A protection system, a charging cable, and a charging device

Abstract

An embodiment of the present invention provides a protection system and a charging device, including a temperature detection unit, a first control unit, a power data sending unit, a power data receiving unit, a power data decoding unit, and a second control unit; the output end of the temperature detection unit is connected to the input end of the first control unit, the output end of the first control unit is connected to the first end of the power data sending unit, the second end of the power data sending unit is used to connect the power supply line of the charging cable, the power supply line is used to connect the power supply pin of the charging cable, and the power supply pin is also connected to the first end of the power data receiving unit, the second end of the power data receiving unit is connected to the input end of the power data decoding unit, and the output end of the power data decoding unit is connected to the second control unit; in this protection system, when the temperature of the charging cable is too high, the second control unit can control the charging power or the discharging power, playing a role in over-temperature protection, and improving the reliability and safety of the charging cable.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of USB, and in particular to a protection system and a charging cable. Background Art

[0002] With the increasingly stringent requirements of mobile devices for transmission rate, charging power, and interface size, the new generation of USB interface, USB Type-C, has emerged as the times require. USB Type-C, abbreviated as Type-C, is a hardware interface specification for the Universal Serial Bus (USB). To support a maximum output power of 240W, the corresponding USB Power Delivery Specification (USB PD) was also subsequently introduced. The USB PD protocol can support a current of 3A or 5A, with a maximum output voltage of 48V. At the same time, a dedicated channel for power transfer protocol communication is defined in the interface to improve the charging efficiency.

[0003] To meet the increasing charging power requirements of devices, both power supply devices and power receiving devices are gradually increasing the power during charging, including the charging voltage and charging current. The USB Power Delivery (PD) protocol stipulates that it supports a maximum output power of 240W. Correspondingly, the USB cable can carry a current of 3A or 5A, with a maximum output voltage of 48V. At the same time, a dedicated channel for power transfer protocol communication is defined in the interface, which can complete intelligent adaptive charging adjustment between the charging and power receiving devices to improve the charging efficiency. The USB PD protocol stipulates that the USB cable for distinguishing 3A and 5A is whether an electronic tag chip is built into the USB cable. When the charger end recognizes this chip, it will broadcast a charging current greater than 3A to the device.

[0004] However, in actual applications, many hosts ignore the regulations of this USB PD protocol and do not pre-check whether there is an electronic tag in the cable before broadcasting a charging current to the device that may be much larger than the rated current of the cable, which will cause the cable temperature to rise; in addition, in the case of using various USB fast charging protocols, before the fast charging protocol handshake is completed, only a 5V3A output power is supported. Once the fast charging protocol handshake is completed, the supported power can rise to a maximum of 240W, the maximum voltage rises to 48V, and the maximum current rises to 5A. Within this power range, the voltage and current passing through the cable may increase significantly, which will also cause the cable temperature to rise. And the increase in cable temperature will cause the cable to melt, posing a great safety hazard. Summary of the Invention

[0005] The purpose of the embodiments of the present invention is to provide a protection system, a charging cable, and a charging device, which can control the charging power or discharging power when the cable temperature is too high, achieve over-temperature protection, and improve the system safety.

[0006] To solve the above technical problems, a technical solution adopted in an embodiment of the present invention is: to provide a protection system, the protection system includes a temperature detection unit, a first control unit, a power data sending unit, a power data receiving unit, a power data decoding unit, and a second control unit; an output end of the temperature detection unit is connected to an input end of the first control unit, an output end of the first control unit is connected to a first end of the power data sending unit, a second end of the power data sending unit is used to connect a power supply line of a charging cable, the power supply line is used to connect a power supply pin of the charging cable, and the power supply pin is also connected to a first end of the power data receiving unit, a second end of the power data receiving unit is connected to an input end of the power data decoding unit, and an output end of the power data decoding unit is connected to the second control unit; wherein, the temperature detection unit is used to detect the temperature of the charging cable and output a corresponding voltage signal to the first control unit according to the temperature; the first control unit is used to output an encoded signal to the power data sending unit according to the voltage signal; the power data sending unit is used to control the current of the power supply line according to the encoded signal; the power data receiving unit is used to obtain the voltage of the power supply pin and output the voltage to the power data decoding unit; the power data decoding unit is used to obtain a decoded signal according to the voltage and send the decoded signal to the second control unit; the second control unit is used to determine whether it is overheated according to the decoded signal and control the charging power or the discharging power when it is overheated.

