Protection circuit and electronic equipment

Abstract

The invention relates to a protection circuit and electronic equipment, and relates to the technical field of electronic information. The problem that an external port is damaged by an EOS is solved. The protection circuit is applied to the electronic equipment with an external port and a processing chip. The protection circuit comprises a first protection unit and a second protection unit. The first end of the first protection unit is used for being coupled with a pin of an external port, and the second end of the first protection unit is used for being coupled with a processing chip. The first protection unit is configured to isolate the direct current stress and / or surge stress of the first end of the first protection unit from the second end of the first protection unit. The first end of the second protection unit is coupled with the first end of the first protection unit, and the second end of the second protection unit is coupled with the grounding end. The second protection unit is configured to reduce surge stress and / or electrostatic stress of the first end of the first protection unit.

Description

Technical Field

[0001] The present disclosure relates to the field of electronic information technology, and in particular to a protection circuit and electronic equipment. Background Art

[0002] With the rapid development of electronic information technology, electronic devices can use their own external ports to connect to some external devices, so as to realize functions that the electronic devices themselves cannot realize; or, electronic devices can also use their own external ports to connect to chargers to charge the internal batteries of the electronic devices.

[0003] Usually, the external ports of electronic devices are exposed. In this way, the external ports are easily exposed to electrical over stress (EOS) from the environment, causing damage to the external ports and making at least some of the functions of the external ports lose. Therefore, there is an urgent need in the market for a design that can prevent EOS from damaging the external ports. Summary of the invention

[0004] The embodiments of the present application provide a protection circuit and an electronic device for solving the problem of damage to an external port caused by EOS.

[0005] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0006] In a first aspect, a protection circuit is provided. The protection circuit is applied to an electronic device having an external port and a processing chip. The protection circuit includes a first protection unit and a second protection unit. The first end of the first protection unit is used to couple a pin of the external port, and the second end of the first protection unit is used to couple the processing chip. The first protection unit is configured to isolate the DC stress and / or surge stress of the first end of the first protection unit from the second end of the first protection unit. The first end of the second protection unit is coupled to the first end of the first protection unit, and the second end of the second protection unit is coupled to the ground end. The second protection unit is configured to reduce the surge stress and / or electrostatic stress of the first end of the first protection unit.

[0007] The following description will be given by taking an electronic device as a mobile phone, an external port including a Type-C port of the mobile phone, and a processing chip as a system on chip (SOC) as an example, but this should not be taken as a limitation on the electronic device, the external port and the processing chip.

[0008] The protection circuit may include a first protection unit and a second protection unit. The first protection unit may be coupled to a pin in the Type-C port, and the first protection unit may be coupled to the SOC in the mobile phone. It can be understood that the first end of the first protection unit serves as the input end of the protection circuit, and the second end of the first protection unit serves as the output end of the protection circuit.

[0009] The first end of the second protection unit is coupled to the first end of the first protection unit, and the second end of the second protection unit is coupled to the ground end. It can be understood that the second protection unit is connected in series between the first end of the first protection unit and the ground end.

[0010] Since the Type-C port of the mobile phone is exposed, it is easy for the Type-C port to introduce EOS from the environment, thereby causing damage to the Type-C port, causing at least some of the functions of the Type-C port to be lost. For example, if the Type-C port is used as a charging port with a fast charging function, if the Type-C port is damaged by EOS, the Type-C port will lose its fast charging function as a charging port. For example, if the Type-C port is used as a data transmission port, if the Type-C port is damaged by EOS, the Type-C port will lose its data transmission function as a data transmission port.

[0011] EOS mainly includes electrostatic stress, surge stress and DC stress. Among them, the electrostatic stress of the Type-C port is mainly due to the stress caused by factors such as friction electrification in the environment. The voltage value corresponding to the electrostatic stress is very large and can reach several thousand volts. The surge stress of the Type-C port is the stress caused by the plugging and unplugging of the Type-C plug at the Type-C port. The voltage value corresponding to the surge stress can be more than ten volts to several tens of volts. DC stress is mainly caused by the external conductor (such as liquid infiltrating the Type-C port) forming a path between different pins in the Type-C port, resulting in a large DC voltage on the pins. The voltage value corresponding to the DC stress can be more than ten volts to several tens of volts.

[0012] Among them, electrostatic stress occurs for a shorter time, which is nanosecond level stress; surge stress occurs for a slightly longer time, which is microsecond level stress; and DC stress occurs for the longest time, which is millisecond to second level stress.

[0013] In the embodiments of the present application, when at least one of the above-mentioned electrostatic stress, surge stress and DC stress occurs to the pins of the Type-C port, EOS can avoid damage to the SOC by EOS after being protected by the second protection unit and the first protection unit in sequence.

[0014] The second protection unit is coupled to the first end of the first protection unit. It can be understood that the signal of the pin in the Type-C port first passes through the protection of the second protection unit, then passes through the protection of the first protection unit, and finally flows from the second end of the first protection unit to the mobile phone chip, thereby completing a signal transmission from the pin in the Type-C port to the SOC.

[0015] The type of stress protection performed by the first protection unit may be different from the type of stress protection performed by the second protection unit.

[0016] The first protection unit may be configured to isolate the SOC from the DC stress and / or surge stress on the pins of the Type-C port. Exemplarily, the first protection unit isolates the SOC from the DC stress on the pins of the Type-C port. Exemplarily, the first protection unit isolates the SOC from the surge stress on the pins of the Type-C port. Exemplarily, the first protection unit isolates the SOC from the DC stress and surge stress on the pins of the Type-C port. Exemplarily, the first protection unit isolates the SOC from the DC stress and surge stress on the pins of the Type-C port.

