Protection circuit for port circuit, port circuit and electronic device

Abstract

The present application provides a protection circuit for a port circuit, a port circuit and an electronic device. The protection circuit comprises a first switch circuit, a signal generation circuit and a second switch circuit. The first switch circuit is connected in series between a signal terminal of a communication port of a port circuit and a signal terminal of a conversion chip of the port circuit. The first switch circuit is used such that a high voltage signal at the communication port is prevented from entering the conversion chip when the first switch circuit is disconnected. The signal generation circuit is respectively connected to power supply terminals of the first switch circuit and of the communication port, and is used to access a first power supply signal. The signal generation circuit is used to output a control voltage to the first switch circuit on the basis of the first power supply signal. The second switch circuit is respectively connected to the signal terminal of the communication port, the first switch circuit and a feedback terminal of the conversion chip. The second switch circuit is used to access a second power supply signal outputted by the conversion chip by means of the feedback terminal. The protection circuit provided in the present application can protect the conversion chip and reduce the costs of the port circuit.

Description

Port circuit protection circuits, port circuits and electronic devices

[0001] This application claims priority to Chinese Patent Application No. CN202422750503.2, filed on November 11, 2024, entitled "Protection Circuit for Port Circuit, Port Circuit and Electronic Device", the entirety of which is incorporated herein by reference. [Technical Field]

[0002] This application relates to the field of electronic technology, and in particular to a protection circuit for a port circuit, a port circuit, and an electronic device. [Background Technology]

[0003] In existing port circuits, the signal pins of the conversion chips have low withstand voltages. For example, the configuration channel (CC) pin and the sideband use (SBU) pin of the conversion chip have withstand voltages of 5-6V. If a voltage signal exceeding the withstand voltage of the signal pin is accidentally introduced, the conversion chip will be damaged.

[0004] To protect the conversion chip, the existing technology involves adding highly integrated protection chips with separate signal pins on the conversion chip. However, highly integrated protection chips are expensive, leading to increased costs for port circuitry. [Summary of the Invention]

[0005] To address the aforementioned technical problems, this application provides a protection circuit for a port circuit, a port circuit, and an electronic device to protect the signal terminals of a conversion chip while reducing the cost of the port circuit.

[0006] This application provides a protection circuit for a port circuit, which includes a first switching circuit, a signal generating circuit, and a second switching circuit. The first switching circuit is connected in series between the signal terminal of the communication port of the port circuit and the signal terminal of the conversion chip of the port circuit. The first switching circuit is used to isolate the high voltage signal at the communication port from entering the conversion chip when disconnected. The signal generating circuit is connected to the first switching circuit and the power supply terminal of the communication port respectively, and is used to receive a first power supply signal. The signal generating circuit is used to output a control voltage to the first switching circuit based on the first power supply signal. The second switching circuit is connected to the signal terminal of the communication port, the first switching circuit, and the feedback terminal of the conversion chip respectively. The second switching circuit is used to receive the second power supply signal output by the conversion chip through the feedback terminal.

[0007] In one embodiment, the first switching circuit includes a first switching transistor and a diode. The first communication terminal of the first switching transistor is connected to the signal terminal of the communication port and the second switching circuit, respectively. The second communication terminal of the first switching transistor is connected to the signal terminal of the conversion chip, and the control terminal of the first switching transistor is connected to the signal generating circuit. The cathode of the diode is connected to the first communication terminal of the first switching transistor, and the anode of the diode is connected to the second communication terminal of the first switching transistor and the signal terminal of the conversion chip, respectively. When an external device needs to supply power to the protection circuit, the second switching circuit is turned on to supply power to the protection circuit after the external device is connected to the communication port. The signal generating circuit outputs a control voltage based on the first power supply signal from the external device to turn on the first switching transistor. The conversion chip outputs a second power supply signal to the second switching circuit to turn off the second switching circuit. Alternatively, when the external device does not need to supply power to the protection circuit, both the first switching transistor and the second switching circuit are in a conducting state. After the external device is connected to the communication port, the branch containing the external device, the first switching transistor, and the conversion chip is turned on. The conversion chip sends a signal to the external device through the diode and outputs a second power supply signal to the second switching circuit to turn off the second switching circuit.

[0008] In one embodiment, the second switching circuit includes a second switching transistor, a pull-down resistor, and a first resistor. The first communication terminal of the second switching transistor is connected to the signal terminal of the communication port and the first switching circuit, respectively. One end of the pull-down resistor is connected to the second communication terminal of the second switching transistor, and the other end of the pull-down resistor is grounded. One end of the first resistor is connected to the control terminal of the second switching transistor and the signal terminal of the conversion chip, respectively, and the other end of the first resistor is grounded.

