Circuit and method for diagnosing abnormality of circuit switch

Abstract

The invention provides a circuit and method for diagnosing the abnormality of a circuit switch, the circuit for diagnosing the abnormality of the circuit switch comprises a battery end, an output end, a plurality of parallel branches, a voltage source, a voltage detection device and a multi-channel electronic switch, and the parallel branches are provided with a plurality of switching elements; wherein the switch piece comprises a connecting end and a detection end, the connecting end of the switch piece is electrically connected with the battery end or the output end, and the detection end of the switch piece is connected with the first end of the multi-channel electronic switch; the output end of the voltage source is used for being electrically connected with the second end of the multi-channel electronic switch, and the multi-channel electronic switch is used for conducting the electrical connection between the voltage source and the switching element; the voltage detection device is used for measuring the voltage of the detection end. According to the invention, whether a short circuit or an open circuit occurs in any switching element on any parallel branch can be diagnosed in real time, the current borne by other branches in the array is prevented from being increased, and the problem that a certain switching element cannot be effectively disconnected when the open circuit fails is solved.

Description

Technical Field

[0001] The present invention relates to the field of circuit safety technology, and in particular to a circuit and method for diagnosing circuit switch abnormality. Background Art

[0002] The switch component in the circuit is usually connected between the battery terminal and the output terminal of the circuit. The output terminal of the circuit is connected to an external device. The switch component is used to turn on or off the circuit. Usually, the switch component is n parallel branches, each branch has a switch. Through this setting, the branch is prevented from being affected by a large current on the switch.

[0003] When a problem occurs in the switch components on the parallel branch, such as a closing failure or a circuit breaking failure, no matter which problem occurs, the functional safety of the circuit design will be reduced. When some of the switch components fail to close, the switch components cannot be closed effectively, which increases the current borne by other branches in the array. When the circuit breaks, the switch cannot be effectively disconnected. Therefore, it is necessary to frequently check whether each switch component is damaged to ensure the safety of the entire circuit.

[0004] However, in the circuit of the prior art, since the voltages of the parallel branches are the same, the switch state of the branch cannot be determined by conventionally reading the voltages at both ends of the parallel branch, resulting in the inability to detect whether each switch component is damaged.

[0005] Therefore, how to detect the switch components on the parallel branches is a technical problem that those skilled in the art need to solve urgently. Summary of the invention

[0006] In order to solve the above technical problems, the present invention proposes a circuit and method for diagnosing circuit switch abnormality. The present invention sets multiple switch components on the switch branch and sets redundant switch branches to detect the switch state and failure of the switch component without affecting the stable operation of the system charge and discharge. The technical solution of the present invention is implemented as follows:

[0007] The first aspect of the present invention discloses a circuit for diagnosing abnormal circuit switches, the circuit for diagnosing abnormal circuit switches comprising a battery terminal, an output terminal, a plurality of parallel branches, a voltage source, a voltage detection device and a multi-channel electronic switch, wherein the parallel branches are provided with a plurality of switch elements; wherein:

[0008] The switch element comprises a connection end and a detection end, the connection end of the switch element is electrically connected to the battery end or the output end, and the detection end of the switch element is connected to the first end of the multi-channel electronic switch;

[0009] The output end of the voltage source is used to be electrically connected to the second end of the multi-channel electronic switch, and the multi-channel electronic switch is used to conduct the electrical connection between the voltage source and the switch element;

[0010] The voltage detection device is used to measure the voltage of the detection end.

[0011] Preferably, the output end is connected to a load device, and the battery end supplies power to the load device, or,

[0012] The output end is connected to a charging device, and the charging device is used to charge the battery end.

[0013] Preferably, the switch element is an N-type MOS tube;

[0014] Each of the parallel branches includes a charging MOS tube, a discharging MOS tube, a first diode and a second diode;

[0015] The source electrode of the charging MOS tube is connected to the positive electrode of the first diode, and the drain electrode of the charging MOS tube is connected to the negative electrode of the first diode;

[0016] The source of the discharge MOS tube is connected to the anode of the second diode, and the drain of the discharge MOS tube is connected to the cathode of the second diode;

[0017] The current directions of the first diode and the second diode are opposite.

