Over-temperature protection circuit and method

Abstract

According to the over-temperature protection circuit, a temperature detection module senses the temperature of a designated area of a cable and generates a temperature detection signal, and a main control module judges whether the temperature exceeds a preset threshold value or not according to the temperature detection signal and generates a corresponding level signal; and then the connection identification module adjusts the resistance value of the access configuration channel according to the level signal output by the main control module so as to ensure that the power supply end can identify the power receiving end at the normal temperature and block the identification when the cable is over-temperature. According to the invention, the accuracy of cable temperature detection can be effectively improved, and the over-temperature state of the cable can be identified in time.

Description

Technical Field

[0001] The present invention relates to the field of electronic technology, and in particular to an over-temperature protection circuit and method. Background Art

[0002] Since the release of the charging protocol USB PD 3.1, the power limit of USB fast charging technology has been increased to 240W. For such a high transmission power, the cable needs to have extremely high safety performance. For example, during the transmission of 240W power, if the cable temperature is too high, it may not only cause data transmission errors, but also seriously endanger the safety of the device and the user. Therefore, how to effectively implement over-temperature protection of the cable has become an urgent problem to be solved.

[0003] The existing over-temperature protection scheme, the electronic marker (eMarker) junction temperature protection scheme, relies on the junction temperature detection mechanism integrated in the eMarker chip for protection. In essence, it achieves over-temperature protection by detecting the internal temperature of the eMarker chip. However, the junction temperature inside the chip cannot fully and accurately reflect the actual temperature of the cable, resulting in insufficient temperature detection accuracy, which not only affects the reliability of the protection scheme, but may also delay the protection action due to the inability to capture the actual over-temperature state of the cable in time, thereby increasing safety hazards. Summary of the invention

[0004] The purpose of the embodiments of the present invention is to provide an over-temperature protection circuit and method, which can effectively improve the accuracy of cable temperature detection and timely identify the over-temperature state of the cable.

[0005] The first aspect of the present invention provides an over-temperature protection circuit, comprising: N temperature detection modules, a main control module and N connection identification modules; wherein each temperature detection module and the corresponding connection identification module are arranged in pairs in different designated areas of the cable; all the connection identification modules are connected in series on the configuration channel of the cable; N≥1;

[0006] The temperature detection module is used to sense the temperature of the designated area, generate a corresponding temperature detection signal and transmit it to the main control module;

[0007] The main control module is used to determine whether the temperature exceeds a preset threshold value according to the received temperature detection signal; if the temperature does not exceed the preset threshold value, generate a first level signal; if the temperature exceeds the preset threshold value, or when there is no driving voltage input, generate a corresponding second level signal; and transmit the first level signal or the second level signal to the connection identification module corresponding to the temperature detection signal;

[0008] The connection identification module is used to switch the internal connection state according to the received level signal to adjust the resistance value connected to the configuration channel, so that when the first level signal is received, the resistance value can allow the power supply end to continuously identify the power receiving end; and when the second level signal is received, the resistance value can allow the power supply end to identify the power receiving end when the temperature does not exceed the preset threshold, and block the power supply end from identifying the power receiving end when the temperature exceeds the preset threshold.

[0009] Optionally, the over-temperature protection circuit further includes: a power bus module;

[0010] The power bus module is used to control the on / off state of the power bus according to whether the power supply end recognizes the power receiving end.

[0011] Optionally, the connection identification module includes: a switch unit and a positive temperature coefficient thermistor;

[0012] The switch unit is used to connect the conduction line to the configuration channel when receiving the first level signal; and to connect the positive temperature coefficient thermistor to the configuration channel when receiving the second level signal.

[0013] Optionally, the positive temperature coefficient thermistor is arranged on the line where the configuration channel is located;

[0014] The switch unit includes a first connection end, a second connection end and a control end;

[0015] The control end is connected to the output end corresponding to the main control module;

[0016] The first connection end is connected to the first end of the positive temperature coefficient thermistor, and the second connection end is connected to the second end of the positive temperature coefficient thermistor, so that when the switch unit receives the first level signal, the conductive path is formed between the first connection end and the second connection end; and when the switch unit receives the second level signal, the first connection end and the second connection end are in a disconnected state.

[0017] Optionally, the switch unit includes: a first switch tube and a second switch tube;

[0018] The input end of the first switch tube is connected to the input end of the second switch tube;

[0019] The output end of the first switch tube is the first connection end of the switch unit;

[0020] The output end of the second switch tube is the second connection end of the switch unit;

[0021] The control ends of the first switch tube and the second switch tube are both connected to the corresponding output ends of the main control module.

[0022] Optionally, the switch unit is a multi-way switch, comprising: a common terminal, a normally open terminal, a normally closed terminal and a control terminal;

[0023] The control end is connected to the output end corresponding to the main control module;

[0024] The common terminal is used to input the first interface signal of the configuration channel;

[0025] The normally closed end is connected to the first end of the positive temperature coefficient thermistor; wherein the second end of the positive temperature coefficient thermistor is used to output the first interface signal;

[0026] The normally open end is connected to the first end of the conductive circuit; wherein the second end of the conductive circuit is connected to the second end of the positive temperature coefficient thermistor.

[0027] Optionally, the temperature detection module includes: a fixed resistor and a thermistor;

[0028] The first end of the fixed resistor is connected to the first end of the thermistor; wherein the second end of the fixed resistor is used to access a first fixed voltage, and the second end of the thermistor is used to access a second fixed voltage;

[0029] The thermistor is used to change the level at the first end of the thermistor when the temperature changes, so as to generate the temperature detection signal.

[0030] Optionally, the over-temperature protection circuit further includes: a power supply transformer module;

[0031] The power supply transformer module is used to perform voltage conversion on the power supply voltage to generate an output voltage; wherein the output voltage is used to provide a driving voltage for the main control module and a fixed access voltage for the temperature detection module.

[0032] Optionally, the over-temperature protection circuit further includes: an electronic tag module;

[0033] The electronic label module is used to provide the attribute data of the cable to the power supply end.

[0034] A second aspect of the present invention provides an over-temperature protection method, which is applied to the over-temperature protection circuit described in any of the above embodiments, including:

[0035] Based on the temperature detection module sensing the temperature of a specified area in the cable, a corresponding temperature detection signal is generated;

[0036] According to the main control module and the temperature detection signal, determine whether the temperature exceeds a preset threshold; if it does not exceed the preset threshold, generate a first level signal; if it exceeds the preset threshold, or when there is no driving voltage input to the main control module, generate a corresponding second level signal;

[0037] Based on the generated level signal, the internal connection state of the connection identification module corresponding to the temperature detection signal is switched to adjust the resistance value of the connection identification module access configuration channel, so that when the first level signal is generated, the resistance value can allow the power supply end to continuously identify the power receiving end; and when the second level signal is generated, the resistance value can allow the power supply end to identify the power receiving end when the temperature does not exceed the preset threshold value, and block the power supply end from identifying the power receiving end when the temperature exceeds the preset threshold value.