[0009] In one embodiment, the signal generation circuit includes a linear voltage regulator circuit connected to a power supply terminal and a first switching circuit, for outputting a control voltage based on a first power supply signal to control the operation of the first switching circuit.

[0010] In one embodiment, the signal generation circuit further includes a voltage divider circuit connected to the linear regulator circuit for outputting a second control voltage based on the first control voltage output by the linear regulator circuit. The signal terminals include a CC signal terminal and an SBU signal terminal. The first switching circuit includes two sub-first switching circuits: one sub-first switching circuit is connected in series between the CC signal terminal of the communication port and the CC signal terminal of the conversion chip, and is also connected to the linear regulator circuit; the other sub-first switching circuit is connected in series between the SBU signal terminal of the communication port and the SBU signal terminal of the conversion chip, and is also connected to the voltage divider circuit.

[0011] In one embodiment, the signal terminals include a CC signal terminal and / or an SBU signal terminal.

[0012] In one embodiment, the CC signal terminal includes two sub-CC signal terminals, and the SBU signal terminal includes two sub-SBU signal terminals; the first switching circuit includes four sub-first switching circuits, wherein two sub-first switching circuits are respectively connected in series between the sub-CC signal terminal of the communication port and the sub-CC signal terminal of the conversion chip, and the other two sub-first switching circuits are respectively connected in series between the sub-SBU signal terminal of the communication port and the sub-SBU signal terminal of the conversion chip, wherein one sub-CC signal terminal of the communication port is connected to the second switching circuit.

[0013] In one embodiment, the first switching circuit further includes a clamping diode, the two ends of which are respectively connected to the second communication terminal and the control terminal of the first switching transistor.

[0014] In one embodiment, the first switching transistor, the diode, and the clamping diode are integrally formed.

[0015] In one embodiment, the second switching circuit includes: a second switching transistor, a pull-down resistor, and a first resistor. The first communication terminal of the second switching transistor is connected to the signal terminal of the communication port and the first communication terminal of the first switching transistor, respectively. The control terminal of the second switching transistor is connected to the feedback terminal of the conversion chip. One end of the pull-down resistor is connected to the second communication terminal of the second switching transistor, and the other end of the pull-down resistor is grounded. One end of the first resistor is connected to the control terminal of the second switching transistor and the signal terminal of the conversion chip, respectively. The other end of the first resistor is grounded.

[0016] In one embodiment, the signal terminals include a CC signal terminal and an SBU signal terminal. The first switching circuit includes two sub-first switching circuits. One sub-first switching circuit is connected in series between the CC signal terminal of the communication port and the CC signal terminal of the conversion chip. The other sub-first switching circuit is connected in series between the SBU signal terminal of the communication port and the SBU signal terminal of the conversion chip. The signal generation circuit includes: a linear voltage regulator circuit connected to the power supply terminal and the control terminal of the first switching transistor of the sub-first switching circuit, used to output a control voltage based on a first power supply signal to control the operation of the sub-first switching circuit; and a voltage divider circuit connected to the linear voltage regulator circuit and the control terminal of the first switching transistor of the other sub-first switching circuit, used to output a second control voltage based on the first control voltage output by the linear voltage regulator circuit to control the operation of the other sub-first switching circuit.

[0017] In one embodiment, the first switching circuit includes a first switching transistor and a diode, and the second switching circuit includes a second switching transistor, a pull-down resistor, and a first resistor. The first communication terminal of the first switching transistor is connected to the signal terminal of a communication port, the second communication terminal of the first switching transistor is connected to the signal terminal of a conversion chip, and the control terminal of the first switching transistor is connected to a signal generation circuit. The cathode of the diode is connected to the first communication terminal of the first switching transistor, and the anode of the diode is connected to both the second communication terminal of the first switching transistor and the signal terminal of the conversion chip. The first communication terminal of the second switching transistor is connected to a sub-CC signal terminal and the first communication terminal of the first switching transistor connected to the CC signal terminal. The control terminal of the second switching transistor is connected to the feedback terminal of the conversion chip. One end of the pull-down resistor is connected to the second communication terminal of the second switching transistor, and the other end of the pull-down resistor is grounded. The first resistor... One end of the resistor is connected to the control terminal of the second switch and the signal terminal of the conversion chip, respectively, and the other end of the first resistor is grounded. When an external device needs to power the protection circuit, the second switch is turned on when the external device is connected to the communication port to power the protection circuit. The signal generation circuit outputs a control voltage based on the first power supply signal generated by the external device to turn on the first switch. The conversion chip then outputs a second power supply signal to the second switch to turn it off. Alternatively, when the external device does not need to power the protection circuit, both the first and second switches are in the on state. When the external device is connected to the communication port, the branch containing the external device, the first switch, and the conversion chip is turned on. The conversion chip sends a signal to the external device through a diode and outputs a second power supply signal to the second switch to turn it off.