[0018] Preferably, the drains of the charging MOS tube and the discharging MOS tube are the detection ends, and the drains of the charging MOS tube and the discharging MOS tube are connected; the sources of the charging MOS tube and the discharging MOS tube are the connection ends, the connection end of the charging MOS tube is connected to the output end, and the connection end of the discharging MOS tube is connected to the battery end;

[0019] The voltage of the voltage source is greater than the voltages of the battery terminal and the output terminal.

[0020] Preferably, in each of the parallel branches, the source electrodes of the charging MOS tube and the discharging MOS tube are detection terminals, the source electrodes of the charging MOS tube and the discharging MOS tube are connected, the drain electrodes of the charging MOS tube and the discharging MOS tube are connection terminals, the connection terminal of the charging MOS tube is connected to the output terminal, and the connection terminal of the discharging MOS tube is connected to the battery terminal;

[0021] The voltage of the voltage source is lower than the voltages of the battery terminal and the output terminal.

[0022] Preferably, a current source is further included, the output end of the voltage source is electrically connected to the input end of the current source, and the input end of the current source is electrically connected to the second end of the multi-channel electronic switch.

[0023] Preferably, it also includes a resistor and a test diode, the output end of the voltage source is electrically connected to the first end of the resistor, the second end of the resistor is electrically connected to the anode of the test diode, and the cathode of the test diode is electrically connected to the second end of the multi-channel electronic switch.

[0024] The second aspect of the present invention discloses a circuit switch abnormality diagnosis method, the method using the above-mentioned circuit switch abnormality diagnosis circuit, comprising the following steps:

[0025] S1, disconnect the path between the switch to be tested and the battery terminal or output terminal, and close other parallel branches;

[0026] S2, close the switch to be tested, and measure whether the voltage at the detection end of the switch to be tested is the output end or the battery end voltage. If not, the closure of the switch to be tested fails;

[0027] S3, disconnect the switch element to be tested, and measure whether the voltage at the detection end of the switch element to be tested is the voltage of the voltage source. If not, the switch element to be tested fails to be disconnected.

[0028] Preferably, before step S2, an electrical connection is established between the detection terminal of the switch element to be tested and the voltage source.

[0029] Preferably, the switch element is a MOS tube; when the detection end of the switch element is the drain end of the MOS tube, the voltage of the voltage source is greater than the voltage of the battery end or the output end; when the detection end is the drain end of the MOS tube, the voltage of the voltage source is less than the voltage of the battery end or the output end.

[0030] The advantages of the present invention are as follows:

[0031] The present invention can diagnose in real time whether any switch component on any parallel branch is short-circuited or open-circuited, prevent the current borne by other branches in the array from increasing, solve the problem that a switch component cannot be effectively disconnected when the circuit fails to open, and a switch component cannot be effectively closed when the circuit fails to close, and effectively ensure the safety of the entire circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only one embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] The same parts are denoted by the same reference numerals. It should be noted that the words "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to directions in the drawings, and the words "bottom" and "top", "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0034] Figure 1 It is a schematic diagram of a circuit embodiment for diagnosing abnormality of a circuit switch; as the figure that best illustrates the technical content of the present invention, this figure is also designated as the abstract figure;

[0035] It should be noted that in order to simplify the structure, Figure 1 The circuit to be tested has only three parallel branches, but this is only an example and does not represent a limitation of the present invention. In actual applications, the circuit to be tested may include two or more than three parallel branches.

[0036] Figure 2 For the Figure 1 A structural diagram of the embodiment shown in FIG. 1 after the current source is replaced with a resistor and a test diode;

[0037] Figure 3 A schematic diagram of the structure of another circuit embodiment for diagnosing abnormality of a circuit switch;

[0038] Figure 4 It is a structural schematic diagram of an embodiment of a circuit switch abnormality diagnosis system;

[0039] Figure 5 for Figure 4 The preferred embodiment shown.

[0040] In the above drawings, the figure numbers represent:

[0041] 1. Battery terminal;

[0042] 2. Load end;

[0043] 3. Parallel branches;

[0044] 4. Discharge MOS tube;

[0045] 5. Charging MOS tube;

[0046] 6. Detection end;

[0047] 7. Voltage source;

[0048] 8. Voltage detection device;

[0049] 9. Multi-channel electronic switch;

[0050] 10, current source;

[0051] 11, resistor;

[0052] 12. Test diode;

[0053] 13, driving module; 13-1, driving unit; 13-2, latch unit;

[0054] 14, SPI interface;

[0055] 15, register;

