A cable over-temperature protection circuit

Abstract

The application provides a cable over-temperature protection circuit, which comprises an electrically weak conduction module, a voltage stabilizing power supply module, a control module and a power supply switch, the configuration channel ports of first and second cable plugs are connected through the electrically weak conduction module; the voltage stabilizing power supply module is used for connecting the power supply bus port of the first cable plug and the power supply bus port of the control module at two ends respectively, and the control module is powered by the first cable plug through the voltage stabilizing power supply module; the temperature monitoring port of the control module is used for receiving a temperature signal about the cable, the power supply control port is connected with the controlled end of the power supply switch arranged between the power supply bus port of the first cable plug and the power supply bus port of the second cable plug, and the control module controls the power supply switch to be turned off when the cable over-temperature is determined according to the temperature signal, so that the phenomenon of power-on and power-off alternation is avoided during the over-temperature protection, and the service life of the device port is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the electrical field, and particularly to a cable over-temperature protection circuit. BACKGROUND

[0002] The temperature of the charging cable gradually increases with the charging process. Generally, the greater the charging power, the faster the temperature of the cable rises. At present, the power of the device charged by the Universal Serial Bus Fast Charging Technology has reached 240 watts. For the cable, it needs to have super high safety performance requirements. If power is not turned off in time when the temperature is too high, there is a risk of cable damage at high temperature, and even a fire may occur.

[0003] In the traditional cable over-temperature protection design, two E-Marker chips integrated with temperature protection are usually arranged in the USB Type-C cable. When the temperature of the cable is too high, the E-Marker chip or the switching power supply is turned off. During the over-temperature protection period, the cable temperature may recover for a short time to supply power, so that the device is in an alternating state of power-on and power-off, which shortens the service life of the device port. SUMMARY

[0004] The present application provides a cable over-temperature protection circuit, which can solve the defect of shortening the service life of the device port by constructing an improved cable over-temperature protection circuit.

[0005] In order to solve the above technical problems, the present application provides a cable over-temperature protection circuit, comprising:

[0006] The first end of the no-electricity weak conduction module is used for connecting with the configuration channel port of the first cable plug, and the second end is used for connecting with the configuration channel port of the second cable plug. The no-electricity weak conduction module is in a weak conduction state under no electricity condition.

[0007] The input end of the voltage stabilizing power supply module is used for connecting with the power bus port of the first cable plug, and the output end is connected with the power bus port of the control module.

[0008] The temperature monitoring port of the control module is used to receive a temperature signal of the cable, and the power supply control port is connected with the controlled end of the power supply switch; wherein, the control module is used to send an over-temperature protection signal to the controlled end of the power supply switch through the power supply control port to control the power supply switch to be turned off when it is determined that the cable is over-temperature according to the temperature signal; the control module is also used to send a normal power supply signal to the controlled end of the power supply switch through the power supply control port to control the power supply switch to be turned on when it is determined that the cable temperature is normal according to the temperature signal.

[0009] The first end of the power supply switch is used to connect with the configuration channel port of the first cable plug, and the second end is used to connect with the configuration channel port of the second cable plug.

[0010] Compared with the prior art, the embodiment of the application provides a cable over-temperature protection circuit, which comprises a non-electric weak conduction module, a voltage stabilizing power supply module, a control module and a power supply switch. The two ends of the non-electric weak conduction module are used to connect with the configuration channel ports of the first cable plug and the second cable plug, realizing connection detection between two devices to enable the power supply device to supply power. The two ends of the voltage stabilizing power supply module are respectively used to connect with the power supply bus port of the first cable plug and the power supply bus port of the control module, and the first cable plug is used to supply power to the control module through the voltage stabilizing power supply module. The temperature monitoring port of the control module is used to receive a temperature signal of the cable, and the power supply control port is connected with the controlled end of the power supply switch arranged between the power supply bus port of the first cable plug and the power supply bus port of the second cable plug. In the embodiment of the application, the control module is used to send a normal power supply signal to the controlled end of the power supply switch through the power supply control port when it is determined that the cable temperature is normal according to the temperature signal, and send an over-temperature protection signal to the controlled end of the power supply switch through the power supply control port when it is determined that the cable is over-temperature according to the temperature signal, to control the power supply switch to be turned off. The use of the cable over-temperature protection circuit can avoid the phenomenon of alternating power-on and power-off during the over-temperature protection of the cable, and prolong the service life of the device port. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 is a structure schematic diagram of a cable over-temperature protection circuit provided by the preferred embodiment of the application;

[0012] Figure 2 is a structure schematic diagram of a cable over-temperature protection circuit provided by the preferred embodiment of the application;

[0013] Figure 3 is a structure schematic diagram of a cable over-temperature protection circuit provided by the preferred embodiment of the application;

[0014] Figure 4is a structure schematic view of a cable over-temperature protection circuit provided by a preferred embodiment of the present application;

[0015] Figure 5 is a structure schematic view of a cable over-temperature protection circuit provided by a preferred embodiment of the present application;

[0016] Figure 6 is a structure schematic view of a cable over-temperature protection circuit provided by a preferred embodiment of the present application;

[0017] Figure 7 is a structure schematic view of a cable over-temperature protection circuit provided by a preferred embodiment of the present application;

[0018] Figure 8 is a structure schematic view of a cable over-temperature protection circuit provided by a preferred embodiment of the present application;

[0019] Figure 9 is a structure schematic view of a cable over-temperature protection circuit provided by a preferred embodiment of the present application.

[0020] Wherein; 1, weak conduction module without electricity; 2, control module; 3, power supply orientation detection module; 4, first voltage comparison module; 5, second voltage comparison module; PLUG-A, first cable plug; PLUG-B, second cable plug; CCA, configuration channel port of first cable plug; CCB, configuration channel port of second cable plug; VBUS1, power supply bus port of first cable plug; VBUS2, power supply bus port of second cable plug; VCC', power supply bus port of control module; S1, second pull-up switch; S2, second weak conduction switch without electricity; S3, first weak conduction switch without electricity; S4, first pull-up switch; S5, grounding switch; S6, power supply switch; R1, fifth feedback resistor; R2, fifth voltage dividing resistor; R3, second feedback resistor; R4, second voltage dividing resistor; R5, fourth feedback resistor; R6, fourth voltage dividing resistor; R7, first feedback resistor; R8, first voltage dividing resistor; R9, third feedback resistor; R10, third voltage dividing resistor; Rp-A, second pull-up resistor; Rp-B, first pull-up resistor; Rd, grounding resistor; C_S1, second pull-up control port; C_S2, second configuration control port; C_S3, first configuration control port; C_S4, first pull-up control port; C_S5, grounding control port; C_S6, power supply control port; LDO, voltage stabilizing power supply module; D1, first unidirectional conduction module; D2, second unidirectional conduction module; VBUSA, first receiving port; VBUSB, second receiving port; COMP_CC, orientation signal receiving port; NTC, temperature monitoring port; Rntc, thermistor; U_VBUS1, first operational amplifier; U_VBUS2, second operational amplifier; U_CC, third operational amplifier. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0022] Please refer to Figure 1 The preferred embodiment of the present application provides a cable over-temperature protection circuit, which comprises a weak conduction module 1, a voltage stabilizing power supply module LDO, a control module 2 and a power supply switch S6.

[0023] The weak conduction module 1 is connected with the configuration channel port CCA of the first cable plug PLUG-A at the first end and connected with the configuration channel port CCB of the second cable plug PLUG-B at the second end; wherein the weak conduction module 1 is in a weak conduction state under no electricity condition.

[0024] The voltage stabilizing power supply module LDO is connected with the power supply bus port VBUS1 of the first cable plug PLUG-A at the input end and connected with the power supply bus port VCC' of the control module 2 at the output end.

[0025] The temperature monitoring port NTC of the control module 2 is used to receive the temperature signal of the cable, and the power supply control port C_S6 is connected with the controlled end of the power supply switch S6; wherein the control module 2 is used to send an over-temperature protection signal to the controlled end of the power supply switch S6 through the power supply control port C_S6 to control the power supply switch S6 to be opened when it is determined that the cable is over-temperature according to the temperature signal; the control module 2 is also used to send a normal power supply signal to the controlled end of the power supply switch S6 through the power supply control port C_S6 to control the power supply switch S6 to be closed when it is determined that the cable temperature is normal according to the temperature signal.