[0017] The second protection unit may be configured to reduce the electrostatic stress and / or surge stress of the first end of the first protection unit. Exemplarily, the second protection unit may reduce the electrostatic stress of the first end of the first protection unit. Exemplarily, the second protection unit may reduce the surge stress of the first end of the first protection unit. Exemplarily, the second protection unit may reduce the electrostatic stress and surge stress of the first end of the first protection unit.

[0018] It can be understood that after EOS appears on the pin of the Type-C port, the second protection unit will first protect the electrostatic stress and / or surge stress of the first end of the first protection unit, and then the first protection unit will protect the DC stress and / or surge stress in the EOS, so that after being protected by the first protection unit and the second protection unit, the EOS appearing on the pin of the Type-C port will not cause damage to the SOC.

[0019] In some feasible implementations of the first aspect, the first protection unit includes a switch subcircuit. A first end of the switch subcircuit is used to couple a pin of an external port, and a second end of the switch subcircuit is used to couple a processing chip. Isolating the DC stress and / or surge stress at the first end of the first protection unit from the second end of the first protection unit includes: isolating the first end of the switch subcircuit from the second end of the switch subcircuit.

[0020] In some examples, the switch subcircuit can detect by itself whether there is DC stress and / or surge stress on the pin of the Type-C port. Exemplarily, the voltage value corresponding to the DC stress and / or surge stress is large, so the switch subcircuit can determine whether there is DC stress and / or surge stress on the pin of the Type-C port by detecting the voltage at the first end of the switch subcircuit.

[0021] When the switch subcircuit detects that the voltage at the first end of the switch subcircuit is greater than or equal to a preset threshold, it determines that there is DC stress and / or surge stress in the voltage at the first end of the switch subcircuit, disconnects the first end of the switch subcircuit and the second end of the switch subcircuit, thereby disconnecting the connection between the pin of the Type-C port and the SOC, isolating the DC stress and / or surge stress from the SOC, and protecting against EOS, thereby preventing EOS from damaging the SOC.

[0022] When the switch subcircuit detects that the voltage at the first end of the switch subcircuit is less than a preset threshold, it determines that there is no DC stress and / or surge stress at the voltage at the first end of the switch subcircuit, maintains conduction between the first end of the switch subcircuit and the second end of the switch subcircuit, thereby conducting the connection between the pin of the Type-C port and the SOC, and completing the signal transmission from the pin of the Type-C port to the SOC.

[0023] In other examples, the switch sub-circuit can receive control from other units to disconnect the connection between the pins of the Type-C port and the SOC when the switch sub-circuit is subject to DC stress and / or surge stress on the pins of the Type-C port, and to connect the connection between the pins of the Type-C port and the SOC when the pins of the Type-C port are not subject to DC stress and / or surge stress.

[0024] Exemplarily, the protection circuit 200 may further include a control unit. The control unit is coupled to the control terminal of the switch subcircuit. The control unit is configured to provide a control voltage to the control terminal of the switch subcircuit.

[0025] For example, the control unit can detect whether there is DC stress and / or surge stress on the pins of the Type-C port. When there is no DC stress and / or surge stress on the pins of the Type-C port, the control unit can output a first control voltage; when there is DC stress and / or surge stress on the pins of the Type-C port, the control unit can output a second control voltage.

[0026] When the control end of the switch sub-circuit receives the first control voltage, the first end of the switch sub-circuit and the second end of the switch sub-circuit are maintained conductive, thereby conductively connecting the pin of the Type-C port and the SOC, and completing the signal transmission from the pin of the Type-C port to the SOC.

[0027] When the control end of the switch sub-circuit receives the second control voltage, the connection between the first end of the switch sub-circuit and the second end of the switch sub-circuit is disconnected, thereby disconnecting the connection between the pin of the Type-C port and the SOC, isolating the DC stress and / or surge stress from the SOC, and protecting against EOS, thereby preventing EOS from damaging the SOC.

[0028] In some feasible implementations of the first aspect, the protection circuit further includes a control unit. The switch subcircuit includes a transistor. A first electrode of the transistor is used to couple a pin of an external port, a second electrode of the transistor is used to couple a processing chip, and a control electrode of the transistor is coupled to the control unit. Isolating the first end of the switch subcircuit from the second end of the switch subcircuit includes: isolating the first electrode of the transistor from the second electrode of the transistor.

[0029] The transistor T may be a P-channel transistor or an N-channel transistor. The transistor T is an N-channel transistor as an example for description.

[0030] In some examples, when there is no DC stress and / or surge stress on the pin of the Type-C port, the control unit can output a high voltage signal (first control voltage), the control end of the switch subcircuit receives the high voltage signal, and maintains the conduction between the first end of the switch subcircuit and the second end of the switch subcircuit, thereby conducting the connection between the pin of the Type-C port and the SOC, and completing the signal transmission from the pin of the Type-C port to the SOC. When there is DC stress and / or surge stress on the pin of the Type-C port, the control unit can output a low voltage signal (second control voltage), the control end of the switch subcircuit receives the low voltage signal, disconnects the connection between the first end of the switch subcircuit and the second end of the switch subcircuit, thereby disconnecting the connection between the pin of the Type-C port and the SOC, isolating the DC stress and / or surge stress from the SOC, and realizing protection against EOS, and preventing EOS from damaging the SOC.

[0031] In other examples, the control unit may provide a constant control voltage to the control end of the switch subcircuit. For example, the voltage value of the control voltage may be 5V, 6V, 8V, 10V, etc., which is not limited in this application. The transistor T conducts or disconnects the connection between the pin of the Type-C port and the SOC based on the voltage difference between the voltage of the control electrode of the transistor T and the voltage value of the second electrode of the transistor T.