[0056] 16, protection unit; OTP, over temperature comparison unit; OCP, over current comparison unit, SCP, short circuit comparison unit; UVP, under voltage comparison unit;

[0057] 17, GPIO unit;

[0058] 18. Hardware overcurrent protection;

[0059] 19, logic control module;

[0060] 20, wake up from sleep mode;

[0061] 21, BUCK circuit;

[0062] 22, diagnostic unit;

[0063] 23, host computer;

[0064] 24. External detection element. DETAILED DESCRIPTION

[0065] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention and the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0066] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by technicians in the technical field to which the present invention belongs; the terms used in the specific implementation methods are only for the purpose of describing specific embodiments and are not intended to limit the present invention; the terms "including" and "having" in the specification and claims of the present invention and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0067] In the description of the specific implementation methods of the present invention, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present invention, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0068] Reference to "embodiments" in the present invention means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in the present invention may be combined with other embodiments.

[0069] In the description of the embodiments of the present invention, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in the present invention generally indicates that the associated objects before and after are in an "or" relationship.

[0070] The embodiments of the present invention will be described in more detail below by way of examples. It should be noted that the embodiments of the present invention are not limited to these examples.

[0071] The present application provides a circuit for diagnosing abnormality of a circuit switch, such as Figure 1 As shown, it includes a battery terminal 1, a load terminal 2 (output terminal), a plurality of parallel branches 3, a voltage source 7, a current source 10, a voltage detection device 8 and a multi-channel electronic switch 9, and each parallel branch 3 is provided with a plurality of switch elements.

[0072] Among them, the switch element includes a connecting end and a detection end 6, the connecting end of the switch element is electrically connected to the battery end 1 or the load end 2, and the detection end 6 of the switch element is connected to the first end of the multi-channel electronic switch 9; the load end 2 of the voltage source 7 is used to be electrically connected to the second end of the multi-channel electronic switch 9, and the multi-channel electronic switch 9 is used to conduct the electrical connection between the voltage source 7 and the switch element; the load end 2 of the voltage source 7 is electrically connected to the input end of the current source 10, and the input end of the current source 10 is electrically connected to the second end of the multi-channel electronic switch 9; the voltage detection device 8 is used to measure the voltage of the detection end 6.

[0073] Through the above-mentioned arrangement, when measuring the state of one of the switch components, the switch states of other switch components are adjusted, and combined with the voltage value detected by the voltage detection device 8, the switch state of the switch component to be detected can be determined, and based on the switch command issued to the measuring switch component and combined with the switch state of the switch component to be detected, it can be determined whether the switch component has a fault.

[0074] In one embodiment, the load terminal 2 is used to connect a load device, and the battery terminal 1 is used to supply power to the load device.

[0075] In another embodiment, the load end 2 is connected to a charging device, and the charging device is used to charge the battery end 1 .

[0076] In one embodiment, the switch element is an N-type MOS tube; each parallel branch 3 includes a charging MOS tube 5, a discharging MOS tube 4, a first diode and a second diode; the source of the charging MOS tube 5 is connected to the positive electrode of the first diode, and the drain of the charging MOS tube 5 is connected to the negative electrode of the first diode; the source of the discharging MOS tube 4 is connected to the positive electrode of the second diode, and the drain of the discharging MOS tube 4 is connected to the negative electrode of the second diode; the current directions of the first diode and the second diode are opposite.

[0077] The drains of the charging MOS tube 5 and the discharging MOS tube 4 are the detection terminals 6, and the drains of the charging MOS tube 5 and the discharging MOS tube 4 are connected; the sources of the charging MOS tube 5 and the discharging MOS tube 4 are the connection terminals, the connection terminal of the charging MOS tube 5 is connected to the load terminal 2, and the connection terminal of the discharging MOS tube 4 is connected to the battery terminal 1; the voltage of the voltage source 7 is greater than the voltage of the battery terminal 1 and the load terminal 2.

[0078] In this embodiment, the voltage source 7 and the current source 10 are connected in series, and are connected to the detection terminal 6 on the n parallel branches 3 through a multi-channel electronic switch 9; the voltage source 7 provides a saturation voltage, and the current source 10 provides a load current; the voltage detection device 8 reads the voltage value of the detection terminal 6 on the n parallel branches 3 in real time.