[0026] The first end of the power supply switch S6 is connected with the power supply bus port VBUS1 of the first cable plug PLUG-A, and the second end is connected with the power supply bus port VBUS2 of the second cable plug PLUG-B.

[0027] Specifically, the first cable plug PLUG-A and the second cable plug PLUG-B both have a power bus port, a configuration channel port and a ground port GND for grounding. Taking the first cable plug PLUG-A as an example, the first cable plug PLUG-A is powered through the power bus port, and the second cable plug PLUG-B obtains power through the power bus port for charging or maintaining operation. The configuration channel port is used to detect whether the two devices are connected or not.

[0028] Specifically, the main function of the cable over-temperature protection circuit is to stop power supply to the powered device in time when the cable temperature is too high, and to avoid alternating power-on and power-off during over-temperature protection, thereby prolonging the service life of the cable. The cable over-temperature protection circuit mainly includes a weak conduction module 1, a voltage stabilizing power supply module LDO, a control module 2 and a power supply switch S6. The weak conduction module 1 has two ends respectively connected to the configuration channel port CCA of the first cable plug PLUG-A and the configuration channel port CCB of the second cable plug PLUG-B. The power supply switch S6 has two ends respectively connected to the power bus port VBUS1 of the first cable plug PLUG-A and the power bus port VBUS2 of the second cable plug PLUG-B. The input end of the voltage stabilizing power supply module LDO is connected to the power bus port VBUS1 of the first cable plug PLUG-A. The output end VCC of the voltage stabilizing power supply module LDO is connected to the power bus port VCC’ of the control module 2.

[0029] Assuming that the LDO is a low-dropout linear regulator, the first device connected by the first cable plug PLUG-A is a power supply device (Source), and the second device connected by the second cable plug PLUG-B is a powered device (Sink), the working principle of the cable over-temperature protection circuit is as follows: (1) The control module 2 serves as the main control of the cable, and the no-power weak conduction module 1 is in a weak conduction state in the absence of power. In the absence of power supply of the control module 2, the configuration channel signal (CC) of the Source end is sent out from CCA, reaches the Sink end through the no-power weak conduction module 1, thereby completing the Type-C connection detection, and then the Source end inputs to the LDO through the VBUS1, and the LDO starts to supply power to the control module 2. (2) After the control module 2 is powered on, it will first obtain the temperature signal of the cable. If the temperature is normal (i.e., it is determined that the temperature of the cable is less than the set temperature threshold), a normal power supply signal is sent to the controlled end of the power supply switch S6 through the power supply control port C_S6, the power supply switch S6 is controlled to be closed, and the Source end is allowed to normally supply power to the Sink end. It can be understood that the normal power supply signal is actually an electrical signal that triggers the power supply switch S6 to be closed. If the temperature is abnormal (i.e., it is determined that the temperature of the cable is greater than or equal to the set temperature threshold), an over-temperature protection signal is sent to the controlled end of the power supply switch S6 through the power supply control port C_S6, the power supply switch S6 is controlled to be opened, and the Source end stops supplying power to the Sink end, thereby achieving temperature protection. It can be understood that the over-temperature protection signal is actually an electrical signal that triggers the power supply switch S6 to be opened. (3) Optionally, since the control module 2 is supplied with power by the Source end through the VBUS1 and the LDO, the control module 2 can continue to monitor the temperature of the cable and keep the power supply switch S6 in an open state when the temperature of the cable is too high, thereby avoiding the alternation of power supply and power-off between the Source end and the Sink end. Alternatively, the control module 2 is also provided with a configuration control port for connecting the no-power weak conduction module 1. When the control module 2 sends an over-temperature protection signal to the controlled end of the power supply switch S6, a disconnection signal is sent to the no-power weak conduction module 1 through the configuration control port of the control module 2 to control the no-power weak conduction module 1 to be disconnected. In the case where the no-power weak conduction module 1 and the power supply switch S6 are both closed, the Source end stops supplying power to the control module 2 by closing the VBUS1, but since the no-power weak conduction module 1 is in a weak conduction state in the absence of power, the Source end re-connects with the Sink end to realize Type-C connection detection. After completing the connection detection, the Source end re-supplies power to the control module 2 through the LDO, and the control module 2 can continue to monitor the temperature of the cable and keep the power supply switch S6 in an open state when the temperature of the cable is too high, thereby avoiding the alternation of power supply and power-off between the Source end and the Sink end.

[0030] Compared with the prior art, the cable over-temperature protection circuit provided by the embodiment of the application comprises a non-electric weak conduction module 1, a voltage stabilizing power supply module LDO, a control module 2 and a power supply switch S6, two ends of the non-electric weak conduction module 1 are used to be connected with configuration channel ports CCB of a first cable plug PLUG-A and a second cable plug PLUG-B, so as to realize connection detection between two devices for power supply of the power supply device; an input end and an output end of the voltage stabilizing power supply module LDO are used to be connected with a power supply bus port VBUS1 of the first cable plug PLUG-A and a power supply bus port VCC' of the control module 2 respectively, a grounding end of the voltage stabilizing power supply module LDO is used to be grounded, and the control module 2 is powered by the voltage stabilizing power supply module LDO through the first cable plug PLUG-A; a temperature monitoring port NTC of the control module 2 is used to receive a temperature signal about the cable, and a power supply control port C_S6 is connected with a controlled end of the power supply switch S6 arranged between the power supply bus port VBUS1 of the first cable plug PLUG-A and the power supply bus port VBUS2 of the second cable plug PLUG-B, in the embodiment of the application, the control module 2 is used to send a normal power supply signal to the controlled end of the power supply switch S6 through the power supply control port C_S6 when it is determined that the cable temperature is normal according to the temperature signal, and send an over-temperature protection signal to the controlled end of the power supply switch S6 through the power supply control port C_S6 when it is determined that the cable is over-temperature according to the temperature signal, so as to control the power supply switch S6 to be disconnected, and the cable over-temperature protection circuit can avoid the phenomenon of alternating power-on and power-off during over-temperature protection of the cable, and prolong the life of the device port.

[0031] In a preferred embodiment, referring to Figure 2 On the basis of the above embodiment, the non-electric weak conduction module 1 comprises a first non-electric weak conduction switch S3, a first end of the first non-electric weak conduction switch S3 is connected with a first end of the non-electric weak conduction module 1 and a first end of the grounding module respectively, a second end of the first non-electric weak conduction switch S3 is connected with a second end of the non-electric weak conduction module 1 and a first end of the first pull-up module respectively, and a controlled end of the first non-electric weak conduction switch S3 is connected with a first configuration control port C_S3 of the control module 2;

[0032] The circuit further comprises the ground module and the first pull-up module; the ground module comprises a ground resistor Rd and a ground switch S5 connected in series, a second end of the ground module is used for grounding, and a controlled end of the ground resistor Rd is connected with a ground control port C_S5 of the control module 2; the first pull-up module comprises a first pull-up resistor Rp-B and a first pull-up switch S4 connected in series, a second end of the first pull-up module is used for connecting the voltage stabilizing power supply module LDO, and a controlled end of the first pull-up switch S4 is connected with a first pull-up control port C_S4 of the control module 2;

[0033] The control module 2 is further configured to: when the over-temperature protection signal is sent to the controlled end of the power supply switch S6 through the power supply control port C_S6, send an open signal to the controlled end of the first weak conduction switch S3 through the first configuration control port C_S3 to control the first weak conduction switch S3 to open; after the first weak conduction switch S3 automatically recovers from the open state to the weak conduction state, if it is determined that the cable over-temperature, send an open signal to the controlled end of the first weak conduction switch S3 through the first configuration control port C_S3, send a closed signal to the controlled end of the first pull-up switch S4 through the first pull-up control port C_S4, and send a closed signal to the controlled end of the ground switch S5 through the ground control port C_S5, to control the first weak conduction switch S3 to open, and the first pull-up switch S4 and the ground switch S5 to close;

[0034] The first device connected with the first cable plug PLUG-A is configured to output a low-level voltage through a power bus port VBUS1 of the first cable plug PLUG-A when the first weak conduction switch S3 is in the open state, and the first pull-up switch S4 and the ground switch S5 are in the closed state.

