detection device;

[0074] 1: Secondary battery unit;

[0075] 2: Battery pack;

[0076] 3: Charging and discharging circuit;

[0077] 4: Fuse;

[0078] 5: Current sensing resistor;

[0079] 6: Temperature sensor;

[0080] 7: Second protection circuit;

[0081] 10: First IC;

[0082] 11: The first A / D converter;

[0083] 12: First Control Unit;

[0084] 13: First Department of Communications;

[0085] 14: Analog input terminals;

[0086] 15: First reference terminal;

[0087] 16: First communication terminal;

[0088] 17: Communication line;

[0089] 20: Second IC;

[0090] 21: Second A / D converter;

[0091] 22: Second Control Unit;

[0092] 23: Second Department of Communications;

[0093] 25: Second reference terminal;

[0094] 26: Second communication terminal;

[0095] 30: Reference signal generation unit;

[0096] 31: Power supply circuit;

[0097] 32: Voltage conversion circuit;

[0098] VP: Power supply voltage;

[0099] VDD1: Drive voltage of the first IC;

[0100] VDD2: The driving voltage of the second IC;

[0101] CL: Charge / discharge path.

Claims

1. An A / D converter fault detection device, comprising a first IC and a second IC, The first IC has: The first reference terminal is used to acquire the first analog value of a specified reference signal; A first A / D converter, configured to convert the first analog value detected via the first reference terminal into a first digital signal at a first resolution; and The first communication terminal is used for communication with other devices. The second IC has: The second reference terminal is used to acquire the second analog value of the specified reference signal; A second A / D converter, configured to convert the second analog value detected via the second reference terminal into a second digital signal at a second resolution; and The second communication terminal is used to connect with the first communication terminal for communication. in, The first IC is capable of transmitting the first digital signal from the first communication terminal to the second communication terminal. The first digital signal is a signal obtained by using the first A / D converter to perform A / D conversion on the first analog value of the predetermined reference signal detected through the first reference terminal at the first resolution. The second IC is configured to compare the first digital signal and the second digital signal received through the second communication terminal, and to determine that a fault has occurred if the difference between the first digital signal and the second digital signal exceeds a predetermined reference value. The second digital signal is a signal obtained by using the second A / D converter to perform A / D conversion on the second analog value of the predetermined reference signal detected through the second reference terminal at the second resolution.

2. The A / D converter fault detection device according to claim 1, wherein, The first resolution is different from the second resolution. The second IC is configured to compare the first digital signal and the second digital signal after standardization according to the first resolution and the second resolution.

3. The A / D converter fault detection device according to claim 2, wherein, The second IC is configured to normalize the higher resolution of either the first resolution or the second resolution to match the lower resolution.

4. The A / D converter fault detection device according to claim 3, wherein, Make the first resolution higher than the second resolution.

5. The A / D converter fault detection device according to claim 1, wherein, It also includes a reference signal generation unit, which generates the specified reference signal.

6. The A / D converter fault detection device according to claim 5, wherein, The specified reference signal is the specified reference voltage.

7. The A / D converter fault detection device according to claim 6, wherein, The reference signal generation unit includes a voltage conversion circuit that converts the driving voltage used to drive the first IC or the second IC into a predetermined reference voltage whose voltage value is lower than that of the driving voltage.

8. The A / D converter fault detection device according to claim 1, wherein, The first IC also includes analog input terminals for inputting external analog signals. The first IC is configured to use the first A / D converter to convert an external analog signal input from the analog input terminal into a digital value and send the digital value from the first communication terminal to the second communication terminal.

9. A power supply device, comprising: A / D converter fault detection device according to any one of claims 1 to 8; One or more secondary battery cells; and A charging and discharging circuit that charges and discharges the one or more secondary battery cells. in, The first IC is an analog front-end, or AFE, that measures the temperature or current value of the one or more secondary battery cells. The second IC is a microcontroller, or MCU, that manages the power supply device.

10. A fault detection method for an A / D converter fault detection device, wherein the A / D converter fault detection device comprises a first IC and a second IC. The first IC has: The first reference terminal is connected to the specified reference signal; A first A / D converter, configured to convert a first analog value of the predetermined reference signal detected via the first reference terminal into a first digital signal at a first resolution; and The first communication terminal is used for communication with other devices. The second IC has: The second reference terminal is connected to the specified reference signal; A second A / D converter, configured to convert a second analog value of the predetermined reference signal detected via the second reference terminal into a second digital signal at a second resolution; and The second communication terminal is used to connect with the first communication terminal for communication. The fault detection method includes the following steps: The first IC detects the first analog value of the specified reference signal through the first reference terminal, converts the first analog value into the first digital signal at the first resolution using the first A / D converter, and sends the first digital signal from the first communication terminal to the second communication terminal. The second IC detects the second analog value of the specified reference signal through the second reference terminal, and uses the second A / D converter to convert the second analog value into the second digital signal at the second resolution; The second IC receives the first digital signal from the first IC via the second communication terminal; The second IC compares the first digital signal with the second digital signal based on the first digital signal and the second digital signal, and determines that a fault has occurred if the difference between the first digital signal and the second digital signal exceeds a predetermined reference value.

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