[0079] In other embodiments, Figure 2 As shown, the current source 10 can also be replaced by a resistor 11 and a test diode 12 connected in series, the load end 2 of the voltage source 7 is electrically connected to the first end of the resistor 11, the second end of the resistor 11 is electrically connected to the positive electrode of the test diode 12, and the negative electrode of the test diode 12 is electrically connected to the second end of the multi-channel electronic switch 9. The functions of the resistor 11 and the test diode 12 are the same as those of the current source 10, both of which are to provide a load current to the voltage source 7.

[0080] Through the above arrangement, the current flow direction of the MOS tube itself has directionality (from drain to source). By setting the voltage value of the voltage source 7 to be greater than the voltage value of the battery terminal 1 and the load terminal 2, under the arrangement in which the drains of the two MOS tubes on the parallel branch 3 are connected, when detecting whether the MOS tube to be tested can be closed, the MOS tube to be tested can be turned on. The multi-channel electronic switch 9 can realize that multiple groups of MOS tubes share the same voltage source 7 and current source 10 series circuit, and the voltage detection device 8 (ADC circuit in this embodiment) can read in real time. Figure 1The voltage value of any detection terminal 6 in the three parallel branches 3.

[0081] In other embodiments, Figure 3 As shown, each parallel branch 3 includes a charging MOS tube 5, a discharging MOS tube 4, a first diode and a second diode; the source of the charging MOS tube 5 is connected to the positive electrode of the first diode, and the drain of the charging MOS tube 5 is connected to the negative electrode of the first diode; the source of the discharging MOS tube 4 is connected to the positive electrode of the second diode, and the drain of the discharging MOS tube 4 is connected to the negative electrode of the second diode; the current directions of the first diode and the second diode are opposite.

[0082] In each parallel branch 3, the source of the charging MOS tube 5 and the discharging MOS tube 4 is the detection terminal 6, the source of the charging MOS tube 5 and the discharging MOS tube 4 are connected, the drain of the charging MOS tube 5 and the discharging MOS tube 4 are the connection terminals, the connection terminal of the charging MOS tube 5 is connected to the load terminal 2, and the connection terminal of the discharging MOS tube 4 is connected to the battery terminal 1; the voltage of the voltage source 7 is less than the voltage of the battery terminal 1 and the load terminal 2.

[0083] In this embodiment, the source electrodes of the charging MOS tube 5 and the discharging MOS tube 4 on each parallel branch 3 are connected, and the detection terminal 6 is the source electrode of the charging MOS tube 5 and the discharging MOS tube 4; the voltage source 7 is connected in series with the current source 10, and is connected to the detection terminals 6 on the n parallel branches 3 through a multi-channel electronic switch 9; the voltage of the voltage source 7 is less than the voltage of the battery terminal 1 and the load terminal 2 of the circuit to be tested; in this way, it can be ensured that the current direction during detection is the same as the current direction of the MOS tube to be detected.

[0084] Based on the above circuit switch abnormality diagnosis circuit, the present application also discloses a circuit switch abnormality diagnosis method, comprising the following steps:

[0085] S1, disconnect the path between the switch to be tested and the battery terminal or the output terminal, close other parallel branches; conduct the electrical connection between the detection terminal of the switch to be tested and the voltage source;

[0086] Specifically, the switch element is a MOS tube. When the detection end of the switch element is the drain end of the MOS tube, the voltage of the voltage source is greater than the voltage of the battery end or the output end; when the detection end is the drain end of the MOS tube, the voltage of the voltage source is less than the voltage of the battery end or the output end.

[0087] S2, close the switch to be tested, and measure whether the voltage at the detection end of the switch to be tested is the output end or the battery end voltage. If not, the closure of the switch to be tested fails;

[0088] S3, disconnect the switch element to be tested, and measure whether the voltage at the detection end of the switch element to be tested is the voltage of the voltage source. If not, the switch element to be tested fails to be disconnected.

[0089] The specific diagnostic methods are described in detail below:

[0090] In one embodiment, the drain electrodes of the charging MOS tube 5 and the discharging MOS tube 4 in the diagnostic circuit are electrically connected, and the specific diagnostic steps of the discharging MOS tube 4 on the parallel branch 3 are as follows:

[0091] S1, when detecting the discharge MOS tube 4, the charging MOS tube 5 is always in the disconnected state:

[0092] S2, close the discharge MOS tube 4: if the voltage of the detection terminal 6 read by the voltage detection device 8 is the voltage of the battery terminal 1, the discharge MOS tube 4 is closed normally; if the voltage of the detection terminal 6 read by the voltage detection device 8 is not the voltage of the battery terminal 1, the discharge MOS tube 4 fails to close.