[0035] The control module 2 is further configured to: when the first cable plug PLUG-A outputs the low-level voltage through the power bus port VBUS1, control the power supply switch S6 to close.

[0036] Specifically, as shown in FIG. 1, the first weak conduction switch S3 is in the open state, and the first pull-up switch S4 and the ground switch S5 are in the closed state. Figure 2In the circuit shown, the first cable plug PLUG-A side is the Source end, the second cable plug PLUG-B is the Sink end, and the control module 2 determines the cable temperature anomaly and controls the power supply switch S6 to be disconnected, and sends a disconnection signal to the controlled end of the first no-electricity weak conduction switch S3 through the first configuration control port C_S3 to control the first no-electricity weak conduction switch S3 to be disconnected, and then the first cable plug PLUG-A stops supplying power to the outside. The control module 2 is powered off, the first no-electricity weak conduction switch S3 automatically recovers from the disconnected state to the weak conduction state, and then the Source end and the Sink end re-detect the connection. When it is determined that the Source end and the Sink end are in a connected state, the Source end will re-supply power to the control module 2 through VBUS1 and the voltage stabilizing power supply module LDO. The control module 2 continues to detect the cable temperature after power-on, and if it is determined that the cable is overheated, the control module 2 can perform one of the following operations: 1. Control the power supply switch S6 to remain in the disconnected state and not supply power to the Sink end; 2. Control the first no-electricity weak conduction switch S3 to be disconnected, control the ground switch S5 and the first pull-up switch S4 to be closed, and ensure that the cable exposes a ground resistance Rd to the Source end and exposes the first pull-up resistance Rp-B to the Sink end, so that the Source end can provide output to VBUS to ensure that the control module 2 has power, and the Sink end is provided with low-level voltage (such as 5V) through VBUS1. When the control module 2 determines that the Source end provides low-level voltage, the control module 2 controls the power supply switch S6 to be closed, and the low-level voltage provided by the Source end is transmitted to the Sink end through the power supply switch S6, which not only makes the temperature rising rate of the cable temperature much smaller than the temperature falling rate, but also continues to supply power to the Sink end.

[0037] Further, the circuit further comprises a first voltage comparison module 4, a first input end of the first voltage comparison module 4 is connected with the power bus port VBUS1 of the first cable plug PLUG-A, a second input end of the first voltage comparison module 4 is connected with the output end of the voltage stabilizing power supply module LDO, and an output end of the first voltage comparison module 4 is connected with a first receiving port VBUSA of the control module 2;

[0038] When the first cable plug PLUG-A outputs the low-level voltage through the power bus port VBUS1, the power supply switch S6 is controlled to be closed, which comprises: when it is determined according to the signal received by the first receiving port VBUSA that the first cable plug PLUG-A outputs the low-level voltage through the power bus port VBUS1, the power supply switch S6 is controlled to be closed.

[0039] Specifically, the two input ends of the first voltage comparison module 4 are respectively connected with the power bus port VBUS1 of the first cable plug PLUG-A and the output end of the voltage stabilizing power module LDO, and the input voltages of the two input ends are compared when the cable temperature is too high, and the comparison result is output to the first receiving port VBUSA of the control module 2. The control module 2 determines whether the voltage output by the power bus port VBUS1 of the first cable plug PLUG-A is a low-level voltage by analyzing the data received by the first receiving port VBUSA. If yes, the power supply switch S6 is controlled to be closed through the power supply control port C_S6, so that the first cable plug PLUG-A provides a low-level voltage to the second cable plug PLUG-B. If no, the power supply switch S6 remains in the open state.

[0040] As shown in the example, Figure 3 As shown in the example, it is assumed that the first voltage comparison module 4 includes a first operational amplifier U_VBUS1, a first feedback resistor R7, a first voltage dividing resistor R8, a second feedback resistor R3 and a second voltage dividing resistor R4. The first end of the first feedback resistor R7 is connected with the power bus port VBUS1 of the first cable plug PLUG-A, and the second end of the first feedback resistor R7 is respectively connected with the non-inverting input end of the first operational amplifier U_VBUS1 and the first end of the first voltage dividing resistor R8. The second end of the first voltage dividing resistor R8 is used for grounding. The output end of the first operational amplifier U_VBUS1 is connected with the first receiving port VBUSA of the control module 2. The first end of the second feedback resistor R3 is connected with the output end VCC of the voltage stabilizing power module LDO, and the second end of the second feedback resistor R3 is respectively connected with the inverting input end of the first operational amplifier U_VBUS1 and the first end of the second voltage dividing resistor R4. The second end of the second voltage dividing resistor R4 is used for grounding. The voltage input to the inverting input end of the first operational amplifier U_VBUS1 is about 5.5V, and the low-level voltage is about 5V.

[0041] In a preferred embodiment, the controlled end of the weak conduction module 1 is connected with the configuration control port of the control module 2. The control module 2 is further configured to send a strong conduction signal to the controlled end of the weak conduction module 1 through the configuration control port after sending the normal power supply signal to the controlled end of the power supply switch S6 through the power supply control port C_S6, so as to control the weak conduction module 1 to be in a strong conduction state.

[0042] Specifically, the weak conduction module 1 further has a controlled end connected with the configuration control port of the control module 2. The control module 2 controls the weak conduction module 1 to be in a strong conduction state when it is determined that the cable temperature is normal, so as to facilitate the subsequent PD message communication signal to pass through, where PD is the Chinese full name of Power Delivery and the English full name is Power Delivery.

[0043] In a preferred embodiment, as shown in Figure 4 Figure 1 The circuit further comprises a first unidirectional conductive module D1 and a second unidirectional conductive module D2 on the basis of the circuit;

[0044] The input end of the voltage stabilizing power module LDO is connected with the power bus port VBUS1 of the first cable plug PLUG-A, and the output end is connected with the power bus port VCC' of the control module 2, and the voltage stabilizing power module LDO comprises:

[0045] The input end of the first unidirectional conductive module D1 is connected with the power bus port VBUS1 of the first cable plug PLUG-A, the output end of the first unidirectional conductive module D1 is connected with the input end of the voltage stabilizing power module LDO, and the output end of the voltage stabilizing power module LDO is connected with the power bus port VCC' of the control module 2; wherein one of the first cable plug PLUG-A and the second cable plug PLUG-B is used to connect the power supply device, and the other is used to connect the powered device.

[0046] Specifically, assuming that the first unidirectional conductive module D1 and the second unidirectional conductive module D2 are diodes, in the embodiment, the power supply device can be the first cable plug PLUG-A or the second cable plug PLUG-B, when the power supply device is the first cable plug PLUG-A, the power bus port VBUS1 of the first cable plug PLUG-A outputs voltage, which is transmitted to the voltage stabilizing power module LDO through the first unidirectional conductive module D1, and the voltage stabilizing power module LDO provides stable voltage for the control module 2. When the power supply device is the second cable plug PLUG-B, the power bus port VBUS2 of the second cable plug PLUG-B outputs voltage, which is transmitted to the voltage stabilizing power module LDO through the second unidirectional conductive module D2, and the voltage stabilizing power module LDO provides stable voltage for the control module 2.

[0047] Further, as shown in Figure 5 ​As shown, the non-electric weak conduction module 1 includes a first non-electric weak conduction switch S3 and a second non-electric weak conduction switch S2, the first end of the second non-electric weak conduction switch S2 is respectively connected with the configuration channel port CCA of the first cable plug PLUG-A and the first end of the second pull-up module, the second end of the second non-electric weak conduction switch S2 is respectively connected with the first end of the first non-electric weak conduction switch S3, the power supply orientation detection module 3 and the first end of the grounding module, the first end of the first non-electric weak conduction switch S3 is also respectively connected with the power supply orientation detection module 3 and the first end of the grounding module, and the second end of the first non-electric weak conduction switch S3 is respectively connected with the first end of the first pull-up module and the configuration channel port CCB of the second cable plug PLUG-B;

[0048] The circuit further includes the first pull-up module, the second pull-up module, the grounding module and the power supply orientation detection module 3; the grounding module includes a grounding resistor Rd and a grounding switch S5 connected in series, the second end of the grounding module is used for grounding, and the controlled end of the grounding resistor Rd is connected with the grounding control port C_S5 of the control module 2; the first pull-up module includes a first pull-up resistor Rp-B and a first pull-up switch S4 connected in series, the second end of the first pull-up module is connected with the output end of the voltage stabilizing power supply module LDO, and the controlled end of the first pull-up switch S4 is connected with the first pull-up control port C_S4 of the control module 2; the second pull-up module includes a second pull-up resistor Rp-A and a second pull-up switch S1 connected in series, the second end of the second pull-up module is connected with the output end of the voltage stabilizing power supply module LDO, and the controlled end of the second pull-up switch S1 is connected with the second pull-up control port C_S1 of the control module 2; the first input end of the power supply orientation detection module 3 is respectively connected with the first end of the first non-electric weak conduction switch S3 and the second end of the second non-electric weak conduction switch S2, the second input end of the power supply orientation detection module 3 is connected with the output end of the voltage stabilizing power supply module LDO, and the output end of the power supply orientation detection module 3 is connected with the orientation signal receiving port COMP_CC of the control module 2.