[0018] This application provides a port circuit, which includes a communication port, a conversion chip and the aforementioned protection circuit. A first switch circuit is connected in series between the signal terminal of the communication port and the signal terminal of the conversion chip. A signal generation circuit is connected to the power supply terminal of the communication port. A second switch circuit is connected to the signal terminal of the communication port and the feedback terminal of the conversion chip.

[0019] This application provides an electronic device that includes the aforementioned port circuit.

[0020] In one embodiment, the electronic device includes a hub or docking station.

[0021] The beneficial effects of this application are as follows: The protection circuit of this application includes a first switching circuit, a signal generating circuit, and a second switching circuit. The first switching circuit is connected in series between the communication port and the signal terminal of the conversion chip. When a high voltage signal is introduced into the signal terminal of the communication port, the first switching circuit can isolate the high voltage signal from entering the conversion chip after the first switching circuit, thus protecting the conversion chip from damage by the high voltage signal and effectively protecting the safety of the conversion chip. In addition, compared with a highly integrated protection chip, the first switching circuit is a discrete circuit structure, which can reduce the cost of the protection circuit and thus reduce the cost of the port circuit. [Attached Image Description]

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0023] Figure 1 is a schematic diagram of the structure of an embodiment of the electronic device provided in this application;

[0024] Figure 2 is a schematic diagram of a port circuit according to an embodiment of the present application;

[0025] Figure 3 is a circuit diagram of an embodiment of the port circuit provided in this application.

Detailed Implementation Methods

[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0027] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0028] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0029] This application provides an electronic device. Referring to FIG1, FIG1 is a schematic structural diagram of an embodiment of the electronic device provided in this application. The electronic device 20 includes a port circuit 10. Referring to FIG2, FIG2 is a schematic structural diagram of an embodiment of the port circuit provided in this application. The port circuit 10 includes a communication port 100, a conversion chip 300, and a protection circuit 200. The protection circuit 200 is connected to both the communication port 100 and the conversion chip 300. The protection circuit 200 of the communication port 100 is used to isolate the high-voltage signal at the communication port 100 from entering the conversion chip 300. In this application, the high-voltage signal refers to an electrical signal higher than the withstand voltage value of the signal terminal of the conversion chip 300. It can be understood that the external terminals of the conversion chip 300 are mapped onto the communication port 100 to realize the electrical and signal connection between the conversion chip 300 and external devices through the communication port 100. The external devices can be computers, mobile phones, tablets, etc., and are not limited here.

[0030] In one embodiment, the electronic device 20 may be a hub or a docking station, and there is no limitation thereof.

[0031] In one embodiment, referring to FIG2, the protection circuit 200 includes a first switching circuit 210, a signal generating circuit 220, and a second switching circuit 230. The first switching circuit 210 is connected in series between the signal terminals of the communication port 100 and the signal terminals of the conversion chip 300. The first switching circuit 210 is used to prevent the high-voltage signal at the communication port 100 from entering the conversion chip 300 when disconnected. The signal generating circuit 220 is connected to the first switching circuit 210 and the power supply terminal of the communication port 100, and is used to receive the first power supply signal V1. The second switching circuit 230 is connected to the signal terminals of the communication port 100, the first switching circuit 210, and the feedback terminal of the conversion chip 300, respectively. The second switching circuit 230 receives the second power supply signal V2 output by the conversion chip 300 through the feedback terminal.