[0007] In some embodiments, the charging cable includes an electronic tag chip; the first control unit and the power data receiving unit are disposed in the electronic tag chip.

[0008] In some embodiments, the temperature detection unit is disposed in the electronic tag chip.

[0009] In some embodiments, the temperature detection unit includes an NTC thermistor, a power supply, and a first comparator; a first end of the NTC thermistor is respectively connected to the power supply and a first input end of the first comparator, a second input end of the first comparator is connected to a reference voltage, and an output end of the first comparator is connected to an input end of the first control unit.

[0010] In some embodiments, the first control unit is further used to perform debounce delay processing on the voltage signal and output the encoded signal according to the voltage signal after the debounce delay processing.

[0011] In some embodiments, the power data sending unit includes a switching transistor and a load; a first end of the switching transistor is connected to an output end of the first control unit, a second end of the switching transistor is connected to a first end of the load, and a second end of the load is connected to the power supply line.

[0012] In some embodiments, the protection system further includes a power supply unit; a first end of the power supply unit is connected to the power supply line, and a second end of the power supply unit is respectively connected to the temperature detection unit and the first control unit, and the power supply unit is configured to supply power to the temperature detection unit and the first control unit.

[0013] In some embodiments, the power data receiving unit includes a first resistor; a first end of the first resistor is configured to be connected to a power supply of the power supply pin, and a second end of the first resistor is respectively connected to an input end of the power data decoding unit and the power supply pin.

[0014] In some embodiments, the power data decoding unit includes a first low-pass filter, a second low-pass filter, and a second comparator; a first end of the first low-pass filter is connected to a second end of the power data receiving unit, a second end of the first low-pass filter is respectively connected to a first input end of the second comparator and a first end of the second low-pass filter, a second end of the second low-pass filter is connected to a second input end of the second comparator, and an output end of the second comparator is connected to the second control unit.

[0015] In some embodiments, when the second control unit is disposed in the power supply device, the second control unit is configured to: control the output power and / or output a first indication signal to the power receiving device when overheating occurs, where the first indication signal is used to indicate overheating or a change in the output power of the power supply device.

[0016] In some embodiments, when the second control unit is disposed in the power receiving device, the second control unit is configured to: control the received power and / or output a second indication signal to the power receiving device when overheating occurs, where the second indication signal is used to indicate overheating or a change in the output power of the power supply device.

[0017] In a second aspect, an embodiment of the present invention further provides a charging device, and the charging device includes the protection system as described in the first aspect.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: Different from the prior art, the embodiments of the present invention provide a protection system and a charging device, including a temperature detection unit, a first control unit, a power data sending unit, a power data receiving unit, a power data decoding unit, and a second control unit; the output end of the temperature detection unit is connected to the input end of the first control unit, the output end of the first control unit is connected to the first end of the power data sending unit, the second end of the power data sending unit is used to connect the power supply line of the charging cable, the power supply line is used to connect the power supply pin of the charging cable, and the power supply pin is also connected to the first end of the power data receiving unit, the second end of the power data receiving unit is connected to the input end of the power data decoding unit, and the output end of the power data decoding unit is connected to the second control unit; in this protection system, when the temperature of the charging cable is too high, the second control unit can control the charging power or the discharging power, playing a role in over-temperature protection, and improving the reliability and safety of the charging cable. Description of the Drawings

[0019] In one or more embodiments, exemplary illustrations are provided through the pictures in the corresponding drawings. These exemplary illustrations do not limit the embodiments. Elements / modules and steps with the same reference numerals in the drawings are represented as similar elements / modules and steps. Unless otherwise stated, the drawings in the figures do not constitute a proportional limitation.