[0049] Specifically, in this embodiment, the low-voltage conduction module 1 includes a first low-voltage conduction switch S3 and a second low-voltage conduction switch S2. The circuit also includes a first pull-up module, a second pull-up module, a grounding module, and a power supply orientation detection module 3. The first input terminal of the power supply orientation detection module 3 is connected between the connection lines of the first low-voltage conduction switch S3 and the second low-voltage conduction switch S2. The control module 2 controls the on / off states of the grounding switch S5, the first low-voltage conduction switch S3, and the first low-voltage conduction switch S2, and collects the output of the power supply orientation detection module 3. Based on the output of the power supply orientation detection module 3, it determines which of the first cable plug PLUG-A and the second cable plug PLUG-B is the power supply device and which is the receiving device. After identifying the power supply device, when the control module 2 determines that the cable temperature is abnormal, it can control the on / off states of the grounding switch S5, the second pull-up switch S1, and the first pull-up switch S4 to make the power supply device output a low-level voltage, and control the power supply switch S6 to close, so that the power supply device provides a low-level voltage to the receiving device.

[0050] Furthermore, such as Figure 5 As shown, the controlled terminal of the first low-voltage switch S3 is connected to the first configuration control port C_S3 of the control module 2, and the controlled terminal of the second low-voltage switch S2 is connected to the second configuration control port C_S2 of the control module 2. The control module 2 is further used for:

[0051] When the over-temperature protection signal is sent to the controlled terminal of the power supply switch S6 through the power supply control port C_S6, disconnection signals are sent to the controlled terminals of the first power-off weak conduction switch S3 and the second power-off weak conduction switch S2 through the first configuration control port C_S3 and the second configuration control port C_S2, respectively, to control the first power-off weak conduction switch S3 and the second power-off weak conduction switch S2 to disconnect.

[0052] After the first low-voltage switch S3 and the second low-voltage switch S2 automatically return to the low-voltage conducting state from the open state, if it is determined that the cable is overheating and the first device connected to the first cable plug PLUG-A is the power supply device, a disconnect signal is sent to the controlled terminal of the first low-voltage switch S3 through the first configuration control port C_S3, a closed signal is sent to the controlled terminal of the first pull-up switch S4 through the first pull-up control port C_S4, a closed signal is sent to the controlled terminal of the grounding switch S5 through the grounding control port C_S5, and a closed signal is sent to the controlled terminal of the second low-voltage switch S2 through the second configuration control port C_S2, so as to control the first low-voltage switch S3 to open, the second low-voltage switch S2, the first pull-up switch S4 and the grounding switch S5 to close.

[0053] After the first no-voltage weak conduction switch S3 and the second no-voltage weak conduction switch S2 automatically recover from the open state to the weak conduction state, if it is determined that the cable is over-temperature and it is determined that the second device connected by the second cable plug PLUG-B is the power supply device, the control module 2 sends the open signal to the controlled end of the second no-voltage weak conduction switch S2 through the second configuration control port C_S2, sends the closed signal to the controlled end of the second pull-up switch S1 through the second pull-up control port C_S1, sends the closed signal to the controlled end of the ground switch S5 through the ground control port C_S5, and sends the closed signal to the controlled end of the first no-voltage weak conduction switch S3 through the first configuration control port C_S3, so as to control the second no-voltage weak conduction switch S2 to be open and the first no-voltage weak conduction switch S3, the second pull-up switch S1 and the ground switch S5 to be closed.

[0054] The first device connected by the first cable plug PLUG-A is configured to output a low-level voltage through the power bus port of the first cable plug PLUG-A when the first no-voltage weak conduction switch S3 is in the open state and the second no-voltage weak conduction switch S2, the first pull-up switch S4 and the ground switch S5 are in the closed state; or the second device connected by the second cable plug PLUG-B is configured to output a low-level voltage through the power bus port of the second cable plug PLUG-B when the second no-voltage weak conduction switch S2 is in the open state and the first no-voltage weak conduction switch S3, the second pull-up switch S1 and the ground switch S5 are in the closed state.

[0055] The control module 2 is further configured to control the power supply switch S6 to be closed when the power bus port of the power supply device outputs the low-level voltage.

[0056] Specifically, the working principle of the cable over-temperature protection circuit also includes: when the control module 2 determines that the cable temperature is abnormal, it controls the power supply switch S6, the first no-power weak conduction switch S3, the second no-power weak conduction switch S2, the first pull-up switch S4, the second pull-up switch S1, and the grounding switch S5 to open, the power supply equipment stops supplying power to the outside, the control module 2 is powered down, the first no-power weak conduction switch S3 and the second no-power weak conduction switch S2 automatically return to the weak conduction state from the open state, and then the power supply equipment and the power receiving equipment re-establish the connection relationship, the power supply equipment supplies power to the control module 2, and after the control module 2 is powered on again, if it determines that the first cable plug PLUG-A side is the power supply equipment and the cable temperature is abnormal, it controls the first no-power weak conduction switch S3 to open, the second no-power weak conduction switch S2, the first pull-up switch S4, and the grounding switch S5 to close, and if it determines that the second cable plug PLUG-B side is the power supply equipment and the cable temperature is abnormal, it controls the second no-power weak conduction switch S2 to open, the first no-power weak conduction switch S3, the second pull-up switch S1, and the grounding switch S5 to close. After the above operations are completed, the power supply bus port of the power supply equipment outputs a low-level voltage. The control module 2 controls the power supply switch S6 to close, and transmits the low-level voltage output by the power supply bus port of the power supply equipment to the powered device.

[0057] Furthermore, such as Figure 6 As shown, the circuit also includes a first voltage comparison module 4 and a second voltage comparison module 5; the first input terminal of the first voltage comparison module 4 is connected to the power bus port VBUS1 of the first cable plug PLUG-A, the second input terminal of the first voltage comparison module 4 is connected to the output terminal of the regulated power supply module LDO, and the output terminal of the first voltage comparison module 4 is connected to the first receiving port BVBUSA of the control module 2; the first input terminal of the second voltage comparison module 5 is connected to the power bus port VBUS2 of the second cable plug PLUG-B, the second input terminal of the second voltage comparison module 5 is connected to the output terminal of the regulated power supply module LDO, and the output terminal of the second voltage comparison module 5 is connected to the second receiving port VBUSB of the control module 2;

[0058] The step of controlling the power supply switch S6 to close when the power supply device outputs the low-level voltage at the power bus port includes: controlling the power supply switch S6 to close when it is determined, based on the signals received by the first receiving port BVBUSA and the second receiving port VBUSB, that the power supply device outputs the low-level voltage at the power bus port.

[0059] Specifically, in the embodiment, the first voltage comparison module 4 and the second voltage comparison module 5 are added in the circuit, two input ends of the first voltage comparison module 4 are connected with the power bus port VBUS1 of the first cable plug PLUG-A and the output end of the voltage stabilizing power supply module LDO respectively, for comparing the voltage at the power bus port VBUS1 of the first cable plug PLUG-A with the output end voltage of the voltage stabilizing power supply module LDO, two input ends of the second voltage comparison module 5 are connected with the power bus port VBUS2 of the second cable plug PLUG-B and the output end of the voltage stabilizing power supply module LDO respectively, for comparing the voltage at the power bus port VBUS2 of the second cable plug PLUG-B with the output end voltage of the voltage stabilizing power supply module LDO, and whether the power supply device outputs low-level voltage is determined according to the two comparison results. When it is determined that the power supply device outputs low-level voltage, the control device controls the power supply switch S6 to be closed, and the power supply device provides low-voltage power supply service for the power receiving device.