[0032] It can be known that the power supply for port circuit 10 can come from an external device connected through communication port 100, i.e., the external device supplies power to protection circuit 200, or from other power supply devices, i.e., other power supply devices supply power to protection circuit 200. In this case, port circuit 10 can charge the connected external device. The power supply terminal of communication port 100 is then connected to the power supply terminal of conversion chip 300. Specifically, in the mode where the external device supplies power to protection circuit 200, when the external device is connected to communication port 100, the branch containing the external device and the second switch circuit 230 is connected, the voltage at the signal terminal of the external device is pulled down, and the external device supplies power to port circuit 10. Signal generation circuit 220 outputs a control voltage (not shown in the figure) to the first switch circuit 210 based on the first power supply signal V1, causing the first switch circuit 210 to conduct. Simultaneously, conversion chip 300 outputs a second power supply signal V2 to the second switch circuit 230 to turn off the second switch circuit 230, thus enabling normal communication between the external device, the first switch circuit 210, and conversion chip 300. When other power supply devices supply power to port circuit 10, the first switch circuit 210 and the second switch circuit 230 are in the ON state. After an external device is connected to communication port 100, the conversion chip 300 sends a signal to the external device through the first switch circuit 210 and provides a second power supply signal V2 to the second switch circuit 230 to turn off the second switch circuit 230. Thus, the external device, the first switch circuit 210, and the conversion chip 300 can communicate normally. When a high-voltage signal enters the signal terminal of communication port 100, the first switch circuit 210 disconnects to isolate the high-voltage signal, thereby protecting the signal terminal of the conversion chip 300 from damage by the high-voltage signal and achieving the effect of protecting the conversion chip 300.

[0033] The protection circuit 200 of this embodiment includes a first switching circuit 210, a signal generating circuit 220, and a second switching circuit 230. The first switching circuit 210 is connected in series between the communication port 100 and the signal terminal of the conversion chip 300. When a high-voltage signal enters the signal terminal of the communication port 100, the first switching circuit 210 disconnects, thus isolating the high-voltage signal from entering the conversion chip 300 downstream of the first switching circuit 210, protecting the conversion chip 300 from damage by the high-voltage signal, and effectively protecting the conversion chip 300. In addition, compared with a highly integrated protection chip, the first switching circuit 210 is a discrete circuit structure, which can reduce the cost of the protection circuit 200, thereby reducing the cost of the communication port 100 circuit. Furthermore, by setting the signal generating circuit 220 and the second switching circuit 230, the protection circuit 200 can respectively realize the detection of external device access of the port circuit 10 and the conduction control of the first switching circuit, which can increase the functionality of the protection circuit 200 and enhance its practicality.

[0034] In one embodiment, referring to FIG3, FIG3 is a circuit diagram of an embodiment of the port circuit provided in this application. The first switching circuit 210 includes a first switching transistor Q11 and a diode D11. The first communication terminal of the first switching transistor Q11 is connected to the signal terminal of the communication port 100, the second switching circuit 230 and the cathode of the diode D11, respectively. The second communication terminal of the first switching transistor Q11 is connected to the signal terminal of the conversion chip 300 and the anode of the diode D11. The control terminal of the first switching transistor Q11 is connected to the signal generation circuit 220. When the external device supplies power to the protection circuit 200, after the external device is connected to the communication port 100, the second switching circuit 230 is turned on, thereby supplying power to the signal generation circuit 220 and the conversion chip 300. The signal generation circuit 220 outputs a control voltage to the control terminal of the first switching circuit 210 based on the first power supply signal V1, causing the first switching transistor Q11 to turn on. At the same time, the conversion chip 300 outputs a second power supply signal V2 to the second switching circuit 230 to turn off the second switching circuit 230, so that the external device can communicate normally with the conversion chip 300 through the first switching transistor Q11. Alternatively, when the external device does not need to supply power to the protection circuit 200, that is, when other power supply devices supply power to the port circuit 10 so that the port circuit 10 supplies power to the external device, the first switch Q11 and the second switch circuit 230 are both in the on state. After the external device is connected to the communication port 100, the conversion chip 300 sends a signal to the external device through the diode D11 and provides a second power supply signal V2 to the second switch circuit 230 to turn off the second switch circuit 230. Thus, the external device can communicate normally with the conversion chip 300 through the first switch Q11. After the information communication, the port circuit 10 supplies power to the external device. When a high-voltage signal enters the signal terminal of communication port 100, the voltages of both the signal terminal of communication port 100 and the signal terminal of conversion chip 300 increase. However, when the voltage at the signal terminal of conversion chip 300 rises to the threshold value of the first switching transistor Q11, for example, 5.5V, the first switching transistor Q11 enters the saturation region. The voltage at the signal terminal of conversion chip 300 will not increase with the voltage at the signal terminal of communication port 100, but will be clamped to a fixed value. Therefore, the first switching transistor Q11 can isolate the high-voltage signal from entering the signal terminal of conversion chip 300, and can protect the signal terminal of conversion chip 300 from damage by the high-voltage signal, effectively protecting conversion chip 300.