[0032] When there is no DC stress and / or surge stress on the pin of the Type-C port, the voltage difference between the voltage of the control electrode of transistor T and the voltage value of the second electrode of transistor T is greater than zero, and transistor T turns on the connection between the first electrode of transistor T and the second electrode of transistor T, thereby turning on the connection between the pin of the Type-C port and the SOC, completing the signal transmission from the pin of the Type-C port to the SOC.

[0033] In the case where DC stress and / or surge stress exists on the pin of the Type-C port, the voltage of the DC stress and / or surge stress is transmitted to the second electrode of the transistor T, so that the voltage of the second electrode of the transistor T is pulled up, and the voltage difference between the voltage of the control electrode of the transistor T and the voltage value of the second electrode of the transistor T is less than zero, and the transistor T cuts off the connection between the first electrode of the transistor T and the second electrode of the transistor T, thereby disconnecting the connection between the pin of the Type-C port and the SOC, isolating the DC stress and / or surge stress from the SOC, realizing protection against EOS, and preventing EOS from damaging the SOC.

[0034] In some feasible implementations of the first aspect, the first protection unit includes a capacitor. A first plate of the capacitor is used to couple a pin of an external port, and a second plate of the capacitor is used to couple a processing chip. Isolating a DC stress and / or a surge stress at a first end of the first protection unit from a second end of the first protection unit includes: isolating a DC stress of the first plate of the capacitor from the second plate of the capacitor.

[0035] The capacitor can allow AC signals to pass through, and the capacitor can block the transmission of DC stress. That is, the AC signal on the pin of the external port can pass through the capacitor and be transmitted to the processing chip, and the DC stress on the pin of the external port is blocked by the capacitor and cannot be transmitted to the processing chip.

[0036] In some feasible implementations of the first aspect, the first protection unit includes a switch. The first contact of the switch is used to couple a pin of an external port, the second contact of the switch is used to couple a processing chip, and the first contact is connected or disconnected with the second contact. The DC stress and / or surge stress at the first end of the first protection unit is isolated from the second end of the first protection unit, including: when the voltage of the first contact is greater than or equal to a preset threshold, the first contact is disconnected from the second contact, and the DC stress and / or surge stress of the first contact is isolated from the second contact.

[0037] The first contact is disconnected from the second contact, which is equivalent to disconnecting the connection between the pin of the Type-C port and the SOC, thereby isolating the DC stress and / or surge stress from the SOC, achieving protection against EOS and preventing EOS from damaging the SOC.

[0038] In some feasible implementations of the first aspect, the second protection unit includes a first overvoltage protection subcircuit. The first end of the first overvoltage protection subcircuit is coupled to the first end of the first protection unit, and the second end of the first overvoltage protection subcircuit is coupled to the ground end. Reducing the surge stress and / or electrostatic stress at the first end of the first protection unit includes: when the voltage at the first end of the first overvoltage protection subcircuit is greater than or equal to a preset first starting voltage, the first end of the first overvoltage protection subcircuit is connected to the second end of the first overvoltage protection subcircuit to reduce the voltage at the first end of the first protection unit.

[0039] The first overvoltage protection subcircuit includes a protection state and a non-protection state. When the first overvoltage protection subcircuit is in the protection state, the first end of the first overvoltage protection subcircuit is connected to the second end of the first overvoltage protection subcircuit, so that the first end of the first protection unit is connected to the ground end, thereby pulling down the voltage at the first end of the first protection unit. When the first overvoltage protection subcircuit is in the non-protection state, the first end of the first overvoltage protection subcircuit is disconnected from the second end of the first overvoltage protection subcircuit, so that the first end of the first protection unit is disconnected from the ground end, so that the signal of the pin of the Type-C port is smoothly transmitted to the first protection unit.

[0040] Whether the first overvoltage protection subcircuit is in a protection state or a non-protection state may depend on the voltage at the first end of the first overvoltage protection subcircuit. Exemplarily, when the voltage at the first end of the first overvoltage protection subcircuit is greater than or equal to a preset first start-up voltage, the first overvoltage protection subcircuit may be in a protection state; when the voltage at the first end of the first overvoltage protection subcircuit is less than the first start-up voltage, the first overvoltage protection subcircuit may be in a non-protection state.

[0041] In some feasible implementations of the first aspect, the first overvoltage protection subcircuit includes a first transient voltage suppression tube. The first pole of the first transient voltage suppression tube is coupled to the first end of the first protection unit, and the second pole of the first transient voltage suppression tube is coupled to the ground end. The first end of the first overvoltage protection subcircuit is connected to the second end of the first overvoltage protection subcircuit, including: connecting the first pole of the first transient voltage suppression tube to the second pole of the first transient voltage suppression tube.

[0042] The first transient voltage suppressor tube may be a unidirectional transient voltage suppressor tube or a bidirectional transient voltage suppressor tube, and this application does not limit this.

[0043] When the voltage of the first pole of the first transient voltage suppression tube is greater than or equal to the preset first starting voltage, the first pole of the first transient voltage suppression tube is connected to the second pole of the first transient voltage suppression tube, so that the first end of the first protection unit is connected to the ground end, thereby pulling down the voltage at the first end of the first protection unit.

[0044] When the voltage of the first pole of the first transient voltage suppression tube is less than the preset first starting voltage, the first pole of the first transient voltage suppression tube is disconnected from the second pole of the first transient voltage suppression tube, so that the first end of the first protection unit is disconnected from the ground end, so that the signal of the pin of the Type-C port is smoothly transmitted to the first protection unit.