[0093] S3, disconnect the discharge MOS tube 4: if the voltage of the detection terminal 6 read by the voltage detection device 8 is the voltage of the voltage source 7, the discharge MOS tube 4 is disconnected normally; if the voltage of the detection terminal 6 read by the voltage detection device 8 is not the voltage of the voltage source 7, the discharge MOS tube 4 is disconnected and fails.

[0094] The specific diagnostic steps for the charging MOS tube 5 on the parallel branch 3 are as follows:

[0095] S1, when detecting the charging MOS tube 5, the discharging MOS tube 4 is always in the disconnected state:

[0096] S2, close the charging MOS tube 5: if the voltage of the detection terminal 6 read by the voltage detection device 8 is the voltage of the load terminal 2, the charging MOS tube 5 is closed normally; if the voltage of the detection terminal 6 read by the voltage detection device 8 is not the voltage of the load terminal 2, the closing of the charging MOS tube 5 fails;

[0097] S3, disconnect the charging MOS tube 5: if the voltage of the detection terminal 6 read by the voltage detection device 8 is the voltage of the voltage source 7, the charging MOS tube 5 is normally disconnected; if the voltage of the detection terminal 6 of the charging MOS tube 5 is not the voltage of the voltage source 7, the charging MOS tube 5 is disconnected and fails.

[0098] In one embodiment, the source electrodes of the charging MOS tube 5 and the discharging MOS tube 4 in the diagnosis circuit are electrically connected, and the specific diagnosis steps of the discharging MOS tube 4 on the parallel branch 3 are as follows:

[0099] S1, when detecting the discharge MOS tube 4, the charging MOS tube 5 is always in the disconnected state:

[0100] S2, close the discharge MOS tube 4: if the voltage of the detection terminal 6 read by the voltage detection device 8 is the voltage of the battery terminal 1, the discharge MOS tube 4 is closed normally; if the voltage of the detection terminal 6 read by the voltage detection device 8 is not the voltage of the battery terminal 1, the discharge MOS tube 4 fails to close;

[0101] In a preferred embodiment, before step S2, the electrical connection between the detection terminal of the switch element to be tested and the voltage source is turned on.

[0102] S3, disconnect the discharge MOS tube 4: if the voltage of the detection terminal 6 read by the voltage detection device 8 is the voltage of the voltage source 7, the discharge MOS tube 4 is disconnected normally; if the voltage of the detection terminal 6 read by the voltage detection device 8 is not the voltage of the voltage source 7, the discharge MOS tube 4 is disconnected and fails.

[0103] The specific diagnostic steps for the charging MOS tube 5 on the parallel branch 3 are as follows:

[0104] S1, when detecting the charging MOS tube 5, the discharging MOS tube 5 is always in the disconnected state;

[0105] S2, close the charging MOS tube 5: if the voltage of the detection terminal 6 read by the voltage detection device 8 is the voltage of the load terminal 2, the charging MOS tube 5 is closed normally; if the voltage of the detection terminal 6 read by the voltage detection device 8 is not the voltage of the load terminal 2, the closing of the charging MOS tube 5 fails;

[0106] S3, disconnect the charging MOS tube 5: if the voltage of the detection terminal 6 read by the voltage detection device 8 is the voltage of the voltage source 7, the charging MOS tube 5 is disconnected normally; if the voltage of the detection terminal 6 read by the voltage detection device 8 is not the voltage of the voltage source 7, the charging MOS tube 5 is disconnected and fails.

[0107] Based on the above switch diagnosis circuit and diagnosis method, the present application also discloses a circuit switch abnormality diagnosis system, such as Figure 4 As shown, it includes a battery terminal 1, a load terminal 2 (output terminal), a plurality of parallel branches 3, a diagnostic module, a drive module 13, an SPI interface 14, a register 15, a protection unit 16, a GPIO unit 17, a hardware overcurrent protection 18, a logic control module 19 and a wake-up and sleep 20.