[0035] The first switching circuit 210 in this embodiment only includes the first switching transistor Q11 and the diode D11. It has a simple structure, is easy to implement, has few components, and is low in cost.

[0036] In one embodiment, the first switching transistor Q11 includes either a transistor or a power transistor, without limitation.

[0037] In one embodiment, the first switching circuit 210 further includes a clamping diode D12, the two ends of which are connected to the second communication terminal and the control terminal of the first switching transistor Q11, respectively.

[0038] In one embodiment, the first switch Q11, diode D11, and clamping diode D12 are integrally formed, that is, the first switch Q11, diode D11, and clamping diode D12 are integrated. Diode D11 and clamping diode D12 are added to the first switch Q11 during manufacturing, which can improve the stability of the first switching circuit 210.

[0039] In one embodiment, the second switching circuit 230 includes a second switching transistor Q31, a pull-down resistor R31, and a first resistor R32. The first communication terminal of the second switching transistor Q31 is connected to the signal terminal of the communication port 100 and the first switching circuit 210. The second communication terminal of the second switching transistor Q31 is connected to one end of the pull-down resistor R31, and the other end of the pull-down resistor R31 is grounded (GND). One end of the first resistor R32 is connected to the control terminal of the second switching transistor Q31 and the feedback terminal of the conversion chip 300, and the other end of the first resistor R32 is grounded (GND). In the mode where the external device powers the protection circuit 200, when the communication port 100 is connected to the external device, the branch containing the external device, the second switch Q31, the first resistor R32, and the pull-down resistor R31 is connected. The voltage at the signal terminal of the external device is pulled down, and the external device powers the port circuit 10. After the conversion chip 300 is powered, it outputs the second power supply signal V2 to the control terminal of the second switch Q31, causing the second switch Q31 to turn off, thereby restoring the voltage at the signal terminal of the external device. The external device can then communicate normally with the conversion chip 300 through the first switch circuit 210. In the mode where the external device does not power the protection circuit 200, the first switch circuit 210 and the second switch Q31 are in the on state. When the communication port 100 is connected to the external device, the conversion chip 300 provides the second power supply signal V2 to the second switch Q31, causing the second switch Q31 to turn off. Thus, the external device can then communicate normally with the conversion chip 300 through the first switch circuit 210.

[0040] The second switching circuit 230 in this embodiment, by setting a second switching transistor Q31, a first resistor R32 and a pull-down resistor R31, allows the second switching transistor Q31 to conduct without a control signal when an external device is connected to the communication port 100 or when it is not powered by an external device. This enables automatic detection of external device access, facilitates the connection between external devices and the conversion chip 300, and the second switching circuit 230 has a simple structure, is easy to implement, has few electronic components, and is low in cost.

[0041] In one embodiment, the second switching transistor Q31 includes either a transistor or a power transistor, without limitation.

[0042] In one embodiment, to enhance the anti-interference capability of the second switching circuit 230, the second switching circuit 230 further includes a resistor R33. The two ends of the resistor R33 are respectively connected to the feedback terminal of the conversion chip 300 and one end of the first resistor R32. The resistor R33 and the first resistor R32 cooperate to form a voltage divider circuit, so that the second power supply signal V2 enters the second switching transistor Q31 after being divided by voltage, which can protect the second switching transistor Q31 and thus enhance the anti-interference capability of the second switching circuit 230.

[0043] In one embodiment, the pull-down resistor R31 has a resistance of 5.1 kΩ, the resistor R33 has a resistance of 10 kΩ, and the first resistor R32 has a resistance of 100 kΩ. The resistors in this embodiment are all conventional, general-purpose resistor values, and no special resistors are involved. Therefore, it eliminates the need for resistors with unconventional resistance values, such as digital potentiometers, thus reducing the cost of the protection circuit 200. In other embodiments, the resistance values ​​of the pull-down resistor R31, resistor R33, and first resistor R32 can also be other reasonable, conventional, general-purpose resistor values, and this is not limited thereto.