[0038] Compared with the prior art, the embodiments of the present invention provide an over-temperature protection circuit and method. The over-temperature protection circuit senses the temperature of a specified area of ​​the cable through a temperature detection module and generates a temperature detection signal. The main control module determines whether the temperature exceeds a preset threshold value based on the temperature detection signal and generates a corresponding level signal. The connection identification module then adjusts the resistance value of the access configuration channel based on the level signal output by the main control module to ensure that the power supply end can identify the power receiving end at normal temperature, and blocks the identification when the cable is overheated.

[0039] In addition, the connection identification module in the embodiment of the present invention includes: a switch unit and a positive temperature coefficient thermistor. The switch unit switches the internal connection state of the connection identification module according to the different level signals (first level signal and second level signal) received. When the first level signal (corresponding to normal temperature) is received, the switch unit connects the conductive line to the configuration channel. Therefore, at normal temperature, the configuration channel can communicate through a low-impedance line to ensure the reliability of communication. When the second level signal (corresponding to cable overtemperature or no power supply) is received, the switch unit connects the positive temperature coefficient thermistor to the configuration channel. Once the main control module determines that the cable is overheated, the first level signal is immediately replaced with the second level signal, and the communication is blocked using the positive temperature coefficient thermistor. After the power supply is disconnected, it is still under the control of the second level signal, and the delay characteristics of the positive temperature coefficient thermistor to the temperature drop are continued to be used to avoid repeated temperature drop processes, so as to prevent the power supply end from frequently identifying the power receiving end. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a structural schematic diagram of an optional embodiment of the over-temperature protection circuit provided by the present invention;

[0041] Figure 2 is a circuit schematic diagram of an optional embodiment of the over-temperature protection circuit provided by the present invention;

[0042] Figure 3 It is a structural schematic diagram of another optional embodiment of the over-temperature protection circuit provided by the present invention. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 technical field without creative work are within the scope of protection of the present invention.

[0044] The present invention involves cables, including but not limited to charging cables, power cables, etc., which are determined when the embodiments of the present invention are applied to specific products or technologies. The embodiments of the present invention can use a pair of temperature detection modules and connection identification modules to perform temperature detection and communication blocking on any specified area in the cable (including but not limited to the charging port in the charging cable); several pairs of temperature detection modules and connection identification modules can also be set in multiple areas of the cable. After receiving the temperature detection signal from any temperature detection module and making an over-temperature judgment, the main control module will send the generated level signal to the connection identification module corresponding to the temperature detection module (temperature detection signal).

[0045] In the following, an over-temperature protection circuit and method provided by an embodiment of the present invention are described by taking a charging cable as a cable, and using two pairs of temperature detection modules and connection identification modules (i.e., connection identification module 110 and temperature detection module 310, connection identification module 120 and temperature detection module 320), which are respectively arranged in two charging ports of the charging cable.

[0046] See also Figure 1 , is a structural schematic diagram of an optional embodiment of the over-temperature protection circuit provided by the present invention.

[0047] An embodiment of the present invention provides an over-temperature protection circuit, comprising N temperature detection modules, a main control module 200 and N connection identification modules; wherein each temperature detection module and the corresponding connection identification module are arranged in pairs in different designated areas of the cable; all the connection identification modules are connected in series on the configuration channel CC1-CC1 of the cable; N≥1;

[0048] The temperature detection module is used to sense the temperature of the designated area, generate a corresponding temperature detection signal and transmit it to the main control module 200;

[0049] The main control module 200 is used to determine whether the temperature exceeds a preset threshold value according to the received temperature detection signal; if the temperature does not exceed the preset threshold value, generate a first level signal; if the temperature exceeds the preset threshold value, or when there is no driving voltage input, generate a corresponding second level signal; and transmit the first level signal or the second level signal to the connection identification module corresponding to the temperature detection signal;

[0050] The connection identification module is used to switch the internal connection state according to the received level signal to adjust the resistance value connected to the configuration channel CC1-CC1, so that when the first level signal is received, the resistance value can allow the power supply end SOURCE to continue to identify the power receiving end SINK; and when the second level signal is received, the resistance value can allow the power supply end SOURCE to identify the power receiving end SINK when the temperature does not exceed the preset threshold, and block the power supply end SOURCE from identifying the power receiving end SINK when the temperature exceeds the preset threshold.

[0051] It should be noted that when the power supply device is connected to the power supply end SOURCE of the cable (such as a charging cable) and the powered device is connected to the powered end SINK, the power supply end SOURCE will identify the powered end SINK through the configuration channel CC1-CC1, as well as whether it has a powered device inserted and the insertion direction, and the power supply end SOURCE will also provide the powered device with the power supply capability information of the power supply device or perform USB PD and other communications. Once the power supply end SOURCE fails to identify the powered end SINK through the configuration channel CC1-CC1 (equivalent to the power supply device failing to identify the powered device), the power supply device will disconnect the power supply, resulting in no driving voltage for the main control module 200. Therefore, in an embodiment of the present invention, all connection identification modules are connected in series on the configuration channel CC1-CC1 of the cable, and the resistance value of the connection identification module connected to the configuration channel CC1-CC1 is adjusted according to the temperature change. If the temperature exceeds the preset threshold, the connected resistance value can block the power supply end SOURCE from identifying the powered end SINK, so that the power supply device disconnects the power supply, thereby playing a role in protecting the circuit.

[0052] Specifically, the N temperature detection modules are used to detect the temperatures of different designated areas of the cable and generate corresponding temperature detection signals; and the N connection identification modules cooperate with the corresponding temperature detection modules to adjust the resistance value of their access configuration channels CC1-CC1.