[0108] Each parallel branch 3 includes a charging MOS tube 5, a discharging MOS tube 4, a first diode and a second diode; the source of the charging MOS tube 5 is connected to the positive electrode of the first diode, and the drain of the charging MOS tube 5 is connected to the negative electrode of the first diode; the source of the discharging MOS tube 4 is connected to the positive electrode of the second diode, and the drain of the discharging MOS tube 4 is connected to the negative electrode of the second diode; the current directions of the first diode and the second diode are opposite, the source of the charging MOS tube 5 and the discharging MOS tube 4 are the detection terminal 6, the source of the charging MOS tube 5 and the discharging MOS tube 4 are connected, the drain of the charging MOS tube 5 and the discharging MOS tube 4 are the connection terminal, the connection terminal of the charging MOS tube 5 is connected to the load terminal 2, and the connection terminal of the discharging MOS tube 4 is connected to the battery terminal 1; the voltage of the voltage source is less than the voltage of the battery terminal 1 and the load terminal 2.

[0109] The driving module 13 is connected to each parallel branch 3 and controls the switch of each parallel branch 3 and the closing and opening of the charging MOS tube 5 and the discharging MOS tube 4 on the parallel branch.

[0110] Specifically, the driving module 13 includes a driving unit 13-1 and a latch unit 13-2. The driving unit 13-1 includes a charging drive and a discharging drive, and controls the closing and opening of the MOS tube through the GAn / GBn and Sn pins. When the single-chip microcomputer or the driving unit 13-1 is abnormal, the latch unit 13-2 can keep the MOS tube closed and open normally.

[0111] In this embodiment, the diagnostic module includes a Buck circuit, a current source 10, a resistor 11, a test diode 12, a multi-channel electronic switch 9, a voltage detection device 8 (in this embodiment, the voltage detection device 8 is an ADC unit) and a VBAT for connecting the voltage source 7. VBAT is connected in series with the Buck circuit. The detection terminal 6 is connected to the first end of the multi-channel electronic switch 9; the load terminal 2 of the voltage source is used to be electrically connected to the second end of the multi-channel electronic switch 9, and the multi-channel electronic switch 9 is used to conduct the electrical connection between the voltage source and the switch element; the load terminal 2 of the voltage source is electrically connected to the input end of the current source 10, and the input end of the current source 10 is electrically connected to the second end of the multi-channel electronic switch 9; the voltage detection device 8 is used to measure the voltage of the detection terminal 6.

[0112] The SPI interface 14 implements interaction with the host computer, uploads the diagnosis results and alarms to the host computer, and transmits the instructions issued by the host computer to the logic control module 19.

[0113] The register 15 is connected in communication with the protection unit 16, the hardware overcurrent protection 18, the diagnosis module and other modules, and is used to store various information.

[0114] The protection unit 16 includes an over-temperature comparison unit OTP, an over-current comparison unit OCP, a short-circuit comparison unit SCP and an under-voltage comparison unit UVP. The comparison result can be output to the register 15 or the control drive module 13, and connected to the outside of the diagnostic system through a hard-wired error reporting FAULT pin.

[0115] The GPIO unit 17 can be configured as a digital or analog input and output interface.

[0116] The hardware overcurrent protection 18 needs to be used with an external shunt. The two pins of the external shunt are connected to ISP and ISN for use. The same shunt can be shared with the entire system. The charge and discharge current thresholds can be set through REF1 and REF2. When an overcurrent scenario occurs, the result will be connected to the outside of the diagnostic system through the pin. In addition, the HOCP control drive module 13 will disconnect the MOS array to disconnect the charge and discharge circuit of the entire circuit to be detected, and protect the circuit to be detected.

[0117] The logic control module 19 controls the working sequence of each unit, and the host computer can directly operate the logic control module 19 through the SPI interface 14. At the same time, a state machine is also integrated to control the working state of the system: full-function mode, normal sleep mode, deep sleep mode, and power-off mode.

[0118] The switch abnormality diagnosis system is powered by the positive VBAT+ of the battery through the VCC pin. VBAT+ is connected to the SW pin through the inductor L to power the drive module 13.

[0119] In addition, the switch abnormality diagnosis system also includes a wake-up sleep module 20, which is communicatively connected to the logic control module 19. The wake-up sleep module includes a WAKEUP pin, which can trigger the wake-up sleep module 20 to send a start signal to the logic control module 19 to start the entire diagnostic system.