[0044] In one embodiment, the signal generation circuit 220 includes a linear voltage regulator circuit 221. The linear voltage regulator circuit 221 is connected to the power supply terminal of the communication port 100 and the first switching circuit 210, and is used to output a control voltage based on the first power supply signal V1 to control the first switching circuit 210 to conduct. Understandably, the linear voltage regulator circuit 221 converts the first power supply signal V1, and can still output a small and stable control voltage even when the amplitude of the first power supply signal V1 increases. This allows it to continue controlling the first switching circuit 210 to conduct while protecting the first switching circuit 210, thus enhancing the stability of the first switching circuit 210. Furthermore, the signal generation circuit 220 in this embodiment has a simple structure and is easy to implement.

[0045] In one embodiment, the linear regulator circuit 221 can be a conventional linear regulator circuit, or it can be an integrated power conversion chip, which is not limited here.

[0046] In one embodiment, the linear voltage regulator circuit 221 includes a power conversion chip 300 and peripheral circuitry for maintaining the normal operation of the power conversion chip 300.

[0047] In one embodiment, the signal generation circuit 220 includes a feedback resistor R22 and a resistor R21 with variable resistance. The feedback resistor R22 and resistor R21 are connected in series and are respectively connected to the output terminal and the feedback terminal of the linear voltage regulator circuit 221. The feedback resistor R22 can be used to adjust the control voltage output by the linear voltage regulator circuit 221. Understandably, by adjusting the value of the feedback resistor R22, the value of the control voltage output by the power supply linear voltage regulator circuit 221 can be adjusted, thus enabling compatibility with the different control voltage requirements of different first switching circuits 210.

[0048] In one embodiment, the feedback resistor R22 includes a digital potentiometer (not shown) and / or a fixed resistor. The control terminal of the digital potentiometer can be connected to the control terminal of the port circuit 10. The port circuit 10 can change the output of the digital potentiometer to adjust the resistance value of the feedback resistor R22, thereby adjusting the control voltage output by the linear voltage regulator circuit 221. This embodiment achieves the adjustability of the feedback resistor R22 by setting a digital potentiometer. Since the digital potentiometer can output unconventional resistance values, precise adjustment of the control voltage can be achieved.

[0049] In one embodiment, the control voltage includes a first control voltage EN_V1 and a second control voltage EN_V2. The signal generation circuit 220 further includes a voltage divider circuit (not shown in the figure), which is connected to the linear regulator circuit 221. The voltage divider circuit is used to output the second control voltage EN_V2 based on the first control voltage EN_V1 output by the linear regulator circuit 221. The signal terminals include a CC signal terminal and an SBU signal terminal. The first switching circuit 210 includes two sub-first switching circuits (not shown in the figure). One sub-first switching circuit is connected in series between the communication port 100 and the CC signal terminal of the conversion chip 300, and is connected to the linear regulator circuit 221. The other sub-first switching circuit 210 is connected in series between the communication port 100 and the SBU signal terminal of the conversion chip 300, and is connected to the voltage divider circuit. Understandably, the signal generation circuit 220 is equipped with a linear voltage regulator circuit 221 and a voltage divider circuit to output a first control voltage EN_V1 and a second control voltage EN_V2, respectively, to meet the different control voltage requirements of the sub-first switching circuit on different signal terminals of the conversion chip 300. This can reduce the number of signal generation circuits 220 or linear voltage regulator circuits 221 and reduce the cost of the protection circuit 200.

[0050] In one embodiment, the voltage divider circuit includes resistors R23 and R24, wherein either resistor R23 or R24 ​​can be a digital potentiometer. This embodiment uses a digital potentiometer as the dividing resistor, which can output different resistance values. Therefore, the output of the digital potentiometer can be controlled to adjust the value of the second control voltage EN_V2 to accommodate the control voltage requirements of the sub-first switching circuit on different signal terminals.

[0051] In one embodiment, the signal terminals include a CC signal terminal and / or an SBU signal terminal. In this embodiment, a first switching circuit 210 is provided between the CC signal terminal and / or the SBU signal terminal between the communication port 100 and the conversion chip 300. This first switching circuit 210 isolates the high-voltage signal at the communication port 100 from entering the conversion chip 300, thus protecting the CC signal terminal and SBU signal terminal of the conversion chip 300 and reducing the probability of damage to the conversion chip 300.