[0053] Each temperature detection module is set in a different designated area of ​​the cable, senses the temperature of the designated area in real time, generates a corresponding temperature detection signal and transmits it to the main control module 200. When the main control module 200 receives the temperature detection signal of any temperature detection module, it determines whether the current temperature of the designated area exceeds the preset threshold value of the internal configuration. When the temperature does not exceed the preset threshold value, the main control module 200 generates a first level signal, indicating that the temperature of the designated area is normal; when the temperature exceeds the preset threshold value, the main control module 200 generates a second level signal, indicating that the temperature of the designated area is abnormal (too high). In addition, when there is no driving voltage input to the main control module 200, the voltage (level) of the corresponding output end of the main control module 200 defaults to a second level signal, which ensures that the circuit can enter the protection state in any abnormal situation on the one hand, and ensures that the connection identification module can maintain the internal connection state when the power supply is disconnected on the other hand. The second level signal in the embodiment of the present invention includes: when the temperature exceeds the preset threshold value, the second level signal SignalA generated by the main control module 200, and when there is no driving voltage input, the main control module 200 defaults to generate a second level signal SignalB (usually 0 level). Whether the two second level signals SignalA and SignalB are the same value or different values ​​is not specifically limited in the embodiment of the present invention, and is determined in actual application of the present invention.

[0054] The connection identification module and the temperature detection module are set in pairs, and are mainly used to adjust the resistance value of the cable according to the level signal sent by the main control module 200, thereby controlling the power supply state. Taking the combination of the connection identification module 110 and the temperature detection module 310 as an example, the control process is described as follows:

[0055] When the connection identification module 110 receives the first level signal sent by the main control module 200, it indicates that the current temperature of the designated area 1 is normal. At this time, the connection identification module 110 will adjust its internal connection state to keep the resistance value within a normal range, allowing the power supply end SOURCE of the cable to continue to identify the power receiving end SINK, so that the power supply device can maintain normal power supply;

[0056] When the connection identification module 110 receives the second level signal, it indicates that the current temperature of the designated area 1 is abnormal. At this time, the connection identification module 110 will switch its internal connection state, increase the resistance value in the cable, so that the power supply end SOURCE can no longer identify the power receiving end SINK, and then disconnect the power supply of the power supply device to avoid safety hazards caused by excessive temperature.

[0057] In addition, when the main control module 200 is disconnected from the power supply by the power supply device and there is no driving voltage, the connection identification module 110 will continue to maintain the internal connection state of over-temperature protection. Among them, the resistance value of the access configuration channel CC1-CC1 has the characteristics of "allowing the power supply end SOURCE to identify the power receiving end SINK when the temperature of the cable designated area 1 does not exceed the preset threshold, and blocking the power supply end SOURCE from identifying the power receiving end SINK when the temperature exceeds the preset threshold", which means that under the second level signal, the resistance value of the connection identification module 110 access configuration channel CC1-CC1 has a positive temperature change characteristic. As the temperature decreases, the resistance value will also decrease. Therefore, when there is no power supply, once the resistance value drops to a resistance threshold that allows the power supply end SOURCE to identify the power receiving end SINK, and the temperature of the designated area 1 does not exceed the preset threshold, the power supply device will resume normal power supply. Subsequently, the main control module 200 will also resume receiving the temperature detection signal and continue to perform temperature judgment and corresponding control work.

[0058] In summary, when the connection identification module 110 receives a first level signal, the resistance value of the access configuration channel CC1-CC1 is maintained below a preset resistance threshold, allowing the power supply end SOURCE to continuously identify the power receiving end SINK; and when the connection identification module 110 receives a second level signal, the resistance value has a positive temperature change characteristic, allowing the power supply end SOURCE to identify the power receiving end SINK when the temperature does not exceed the preset threshold, and blocking the power supply end SOURCE from identifying the power receiving end SINK when the temperature exceeds the preset threshold.

[0059] Similarly, the control process of other combinations such as the connection identification module 120 and the temperature detection module 320 is also consistent with the above process.

[0060] It is worth noting that all connection identification modules are connected in series on the cable configuration channel CC1-CC1 to form a series protection mechanism. In this series structure, any temperature abnormality detected by a temperature detection module will trigger the corresponding connection identification module to switch state, thereby increasing the resistance value in the configuration channel CC1-CC1 and eventually disconnecting the power supply. This series protection mechanism ensures that each monitoring point (specified area) of the cable can independently perform temperature monitoring and protection, forming a comprehensive over-temperature protection circuit.

[0061] See also Figure 2 , is a structural schematic diagram of another optional embodiment of the over-temperature protection circuit provided by the present invention.

[0062] As an improvement of the above solution, the over-temperature protection circuit further includes: a power bus VBUS-VBUS module;

[0063] The power bus VBUS-VBUS module is used to control the on-off state of the power bus VBUS-VBUS according to whether the power supply end SOURCE recognizes the power receiving end SINK.

[0064] It should be noted that when the connection identification module receives the first level signal sent by the main control module 200, it indicates that the temperature is normal, and the connection identification module switches the internal connection state and adjusts the resistance value of the access configuration channel CC1-CC1 to keep it within a normal range. In this state, the power supply end SOURCE can identify the power receiving end SINK, and the power bus VBUS-VBUS module controls the power bus VBUS-VBUS to keep it connected, allowing the power supply device to charge.

[0065] When the connection identification module receives the second level signal, it indicates that the temperature is abnormal. The connection identification module switches the internal connection state and increases the resistance value to block the power supply end SOURCE from identifying the power receiving end SINK. After the power bus VBUS-VBUS module determines that the power supply end SOURCE cannot identify the power receiving end SINK, it automatically cuts off the power bus VBUS-VBUS to avoid safety risks caused by overheating.

[0066] In the absence of external power supply, the connection identification module maintains the internal connection state of over-temperature protection through the second level signal. When the temperature drops, the resistance value of the access configuration channel CC1-CC1 also decreases. When the resistance value drops to the preset resistance threshold, the power supply end SOURCE re-identifies the power receiving end SINK, reconnects the power bus VBUS-VBUS, and the power supply returns to normal. At the same time, the main control module 200 continues to judge the temperature to ensure that the cable operates within a safe range.

[0067] See also Figure 3 , is a circuit schematic diagram of an optional embodiment of the over-temperature protection circuit provided by the present invention.

[0068] As an optional solution of the above solution, the connection identification module includes: a switch unit and a positive temperature coefficient thermistor;

[0069] The switch unit is used to connect the conduction line to the configuration channel CC1-CC1 when receiving the first level signal; and connect the positive temperature coefficient thermistor to the configuration channel CC1-CC1 when receiving the second level signal.

[0070] It should be noted that the positive temperature coefficient thermistor (PTC) resistor in the connection identification module 110 is labeled PTC1, and the PTC resistor in the connection identification module 120 is labeled PTC2. The switch unit can switch the internal connection state of the connection identification module when receiving different level signals. The specific working process is as follows:

[0071] When the power supply device and the powered device are respectively connected to the power supply end SOURCE and the powered end SINK of the cable, if the power supply device recognizes the insertion and direction of the powered device through the configuration channel CC1-CC1 in the cable, after a maximum of 200ms, the power supply device will provide a 5V voltage to the powered device on the power bus VBUS-VBUS, and will also provide a driving voltage to the main control module 200 (such as converting the voltage on the power bus VBUS-VBUS through the low voltage difference regulator LDO in the power supply transformer module 400), and provide a fixed voltage (such as a pull-up source) to the temperature detection module.