[0120] In a preferred embodiment, Figure 5 As shown, the diagnostic system also includes a diagnostic unit 22, which is communicatively connected to the diagnostic module and the driving module 13; wherein the diagnostic unit 22 is configured to: after receiving the diagnostic signal, send a switch signal to the driving module 13, send a voltage detection signal to the diagnostic module, receive voltage information from the diagnostic module, and determine whether the detected MOS tube is faulty based on the voltage information and generate diagnostic result information; the driving module 13 is configured to: after receiving the switch signal, adjust the on or off of each MOS tube; the diagnostic module is configured to: after receiving the voltage detection signal, detect the voltage of the detection terminal 6, generate voltage information, and send it to the diagnostic unit 22.

[0121] Specifically, the multi-channel electronic switch 9 and the voltage detection device 8 in the diagnosis module are both in communication connection with the diagnosis unit 22. The multi-channel electronic switch 9 is configured to conduct the electrical connection between the voltage source 7 and the detection terminal 6 to be detected after receiving the voltage detection signal. The voltage detection device 8 is configured to detect the voltage of the corresponding detection terminal 6 after receiving the voltage detection signal, and generate voltage information to send to the diagnosis unit 22.

[0122] In this embodiment, the logic control module 19 is configured as: being communicatively connected with the diagnostic unit 22, for sending a diagnostic signal to the diagnostic unit 22, and receiving diagnostic result information of the diagnostic unit 22; being communicatively connected with the drive module 13, for sending a switch signal to the drive module 13; being communicatively connected with the SPI interface 14, realizing a communication connection with the host computer 23 through the SPI interface 14, and receiving instructions from the host computer 23.

[0123] In specific applications, the host computer 23 can send a detection instruction to the logic control module 19. After receiving the detection instruction, the logic control module 19 sends a diagnostic signal to the diagnostic unit 22, so that the diagnostic unit 22 sends a number of voltage detection signals in sequence to the multi-channel electronic switch 9 and the voltage detection device 8 in the diagnostic module (wherein the voltage detection signal corresponds to each switch component), thereby realizing fault detection of each switch component.

[0124] In addition, the logic control module 19 is communicatively connected with the driving module 13 , so that the logic control module 19 can send a switch signal to the driving module 13 alone to control the on or off of each MOS tube.

[0125] In this embodiment, the GPIO unit 17 is communicatively connected to the logic control module 19, and the logic control module 19 is communicatively connected to the external detection element 24 through the GPIO unit 17. The logic control module 19 is used to receive real-time detection information from the external detection element 24 and send a switch signal to the driving module 13 according to the detection information.

[0126] Specifically, the external detection element 24 can be an NTC thermistor, which can send temperature information (detection information) to the logic control module 19 through the GPIO unit 17, so that the logic control module 10 sends a switch signal to the drive module 13 according to the temperature information to open or close the parallel branch 3.

[0127] The specific diagnosis process of this embodiment is as follows (taking the discharge MOS tube 4 and the charge MOS tube 5 on a parallel branch 3 as an example):

[0128] S1, when detecting the discharge MOS tube 4, the charging MOS tube 5 is always in the disconnected state:

[0129] S2, close the discharge MOS tube 4: if the voltage of the detection terminal 6 read by the voltage detection device 8 is the voltage of the battery terminal 1, the discharge MOS tube 4 is closed normally; if the voltage of the detection terminal 6 read by the voltage detection device 8 is not the voltage of the battery terminal 1, the discharge MOS tube 4 fails to close;

[0130] S2, disconnect the discharge MOS tube 4: if the voltage of the detection terminal 6 read by the voltage detection device 8 is the voltage source voltage, the discharge MOS tube 4 is disconnected normally; if the voltage of the detection terminal 6 read by the voltage detection device 8 is not the voltage source voltage, the discharge MOS tube 4 is disconnected and fails.

[0131] The specific diagnostic steps for the charging MOS tube 5 on the parallel branch 3 are as follows:

[0132] S1, when detecting the charging MOS tube 5, the discharging MOS tube 5 is always in the disconnected state;

[0133] S2, close the charging MOS tube 5: if the voltage of the detection terminal 6 read by the voltage detection device 8 is the voltage of the load terminal 2, the charging MOS tube 5 is closed normally; if the voltage of the detection terminal 6 read by the voltage detection device 8 is not the voltage of the load terminal 2, the closing of the charging MOS tube 5 fails;

[0134] S3, disconnect the charging MOS tube 5: if the voltage of the detection terminal 6 read by the voltage detection device 8 is the voltage source voltage, the charging MOS tube 5 is disconnected normally; if the voltage of the detection terminal 6 read by the voltage detection device 8 is not the voltage source voltage, the charging MOS tube 5 is disconnected and fails.