[0020] Figure 1 It is a schematic structural diagram of a protection system provided by an embodiment of the present invention;

[0021] Figure 2 It is a schematic structural diagram of a charging cable provided by an embodiment of the present invention;

[0022] Figure 3 It is a schematic circuit diagram of a temperature detection unit provided by an embodiment of the present invention;

[0023] Figure 4 It is a schematic diagram showing the change of the resistance value of an NTC thermistor with temperature provided by an embodiment of the present invention;

[0024] Figure 5 It is a schematic diagram of a partial circuit structure of a protection system provided by an embodiment of the present invention;

[0025] Figure 6 It is a schematic diagram showing the change of the current on the power supply line with the coding signal provided by an embodiment of the present invention;

[0026] Figure 7 It is a schematic diagram of the waveforms of high-frequency periodic ripple, non-ripple, and random ripple provided by an embodiment of the present invention;

[0027] Figure 8It is a schematic diagram of a partial circuit structure of another protection system provided by an embodiment of the present invention;

[0028] Figure 9 It is a schematic diagram of a circuit structure of a power data decoding unit provided by an embodiment of the present invention;

[0029] Figure 10 It is a schematic diagram of the voltage of a power supply pin and the waveform of a decoded signal provided by an embodiment of the present invention. Detailed implementation manners

[0030] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made. These all belong to the protection scope of the present invention.

[0031] To facilitate the understanding of the present application, the present application will be described in more detail below with reference to the accompanying drawings and specific embodiments. Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not used to limit this application. The term "and / or" used in this specification includes any and all combinations of one or more of the related listed items.

[0032] It should be noted that if there is no conflict, the various features in the embodiments of the present invention can be combined with each other, and all are within the protection scope of this application. In addition, although the functional modules are divided in the device schematic diagram, in some cases, the division can be different from that in the device. In addition, the terms "first", "second", etc. used herein do not limit the data and execution order, but only distinguish the same items or similar items with basically the same functions and effects.

[0033] In a first aspect, an embodiment of the present invention provides a protection system. Please refer to Figure 1 , the protection system includes a temperature detection unit 11, a first control unit 12, a power data sending unit 13, a power data receiving unit 21, a power data decoding unit 22, and a second control unit 23.

[0034] The output end of the temperature detection unit 11 is connected to the input end of the first control unit 12. The output end of the first control unit 12 is connected to the first end of the power data sending unit 13. The second end of the power data sending unit 13 is used to connect to the power supply line of the charging cable, and the power supply line is used to connect to the power supply pin VCONN of the charging cable. The power supply pin VCONN is also connected to the first end of the power data receiving unit 21. The second end of the power data receiving unit 21 is connected to the input end of the power data decoding unit 22. The output end of the power data decoding unit 22 is connected to the second control unit 23.

[0035] Among them, the temperature detection unit 11 is used to detect the temperature of the charging cable and output a corresponding voltage signal to the first control unit 12 according to the temperature. The first control unit 12 is used to output an encoded signal to the power data sending unit 13 according to the voltage signal. The power data sending unit 13 is used to control the current of the power supply line according to the encoded signal. The power data receiving unit 21 is used to obtain the voltage of the power supply pin VCONN and output the voltage to the power data decoding unit 22. The power data decoding unit 22 is used to obtain a decoded signal according to the voltage and send the decoded signal to the second control unit 23. The second control unit 23 is used to determine whether it is overheated according to the decoded signal and control the charging power or discharging power when it is overheated.

[0036] Please refer to Figure 2 , for the charging cable, it includes two connection ports 30. Both of the two connection ports 30 include interfaces 31. At least one of the two connection ports 30 further includes an electronic tag chip 32. In Figure 2 the illustrated embodiment, both of the two connection ports 30 include an electronic tag chip 32. In actual application, only one connection port 30 may include an electronic tag chip 32. Among them, the two interfaces 31 are a USB male head and a USB female socket respectively. In this charging cable, the power supply pins VBUS of the two interfaces 31 are connected to each other, the ground pins GND of the two interfaces 31 are connected to each other, and the communication pins CC of the two interfaces 31 are connected to each other. In this way, when the power supply device is connected to the power receiving device through this charging cable, the power supply device can supply power to the power receiving device. Among them, the connection line between the communication pins CC of the two interfaces 31 can be used to establish a Type C connection and perform protocol communication of USB PD. In addition, when the connection port 30 includes an electronic tag chip 32, the interface 31 is also provided with a power supply pin VCONN. When the power supply device is connected to the power receiving device through this charging cable, this power supply pin VCONN is used to supply power to the electronic tag chip 32. And in the charging cable of the present invention, the power supply pin VCONN of the charging cable is the power supply pin of the electronic tag chip 32 connected to the interface 31, and the power supply line of the charging cable is the connection line between the power supply pin VCONN of the interface 31 and the electronic tag chip 32.