[0072] After the main control module 200 enters the working state (power-on operation) due to the input of the driving voltage, the main control module 200 will first detect whether there is an over-temperature phenomenon in each designated area of ​​the cable; if the temperature is normal, a first level signal is generated, and the first level signal is sent to the corresponding connection identification module through the output end of the main control module 200. For example, the temperature detection module 310 sends the temperature detection signal T1 of the designated area 1 to the input end ADC1 of the main control module 200, and the main control module 200 generates a corresponding first level signal U11 after performing a temperature judgment on the temperature detection signal T1, and sends the first level signal U11 to the corresponding connection identification module 110 through the output end CTL1; similarly, the temperature detection module 320 sends the temperature detection signal T2 of the designated area 2 to the input end ADC2 of the main control module 200, and the main control module 200 generates a corresponding first level signal U21 after performing a temperature judgment on the temperature detection signal T2, and sends the first level signal U21 to the corresponding connection identification module 120 through the output end CTL2.

[0073] After the corresponding connection identification module receives the first level signal (the temperature of the designated area is normal), the switch unit inside it connects the conductive line to the configuration channel CC1-CC1. Since the conductive line has the characteristics of low impedance, its access resistance is usually at the mΩ level and can be ignored. This ensures the reliability of communication, enables the configuration channel CC1-CC1 to work normally, and the power supply end SOURCE continues to identify the power receiving end SINK, allowing the power supply device to charge the power receiving device. For example: when the temperature of all designated areas in the cable is normal, all switch units connect the corresponding conductive lines to the configuration channel CC1-CC1. At this time, the configuration channel CC1-CC1 of the cable (such as a USB Type-C cable) is presented as a "direct connection state" to the outside, allowing the power supply device and the powered device connected to the cable to ignore the resistance value connected (in series) in the configuration channel CC1-CC1, and the power supply device and the powered device will perform USB PD communication on the configuration channel CC1-CC1.

[0074] During charging, since the temperature of some designated areas of the charging cable (such as the cable head) will increase with the increase of charging time, the main control module 200 obtains the temperature detection signal through any temperature detection module. If the detected temperature exceeds the preset threshold set internally, a second level signal will be generated and sent to the connection identification module corresponding to the temperature detection module through the corresponding output terminal. The accuracy and size of the preset threshold can be modified by the program, so that the embodiment of the present invention can not only ensure the threshold accuracy of the over-temperature protection, but also arbitrarily set the over-temperature protection threshold, thereby reducing the hardware cost.

[0075] When the switch unit receives the second level signal (the temperature of the corresponding designated area is too high), the PTC resistor is connected to the configuration channel CC1-CC1. In addition, since the connection identification module and the temperature detection module are arranged in pairs in the designated area of ​​the cable, when the temperature of the designated area is too high, the temperature detection module allows the main control module 200 to generate a second level signal, and controls the corresponding connection identification module to connect the PTC resistor to the configuration channel CC1-CC1 through the switch unit; the PTC resistor also senses the high temperature of the designated area, and the connected resistance value increases, so that the power supply end SOURCE cannot identify the receiving end SINK, and the power supply device therefore disconnects the power supply. It is worth noting that when the temperature of any designated area is overheated, the corresponding PTC resistor connected to the configuration channel CC1-CC1 can block the power supply end SOURCE from identifying the receiving end SINK.

[0076] After the over-temperature protection occurs, the power supply device has no power supply, that is, the main control module 200 has no driving voltage. At this time, the output terminal corresponding to the main control module 200 is defaulted to the second level signal in the present invention, so that the switch unit continues to maintain the internal connection state during the over-temperature protection, that is, the PTC resistor continues to be connected to the configuration channel CC1-CC1. Since the resistance of the PTC has a delay characteristic for the drop in temperature, the power supply is restored only when the temperature drops to a normal range and the PTC resistance is also reduced to allow the power supply device at the power supply end to re-identify the power receiving end SINK, thereby avoiding repeated temperature drop processes and preventing the power supply end SOURCE from frequently identifying the power receiving end SINK. During the period when the power is disconnected and the temperature recovers, if there is no delay characteristic of the PTC resistor as a buffer, the temperature drop process will occur repeatedly, causing the power supply end SOURCE to repeatedly open and close, that is, the "hiccup phenomenon", which not only affects the power supply stability, but also may damage the equipment.

[0077] It is worth noting that the switch unit includes but is not limited to a multi-way switch, a switch tube (such as a MOS tube, a triode) and a combination thereof, which is not specifically limited in the embodiment of the present invention and shall be determined in actual application of the present invention.

[0078] In order to more clearly describe the technical solution provided by the embodiment of the present invention, some specific embodiments of the internal connection of the connection identification module are provided below for reference:

[0079] Example 1: The positive temperature coefficient thermistor is arranged on the line where the configuration channel CC1-CC1 is located;

[0080] The switch unit includes a first connection end, a second connection end and a control end;

[0081] The control end is connected to the output end corresponding to the main control module 200;

[0082] The first connection end is connected to the first end of the positive temperature coefficient thermistor, and the second connection end is connected to the second end of the positive temperature coefficient thermistor, so that when the switch unit receives the first level signal, the conductive path is formed between the first connection end and the second connection end; and when the switch unit receives the second level signal, the first connection end and the second connection end are in a disconnected state.

[0083] It should be noted that the control end of the switch unit is connected to the corresponding output end of the main control module 200 to receive the level signal (control signal) from the main control module 200, that is, the main control module 200 can output different level signals (first level signal or second level signal) to control the on and off state of the switch unit. The switch unit is connected in parallel with the PTC resistor through the connection mode of the first connection end and the second connection end. When the main control module 200 outputs the first level signal to the control end of the switch unit, the switch unit will be turned on; this means that a conductive line will be formed between the first connection end and the second connection end, so that the PTC resistor is short-circuited. When the main control module 200 outputs the second level signal to the control end of the switch unit, the switch unit will be disconnected; this means that the circuit between the first connection end and the second connection end is broken, so that the PTC resistor is connected to the configuration channel CC1-CC1.

[0084] As an improvement of Example 1, the switch unit includes: a first switch tube and a second switch tube;

[0085] The input end of the first switch tube is connected to the input end of the second switch tube;

[0086] The output end of the first switch tube is the first connection end of the switch unit;

[0087] The output end of the second switch tube is the second connection end of the switch unit;

[0088] The control ends of the first switch tube and the second switch tube are both connected to the corresponding output ends of the main control module 200 .