[0060] Further, as shown in Figure 7 the first voltage comparison module 4 includes a first operational amplifier U_VBUS1, a first feedback resistor R7, a first voltage dividing resistor R8, a second feedback resistor R3 and a second voltage dividing resistor R4, and the second voltage comparison module 5 includes a second operational amplifier U_VBUS2, a third feedback resistor R9, a third voltage dividing resistor R10, a fourth feedback resistor R5 and a fourth voltage dividing resistor R6;

[0061] The first end of the first feedback resistor R7 is connected with the power bus port VBUS1 of the first cable plug PLUG-A, and the second end of the first feedback resistor R7 is connected with the non-inverting input end of the first operational amplifier U_VBUS1 and the first end of the first voltage dividing resistor R8 respectively; the second end of the first voltage dividing resistor R8 is used for grounding; the output end of the first operational amplifier U_VBUS1 is connected with the first receiving port VBUSA of the control module 2; the first end of the second feedback resistor R3 is connected with the output end of the voltage stabilizing power supply module LDO, and the second end of the second feedback resistor R3 is connected with the inverting input end of the first operational amplifier U_VBUS1 and the first end of the second voltage dividing resistor R4 respectively; the second end of the second voltage dividing resistor R4 is used for grounding;

[0062] The first end of the third feedback resistor R9 is connected with the power supply bus port VBUS2 of the second cable plug PLUG-B, the second end of the third feedback resistor R9 is connected with the non-inverting input end of the second operational amplifier U_VBUS2 and the first end of the third voltage dividing resistor R10 respectively; the second end of the third voltage dividing resistor R10 is used for grounding; the output end of the second operational amplifier U_VBUS2 is connected with the second receiving port VBUS2 of the control module 2; the first end of the fourth feedback resistor R5 is connected with the output end of the voltage stabilizing power supply module LDO, the second end of the fourth feedback resistor R5 is connected with the inverting input end of the second operational amplifier U_VBUS2 and the first end of the fourth voltage dividing resistor R6 respectively; the second end of the fourth voltage dividing resistor R6 is used for grounding.

[0063] Specifically, the operational amplifier is a direct-coupled multistage amplifying circuit with high voltage amplification, which is widely used in electronic circuits. In the embodiment, the voltage comparison function of the operational amplifier is used to compare the output voltages of the first cable plug PLUG-A and the second cable plug PLUG-B with the output voltage of the voltage stabilizing power supply module LDO. If the output results of the first voltage comparison module 4 and the second voltage comparison module 5 are both 0, it indicates that the output voltage of the power supply device is within the safe range, which is a low-level voltage.

[0064] In a preferred embodiment, as shown in Figure 8 on the basis of Figure 5 , the power supply orientation detection module 3 comprises a third operational amplifier U_CC, a fifth feedback resistor R1 and a fifth voltage dividing resistor R2; the non-inverting input end of the third operational amplifier U_CC is connected with the first end of the first no-voltage weak conduction switch S3 and the second end of the second no-voltage weak conduction switch S2 respectively, the output end of the third operational amplifier U_CC is connected with the orientation signal receiving port COMP_CC of the control module 2, the inverting input end of the third operational amplifier U_CC is connected with the second end of the fifth feedback resistor R1 and the first end of the fifth voltage dividing resistor R2 respectively, the first end of the fifth feedback resistor R1 is used for connecting with the output end of the voltage stabilizing power supply module LDO, and the second end of the fifth voltage dividing resistor R2 is used for grounding;

[0065] The control module 2 is further used for determining the power supply device by the following manner:

[0066] controlling the second no-voltage weak conduction switch S2 and the grounding switch S5 to be closed, and controlling the first no-voltage weak conduction switch S3 to be disconnected, or controlling the first no-voltage weak conduction switch S3 and the grounding switch S5 to be closed, and controlling the second no-voltage weak conduction switch S2 to be disconnected,

[0067] The output signal of the third operational amplifier U_CC is received, and according to the output signal of the third operational amplifier U_CC, it is determined that the power supply device is the first device connected by the first cable plug PLUG-A or the second device connected by the second cable plug PLUG-B.

[0068] Specifically, the power supply device is located on the left and right side of the cable, and the detection is due to the fact that the cable has two Type-C heads, and it cannot be known in advance which head is connected with the power supply device. Therefore, in the embodiment, a power supply orientation detection module 3 including the third operational amplifier U_CC, the fifth feedback resistor R1 and the fifth voltage dividing resistor R2 is arranged in the circuit, the second no-voltage weak conduction switch S2 and the grounding switch S5 are first closed, the first no-voltage weak conduction switch S3 is disconnected, and the output result of the third operational amplifier U_CC is detected. If the output result is 1, it indicates that the Plug-A side is the power supply device, and if the output result is 0, it indicates that the Plug-B side is the power supply device.

[0069] In order to facilitate understanding of the structure and working principle of the circuit, the circuit structure and working process are introduced by taking a specific example, referring to Figure 9 The structure diagram of the cable over-temperature protection circuit is shown. The circuit uses six switches: the second pull-up switch S1, the second no-voltage weak conduction switch S2, the first no-voltage weak conduction switch S3, the first pull-up switch S4, the grounding switch S5 and the power supply switch S6; fourteen resistors: the second pull-up resistor Rp-A, the first pull-up resistor Rp-B, the grounding resistor Rd, the fifth feedback resistor R1, the fifth voltage dividing resistor R2, the second feedback resistor R3, the second voltage dividing resistor R4, the fourth feedback resistor R5, the fourth voltage dividing resistor R6, the thermistor Rntc, the first feedback resistor R7, the first voltage dividing resistor R8, the third feedback resistor R9, the fifth feedback resistor and the third voltage dividing resistor R10; two diodes: the first unidirectional conduction module D1 and the second unidirectional conduction module D2; one control module 2 (i.e., the control module 2); one voltage stabilizing power supply module LDO (such as a low-dropout linear voltage regulator); three comparators: the third operational amplifier U_CC, the first operational amplifier U_VBUS1 and the second operational amplifier U_VBUS2.

[0070] As shown in Figure 9 The connection logic of the circuit provided by the embodiment of the application is as follows:

[0071] 1. The first end of the power supply switch S6 is connected with the power supply bus port VBUS1 of the first cable plug PLUG-A, the second end of the power supply switch S6 is connected with the VBUS of the PLUG-B plug, and the controlled end of the power supply switch S6 is connected with the power supply control port C_S6 of the control module 2.

[0072] 2、the first unidirectional conducting module D1 has its input connected to the first terminal of the power supply switch S6 and its output connected to the input of the voltage regulator module LDO; the second unidirectional conducting module D2 has its input connected to the second terminal of the power supply switch S6 and its output connected to the input of the voltage regulator module LDO;

[0073] 3、the first feedback resistor R7 has its first terminal connected to the first terminal of the power supply switch S6 and its second terminal connected to the first voltage dividing resistor R8 which has its second terminal connected to ground; the second feedback resistor R3 has its first terminal connected to the output VCC of the voltage regulator module LDO and its second terminal connected to the first terminal of the second voltage dividing resistor R4 which has its second terminal connected to ground; the first operational amplifier U_VBUS1 has its + terminal connected to the first terminal of the first voltage dividing resistor R8 and its - terminal connected to the second terminal of the second voltage dividing resistor R4; the output of the first operational amplifier U_VBUS1 is connected to the first receiving port VBUSA of the control module 2.

[0074] 4、the third feedback resistor R9 has its first terminal connected to the second terminal of the power supply switch S6 and its second terminal connected to the first terminal of the third voltage dividing resistor R10 which has its second terminal connected to ground; the fourth feedback resistor R5 has its first terminal connected to the output VCC of the voltage regulator module LDO and its second terminal connected to the first terminal of the fourth voltage dividing resistor R6 which has its second terminal connected to ground; the second operational amplifier U_VBUS2 has its + terminal connected to the first terminal of the third voltage dividing resistor R10 and its - terminal connected to the second terminal of the fourth voltage dividing resistor R6; the output of the second operational amplifier U_VBUS2 is connected to the second receiving port VBUSB of the control module 2.