[0045] It can be understood that the first starting voltage can be understood as the opening voltage of the first transient voltage suppression tube. In addition, the first transient voltage suppression tube also includes a clamping voltage (also called a limiting voltage), which refers to the maximum voltage that the first pole of the first transient voltage suppression tube is allowed to continue to transmit to the first end of the first protection unit after the first pole of the first transient voltage suppression tube and the second pole of the first transient voltage suppression tube are connected. Among them, the clamping voltage of the first transient voltage suppression tube is less than the opening voltage of the first transient voltage suppression tube.

[0046] In some feasible implementations of the first aspect, the first overvoltage protection subcircuit includes a transient voltage suppression tube assembly. A first end of the transient voltage suppression tube assembly is coupled to a first end of the first protection unit, and a second end of the transient voltage suppression tube assembly is coupled to a ground end. The transient voltage suppression tube assembly includes a plurality of second transient voltage suppression tubes connected in series.

[0047] The first end of the transient voltage suppression tube assembly is coupled to the first end of the first protection unit, and the second end of the transient voltage suppression tube assembly is coupled to the ground end. It can be understood that the first end of the transient voltage suppression tube assembly is equivalent to the first end of the first overvoltage protection subcircuit, and the second end of the transient voltage suppression tube assembly is equivalent to the second end of the first overvoltage protection subcircuit.

[0048] The transient voltage suppression tube assembly may include a plurality of second transient voltage suppression tubes connected in series. The first pole of the first second transient voltage suppression tube among the plurality of second transient voltage suppression tubes is coupled to the first end of the first protection unit, the first pole of the second second transient voltage suppression tube is coupled to the second pole of the first second transient voltage suppression tube, and so on, until the second pole of the last second transient voltage suppression tube is coupled to the ground end.

[0049] The multiple second transient voltage suppression tubes are connected in series, so the current passing through each second transient voltage suppression tube is the same. By connecting the multiple second transient voltage suppression tubes in series, the sum of the turn-on voltages of the second transient voltage suppression tubes can be used as the turn-on voltage of the entire transient voltage suppression tube assembly. Therefore, when a single transient voltage suppression tube is lower than the first start-up voltage, the turn-on voltage of the transient voltage suppression tube assembly can be equal to the first start-up voltage by connecting multiple transient voltage suppression tubes in series, thereby achieving the effect of overvoltage protection.

[0050] Exemplarily, the transient voltage suppression tube assembly may include two second transient voltage suppression tubes. Of course, in some other examples, the transient voltage suppression tube assembly may also include more second transient voltage suppression tubes.

[0051] In some feasible implementations of the first aspect, the protection circuit further includes a third protection unit. A first end of the third protection unit is coupled to a second end of the first protection unit, and a second end of the third protection unit is coupled to a ground terminal. The third protection unit is configured to reduce surge stress and / or electrostatic stress at the second end of the first protection unit.

[0052] In some embodiments, in order to prevent DC stress from damaging the second protection unit, the startup voltage of the second protection unit is increased, which will cause the clamping voltage of the second protection unit to also increase, resulting in the clamping voltage of the second protection unit being higher than the safety voltage of the SOC.

[0053] Therefore, the third protection unit can further protect the surge stress and / or electrostatic stress protected by the second protection unit to ensure that the surge stress and / or electrostatic stress protected by the third protection unit is less than or equal to the safety voltage of the SOC, thereby improving the protection performance of the protection circuit to the SOC.

[0054] In other embodiments, even if the clamping voltage of the second protection unit is less than or equal to the safety voltage of the SOC, the third protection unit can further improve the performance of the protection circuit in protecting against surge stress and / or electrostatic stress.

[0055] In the case where there is no surge stress and / or electrostatic stress on the pin of the Type-C port, or when there is surge stress and / or electrostatic stress on the pin of the Type-C port and the second protection unit reduces the voltage of the surge stress and / or electrostatic stress to less than the preset second starting voltage, the voltage at the first end of the third protection unit is less than the preset second starting voltage, the first end of the third protection unit and the second end of the third protection unit are disconnected, so that the second end of the first protection unit is disconnected from the ground end, so that the signal output by the second end of the first protection unit is smoothly transmitted to the SOC and provided to the SOC.

[0056] In the case where surge stress and / or electrostatic stress exists on the pin of the Type-C port and the voltage of the surge stress and / or electrostatic stress is still greater than or equal to the second starting voltage after the second protection unit reduces the voltage, the voltage at the first end of the third protection unit is greater than or equal to the second starting voltage, and the first end of the third protection unit and the second end of the third protection unit are conductive, so that the second end of the first protection unit and the ground end are conductive, thereby pulling down the voltage at the second end of the first protection unit, so as to ensure that the surge stress and / or electrostatic stress protected by the third protection unit is less than or equal to the safety voltage of the SOC, thereby improving the protection performance of the protection circuit for the SOC.

[0057] In some feasible implementations of the first aspect, the third protection unit includes a second overvoltage protection subcircuit. The first end of the second overvoltage protection subcircuit is coupled to the second end of the first protection unit, and the second end of the second overvoltage protection subcircuit is coupled to the ground end. Reducing the surge stress and / or electrostatic stress at the second end of the first protection unit includes: when the voltage at the first end of the second overvoltage protection subcircuit is greater than or equal to a preset second starting voltage, the first end of the second overvoltage protection subcircuit is connected to the second end of the second overvoltage protection subcircuit to reduce the voltage at the second end of the first protection unit.

[0058] The third protection unit may include a second overvoltage protection subcircuit. A first terminal of the second overvoltage protection subcircuit is coupled to a second terminal of the first protection unit, and a second terminal of the second overvoltage protection subcircuit is coupled to a ground terminal.