[0089] It is worth noting that the switch tube in the present invention can be a commonly used triode, MOS tube, or other types of switch devices, and the embodiment of the present invention does not make specific limitations.

[0090] If two MOS tubes are selected as the first switch tube and the second switch tube respectively, the drain (D) in the MOS tube is the output end, the source (S) is the input end, and the gate (G) is the control end. The drain (D) of the first MOS tube is defined as the first connection end of the switch unit; the drain (D) of the second MOS tube is defined as the second connection end of the switch unit; the gates (G) of the two MOS tubes are connected to the corresponding output end of the main control module 200 (such as MCU) to ensure that the main control module 200 can control the two MOS tubes simultaneously through one output end; the sources (S) of the two MOS tubes are connected together; the above process realizes the process of connecting the two MOS tubes back to back.

[0091] like Figure 3As shown, in the connection identification module 110, two PMOS tubes Q1 and Q2 are selected as the first switch tube and the second switch tube respectively (i.e., a dual switch circuit is built); similarly, in the connection identification module 120, two PMOS tubes Q3 and Q4 are selected as the first switch tube and the second switch tube.

[0092] The control logic in the connection identification module 110 is as follows: when the temperature of the designated area is normal, the output terminal CTL1 of the MCU outputs a first level signal (low level), Q1 and Q2 are turned on (ie, V G <V S ), so that a conductive line is formed between the first connection terminal and the second connection terminal. When Q1 and Q2 are turned on, the resistance value of the connected configuration channel CC1-CC1 is extremely small, at the mΩ level, which can be ignored. When the temperature in the specified area is abnormal, the output terminal CTL1 of the MCU outputs a second level signal (high level), and Q1 and Q2 are disconnected (i.e., V G ≥V S ), so that the first connection terminal and the second connection terminal are in a disconnected state, the PTC1 resistor is connected to the configuration channel CC1-CC1, so that the PTC1 resistor at this time blocks the communication of the configuration channel CC1-CC1, and the power supply device disconnects the power supply. When there is no driving voltage input to the main control module 200, the output terminal CTL1 of the MCU is 0V. In this state, the output level is defaulted to the second level signal in the present invention, and Q1 and Q2 are still in a disconnected state (i.e., V G =V S ), the PTC1 resistor is still connected to the configuration channel CC1-CC1. It can be seen that when the two PMOS tubes are connected back to back, when the temperature exceeds the preset threshold, the main control module 200 generates the second level signal SignalA, and when there is no driving voltage input, the main control module 200 generates the second level signal SignalB (usually 0 level) by default. The two second level signals SignalA and SignalB are different values.

[0093] If the connection identification module 110 selects two NMOS transistors M1 and M2 as the first switch transistor and the second switch transistor respectively, when the temperature of the designated area is normal, the output terminal CTL1 of the MCU outputs a first level signal (high level), and M1 and M2 are turned on (i.e., V G >V S ), so that a conductive line is formed between the first connection terminal and the second connection terminal. When the temperature of the designated area is abnormal, the output terminal CTL1 of the MCU outputs a second level signal (low level, which can be 0V), and M1 and M2 are disconnected (i.e., V G ≤V S), so that the first connection terminal and the second connection terminal are in a disconnected state, the PTC1 resistor is connected to the configuration channel CC1-CC1, so that the PTC1 resistor at this time blocks the communication of the configuration channel CC1-CC1, and the power supply device disconnects the power supply. When the main control module 200 has no driving voltage input, the output terminal CTL1 of the MCU is 0V. In this state, the output level is defaulted to the second level signal in the present invention, and M1 and M2 are still in a disconnected state (i.e., V G =V S ), the PTC1 resistor is still connected to the configuration channel CC1-CC1. It can be seen that when the two NMOS tubes are connected back to back, the second level signals SignalA and SignalB can be the same value.

[0094] Example 2: The switch unit is a multi-way switch, including: a common terminal, a normally open terminal, a normally closed terminal and a control terminal;

[0095] The control end is connected to the output end corresponding to the main control module 200;

[0096] The common terminal is used to input the first interface signal of the configuration channel CC1-CC1;

[0097] The normally closed end is connected to the first end of the positive temperature coefficient thermistor; wherein the second end of the positive temperature coefficient thermistor is used to output the first interface signal;

[0098] The normally open end is connected to the first end of the conductive circuit; wherein the second end of the conductive circuit is connected to the second end of the positive temperature coefficient thermistor.

[0099] It should be noted that the multi-way switch in the connection identification module 110 is used as an example to expand the description: the control end of the multi-way switch is connected to the output end CTL1 of the main control module 200, which is used to receive the control signal (first level signal and second level signal) to change the switching state of the multi-way switch. When the output end CTL1 of the MCU outputs the second level signal (low level signal, such as 0V), the common end of the multi-way switch is connected to the normally closed end, and the first interface signal of the common input configuration channel CC1-CC1 is transmitted to the PTC1 resistor through the normally closed end; when the output end CTL1 of the MCU outputs the first level signal (high level signal), the normally closed end of the multi-way switch is disconnected from the common end, and the normally open end is connected to the common end, and the first interface signal input from the common end is transmitted to the conduction line through the normally open end. It can be seen that when using a multi-way switch, the second level signals SignalA and SignalB can be the same value.

[0100] As an optional solution of the above solution, the temperature detection module includes: a fixed resistor and a thermistor;

[0101] The first end of the fixed resistor is connected to the first end of the thermistor; wherein the second end of the fixed resistor is used to access a first fixed voltage, and the second end of the thermistor is used to access a second fixed voltage;

[0102] The thermistor is used to change the level at the first end of the thermistor when the temperature changes, so as to generate the temperature detection signal.

[0103] It should be noted that each temperature detection module uses a fixed resistor and a thermistor in series. The first end of the thermistor is connected to the first end of the fixed resistor to form a common node (such as the first end of the thermistor). The second end of the fixed resistor is used to access a first fixed voltage, and the second end of the thermistor is used to access a second fixed voltage; wherein the first fixed voltage and the second fixed voltage are different in value.

[0104] As the temperature in the specified area changes, the resistance of the thermistor also changes, causing the voltage distribution on the thermistor to change, and the voltage on its common node (V_common) will be used as a temperature detection signal to reflect the current temperature state. The main control module 200 can determine the current temperature of the specified area by reading the voltage value V_common on the common node, such as converting the read voltage value V_common into a corresponding temperature value by looking up a table or formula.