[0075] 5、the first terminal of the thermistor Rntc is connected to the temperature monitoring port NTC of the control module 2 and its second terminal is connected to ground.

[0076] 6、the second terminal of the second weakly conducting switch S2 is connected to the + terminal of the third operational amplifier U_CC; the first terminal of the fifth feedback resistor R1 is connected to the output VCC of the LDO and its second terminal is connected to the first terminal of the fifth voltage dividing resistor R2 which has its second terminal connected to the - terminal of the third operational amplifier U_CC; the output of the third operational amplifier U_CC is connected to the azimuth signal receiving port COMP_CC of the control module 2.

[0077] 7、The first end of the second pull-up resistor Rp-A is connected to the output terminal VCC of the voltage stabilizing power module LDO, the second end of the second pull-up resistor Rp-A is connected to the first end of the second pull-up switch S1, the controlled end of the second pull-up switch S1 is connected to the second pull-up control port C_S1 of the control module 2, the second end of the second pull-up switch S1 is connected to the first end of the second weak-conducting switch S2, and is connected to the CCA of the first cable plug PLUG-A. The controlled end of the second weak-conducting switch S2 is connected to the second configuration control port C_S2 of the control module 2, the second end of the second weak-conducting switch S2 is connected to the first end of the first weak-conducting switch S3, the controlled end of the first weak-conducting switch S3 is connected to the first configuration control port C_S3 of the control module 2, the second end of the first weak-conducting switch S3 is connected to the CCB of the second cable plug PLUG-B. The second end of the first pull-up switch S4 is connected to the second end of the first weak-conducting switch S3, the controlled end of the first pull-up switch S4 is connected to the first pull-up control port C_S4 of the control module 2, the first end of the first pull-up switch S4 is connected to the second end of the first pull-up resistor Rp-B, and the first end of the first pull-up resistor Rp-B is connected to the output terminal VCC of the voltage stabilizing power module LDO.

[0078] 8、The first end of the grounding switch S5 is connected to the second end of the second weak-conducting switch S2, the first end of the first weak-conducting switch S3, and the + terminal of the third operational amplifier U_CC. The controlled end of the grounding switch S5 is connected to the grounding control port C_S5 of the control module 2, the second end of the grounding switch S5 is connected to the first end of the grounding resistor Rd, and the second end of the grounding resistor Rd is connected to the ground.

[0079] The working principle of the cable over-temperature protection circuit is as follows:

[0080] The second weak conduction switch S2 and the first weak conduction switch S3 are weakly conductive in the absence of power supply of the cable, so the configuration channel signal (CC) of the Source end can pass through the second weak conduction switch S2 and the first weak conduction switch S3 to reach the Sink end in the absence of power supply of the control module 2, thereby completing the connection detection of Type-C, and then the Source end inputs to the voltage stabilizing power supply module LDO through the VBUS path to start power supply to the control module 2. After the control module 2 is powered on, it will first detect the temperature, and if the temperature is normal, the power supply switch S6 is opened to allow the Source end to set normal power supply to the Sink end, and the second weak conduction switch S2 and the first weak conduction switch S3 give an explicit control signal to close the CCA and CCB signals, that is, the second weak conduction switch S2 and the first weak conduction switch S3 are in a strong conduction state, facilitating the subsequent PD message communication signal to pass through, and the second pull-up switch S1, the first pull-up switch S4 and the ground switch S5 are disconnected and do not make any resistance pull-up and pull-down treatment to the channel between CCA and CCB; if the temperature is abnormal, the power supply switch S6 will be kept closed to prohibit the Source end to directly power the Sink end (or after judging that the Source end is located on the left and right sides of the cable, the corresponding pull-up resistor (second pull-up resistor Rp-A / first pull-up resistor Rp-B) and pull-down (ground resistor Rd) resistor is turned on, and when the VBUS voltage (i.e. the voltage output by the power supply device) is within the safe 5V range, the power supply switch S6 is turned on to allow the Source end to power the Sink end through the VBUS).

[0081] When the cable reaches the protection threshold due to temperature rise in normal operation, the second pull-up switch S1, the second no-electricity weak conduction switch S2, the first no-electricity weak conduction switch S3, the first pull-up switch S4, the grounding switch S5, and the power supply switch S6 are all disconnected, the power supply from the Source end to the Sink end is disconnected, and temperature protection is realized. At the same time, since the second pull-up switch S1, the second no-electricity weak conduction switch S2, the first no-electricity weak conduction switch S3, the first pull-up switch S4, the grounding switch S5, and the power supply switch S6 are all disconnected, the Source end will close the VBUS to stop supplying power to the control module 2 (here, it is the first protection action taken when the temperature anomaly is detected, after the Source end closes the power supply bus port to stop supplying power to the control module 2, since the second no-electricity weak conduction switch S2 and the first no-electricity weak conduction switch S3 are in a power-off state, CCA and CCB can be directly passed through, so the Source end will provide VBUS voltage to the control module 2 according to the Type-C protocol definition, but at this time the cable temperature is still too high, then the above-mentioned judgment that the Source end is located on the left and right sides of the cable is performed, the corresponding pull-up (second pull-up resistor Rp-A / first pull-up resistor Rp-B) and pull-down (ground resistor Rd) resistors are turned on, and the power supply switch S6 is turned on when the VBUS voltage is in the safe 5V range, allowing the Source end to supply power to the Sink end), and the Type-C connection detection with the Sink end is re-implemented. Since the cable temperature will not immediately decrease, the Source end and the Sink end are reconnected, and the control module 2 supplies power again. At this time, the control module 2 will first detect the temperature when supplying power, if the temperature is normal, the power supply switch S6 is closed, the Source end normally supplies power to the Sink end, if the temperature is too high, the power supply switch S6 is kept closed or the corresponding pull-up resistor and ground resistor are controlled after the Source end is determined to be located on the left and right sides of the cable, and the power supply switch S6 is opened to supply 5V to the Sink end for safe power supply. In this way, when the cable temperature is abnormal, the Source end does not provide normal VBUS power supply to the Sink end or provides a safe 5V power supply.

[0082] When the cable is in temperature protection (because the Source end will actively close the VBUS output according to the Type-C protocol after the second no-current weak conduction switch S2 and the first no-current weak conduction switch S3 are closed when the temperature anomaly is initially detected, and the VBUS output will be closed, which will cause the entire cable circuit to be powered off, but because the second no-current weak conduction switch S2 and the first no-current weak conduction switch S3 can pass through the CCA and CCB signals in the power-off state, the Source end will detect the Sink end again (if the Sink end is not pulled out) and provide a VBUS voltage output according to the Type-C protocol, so at this time the cable is in the initial power-on state. However, the temperature will continue to be detected during the initial power-on, and if the temperature is still too high, it will be determined that it is in temperature protection (the power supply switch S6 is closed to stop the Source end from supplying power to the Sink end or to supply only a 5V safe voltage to the Sink end), and after the cable temperature returns to the normal range, the second pull-up switch S1, the second no-current weak conduction switch S2, the first no-current weak conduction switch S3, the first pull-up switch S4, the ground switch S5, and the power supply switch S6 will all be turned off. Because the second pull-up switch S1, the second no-current weak conduction switch S2, the first no-current weak conduction switch S3, the first pull-up switch S4, the ground switch S5, and the power supply switch S6 are all turned off, the Source end will close the VBUS to stop supplying power to the cable control module 2, and will re-implement Type-C connection detection with the Sink end. Because the temperature has returned to the normal range, after the connection detection is re-completed, the cable will be in a normal working state when the control module 2 is powered on again, allowing the Source end to normally supply power to the Sink end.