[0037] Specifically, the voltage signal includes a first voltage signal and a second voltage signal. In this protection system, when the power supply device is connected to the power receiving device through the charging cable, that is, when one interface 31 is connected to the power supply device and the other interface 31 is connected to the power receiving device, the power supply pin VCONN is powered, and a current will be generated on the power supply line. When the temperature detection unit 11 detects that the temperature is less than the first temperature value, it will output the first voltage signal corresponding to the temperature to the first control unit 12, and the first control unit 12 will not output an encoding signal to the power data sending unit 13. When the temperature detection unit 11 detects that the temperature is greater than the first temperature value, it will output the second voltage signal corresponding to the temperature to the first control unit 12; after receiving the second voltage signal, the first control unit 12 will output an encoding signal to the power data sending unit 13; after receiving the encoding signal, the power data sending unit 13 will control the current on the power supply line to change. At this time, since the current on the power supply line changes, the voltage on the power supply pin VCONN will change. In this way, the power data receiving unit 21 receives the changed voltage and outputs the voltage to the power data decoding unit 22; then, the power data decoding unit 22 can obtain a decoding signal according to the changed voltage and send the decoding signal to the second control unit 23. After receiving the decoding signal, the second control unit 23 can determine whether the charging cable is overheated at this time and control the charging power or the discharging power when overheated, so as to ensure that the temperature does not continue to rise.

[0038] It can be seen that in this protection system, when the temperature of the charging cable is too high, the second control unit 23 can control the charging power or the discharging power, playing a role in over-temperature protection, and can improve the reliability and safety of the charging cable. Moreover, in this embodiment, after the temperature exceeds the first temperature value, without destroying the existing protocol and the functions of each pin, the power supply pin VCONN of the electronic tag chip 32 is reused to actively send a fault instruction, so that the entire system exits the high-power charging mode, thereby limiting the output power of the entire system and improving the reliability of the system.

[0039] In some of the embodiments, please refer to Figure 1 and Figure 2 , the charging cable includes an electronic tag chip 32; the first control unit 12 and the power data receiving unit 21 are provided inside the electronic tag chip 32. Among them, the electronic tag chip 32 can be an E-Marker chip, and various attributes of the charging cable can be read through this chip, including information with identification functions such as the manufacturer, current-carrying capacity, and withstand voltage level. For example, the information with identification functions can be stored in the first control unit 12 in advance. In this way, the first control unit 12 can not only monitor the voltage signal but also have the function of an electronic tag.

[0040] In some embodiments, please refer to Figure 1 andFigure 2 , the temperature detection unit 11 is disposed inside the electronic tag chip 32. In this way, the temperature inside the electronic tag chip 32 can be detected by the temperature detection unit 11 as the temperature of the cable, which can also play a role in over-temperature protection.

[0041] To improve the accuracy of over-temperature protection, in some other embodiments, please refer to Figure 2 , the temperature detection unit 11 is disposed outside the electronic tag chip 32. For example, the temperature detection unit 11 is arranged adjacent to the interface 31 of the charging cable. It can be understood that the impedance at the interface 31 is relatively large, and when the current is too high, the temperature at the interface 31 is higher than that at other positions of the cable. Therefore, arranging the temperature detection unit 11 adjacent to the interface 31 of the charging cable can more truly reflect the temperature of the hot spot area of the cable, thereby improving the accuracy of the system's over-temperature protection. In practical applications, the temperature detection unit 11 can also be disposed in other hot spot areas of the cable, and the hot spot area of the cable is the area where the temperature of the charging cable is relatively high.

[0042] In some of these embodiments, please refer to Figure 3 , the temperature detection unit 11 includes a negative temperature coefficient (NTC) thermistor R0, a power supply I1, and a first comparator U1; the first end of the NTC thermistor R0 is respectively connected to the power supply I1 and the first input terminal of the first comparator U1, the second input terminal of the first comparator U1 is connected to the reference voltage VOT, and the output terminal of the first comparator U1 is connected to the input terminal of the first control unit 12.