[0105] It is worth noting that the thermistor in the embodiment of the present invention may be a PTC resistor or a negative temperature coefficient thermistor (NTC) resistor, which is not specifically limited in the embodiment of the present invention, as long as the voltage at the first end of the thermistor also changes when the temperature changes. The first fixed voltage can be obtained by converting the voltage on the power bus VBUS-VBUS through the low voltage dropout regulator LDO in the power supply transformer module 400, or it can be obtained through other lines, which is not specifically limited in the embodiment of the present invention. The second fixed voltage can be obtained by grounding, or it can be obtained through other lines, which is not specifically limited in the embodiment of the present invention. It should be noted that the NTC resistor in the temperature detection module 310 is labeled NTC1, and the NTC resistor in the temperature detection module 320 is labeled NTC2.

[0106] For example, Figure 3As shown, the temperature detection module 310 includes: a fixed resistor R5 and a NTC1 resistor; similarly, the temperature detection module 320 includes: a fixed resistor R6 and an NTC2. In the temperature detection module 310, the second end of the fixed resistor R5 is connected to the first fixed voltage obtained by converting the voltage on the power bus VBUS-VBUS by the low voltage dropout regulator LDO, and the second end of the NTC1 resistor is connected to the second fixed voltage, which is a 0V voltage obtained by connecting the ground line.

[0107] As an optional solution of the above solution, the over-temperature protection circuit further includes: a power supply transformer module 400;

[0108] The power supply transformer module 400 is used to transform the power supply voltage to generate an output voltage; wherein the output voltage is used to provide a driving voltage for the main control module 200 and a fixed access voltage for the temperature detection module.

[0109] It should be noted that the power supply transformer module 400 may be Figure 3 The low voltage dropout regulator LDO in the power supply bus VBUS-VBUS converts the power supply voltage on the power supply bus VBUS-VBUS into a stable low voltage (output voltage) required by the main control module 200 and the temperature detection module. For example: providing a driving voltage to the main control module 200 so that it can operate normally and handle related control tasks; providing a fixed access voltage (such as a first fixed voltage) for the temperature detection module for resistor voltage division.

[0110] As an optional solution of the above solution, the over-temperature protection circuit further includes: an electronic tag module 500;

[0111] The electronic label module 500 is used to provide the attribute data of the cable to the power supply end SOURCE.

[0112] It should be noted that the attribute data includes but is not limited to the maximum allowable current, voltage level, supported data transmission rate, manufacturer information, model and other identification data information of the cable. By obtaining this data, the power supply SOURCE can dynamically configure appropriate power supply and data transmission parameters according to actual conditions to ensure the compatibility and security of the system. Figure 3 As shown, the electronic tag module 500 includes: an eMarker chip, which is connected to the interface CC2 in the power supply end SOURCE and the power receiving end SINK.

[0113] The existing eMarker junction temperature protection solution, such as using an eMarker chip for junction temperature protection on a cable with a USB Type-C interface, requires placing an eMarker chip at each end of the cable. The reason is that the eMarker chip needs to detect its own internal junction temperature to achieve over-temperature protection. Therefore, when the temperature at either end of the cable is too high, only the eMarker chip at the corresponding end can perform detection and protection, which obviously increases the hardware cost. In contrast, the over-temperature protection circuit provided in the embodiment of the present invention only uses one eMarker chip.

[0114] An embodiment of the present invention further provides an over-temperature protection method, which is applied to the over-temperature protection circuit described in any of the above embodiments, and the method includes:

[0115] Based on the temperature detection module sensing the temperature of a specified area in the cable, a corresponding temperature detection signal is generated;

[0116] According to the main control module 200 and the temperature detection signal, it is determined whether the temperature exceeds a preset threshold; if it does not exceed the preset threshold, a first level signal is generated; if it exceeds the preset threshold, or when there is no driving voltage input to the main control module 200, a corresponding second level signal is generated;

[0117] Based on the generated level signal, the internal connection state of the connection identification module corresponding to the temperature detection signal is switched to adjust the resistance value of the connection identification module access configuration channel CC1-CC1, so that when the first level signal is generated, the resistance value can allow the power supply end SOURCE to continuously identify the power receiving end SINK; and when the second level signal is generated, the resistance value can allow the power supply end SOURCE to identify the power receiving end SINK when the temperature does not exceed the preset threshold, and block the power supply end SOURCE from identifying the power receiving end SINK when the temperature exceeds the preset threshold.

[0118] In order to further reflect the technical effect achieved by an over-temperature protection method provided by the present invention, a specific application example of the inventor in a USB Type-C interface cable is given below (that is, there are two pairs of temperature detection modules and connection identification modules, and the switch units in the connection identification module are two PMOS tubes connected back to back, and the thermistors in the temperature detection module are all NTC resistors; the main control module 200 is an MCU; the power supply transformer module 400 is a low-dropout regulator LDO; the electronic label module 500 is an eMarker chip), and the technical effect of the present invention is explained:

[0119] exist Figure 3In the specific application example shown, the temperature of the USB TYPE-C cable during charging is sensed by an NTC resistor, and the changing voltage on the NTC resistor is collected as a temperature detection signal. When over-temperature occurs, the output of the power supply end is controlled to protect the powered device. Since a PTC resistor is connected in series in the configuration channel CC1-CC1, the PTC resistor can eliminate the unstable power supply phenomenon, i.e., the "hiccup phenomenon", generated when the protection is triggered in the existing NTC over-temperature protection solution.

[0120] like Figure 3 The over-temperature protection circuit shown requires 2 PTC resistors (namely labeled PTC1 and PTC2), 2 NTC resistors (namely labeled NTC1 and NTC2), 4 PMOS tubes (namely labeled Q1, Q2, Q3 and Q4), 6 ordinary resistors / fixed resistors (namely labeled R1, R2, R3, R4, R5 and R6), 1 microcontroller (namely labeled MCU), 1 low-dropout regulator (namely labeled LDO), and 1 ordinary electronic tag chip (labeled eMarker). The eMarker in the embodiment of the present invention is an electronic tag, which is used in the USB Type-C cable to explain the maximum voltage, current and data transmission capacity of the cable to the power supply device. CC1 and CC2 in the power supply end SOURCE and the power receiving end SINK are two pins defined in the USB Type-C charging interface protocol, which are used for the power supply device to identify the insertion and direction of the power receiving device, and the power supply device to provide its own power supply capability to the power receiving device or perform USB PD and other communications.