[0083] The left and right side orientation detection of the Source end is due to the cable having two Type-C heads, and it is unable to be known in advance which head is connected with the Source end. When protection occurs, if the Source end is connected with the first cable plug PLUG-A end, the second no-electricity weak conduction switch S2 and the grounding switch S5 need to be closed, the first no-electricity weak conduction switch S3 is opened, a grounding resistor Rd is exposed to the Source end by the cable, the Source end can normally provide a VBUS voltage to ensure that the control module 2 has electricity, and if the Sink end needs to be provided with a safe 5V VBUS voltage during protection, the first pull-up switch S4 needs to be closed to expose a pull-up resistor to the Sink end. When protection occurs, if the Source end is connected with the second cable plug PLUG-B end, the first no-electricity weak conduction switch S3 and the grounding switch S5 need to be closed, the second no-electricity weak conduction switch S2 is opened, a grounding resistor Rd is exposed to the Source end by the cable, the Source end can normally provide a VBUS voltage to ensure that the control module 2 has electricity, and if the Sink end needs to be provided with a safe 5V VBUS voltage during protection, the second pull-up switch S1 needs to be closed to expose a pull-up resistor to the Sink end.

[0084] The left and right side orientation detection method of the Source end is that the second no-electricity weak conduction switch S2 and the grounding switch S5 are first closed, the first no-electricity weak conduction switch S3 is opened, and the output result of the third operational amplifier U_CC is detected. If the output is 1, it indicates that the first cable plug PLUG-A end is connected to the Source end, and if the output is 0, it indicates that the second cable plug PLUG-B end is connected to the Source end.

[0085] The method for judging whether the VBUS voltage is in the safe 5V range is that the output results of the first operational amplifier U_VBUS1 and the second operational amplifier U_VBUS2 are detected, and if the output results of the two comparators are both 0, it indicates that it is in the safe 5V range. The positive end input of the first operational amplifier U_VBUS1 is sampled by the first feedback resistor R7 and the first voltage dividing resistor R8 to the VBUS1 of the first cable plug PLUG-A end, and the negative end input of the first operational amplifier U_VBUS1 is compared with the output of the voltage stabilizing power module LDO to generate a comparison reference voltage by the voltage division of the resistor second feedback resistor R3 and the second voltage dividing resistor R4. The positive end input of the second operational amplifier U_VBUS2 is sampled by the resistor third feedback resistor R9 and the fifth feedback resistor third voltage dividing resistor R10 to the VBUS2 of the second cable plug PLUG-B end, and the negative end input of the second operational amplifier U_VBUS2 is compared with the output of the voltage stabilizing power module LDO to generate a comparison reference voltage by the voltage division of the resistor fourth feedback resistor R5 and the fourth voltage dividing resistor R6.

[0086] Compared with the prior art, the cable over-temperature protection circuit provided by the embodiment of the application comprises a non-electric weak conduction module 1, a voltage stabilizing power supply module LDO, a control module 2 and a power supply switch S6, two ends of the non-electric weak conduction module 1 are used to be connected with configuration channel ports CCB of a first cable plug PLUG-A and a second cable plug PLUG-B, so as to realize connection detection between two devices for power supply of the power supply device; an input end and an output end of the voltage stabilizing power supply module LDO are used to be connected with a power supply bus port VBUS1 of the first cable plug PLUG-A and a power supply bus port VCC' of the control module 2 respectively, a grounding end of the voltage stabilizing power supply module LDO is used to be grounded, and the control module 2 is powered by the first cable plug PLUG-A through the voltage stabilizing power supply module LDO; a temperature monitoring port NTC of the control module 2 is used to receive a temperature signal about the cable, and a power supply control port C_S6 is connected with a controlled end of the power supply switch S6 arranged between the power supply bus port VBUS1 of the first cable plug PLUG-A and the power supply bus port VBUS2 of the second cable plug PLUG-B, in the embodiment of the application, the control module 2 is used to send a normal power supply signal to the controlled end of the power supply switch S6 through the power supply control port C_S6 when it is determined that the cable temperature is normal according to the temperature signal, and send an over-temperature protection signal to the controlled end of the power supply switch S6 through the power supply control port C_S6 when it is determined that the cable is over-temperature according to the temperature signal, so as to control the power supply switch S6 to be disconnected, and the cable over-temperature protection circuit can avoid the phenomenon of alternating power-on and power-off during over-temperature protection of the cable, and prolong the life of the device port.

[0087] The above is the preferred embodiment of the application, and it should be pointed out that, for those skilled in the art, without departing from the principle of the application, a number of improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the application.

Claims

1. A cable over-temperature protection circuit, characterized in that, include: A power-free weak conduction module, wherein its first end is used to connect to the configuration channel port of a first cable plug, and its second end is used to connect to the configuration channel port of a second cable plug; wherein the power-free weak conduction module is in a weak conduction state when there is no power. A voltage regulator module, the input terminal of which is connected to the power bus port of the first cable plug, and the output terminal of which is connected to the power bus port of the control module; The control module has a temperature monitoring port for receiving temperature signals about the cable, and a power supply control port connected to the controlled end of a power supply switch. Specifically, when the control module determines that the cable is overheating based on the temperature signal, it sends an overheat protection signal to the controlled end of the power supply switch via the power supply control port to control the power supply switch to disconnect. Furthermore, when the control module determines that the cable temperature is normal based on the temperature signal, it sends a normal power supply signal to the controlled end of the power supply switch via the power supply control port to control the power supply switch to close. The power switch has a first end for connecting to the power bus port of the first cable plug and a second end for connecting to the power bus port of the second cable plug.

2. The cable over-temperature protection circuit as described in claim 1, characterized in that, The power-free weak conduction module includes a first power-free weak conduction switch. The first end of the first power-free weak conduction switch is connected to the first end of the power-free weak conduction module and the first end of the grounding module, respectively. The second end of the first power-free weak conduction switch is connected to the second end of the power-free weak conduction module and the first end of the first pull-up module, respectively. The controlled end of the first power-free weak conduction switch is connected to the first configuration control port of the control module. The circuit also includes the grounding module and the first pull-up module; The grounding module includes a grounding resistor and a grounding switch connected in series. The second end of the grounding module is used for grounding, and the controlled end of the grounding resistor is connected to the grounding control port of the control module. The first pull-up module includes a first pull-up resistor and a first pull-up switch connected in series. The second end of the first pull-up module is used to connect to the regulated power supply module, and the controlled end of the first pull-up switch is connected to the first pull-up control port of the control module. The control module is further configured to: when sending the over-temperature protection signal to the controlled end of the power supply switch through the power supply control port, send a disconnect signal to the controlled end of the first power-off weak conduction switch through the first configuration control port to control the first power-off weak conduction switch to disconnect; after the first power-off weak conduction switch automatically recovers from the disconnected state to the weak conduction state, if it is determined that the cable is over-temperature, send a disconnect signal to the controlled end of the first power-off weak conduction switch through the first configuration control port, send a closing signal to the controlled end of the first pull-up switch through the first pull-up control port, and send a closing signal to the controlled end of the grounding switch through the grounding control port to control the first power-off weak conduction switch to disconnect, and the first pull-up switch and the grounding switch to close; The first device connected to the first cable plug is used to output a low-level voltage through the power bus port of the first cable plug when the first no-power weak conduction switch is in the open state and the first pull-up switch and the grounding switch are in the closed state. The control module is also used to: control the power supply switch to close when the low-level voltage is output at the power bus port of the first cable plug.

3. The cable over-temperature protection circuit as described in claim 2, characterized in that, The circuit further includes a first voltage comparison module, the first input terminal of the first voltage comparison module is connected to the power bus port of the first cable plug, the second input terminal of the first voltage comparison module is connected to the output terminal of the regulated power supply module, and the output terminal of the first voltage comparison module is connected to the first receiving port of the control module. The step of controlling the power supply switch to close when the power bus port of the first cable plug outputs the low-level voltage includes: controlling the power supply switch to close when it is determined from the signal received by the first receiving port that the power bus port of the first cable plug outputs the low-level voltage.

4. The cable over-temperature protection circuit as described in claim 1, characterized in that, The controlled terminal of the power-free weak conduction module is connected to the configuration control port of the control module; The control module is further configured to: after sending the normal power supply signal to the controlled end of the power supply switch through the power supply control port, send a strong conduction signal to the controlled end of the power-free weak conduction module through the configuration control port, so as to control the power-free weak conduction module to be in a strong conduction state.