[0059] The second overvoltage protection subcircuit includes a protection state and a non-protection state. When the second overvoltage protection subcircuit is in the protection state, the first end of the second overvoltage protection subcircuit is connected to the second end of the second overvoltage protection subcircuit, so that the second end of the first protection unit is connected to the ground terminal, thereby pulling down the voltage at the second end of the first protection unit. When the second overvoltage protection subcircuit is in the non-protection state, the first end of the second overvoltage protection subcircuit is disconnected from the second end of the second overvoltage protection subcircuit, so that the second end of the first protection unit is disconnected from the ground terminal GND, so that the signal output from the second end of the first protection unit is smoothly transmitted to the SOC, realizing the signal transmission between the pin of the Type-C port and the SOC.

[0060] Whether the second overvoltage protection subcircuit is in a protection state or a non-protection state may depend on the voltage at the first end of the second overvoltage protection subcircuit. Exemplarily, when the voltage at the first end of the second overvoltage protection subcircuit is greater than or equal to a preset second start-up voltage, the second overvoltage protection subcircuit may be in a protection state; when the voltage at the first end of the second overvoltage protection subcircuit is less than the second start-up voltage, the second overvoltage protection subcircuit may be in a non-protection state.

[0061] In some feasible implementations of the first aspect, the protection circuit further includes a first overvoltage protection subcircuit. A second startup voltage corresponding to the second overvoltage protection subcircuit is smaller than a first startup voltage corresponding to the first overvoltage protection subcircuit.

[0062] The second startup voltage corresponding to the third protection unit is less than the first startup voltage corresponding to the second protection unit. Exemplarily, the second startup voltage corresponding to the third protection unit is less than the clamping voltage corresponding to the second protection unit. Furthermore, the output voltage corresponding to the second end of the third protection unit may be less than or equal to the safety voltage of the SOC.

[0063] In some feasible implementations of the first aspect, the second overvoltage protection subcircuit includes a third transient voltage suppression tube. The first pole of the third transient voltage suppression tube is coupled to the second end of the first protection unit, and the second pole of the third transient voltage suppression tube is coupled to the ground end. The first end of the second overvoltage protection subcircuit is connected to the second end of the second overvoltage protection subcircuit, including: connecting the first pole of the third transient voltage suppression tube to the second pole of the third transient voltage suppression tube.

[0064] The third transient voltage suppressor may be a unidirectional transient voltage suppressor or a bidirectional transient voltage suppressor, which is not limited in the embodiments of the present application.

[0065] When the voltage of the first pole of the third transient voltage suppression tube is greater than or equal to the second starting voltage, the first pole of the third transient voltage suppression tube is connected with the second pole of the third transient voltage suppression tube, so that the second end of the first protection unit is connected with the ground end, thereby pulling down the voltage at the second end of the first protection unit. When the voltage of the first pole of the third transient voltage suppression tube is less than the second starting voltage, the first pole of the third transient voltage suppression tube is disconnected from the second pole of the third transient voltage suppression tube, so that the second end of the first protection unit is disconnected from the ground end, so that the signal output from the second end of the first protection unit is smoothly transmitted to the SOC, realizing the signal transmission between the pin of the Type-C port and the SOC.

[0066] It can be understood that the second starting voltage can be understood as the turn-on voltage of the third transient voltage suppressor. In addition, the third transient voltage suppressor also includes a clamping voltage (also called a limiting voltage), which refers to the maximum voltage that the first pole of the third transient voltage suppressor is allowed to continue to transmit to the SOC after the first pole of the third transient voltage suppressor and the second pole of the third transient voltage suppressor are connected. Among them, the clamping voltage of the third transient voltage suppressor is less than the turn-on voltage of the third transient voltage suppressor.

[0067] In some other examples, the second overvoltage protection subcircuit may also include multiple transient voltage suppression tubes. In the case where the second overvoltage protection subcircuit includes multiple transient voltage suppression tubes, the connection relationship and working principle of the multiple transient voltage suppression tubes can refer to the connection relationship and working principle of the multiple second transient voltage suppression tubes in the transient voltage suppression tube assembly, which will not be repeated here.

[0068] In a second aspect, an electronic device is provided. The electronic device comprises: an external port, a processing chip, and a protection circuit coupled to the external port and the processing chip respectively. The protection circuit is any protection circuit in the first aspect.

[0069] The technical effects of the second aspect can be referred to the technical effects of the first aspect, and will not be repeated here.

[0070] In some feasible implementations of the second aspect, the external port includes a plurality of pins, one of which is coupled to the protection circuit and coupled to the processing chip through the protection circuit.

[0071] In some feasible implementations of the second aspect, the external port includes a plurality of pins, wherein the plurality of pins are respectively coupled to different protection circuits, and each of the pins is coupled to the processing chip using the connected protection circuit.

[0072] Exemplarily, multiple pins (e.g., D+ pin, D- pin, and CC pin) in the Type-C port are each connected to a protection circuit, and are coupled to the processing chip through the connected protection circuits. In another exemplary embodiment, each pin in the Type-C port can be connected to a protection circuit, and is coupled to communicate with the processing chip through the connected protection circuits.

[0073] In some feasible implementations of the second aspect, the external port may include at least one of a universal serial bus (USB) port, a high definition multimedia interface (HDMI), and a network card interface.

[0074] The USB port may be, for example, a Type-C port, a micro USB port, etc. The network card interface may be, for example, an RJ45 (registered jack45), etc.

[0075] In some feasible implementations of the second aspect, the processing chip includes a SOC or a microcontrol unit (MCU).