[0043] Among them, the resistance value R of the NTC thermistor R0 NTC decreases exponentially with the increase of the temperature T, as Figure 4 shown. The reference voltage VOT is the voltage of the NTC thermistor R0 corresponding to the first temperature value. In practical applications, the reference voltage VOT can be a fixed value or a dynamic value. Specifically, the reference voltage VOT can be output through a voltage dividing circuit, or output by a control unit, or dynamically adjusted according to preset conditions.

[0044] When the protection system works, after the power supply I1 outputs the current IOT, the current will flow through the NTC thermistor R0, thereby generating a voltage VNTC at the first end of the NTC thermistor R0, and the voltage VNTC = IOT * R NTC . When the temperature T rises, the resistance value R of the NTC thermistor R0 NTC will decrease. In this way, the voltage VNTC will change with the resistance value R of the NTC thermistor R0 NTCIt decreases as the temperature drops, that is, the voltage VNTC decreases as the temperature T rises. Therefore, when the temperature is greater than the first temperature value, the voltage VNTC will be lower than the reference voltage VOT, and the first comparator U1 will output a voltage signal OT of the first level, which is used to indicate that the temperature is higher than the first temperature value at this time. When the temperature is less than the first temperature value, the voltage VNTC will be higher than the reference voltage VOT, and the first comparator U1 will output a voltage signal OT of the second level, which is used to indicate that the temperature is less than the first temperature value at this time. Specifically, the first input terminal of the first comparator U1 can be the positive input terminal, and the second input terminal of the first comparator U1 can be the negative input terminal. At this time, when the temperature is greater than the first temperature value, the voltage signal OT is a high-level signal, and when the temperature is less than the first temperature value, the voltage signal OT is a low-level signal.

[0045] In practical applications, the temperature detection unit can also include a positive temperature coefficient thermistor, a semiconductor device, or any other suitable circuit device. Its specific circuit structure can be set with reference to the prior art and will not be limited here.

[0046] In order to improve the reliability of the protection system, in some embodiments, the first control unit 12 is further configured to perform a debounce delay process on the voltage signal and output an encoded signal according to the voltage signal after the debounce delay process.

[0047] Specifically, when the voltage signal OT changes, for example, when the temperature is greater than the first temperature value and the voltage signal OT changes from a low-level signal to a high-level signal, the first control unit 12 will perform a debounce delay process on the voltage signal OT for a preset time. For example, after the preset time, the voltage signal OT is retrieved again to determine whether the voltage signal OT is a high-level signal or a low-level signal. Alternatively, the duration of the voltage signal OT is obtained to determine whether the duration of the voltage signal OT is greater than or equal to the preset time. If so, it is determined whether the voltage signal OT is a high-level signal or a low-level signal.

[0048] When the voltage signal OT after the debounce delay process is a low-level signal, the first control unit 12 does not trigger subsequent protection actions. When the voltage signal OT after the debounce delay process is a high-level signal, the first control unit 12 will output an encoded signal to the power data sending unit 13, so that the power data sending unit 13 sends the encoded signal to change the current of the power supply line.

[0049] In this embodiment, by performing a debounce delay process on the voltage signal OT, it can be ensured that the received voltage signal OT is stable and reliable, avoiding noise interference, thereby improving the reliability of the protection system. Among them, the debounce delay process can be implemented by software or by a hardware circuit, which will not be limited here. The first control unit 12 can be a microcontroller processor for receiving, processing, and outputting data.

[0050] In some of these embodiments, the encoded signal Tr_Data is a data with a preset frequency and encoding format. A encoding format of the encoded signal Tr_Data is provided below, as shown in Table 1 below.

[0051] Table 1 A encoding format of the encoded signal

[0052] 01010101 00111 00111 00111 11001

[0053] Wherein, the transmission period of each data bit of the encoded signal Tr_Data is Tcyc, and the frequency of the encoded signal Tr_Data is much lower than some ripple frequencies inherent in the power supply line, such as switching ripple, noise and other frequencies. Specifically, its frequency can be 1 kHz, and subsequently, interference from switching ripple and noise to the protection system can be avoided, improving the reliability of the protection system.