[0052] In one embodiment, the CC signal terminal includes two sub-CC signal terminals, and the SBU signal terminal includes two sub-SBU signal terminals. The first switching circuit 210 includes four sub-first switching circuits, wherein two sub-first switching circuits are respectively connected in series between the sub-CC signal terminals of the communication port 100 and the conversion chip 300. The other two sub-first switching circuits are respectively connected in series between the communication port 100 and the sub-SBU signal terminals of the conversion chip 300. The second switching circuit 230 is connected to only one of the sub-CC signal lines and is used to detect whether an external device is connected. For example, the CC signal terminal includes a CC1 signal terminal and a CC2 signal terminal. The second switching circuit 230 can be connected to the CC1 signal terminal of the communication port 100, or the second switching circuit 230 can be connected to the CC2 signal terminal of the communication port 100. Understandably, in this embodiment, a sub-first switch circuit is connected in series with each sub-CC signal line and each sub-SBU signal line of the communication port 100 and the conversion chip 300. When the sub-first switch circuit is disconnected, it isolates the high-voltage signal at the communication port 100 from entering the conversion chip 300, so that each sub-CC signal terminal and each sub-SBU signal terminal of the conversion chip 300 can be protected by the sub-first switch circuit, thereby reducing the probability of damage to the conversion chip 300.

[0053] In one embodiment, the communication port 100 can be a Type-C, Type-A, or Type-B communication port, etc., and is not limited thereto.

[0054] The above are merely embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A protection circuit for a port circuit, characterized in that, include: A first switching circuit is connected in series between the signal terminal of the communication port of the port circuit and the signal terminal of the conversion chip of the port circuit. The first switching circuit is used to isolate the high voltage signal at the communication port from entering the conversion chip when it is disconnected. A signal generation circuit is connected to the power supply terminals of the first switching circuit and the communication port, respectively, for receiving a first power supply signal. The signal generation circuit is used to output a control voltage to the first switching circuit based on the first power supply signal. The second switching circuit is connected to the signal terminal of the communication port, the first switching circuit, and the feedback terminal of the conversion chip, respectively. The second switching circuit is used to receive the second power supply signal output by the conversion chip through the feedback terminal.

2. The protection circuit according to claim 1, wherein, The first switching circuit includes: The first switching transistor has a first communication terminal connected to the signal terminal of the communication port and the second switching circuit, a second communication terminal connected to the signal terminal of the conversion chip, and a control terminal connected to the signal generation circuit. A diode, wherein the cathode of the diode is connected to the first communication terminal of the first switching transistor, and the anode of the diode is connected to the second communication terminal of the first switching transistor and the signal terminal of the conversion chip, respectively. In cases where an external device requires power to the protection circuit, when the external device is connected to the communication port, the second switching circuit is activated to supply power to the protection circuit; the signal generation circuit outputs the control voltage based on the first power supply signal generated by the external device to activate the first switching transistor; and the conversion chip outputs the second power supply signal to the second switching circuit to deactivate the second switching circuit; or When the external device does not need to supply power to the protection circuit, both the first switching transistor and the second switching circuit are in the on state. When the external device is connected to the communication port, the branch containing the external device, the first switching transistor, and the conversion chip is turned on. The conversion chip sends a signal to the external device through the diode and outputs the second power supply signal to the second switching circuit to turn off the second switching circuit.

3. The protection circuit according to claim 1, wherein, The second switching circuit includes: The second switching transistor has its first communication terminal connected to the signal terminal of the communication port and the first switching circuit, respectively. A pull-down resistor, one end of which is connected to the second communication terminal of the second switching transistor, and the other end of which is grounded; A first resistor, one end of which is connected to the control terminal of the second switching transistor and the signal terminal of the conversion chip, and the other end of which is grounded.

4. The protection circuit according to claim 1, wherein, The signal generation circuit includes: A linear voltage regulator circuit, connected to the power supply terminal and the first switching circuit, is used to output the control voltage based on the first power supply signal to control the operation of the first switching circuit.

5. The protection circuit according to claim 4, wherein, The signal generation circuit further includes: A voltage divider circuit is connected to the linear voltage regulator circuit and is used to output a second control voltage based on a first control voltage output by the linear voltage regulator circuit. The signal terminals include CC signal terminals and SBU signal terminals. The first switching circuit includes two sub-first switching circuits. One of the sub-first switching circuits is connected in series between the CC signal terminal of the communication port and the CC signal terminal of the conversion chip, and is connected to the linear voltage regulator circuit. Another sub-first switch circuit is connected in series between the SBU signal terminal of the communication port and the SBU signal terminal of the conversion chip, and is also connected to the voltage divider circuit.

6. The protection circuit according to claim 1, wherein, The signal terminals include CC signal terminals and / or SBU signal terminals.