[0076] In some feasible implementations of the second aspect, the electronic device includes at least one circuit board. The first protection unit and the second protection unit in the protection circuit are located on the same circuit board; or the first protection unit and the second protection unit in the protection circuit are located on different circuit boards.

[0077] In some examples, the above protection circuits are all located on this circuit board. In addition, the pins on the Type-C port and the SOC may also be located on the circuit board. It can be understood that the pins on the Type-C port, the SOC, and the protection circuits respectively connected to the pins and the SOC are all located on the same circuit board.

[0078] In some other examples, the mobile phone may include two circuit boards. The mobile phone may include a first circuit board and a second circuit board. The area of ​​the first circuit board may be smaller than the area of ​​the second circuit board, or may be equal to or larger than the area of ​​the second circuit board, which is not limited in the present application.

[0079] For example, the pins on the Type-C port may be located on a first circuit board, and the above-mentioned protection circuits are all located on a second circuit board.

[0080] For another example, the second protection unit may be located on the first circuit board, and the first protection unit may be located on the second circuit board. In addition, the pins on the Type-C port may be located together with the second protection unit on circuit board 1, and the SOC may be located together with the first protection unit on the second circuit board.

[0081] The mobile phone may further include a flexible printed circuit (FPC). The FPC may connect two circuit boards, for example, the FPC may connect a first circuit board and a second circuit board respectively.

[0082] The FPC may include multiple signal lines, each of which may be coupled to the signal interfaces on two adjacent circuit boards, so that the signal is transmitted outside the two circuit boards, thus realizing signal transmission across the circuit boards. In addition, due to the flexibility of the FPC, the FPC will not limit the layout position of the two connected circuit boards, thus facilitating the space design inside the mobile phone.

[0083] In some feasible implementations of the second aspect, the external port includes a Type-C port, and the Type-C port includes a D+ pin and a D- pin. The electronic device also includes a common-mode inductor, and the common-mode inductor includes a magnetic ring, and a first inductor coil and a second inductor coil respectively wound on the magnetic ring. The first end of the first inductor coil is coupled to the D- pin, and the first end of the second inductor coil is coupled to the D+ pin. The electronic device also includes two protection circuits. In one protection circuit, the first end of the first protection unit is coupled to the second end of the first inductor coil, and the second end of the first protection unit is coupled to the processing chip. In another protection circuit, the first end of the first protection unit is coupled to the second end of the second inductor coil, and the second end of the first protection unit is coupled to the processing chip.

[0084] The first inductor coil, the second inductor coil and the magnetic ring together constitute a common mode inductor. The common mode inductor can filter the common mode electromagnetic interference signal. It can be understood that the first inductor coil can filter the electromagnetic interference signal of the D- pin in the Type-C port; similarly, the second inductor coil can filter the electromagnetic interference signal of the D+ pin in the Type-C port. In this way, the reliability of the signal transmission of the Type-C port can be improved.

[0085] At the same time, protection circuits are provided in the connection circuits between the D+ pin and the D- pin and the SOC respectively, which can also realize the protection of the D+ pin and the D- pin in the Type-C port against EOS, thereby avoiding EOS damage to the SOC and the common-mode inductor. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] Figure 1 A schematic diagram of the structure of a mobile phone provided in some embodiments;

[0087] Figure 2 for Figure 1 A schematic structural diagram of the bottom frame of the mobile phone shown;

[0088] Figure 3 for Figure 2 Schematic diagram of the structure of the Type-C port;

[0089] Figure 4 A schematic diagram of a structure of a protection circuit in a mobile phone provided in an embodiment of the present application;

[0090] Figure 5 for Figure 4 Another structural schematic diagram of the protection circuit shown;

[0091] Figure 6 for Figure 4 Another structural schematic diagram of the protection circuit shown;

[0092] Figure 7 for Figure 4 Another structural schematic diagram of the protection circuit shown;

[0093] Figure 8 A schematic diagram of the structure of another protection circuit in a mobile phone provided in an embodiment of the present application;

[0094] Fig. 9 for Figure 7 Another structural schematic diagram of the protection circuit shown;

[0095] Fig.10 for Figure 8 Another structural schematic diagram of the protection circuit shown;

[0096] Fig.11 for Fig.10 The protection circuit shown is applied to the D+ pin and D- pin of the Type-C port;

[0097] Fig.12 This is a schematic diagram of a structure in which there is no protection circuit between the pins of the Type-C port and the SOC in a mobile phone;

[0098] Fig.13 A schematic diagram of a structure including a second protection unit and excluding a first protection unit between a pin of a Type-C port and a SOC in a mobile phone;

[0099] Fig.14 for Fig.13 A schematic diagram of the structure in which the second protection unit is applied to the D+ pin of the Type-C port;

[0100] Fig.15 A schematic diagram of a structure including a first protection unit and excluding a second protection unit between a pin of a Type-C port and a SOC in a mobile phone;

[0101] Fig.16 A schematic diagram of the layout of a circuit board and a protection circuit in a mobile phone provided in an embodiment of the present application;

[0102] Fig.17 Another schematic diagram of the layout of the circuit board and the protection circuit in the mobile phone provided in the embodiment of the present application. DETAILED DESCRIPTION

[0103] The following will describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments provided by the present application, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present application.

[0104] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, unless otherwise specified, "plurality" means two or more.

[0105] In addition, in the present application, directional terms such as "up", "down", "left" and "right" may be defined including but not limited to the orientation relative to the schematic placement of the components in the drawings. It should be understood that these directional terms may be relative concepts, which are used for relative description and clarification, and may change accordingly according to the change in the orientation of the components in the drawings.