[0054] As shown in Table 1, the encoded signal has an 8-bit preamble and four groups of fixed data combinations. The preamble is a fixed combination of four 01s, which can be used to indicate that the receiving end starts to prepare for receiving data and synchronize the data frequency of the encoded signal Tr_Data to ensure successful reception; the latter four groups of fixed data combinations represent over-temperature information. In practical applications, the encoding format of the encoded signal can be set according to actual needs and does not need to be limited to the limitations in this embodiment.

[0055] In some of these embodiments, the first control unit 12 is further configured to periodically output the encoded signal Tr_Data after determining over-temperature until the over-temperature fault disappears. That is, after determining that the cable is over-temperature, the first control unit 12 periodically outputs the encoded signal Tr_Data to the power data sending unit 13, so that the power data sending unit 13 periodically changes the current, and this period can be set according to actual needs and is not limited here. Through the above settings, the reliability of the protection system can be improved.

[0056] In some of these embodiments, please refer to Figure 5 , the power data sending unit 13 includes a switching transistor Q1 and a load R2; the first end of the switching transistor Q1 is connected to the output end of the first control unit 12, the second end of the switching transistor Q1 is connected to the first end of the load R2, and the second end of the load R2 is connected to the power supply line.

[0057] Specifically, the load R2 can be a second resistor or a current source, and the switching transistor Q1 can be an NMOS transistor. The gate of the NMOS transistor is connected to the output terminal of the first control unit 12, the drain of the NMOS transistor is connected to the first end of the second resistor, and the source of the NMOS transistor is grounded. In this embodiment, after receiving the encoded signal Tr_Data, the power data sending unit 13 can control the on or off of the NMOS transistor to control whether the second resistor is connected to the power supply line, thereby changing the second resistor on the power supply line, and finally changing the current on the power supply line. Specifically, please refer to Figure 5 and Figure 6 , when the encoded signal Tr_Data is 0, the NMOS transistor is turned off, the second resistor is not connected to the power supply line, and the current flowing through the second resistor is 0, that is, the magnitude of the current IVCONN on the power supply line is the normal power supply current magnitude when no additional load is added to the power supply line, which is ICC; when the encoded signal Tr_Data is 1, the NMOS transistor is turned on, the second resistor is connected to the power supply line, and the magnitude of the current flowing through the second resistor is ITr, where ITr = V CONN / R2, V CONN is the voltage of the power supply pin VCONN, R2 is the resistance value of the second resistor, and the current IVCONN on the power supply line is ICC + ITr.

[0058] It can be understood that when the encoded signal Tr_Data is 0 or the first control unit 12 does not output the encoded signal Tr_Data, the first control unit also outputs a low-level signal to the switching transistor Q1 to prevent the load from being connected to the power supply line. Then, when over-temperature protection is not triggered, under normal circumstances, the magnitude of the current on the power supply line should always be ICC, which is a direct current, as shown in the waveform diagram without ripple in Figure 7 . However, in actual applications, there may be high-frequency switching ripple current on the power supply line, and its current waveform diagram may be the waveform diagram with high-frequency periodic ripple, or the waveform diagram with random ripple, etc. By setting the frequency of the encoded signal to be much lower than the frequencies of the switching ripple and noise, the accuracy of subsequent decoding can be improved.

[0059] In some of these embodiments, please continue to refer to Figure 5, the protection system further includes a power supply unit 14. The first end of the power supply unit 14 is connected to the power supply line, and the second end of the power supply unit 14 is respectively connected to the temperature detection unit 11 and the first control unit 12. The power supply unit 14 is used to supply power to the temperature detection unit 11 and the first control unit 12. By providing the power supply unit 14, when the power supply device is connected to the power receiving device through the charging cable, the power supply unit 14 can obtain electrical energy through the power supply line, so as to supply power to the temperature detection unit 11 and the first control unit 12, ensuring the normal operation of the system. Specifically, the power supply unit 14 can be disposed inside the electronic tag chip 32. In this way, the power supply unit 14 can also supply power to the electronic tag chip 32.