[0135] It should be pointed out that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A circuit for diagnosing abnormality of a circuit switch, comprising a battery terminal, an output terminal, and a plurality of parallel branches, wherein the parallel branches are provided with a plurality of switch elements, characterized in that: It also includes a voltage source, a voltage detection device and a multi-channel electronic switch; wherein, The switch element comprises a connection end and a detection end, the connection end of the switch element is electrically connected to the battery end or the output end, and the detection end of the switch element is connected to the first end of the multi-channel electronic switch; The output end of the voltage source is used to be electrically connected to the second end of the multi-channel electronic switch, and the multi-channel electronic switch is used to conduct the electrical connection between the voltage source and the switch element; The voltage detection device is used to measure the voltage of the detection end.

2. A circuit for diagnosing abnormality of a circuit switch according to claim 1, characterized in that: The output end is connected to a load device, and the battery end supplies power to the load device, or, The output end is connected to a charging device, and the charging device is used to charge the battery end.

3. The circuit for diagnosing abnormality of a circuit switch according to claim 2, characterized in that: The switch element is an N-type MOS tube; Each of the parallel branches includes a charging MOS tube, a discharging MOS tube, a first diode and a second diode; The source electrode of the charging MOS tube is connected to the positive electrode of the first diode, and the drain electrode of the charging MOS tube is connected to the negative electrode of the first diode; The source of the discharge MOS tube is connected to the anode of the second diode, and the drain of the discharge MOS tube is connected to the cathode of the second diode; The current directions of the first diode and the second diode are opposite.

4. A circuit for diagnosing abnormality of a circuit switch according to claim 3, characterized in that: The drains of the charging MOS tube and the discharging MOS tube are the detection ends, and the drains of the charging MOS tube and the discharging MOS tube are connected; the sources of the charging MOS tube and the discharging MOS tube are the connection ends, the connection end of the charging MOS tube is connected to the output end, and the connection end of the discharging MOS tube is connected to the battery end; The voltage of the voltage source is greater than the voltages of the battery terminal and the output terminal.

5. The circuit for diagnosing abnormality of a circuit switch according to claim 3, characterized in that: In each of the parallel branches, the source electrodes of the charging MOS tube and the discharging MOS tube are detection terminals, the source electrodes of the charging MOS tube and the discharging MOS tube are connected, the drain electrodes of the charging MOS tube and the discharging MOS tube are connection terminals, the connection terminal of the charging MOS tube is connected to the output terminal, and the connection terminal of the discharging MOS tube is connected to the battery terminal; The voltage of the voltage source is lower than the voltages of the battery terminal and the output terminal.

6. A circuit for diagnosing abnormality of a circuit switch according to claim 3, characterized in that: It also includes a current source, wherein the output end of the voltage source is electrically connected to the input end of the current source, and the input end of the current source is electrically connected to the second end of the multi-channel electronic switch.

7. A circuit for diagnosing abnormality of a circuit switch according to claim 3, characterized in that: It also includes a resistor and a test diode. The output end of the voltage source is electrically connected to the first end of the resistor, the second end of the resistor is electrically connected to the positive electrode of the test diode, and the negative electrode of the test diode is electrically connected to the second end of the multi-channel electronic switch.

8. A circuit switch abnormality diagnosis method, characterized in that: The circuit for diagnosing abnormality of a circuit switch as claimed in claim 1 comprises the following steps: S1, disconnect the path between the switch to be tested and the battery terminal or output terminal, and close other parallel branches; S2, close the switch to be tested, and measure whether the voltage at the detection end of the switch to be tested is the output end or the battery end voltage. If not, the closure of the switch to be tested fails; S3, disconnect the switch element to be tested, and measure whether the voltage at the detection end of the switch element to be tested is the voltage of the voltage source. If not, the switch element to be tested fails to be disconnected.

9. The circuit switch abnormality diagnosis method according to claim 8, characterized in that: Before step S2, the detection terminal of the switch element to be tested is electrically connected to the voltage source.

10. The circuit switch abnormality diagnosis method according to claim 9, characterized in that: The switch element is a MOS tube; when the detection end of the switch element is the drain end of the MOS tube, the voltage of the voltage source is greater than the voltage of the battery end or the output end; When the detection end is the drain end of the MOS tube, the voltage of the voltage source is smaller than the voltage of the battery end or the output end.

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