[0106] When describing some embodiments, the expressions "connected", "connected" and their derivatives may be used. For example, when describing some embodiments, the term "connected" may be used to indicate that two or more components are in direct or indirect physical contact with each other. For example, A and B are connected, which may mean that A and B are connected, or that A and B are connected through other components. In addition, the term "coupled" may be a way of achieving electrical connection for signal transmission, and coupling may refer to direct coupling or indirect coupling.

[0107] “At least one of A, B, and C” has the same meaning as “at least one of A, B, or C” and both include the following combinations of A, B, and C: A only, B only, C only, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B, and C.

[0108] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0109] As used herein, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of variation from the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0110] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0111] The embodiments of the present application provide a protection circuit and an electronic device. The electronic devices provided in the embodiments of the present application may include but are not limited to mobile phones, tablet computers, laptop computers, handheld computers, netbooks, personal digital assistants (PDAs), wearable electronic devices, virtual reality devices, electric vehicles and other processing devices that have data processing functions themselves, and the electronic devices may also include but are not limited to data line adapters, docking stations (also known as port replicators), chargers, headphones, speakers, mice, monitors, keyboards and other external devices that can be connected to the external ports of the processing devices.

[0112] The electronic device provided in the embodiments of the present application may include an external port. The external port may be a universal serial bus (USB) port, such as a Type-C port, a micro USB port, etc.; the external port may also be a high definition multimedia interface (HDMI), a network card interface (such as a registered jack45, referred to as RJ45, etc.), etc., and the embodiments of the present application are not limited to this.

[0113] For ease of understanding, the following description will be made by taking a mobile phone as an electronic device and the mobile phone including a Type-C port as an example, but this should not be used as a limitation on electronic devices and external ports.

[0114] Figure 1 A schematic diagram of the structure of a mobile phone is shown; Figure 2 Shows Figure 1 A schematic structural diagram of the bottom frame of the mobile phone shown; Figure 3 Shows Figure 2 Schematic diagram of the structure of the Type-C port.

[0115] like Figure 1 As shown, the mobile phone 100 may include two long frames 10 extending along a first direction X, and two short frames 20 extending along a second direction Y. The two long frames 10 and the two short frames 20 are alternately connected end to end to form a rectangular closed shape. Among them, the two short frames 20 can be the top frame 21 and the bottom frame 22 of the mobile phone, and the two long frames can be the left frame and the right frame of the mobile phone. Exemplarily, an arc corner can be formed between the long frame 10 and the short frame 20, so that the plane shape of the mobile phone can be a rounded rectangle.

[0116] The mobile phone 100 may include a plurality of buttons. For example, the mobile phone 100 may include a lock screen button 31, a volume + button 32, a volume - button 33, etc. The volume + button 32 and the volume - button 33 may be located on the same long frame 10; the lock screen button 31 may be located on the same long frame 10 as the volume + button 32, or may be located on a different long frame 10 from the volume + button 32. In addition, the lock screen button 31 may also be located on the short frame 20.

[0117] The mobile phone 100 may also include a plurality of openings. Figure 2 As shown, the openings on the bottom frame 22 may include a microphone opening 41, a speaker opening 42, and an external port. The microphone inside the mobile phone is connected to the external environment of the mobile phone through the microphone opening 41 to collect the sound of the external environment of the mobile phone. The sound outlet hole of the speaker module inside the mobile phone is connected to the speaker opening 42 to play the sound to the external environment of the mobile phone.

[0118] The mobile phone may further include a processing chip, which may be a system on chip (SOC), a micro control unit (MCU), or other suitable chips with data processing functions, which are not limited in this application.

[0119] The external port of the mobile phone may include a Type-C port, a micro (micro) USB or other suitable external port. The pins in the external port may be coupled to the processing chip through the internal signal line of the mobile phone to achieve functions such as fast charging and data exchange. For ease of understanding, the following description will be made by taking the example that the external port includes a Type-C port and the processing chip is a SOC, but this should not be used as a limitation on the external port and the processing chip.

[0120] like Figure 2 As shown, the Type-C port 43 can be located at the short frame 20 at the bottom of the mobile phone. In some other examples, the Type-C port can also be located at the short frame at the top of the mobile phone, or the long frame on the left or right. In addition, the number of Type-C ports can be one or more.

[0121] The Type-C port is oval in shape and symmetrical in the direction parallel to the short frame of the phone. In this way, the Type-C plug can be inserted into the Type-C port either frontally or backwards.

[0122] like Figure 3As shown, both the A side and the B side of the Type-C port include 12 pins. Exemplarily, the Type-C interface includes at least two symmetrically arranged VBUS pins (used to provide USB voltage, pins 4 and 9), a channel configuration (CC) pin (used to detect the direction of the connector and determine the type of the external device, pin 5, where the A side is marked as CC1 and the B side is marked as CC2), a D+ pin (pin 6), a D- pin (pin 7), an SBU pin (pin 8 is a spare pin, where the A side is marked as SBU1 and the B side is marked as SBU2), a TX+ pin (pin 2, where the A side is marked as TX1+ and the B side is marked as TX2+), a TX- pin (pin 3, where the A side is marked as TX1- and the B side is marked as TX2-), a RX+ (pin 11, where the A side is marked as RX2+ and the B side is marked as RX1+), a RX- (pin 10, where the A side is marked as RX2- and the B side is marked as RX1-), and a GND (used to provide a ground signal, pins 1 and 12).