[0060] In some of these embodiments, the power data receiving unit 21 includes a first resistor R1. The first end of the first resistor R1 is used to connect to the power supply U2 of the power supply pin VCONN, and the second end of the first resistor R1 is respectively connected to the input end of the power data decoding unit 22 and the power supply pin VCONN. In this way, in this protection system, the actual voltage on the power supply pin VCONN is V1 = V CONN -R1*IVCONN. When the current on the power supply line changes, the actual voltage V1 on the power supply pin VCONN will change. Subsequently, the power data receiving unit 21 obtains the current change by detecting the voltage of the power supply pin VCONN. In practical applications, when the power supply U2 is a non-ideal power supply with a source impedance, then, the first resistor R1 can also be omitted, and the power data receiving unit 21 only includes a connecting wire to connect the power supply pin VCONN to the power data decoding unit 22.

[0061] In some of these embodiments, please refer to Figure 9 , the power data decoding unit 22 includes a first low-pass filter 221, a second low-pass filter 222 and a second comparator U3; the first end of the first low-pass filter 221 is connected to the second end of the power data receiving unit 21, the second end of the first low-pass filter 221 is respectively connected to the first input end of the second comparator U3 and the first end of the second low-pass filter 222, the second end of the second low-pass filter 222 is connected to the second input end of the second comparator U3, and the output end of the second comparator U3 is connected to the second control unit 23.

[0062] Specifically, the first low-pass filter 221 and the second low-pass filter 222 can adopt all suitable low-pass filters in the prior art, and their specific structures can be set according to actual needs and are not limited herein. The first input end of the second comparator U3 is the positive input end, and the second input end of the second comparator U3 is the negative input end. In this embodiment, through two-stage low-pass filters, the preset AC ripple under the period Tcyc can be successfully resolved to generate a decoded signal, such as Figure 10As shown, after the signal with a period of Tcyc in the voltage of the power supply pin VCONN passes through the power supply data decoding unit 22, a decoded signal can be obtained, as shown in Table 2 below.

[0063] Table 2 A coding format of the decoded signal

[0064] 01010101 00111 00111 00111 11001

[0065] Next, after receiving the decoded signal, the second control unit 23 determines whether overheating has occurred. To improve the fault tolerance rate, the second control unit 23 does not need to confirm whether the preamble is complete, but only needs to confirm whether the last four groups of data are complete. If it is complete, it confirms overheating and triggers a protection action. If it is incomplete, it confirms no overheating and does not trigger a protection action.

[0066] In some embodiments, when the second control unit 23 is provided in the power supply device, the second control unit 23 is configured to: control the output power and / or output a first indication signal to the power receiving device when overheating occurs, where the first indication signal is used to indicate overheating or a change in the output power of the power supply device.

[0067] Specifically, when the second control unit 23 is provided in the power supply device, such as in a charger, after the second control unit 23 confirms overheating according to the decoded signal, the second control unit 23 will limit the power output by the power supply device, such as reducing the output power, such as by reducing the output voltage or current to reduce the output power, so that the system outputs within the minimum operable power range, or completely stops outputting power, waits for user intervention or automatic retry, or outputs a first indication signal to the power receiving device to inform the power receiving device that overheating has occurred in the system at this time, or informs the power receiving device that the output power will be reduced at this time, and subsequent power protection can be triggered by the power receiving device.

[0068] In some embodiments, the power supply data receiving unit and the power supply data decoding unit are also provided in the power supply device.

[0069] In some embodiments, when the second control unit 23 is provided in the power receiving device, the second control unit 23 is configured to: control the received power and / or output a second indication signal to the power receiving device when overheating occurs, where the second indication signal is used to indicate overheating or a change in the output power of the power supply device.

[0070] Specifically, the power receiving device can be a mobile phone, a tablet computer, a laptop computer, etc. After the second control unit 23 confirms overheating according to the decoded signal, the second control unit 23 will limit the power output by the power receiving device, such as reducing the received power, such as reducing the received power by reducing the received voltage or current, so that the system outputs within the minimum operable power range, or completely stops receiving power, waits for user intervention or automatically retries, or outputs a first indication signal to the power supply device to inform the power supply device that the system is overheated at this time, or informs the power supply device that the received power will be reduced at this time, and subsequent power protection can be triggered by the power supply device.

[0071] In some of these embodiments, the power data receiving unit and the power data decoding unit are also provided in the power receiving device.

[0072] In a second aspect, an embodiment of the present invention provides a charging device, and the charging device includes the protection system as described in the first aspect. In this embodiment, the protection system has the same structure and function as the protection system described in the first aspect, and will not be described in detail here.