[0121] Any switch unit in the over-temperature protection circuit is controlled by an output terminal of the MCU (such as a GPIO pin), which manages a bidirectional switch circuit obtained by connecting the sources of two PMOS tubes in reverse (i.e., back-to-back connection). An LDO regulator is used in the circuit to provide a driving voltage for the MCU and a fixed access voltage (pull-up voltage) for all NTC resistors. The two NTC resistors are pulled up to the output terminal of the LDO through resistors R5 and R6, respectively, to form a voltage divider circuit. The divided voltage signal (temperature detection signal) is input to the ADC pin of the MCU for temperature detection and monitoring. The PTC resistor is connected in series in the configuration channel CC1-CC1 of the USB Type-C cable. The eMarker chip is a necessary component when the USB Type-C cable transmits more than 100W of power, and is used to identify the power transmission capability and other attribute information of the cable.

[0122] Figure 3 The working logic of the over-temperature protection circuit in is as follows:

[0123] (1) When the powered device is connected to the power supply SOURCE, the power supply will identify the insertion and direction of the powered device at the power supply SINK through CC1 and CC2. After the power supply recognizes the insertion of the powered device, it will provide 5V voltage on the power bus VBUS-VBUS to the powered device within a maximum of 200ms. At the same time, the voltage on the power bus VBUS-VBUS is converted by LDO to power the MCU.

[0124] (2) After the MCU is powered on, it will first detect whether the cable is overheated. If the temperature is normal, the MCU will control the two bidirectional switch circuits (a switch unit composed of two PMOS tubes connected back to back) through CTL1 and CTL2 respectively to make them enter the on state. When any bidirectional switch circuit is turned on, the gate (G) voltage of the PMOS is less than its threshold VGS (that is, the voltage of the source (S)); and when the gate (G) voltage is greater than or equal to VGS, the bidirectional switch circuit will enter the off state. When the PMOS is turned on, its on resistance R DS When the temperature of the entire cable is normal and the two bidirectional switch circuits are both in the on state, the configuration channel CC1-CC1 in the USB Type-C cable is in a "direct connection state" to the outside, so that the two PTC resistors in series in the configuration channel CC1-CC1 are short-circuited, thereby achieving USB PD communication between the power supply device and the powered device.

[0125] (3) During the charging process, as time goes by, the temperature of the USB TYPE-C cable head will increase. The resistance of the NTC resistor will decrease as the temperature increases, while the resistance of the PTC resistor will increase as the temperature increases. The MCU collects the voltage values ​​on the resistors NTC1 and NTC2 respectively through the ADC pins (ADC1 and ADC2). When the resistance of any one or two NTC resistors drops to the set temperature protection threshold (preset threshold), the MCU will trigger the corresponding protection mechanism. The embodiment of the present invention collects temperature data and controls it through the MCU, which has higher accuracy and flexibility than the traditional temperature protection circuit implemented by the combination of NTC and MOS hardware. The protection threshold can not only be flexibly modified and adjusted through software programs, but also reduce hardware costs, while ensuring the reliability of over-temperature protection.

[0126] (4) When the temperature in the cable reaches the temperature protection threshold, the CTL1 and CTL2 pins of the MCU will output a high level (recorded as the second level signal), so that the bidirectional switch circuit composed of the PMOS tubes in the two cable heads of the USB Type-C cable enters the cut-off state. At this time, PTC1 and PTC2 will be connected in series on the configuration channel CC1-CC1. It should be noted that PTC1 and PTC2 are placed at both ends of the USB Type-C cable respectively; when one end of the cable is overheated and the other end is not overheated, the PTC resistance value of the overheated end will increase significantly, resulting in an increase in the total resistance in series in the configuration channel CC1-CC1; and when only a single PTC resistor is used, it is impossible to accurately distinguish the temperature status of the two ends of the cable. For example, a USB Type-C cable has a resistor PCT1 placed at one end and no PCT resistor placed at the other end. If the end without the PCT resistor overheats, the MCU connects PCT1 in series to the configuration channel CC1-CC1 through CTL1. However, since the end with PCT1 does not overheat, the resistance value connected to it is still small. At this time, the power supply device will continue to supply power normally, which may cause damage to the device or cable due to overheating. Therefore, the design of using dual PTC resistors can effectively prevent such situations from happening, ensuring that when either end of the cable overheats, the circuit will respond in time and cut off the power supply to avoid potential risks caused by overheating.

[0127] Since the resistance of PTC1 or PTC2 increases with the increase of temperature, the power supply device will detect the increase of voltage on the configuration channel CC1-CC1, and thus determine that the connection with the powered device is disconnected. The principle is as follows: According to the USB Type-C protocol standard, the power supply device will provide a fixed voltage source or current source on the CC1 and CC2 pins of the power supply end SOURCE, and the powered device will connect a 5.1KΩ pull-down resistor to the CC1 or CC2 pin of the power receiving end SINK; when the USB Type-C cable connects the power supply device and the powered device, the power supply device detects whether the voltage of the CC1 and CC2 pins on the power supply end SOURCE is within the connection threshold range to determine whether the powered device has been inserted and the insertion direction; if the voltage is detected to exceed the connection threshold, the power supply device will consider the connection to be disconnected, thereby cutting off the output of the power bus VBUS-VBUS.

[0128] (5) When the power bus VBUS-VBUS is disconnected, the cable will no longer transmit current or voltage, resulting in no input power to the LDO, and the MCU will stop running. At this time, the switch circuit composed of the PMOS tube enters the cut-off state, and the PTC1 or PTC2 in series in the configuration channel CC1-CC1 begins to gradually cool down. As the temperature drops, the connected resistance value also decreases. When the resistance value of PTC1 or PTC2 drops to a level where the power supply device can re-identify the powered device, the power supply device will re-supply the VBUS voltage. At this time, the LDO supplies power to the MCU, and the MCU starts to resume work.

[0129] (6) If the over-temperature protection circuit provided in the embodiment of the present invention does not use a PTC resistor but directly uses an NTC resistor, the following situations may occur:

[0130] When the device starts charging, the temperature rises and causes the NTC resistance value to exceed the set temperature protection threshold. At this time, the NTC over-temperature protection circuit will increase the voltage on the configuration channel CC1-CC1, making it impossible for the power supply end to identify the powered device, and then disconnect the power bus VBUS-VBUS. Due to the disconnection of the power bus VBUS-VBUS, the power supply of the NTC circuit is also interrupted. After the power supply device recognizes the powered device again, it restarts the power input. At this time, the NTC protection circuit works again, and the power supply end disconnects the power bus VBUS-VBUS again. In this case, if there is no external intervention, this process will continue to cycle, causing frequent hiccups on the power bus VBUS-VBUS, which may damage the powered device.