5. The cable over-temperature protection circuit as described in claim 1, characterized in that, It also includes a first unidirectional conductive module and a second unidirectional conductive module; The voltage regulator module has an input terminal for connecting to the power bus port of the first cable plug, and an output terminal for connecting to the power bus port of the control module, comprising: The input terminal of the first unidirectional conductive module is connected to the power bus port of the first cable plug, and the output terminal of the first unidirectional conductive module is connected to the input terminal of the regulated power supply module, and the output terminal of the regulated power supply module is connected to the power bus port of the control module; the input terminal of the second unidirectional conductive module is connected to the power bus port of the second cable plug, and the output terminal of the second unidirectional conductive module is connected to the input terminal of the regulated power supply module. One of the first cable plug and the second cable plug is used to connect to the power supply equipment, and the other is used to connect to the power receiving equipment.

6. The cable over-temperature protection circuit as described in claim 5, characterized in that, The power-free weak conduction module includes a first power-free weak conduction switch and a second power-free weak conduction switch. The first end of the second power-free weak conduction switch is used to connect to the configuration channel port of the first cable plug and the first end of the second pull-up module, respectively. The second end of the second power-free weak conduction switch is used to connect to the first end of the first power-free weak conduction switch, the power supply orientation detection module, and the first end of the grounding module, respectively. The first end of the first power-free weak conduction switch is also used to connect to the first end of the power supply orientation detection module and the first end of the grounding module, respectively. The second end of the first power-free weak conduction switch is used to connect to the first end of the first pull-up module and the configuration channel port of the second cable plug, respectively. The circuit further includes a first pull-up module, a second pull-up module, a grounding module, and a power supply orientation detection module. The grounding module includes a grounding resistor and a grounding switch connected in series. The second end of the grounding module is used for grounding, and the controlled end of the grounding resistor is connected to the grounding control port of the control module. The first pull-up module includes a first pull-up resistor and a first pull-up switch connected in series. The second end of the first pull-up module is connected to the output end of the regulated power supply module, and the controlled end of the first pull-up switch is connected to the first pull-up control port of the control module. The second pull-up module includes a second pull-up resistor and a second pull-up switch connected in series. The second end of the second pull-up module is connected to the output end of the regulated power supply module, and the controlled end of the second pull-up switch is connected to the second pull-up control port of the control module. The first input end of the power supply orientation detection module is connected to the first end of the first no-power weak conduction switch and the second end of the second no-power weak conduction switch, respectively. The second input end of the power supply orientation detection module is connected to the output end of the regulated power supply module, and the output end of the power supply orientation detection module is connected to the orientation signal receiving port of the control module.

7. The cable over-temperature protection circuit as described in claim 6, characterized in that, The controlled terminal of the first low-voltage switch is connected to the first configuration control port of the control module, and the controlled terminal of the second low-voltage switch is connected to the second configuration control port of the control module. The control module is further configured to: When the over-temperature protection signal is sent to the controlled end of the power supply switch through the power supply control port, disconnection signals are sent to the controlled ends of the first power-off weak conduction switch and the second power-off weak conduction switch through the first configuration control port and the second configuration control port, respectively, to control the first power-off weak conduction switch and the second power-off weak conduction switch to disconnect. After the first and second power-off weak conduction switches automatically return to the weak conduction state from the off state, if it is determined that the cable is overheated and the first device connected to the first cable plug is the power supply device, a disconnect signal is sent to the controlled end of the first power-off weak conduction switch through the first configuration control port, a closed signal is sent to the controlled end of the first pull-up switch through the first pull-up control port, a closed signal is sent to the controlled end of the grounding switch through the grounding control port, and a closed signal is sent to the controlled end of the second power-off weak conduction switch through the second configuration control port, so as to control the first power-off weak conduction switch to be disconnected and the second power-off weak conduction switch, the first pull-up switch and the grounding switch to be closed. After the first and second power-off weak conduction switches automatically return to the weak conduction state from the off state, if it is determined that the cable is overheated and that the second device connected to the second cable plug is the power supply device, the disconnect signal is sent to the controlled end of the second power-off weak conduction switch through the second configuration control port, the closed signal is sent to the controlled end of the second pull-up switch through the second pull-up control port, the closed signal is sent to the controlled end of the grounding switch through the grounding control port, and the closed signal is sent to the controlled end of the first power-off weak conduction switch through the first configuration control port, so as to control the second power-off weak conduction switch to open, the first power-off weak conduction switch, the second pull-up switch and the grounding switch to close; The first device connected to the first cable plug is used to output a low-level voltage through the power bus port of the first cable plug when the first low-voltage switch is in the open state, the second low-voltage switch, the first pull-up switch, and the grounding switch are in the closed state; or, the second device connected to the second cable plug is used to output a low-level voltage through the power bus port of the second cable plug when the second low-voltage switch is in the open state, the first low-voltage switch, the second pull-up switch, and the grounding switch are in the closed state. The control module is also used to: control the power supply switch to close when the power supply bus port of the power supply equipment outputs the low-level voltage.

8. The cable over-temperature protection circuit as described in claim 7, characterized in that, It also includes a first voltage comparison module and a second voltage comparison module; the first input terminal of the first voltage comparison module is connected to the power bus port of the first cable plug, the second input terminal of the first voltage comparison module is connected to the output terminal of the regulated power supply module, and the output terminal of the first voltage comparison module is connected to the first receiving port of the control module; the first input terminal of the second voltage comparison module is connected to the power bus port of the second cable plug, the second input terminal of the second voltage comparison module is connected to the output terminal of the regulated power supply module, and the output terminal of the second voltage comparison module is connected to the second receiving port of the control module. The step of controlling the power supply switch to close when the power bus port of the power supply device outputs the low-level voltage includes: controlling the power supply switch to close when it is determined from the signals received by the first receiving port and the second receiving port that the power bus port of the power supply device outputs the low-level voltage.

9. The cable over-temperature protection circuit as described in claim 8, characterized in that, The first voltage comparison module includes a first operational amplifier, a first feedback resistor, a first voltage divider resistor, a second feedback resistor, and a second voltage divider resistor; the second voltage comparison module includes a second operational amplifier, a third feedback resistor, a third voltage divider resistor, a fourth feedback resistor, and a fourth voltage divider resistor. The first end of the first feedback resistor is connected to the power bus port of the first cable plug, and the second end of the first feedback resistor is connected to the non-inverting input of the first operational amplifier and the first end of the first voltage divider resistor, respectively; the second end of the first voltage divider resistor is used for grounding; the output of the first operational amplifier is connected to the first receiving port of the control module; the first end of the second feedback resistor is connected to the output of the regulated power supply module, and the second end of the second feedback resistor is connected to the inverting input of the first operational amplifier and the first end of the second voltage divider resistor, respectively; the second end of the second voltage divider resistor is used for grounding; The first end of the third feedback resistor is connected to the power bus port of the second cable plug, and the second end of the third feedback resistor is connected to the non-inverting input of the second operational amplifier and the first end of the third voltage divider resistor, respectively; the second end of the third voltage divider resistor is used for grounding; the output of the second operational amplifier is connected to the second receiving port of the control module; the first end of the fourth feedback resistor is connected to the output of the regulated power supply module, and the second end of the fourth feedback resistor is connected to the inverting input of the second operational amplifier and the first end of the fourth voltage divider resistor, respectively; the second end of the fourth voltage divider resistor is used for grounding.

10. The cable over-temperature protection circuit as described in claim 7, characterized in that, The power supply orientation detection module includes a third operational amplifier, a fifth feedback resistor, and a fifth voltage divider resistor. The non-inverting input of the third operational amplifier is connected to the first terminal of the first no-power weak conduction switch and the second terminal of the second no-power weak conduction switch, respectively. The output of the third operational amplifier is connected to the orientation signal receiving port of the control module. The inverting input of the third operational amplifier is connected to the second terminal of the fifth feedback resistor and the first terminal of the fifth voltage divider resistor, respectively. The first terminal of the fifth feedback resistor is used to connect to the output of the regulated power supply module, and the second terminal of the fifth voltage divider resistor is used to ground. The control module is also configured to determine the power supply equipment in the following ways: The system controls the second low-voltage switch and the grounding switch to close, and controls the first low-voltage switch to open; alternatively, the system controls the first low-voltage switch and the grounding switch to close, and controls the second low-voltage switch to open. The system receives the output signal of the third operational amplifier and determines, based on the output signal of the third operational amplifier, whether the power supply device is the first device connected to the first cable plug or the second device connected to the second cable plug.

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