[0073] Specifically, the charging device includes a charger and a charging cable. Among them, the temperature detection unit, the first control unit, and the power data sending unit are provided in the charging cable, and the power data receiving unit, the power data decoding unit, and the second control unit are provided in the charger.

[0074] It should be noted that the device embodiments described above are only illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; under the idea of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and the steps can be implemented in any order, and there are many other changes in different aspects of the present invention as described above. For the sake of brevity, they are not provided in detail; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A protection system, characterized by, The protection system includes a temperature detection unit, a first control unit, a power data sending unit, a power data receiving unit, a power data decoding unit, and a second control unit; The output end of the temperature detection unit is connected to the input end of the first control unit. The output end of the first control unit is connected to the first end of the power data sending unit. The second end of the power data sending unit is used to connect to the power supply line of the charging cable. The power supply line is used to connect to the power supply pin of the charging cable. The power supply pin is also connected to the first end of the power data receiving unit. The second end of the power data receiving unit is connected to the input end of the power data decoding unit. The output end of the power data decoding unit is connected to the second control unit; Wherein, the temperature detection unit is used to detect the temperature of the charging cable and output a corresponding voltage signal to the first control unit according to the temperature; The first control unit is used to output an encoded signal to the power data sending unit according to the voltage signal; The power data sending unit is used to control the current of the power supply line according to the encoded signal; The power data receiving unit is used to obtain the voltage of the power supply pin and output the voltage to the power data decoding unit; The power data decoding unit is used to obtain a decoded signal according to the voltage and send the decoded signal to the second control unit; The second control unit is used to determine whether it is overheated according to the decoded signal and control the charging power or discharging power when it is overheated.

2. The protection system according to claim 1, wherein The charging cable includes an electronic tag chip; The first control unit and the power data receiving unit are arranged in the electronic tag chip.

3. The protection system according to claim 2, wherein The temperature detection unit is arranged in the electronic tag chip.

4. The protection system according to claim 2 or 3, characterized in that, The temperature detection unit includes an NTC thermistor, a power supply, and a first comparator; The first end of the NTC thermistor is respectively connected to the power supply and the first input end of the first comparator. The second input end of the first comparator is connected to a reference voltage. The output end of the first comparator is connected to the input end of the first control unit.

5. The protection system according to claim 4, wherein The first control unit is further used to perform debounce delay processing on the voltage signal and output the encoded signal according to the voltage signal after the debounce delay processing; 6. The protection system according to claim 5, characterized in that, The power data sending unit includes a switching tube and a load; The first end of the switching tube is connected to the output end of the first control unit. The second end of the switching tube is connected to the first end of the load. The second end of the load is connected to the power supply line.

7. The protection system according to claim 2 or 3, characterized in that The protection system further includes a power supply unit; The first end of the power supply unit is connected to the power supply line. The second end of the power supply unit is respectively connected to the temperature detection unit and the first control unit. The power supply unit is used to supply power to the temperature detection unit and the first control unit.

8. The protection system according to claim 2 or 3, characterized in that The power data receiving unit includes a first resistor; The first end of the first resistor is used to connect to the power supply of the power supply pin. The second end of the first resistor is respectively connected to the input end of the power data decoding unit and the power supply pin.

9. The protection system according to claim 6, wherein, The power supply data decoding unit includes a first low-pass filter, a second low-pass filter, and a second comparator; A first end of the first low-pass filter is connected to a second end of the power supply data receiving unit. A second end of the first low-pass filter is respectively connected to a first input end of the second comparator and a first end of the second low-pass filter. A second end of the second low-pass filter is connected to a second input end of the second comparator. An output end of the second comparator is connected to the second control unit.

10. The protection system according to claim 7, wherein when the second control unit is provided in the power supply device, the second control unit is configured to: control the output power and / or output a first indication signal to the power receiving device when overheating, wherein the first indication signal is used to indicate overheating or a change in the output power of the power supply device.

11. The protection system according to claim 7, wherein when the second control unit is provided in the power receiving device, the second control unit is configured to: control the received power and / or output a second indication signal to the power supply device when overheating, wherein the second indication signal is used to indicate overheating or a change in the received power of the power receiving device.

12. A charging device, characterized in that, including the protection system according to any one of claims 1-11.

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