[0131] However, the over-temperature protection circuit provided in the embodiment of the present invention will disconnect the power bus VBUS-VBUS after the over-temperature protection is triggered, and the PTC is connected in series in the configuration channel CC1-CC1. When the power supply end device tries to re-identify the external device, the power supply device cannot immediately identify the powered device due to the large resistance of the PTC. Only when the line temperature drops can the power supply end identify the powered device and re-supply power. Subsequently, the MCU is able to resume work and control the drain and source of Q1, Q2, Q3, and Q4 to be turned on through CTL1 and CTL2. When the PMOS tube is in the on state, its on-resistance RDS (ON) is less than the ohm level and can be ignored. At this time, the configuration channels CC1-CC1 (signal lines) of the power supply end SOURCE and the power receiving end SINK are approximately directly connected. Based on this, the embodiment of the present invention can effectively solve the hiccup phenomenon of the power bus VBUS-VBUS caused by simple NTC protection, thereby realizing stable charging of the powered device by the power supply device.

[0132] Based on this, Figure 3The over-temperature protection circuit shown in the figure only requires one common eMarker chip in the implementation process, instead of two built-in eMarker chips. In addition, by using at least one PTC resistor, one bidirectional switch circuit and one NTC resistor, the hiccups of the power bus VBUS-VBUS during over-temperature protection can be effectively prevented, thereby effectively protecting the safety of the charging device. At the same time, the temperature acquisition solution using MCU combined with NTC resistor can accurately measure the required temperature and provide a programmable temperature threshold, thereby significantly reducing hardware costs.

[0133] The above is only an optional implementation mode of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An over-temperature protection circuit, characterized in that: include: N temperature detection modules, a main control module and N connection identification modules; wherein each temperature detection module and the corresponding connection identification module are arranged in pairs in different designated areas of the cable; all the connection identification modules are connected in series on the configuration channel of the cable; N≥1; The temperature detection module is used to sense the temperature of the designated area, generate a corresponding temperature detection signal and transmit it to the main control module; The main control module is used to determine whether the temperature exceeds a preset threshold value according to the received temperature detection signal; if the temperature does not exceed the preset threshold value, generate a first level signal; if the temperature exceeds the preset threshold value, or when there is no driving voltage input, generate a corresponding second level signal; and transmit the first level signal or the second level signal to the connection identification module corresponding to the temperature detection signal; The connection identification module is used to switch the internal connection state according to the received level signal to adjust the resistance value connected to the configuration channel, so that when the first level signal is received, the resistance value can allow the power supply end to continuously identify the power receiving end; and when the second level signal is received, the resistance value can allow the power supply end to identify the power receiving end when the temperature does not exceed the preset threshold, and block the power supply end from identifying the power receiving end when the temperature exceeds the preset threshold.

2. The over-temperature protection circuit according to claim 1, characterized in that: The over-temperature protection circuit further includes: a power bus module; The power bus module is used to control the on / off state of the power bus according to whether the power supply end recognizes the power receiving end.

3. The over-temperature protection circuit according to claim 1, characterized in that: The connection identification module includes: a switch unit and a positive temperature coefficient thermistor; The switch unit is used to connect the conduction line to the configuration channel when receiving the first level signal; and to connect the positive temperature coefficient thermistor to the configuration channel when receiving the second level signal.

4. The over-temperature protection circuit according to claim 3, characterized in that: The positive temperature coefficient thermistor is arranged on the line where the configuration channel is located; The switch unit includes a first connection end, a second connection end and a control end; The control end is connected to the output end corresponding to the main control module; The first connection end is connected to the first end of the positive temperature coefficient thermistor, and the second connection end is connected to the second end of the positive temperature coefficient thermistor, so that when the switch unit receives the first level signal, the conduction circuit is formed between the first connection end and the second connection end; And when the second level signal is received, the first connection end and the second connection end are in a disconnected state.

5. The over-temperature protection circuit according to claim 4, characterized in that: The switch unit comprises: a first switch tube and a second switch tube; The input end of the first switch tube is connected to the input end of the second switch tube; The output end of the first switch tube is the first connection end of the switch unit; The output end of the second switch tube is the second connection end of the switch unit; The control ends of the first switch tube and the second switch tube are both connected to the corresponding output ends of the main control module.

6. The over-temperature protection circuit according to claim 3, characterized in that: The switch unit is a multi-way switch, including: a common terminal, a normally open terminal, a normally closed terminal and a control terminal; The control end is connected to the output end corresponding to the main control module; The common terminal is used to input the first interface signal of the configuration channel; The normally closed end is connected to the first end of the positive temperature coefficient thermistor; wherein the second end of the positive temperature coefficient thermistor is used to output the first interface signal; The normally open end is connected to the first end of the conductive circuit; wherein the second end of the conductive circuit is connected to the second end of the positive temperature coefficient thermistor.

7. The over-temperature protection circuit according to claim 1, characterized in that: The temperature detection module includes: a fixed resistor and a thermistor; The first end of the fixed resistor is connected to the first end of the thermistor; wherein the second end of the fixed resistor is used to access a first fixed voltage, and the second end of the thermistor is used to access a second fixed voltage; The thermistor is used to change the level at the first end of the thermistor when the temperature changes, so as to generate the temperature detection signal.

8. The over-temperature protection circuit according to claim 1, characterized in that: The over-temperature protection circuit also includes: a power supply transformer module; The power supply transformer module is used to perform voltage conversion on the power supply voltage to generate an output voltage; wherein the output voltage is used to provide a driving voltage for the main control module and a fixed access voltage for the temperature detection module.

9. The over-temperature protection circuit according to claim 1, characterized in that: The over-temperature protection circuit also includes: an electronic tag module; The electronic label module is used to provide the attribute data of the cable to the power supply end.

10. An over-temperature protection method, characterized in that: The over-temperature protection method according to any one of claims 1 to 9 comprises: Based on the temperature detection module sensing the temperature of a specified area in the cable, a corresponding temperature detection signal is generated; According to the main control module and the temperature detection signal, determine whether the temperature exceeds a preset threshold; if it does not exceed the preset threshold, generate a first level signal; if it exceeds the preset threshold, or when there is no driving voltage input to the main control module, generate a corresponding second level signal; Based on the generated level signal, the internal connection state of the connection identification module corresponding to the temperature detection signal is switched to adjust the resistance value of the connection identification module access configuration channel, so that when the first level signal is generated, the resistance value can allow the power supply end to continuously identify the power receiving end; and when the second level signal is generated, the resistance value can allow the power supply end to identify the power receiving end when the temperature does not exceed the preset threshold value, and block the power supply end from identifying the power receiving end when the temperature exceeds the preset threshold value.

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