7. The protection circuit according to claim 6, wherein, The CC signal terminal includes two sub-CC signal terminals, and the SBU signal terminal includes two sub-SBU signal terminals. The first switching circuit includes four sub-first switching circuits, wherein two of the sub-first switching circuits are respectively connected in series between the sub-CC signal terminal of the communication port and the sub-CC signal terminal of the conversion chip, and the other two sub-first switching circuits are respectively connected in series between the sub-SBU signal terminal of the communication port and the sub-SBU signal terminal of the conversion chip, wherein one of the sub-CC signal terminals of the communication port is connected to the second switching circuit.

8. The protection circuit according to claim 2, wherein, The first switching circuit also includes: A clamping diode, the two ends of which are respectively connected to the second communication terminal and the control terminal of the first switching transistor.

9. The protection circuit according to claim 8, wherein, The first switching transistor, the diode, and the clamping diode are integrally formed.

10. The protection circuit according to claim 2, wherein, The second switching circuit includes: The second switching transistor has its first communication terminal connected to the signal terminal of the communication port and the first communication terminal of the first switching transistor, respectively, and its control terminal connected to the feedback terminal of the conversion chip. A pull-down resistor, one end of which is connected to the second communication terminal of the second switching transistor, and the other end of which is grounded; A first resistor, one end of which is connected to the control terminal of the second switching transistor and the signal terminal of the conversion chip, and the other end of which is grounded.

11. The protection circuit according to claim 10, wherein, The signal terminals include a CC signal terminal and an SBU signal terminal. The first switching circuit includes two sub-first switching circuits. One sub-first switching circuit is connected in series between the CC signal terminal of the communication port and the CC signal terminal of the conversion chip. The other sub-first switching circuit is connected in series between the SBU signal terminal of the communication port and the SBU signal terminal of the conversion chip. The signal generation circuit includes: A linear voltage regulator circuit is connected to the power supply terminal and the control terminal of the first switching transistor of the first sub-first switching circuit, and is used to output the control voltage based on the first power supply signal to control the operation of the first sub-first switching circuit. A voltage divider circuit is connected to the control terminal of the first switching transistor of the linear voltage regulator circuit and the other sub-first switching circuit. It is used to output a second control voltage based on the first control voltage output by the linear voltage regulator circuit to control the operation of the other sub-first switching circuit.

12. The protection circuit according to claim 7, wherein, The first switching circuit includes a first switching transistor and a diode, and the second switching circuit includes a second switching transistor, a pull-down resistor, and a first resistor, wherein... The first communication terminal of the first switching transistor is connected to the signal terminal of the communication port, the second communication terminal of the first switching transistor is connected to the signal terminal of the conversion chip, and the control terminal of the first switching transistor is connected to the signal generation circuit. The cathode of the diode is connected to the first communication terminal of the first switching transistor, and the anode of the diode is connected to the second communication terminal of the first switching transistor and the signal terminal of the conversion chip, respectively. The first communication terminal of the second switching transistor is connected to a sub-CC signal terminal and the first communication terminal of the first switching transistor connected to the CC signal terminal, respectively; the control terminal of the second switching transistor is connected to the feedback terminal of the conversion chip. One end of the pull-down resistor is connected to the second communication terminal of the second switching transistor, and the other end of the pull-down resistor is grounded. A first resistor, one end of which is connected to the control terminal of the second switching transistor and the signal terminal of the conversion chip, and the other end of which is grounded; In the case where an external device needs to power the protection circuit, when the external device is connected to the communication port, the second switch is turned on to power the protection circuit; the signal generation circuit outputs the control voltage based on the first power supply signal generated by the external device to turn on the first switch; and the conversion chip outputs the second power supply signal to the second switch to turn it off; or When the external device does not need to supply power to the protection circuit, both the first and second switching transistors are in the ON state. When the external device is connected to the communication port, the branch containing the external device, the first switching transistor, and the conversion chip is turned on. The conversion chip sends a signal to the external device through the diode and outputs the second power supply signal to the second switching transistor to turn off the second switching transistor.

13. A port circuit, characterized in that, include: The communication port, the conversion chip, and the protection circuit according to any one of claims 1-12, wherein the first switching circuit is connected in series between the signal terminal of the communication port and the signal terminal of the conversion chip, the signal generating circuit is connected to the power supply terminal of the communication port, and the second switching circuit is connected to the signal terminal of the communication port and the feedback terminal of the conversion chip respectively.

14. An electronic device, characterized in that, Includes the port circuit described in claim 13.

15. The electronic device according to claim 14, wherein, The electronic device includes a hub or a docking station.

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