[0123] The protection circuit provided in the embodiments of the present application can be connected to the pins in the Type-C port. Exemplarily, a pin (e.g., D+ pin) in the Type-C port is connected to a protection circuit. Exemplarily, multiple pins (e.g., D+ pin, D- pin, and CC pin) in the Type-C port are each connected to a protection circuit. Exemplarily, each pin in the Type-C port is connected to a protection circuit.

[0124] The structure of the protection circuit connected to each pin in the Type-C port is basically the same, so the following description will take one pin in the Type-C port connected to a protection circuit as an example. The structure of the protection circuit connected to other pins in the Type-C port can also refer to the subsequent description.

[0125] Figure 4 The figure shows a schematic diagram of the structure of a protection circuit in a mobile phone.

[0126] like Figure 4 As shown, the protection circuit 200 may include a first protection unit 210 and a second protection unit 220. The first protection unit 210 may be coupled to a pin of the Type-C port, and the first protection unit 210 may be coupled to the SOC in the mobile phone. It can be understood that the first end of the first protection unit 210 serves as the input end of the protection circuit 200, and the second end of the first protection unit 210 serves as the output end of the protection circuit 200.

[0127] The first end of the second protection unit 220 is coupled to the first end of the first protection unit 210, and the second end of the second protection unit 220 is coupled to the ground terminal GND. It can be understood that the second protection unit 220 is connected in series between the first end of the first protection unit 210 and the ground terminal GND.

[0128] Since the Type-C port of the mobile phone is exposed, it is easy for the Type-C port to introduce EOS from the environment, thereby causing damage to the Type-C port, causing at least some of the functions of the Type-C port to be lost. For example, if the Type-C port is used as a charging port with a fast charging function, if the Type-C port is damaged by EOS, the Type-C port will lose its fast charging function as a charging port. For example, if the Type-C port is used as a data transmission port, if the Type-C port is damaged by EOS, the Type-C port will lose its data transmission function as a data transmission port.

[0129] EOS mainly includes electrostatic stress, surge stress and DC stress. Among them, the electrostatic stress of the Type-C port is mainly due to the stress caused by factors such as friction electrification in the environment. The voltage value corresponding to the electrostatic stress is very large and can reach several thousand volts. The surge stress of the Type-C port is the stress caused by the plugging and unplugging of the Type-C plug at the Type-C port. The voltage value corresponding to the surge stress can be more than ten volts to several tens of volts. DC stress is mainly caused by the external conductor (such as liquid infiltrating the Type-C port) forming a path between different pins in the Type-C port, resulting in a large DC voltage on the pins. The voltage value corresponding to the DC stress can be more than ten volts to several tens of volts.

[0130] Among them, electrostatic stress occurs for a shorter time, which is nanosecond level stress; surge stress occurs for a slightly longer time, which is microsecond level stress; and DC stress occurs for the longest time, which is millisecond to second level stress.

[0131] In the embodiments of the present application, when at least one of the above-mentioned electrostatic stress, surge stress and DC stress occurs to the pins of the Type-C port, EOS can avoid damage to the SOC by EOS after being protected by the second protection unit and the first protection unit in sequence.

[0132] like Figure 4As shown, the second protection unit 220 is coupled to the first end a1 of the first protection unit 210. It can be understood that the signal of the pin in the Type-C port first passes through the protection of the second protection unit 220, then passes through the protection of the first protection unit 210, and finally flows from the second end a2 of the first protection unit 210 to the mobile phone chip, thereby completing a signal transmission from the pin in the Type-C port to the SOC.

[0133] The type of stress protection performed by the first protection unit 210 may be different from the type of stress protection performed by the second protection unit 220 .

[0134] The first protection unit 210 may be configured to isolate the SOC from the DC stress and / or surge stress on the pins of the Type-C port. Exemplarily, the first protection unit 210 isolates the SOC from the DC stress on the pins of the Type-C port. Exemplarily, the first protection unit isolates the SOC from the surge stress on the pins of the Type-C port. Exemplarily, the first protection unit isolates the SOC from the DC stress and surge stress on the pins of the Type-C port. Exemplarily, the first protection unit isolates the SOC from the DC stress and surge stress on the pins of the Type-C port.

[0135] The second protection unit 220 may be configured to reduce the electrostatic stress and / or surge stress of the first end a1 of the first protection unit 210. Exemplarily, the second protection unit 220 may reduce the electrostatic stress of the first end a1 of the first protection unit 210. Again exemplarily, the second protection unit 220 may reduce the surge stress of the first end a1 of the first protection unit 210. Again exemplarily, the second protection unit 220 may reduce the electrostatic stress and surge stress of the first end a1 of the first protection unit 210.

[0136] It can be understood that after EOS appears on the pin of the Type-C port, the second protection unit 220 will first protect the electrostatic stress and / or surge stress of the first end a1 of the first protection unit 210, and then the first protection unit 210 will protect the DC stress and / or surge stress in the EOS, so that after being protected by the first protection unit 210 and the second protection unit 220, the EOS appearing on the pin of the Type-C port will not cause damage to the SOC.

[0137] In some embodiments, Figure 5 As shown, the first protection unit 210 may include a switch subcircuit 211. The first end of the switch subcircuit 211 is coupled to the pin of the Type-C port, and the second end of the switch subcircuit 211 is coupled to the SOC. It can be understood that the first end of the switch subcircuit 211 is equivalent to the first end a1 of the first protection unit 210, and the second end of the switch subcircuit 211 is equivalent to the second end a2 of the first protection unit 210.

[0138] The switch subcircuit 211 can disconnect the connection between the pin of the Type-C port and the SOC when there is DC stress and / or surge stress on the pin of the Type-C port, isolate the DC stress and / or surge stress from the SOC, and implement EOS protection to prevent EOS from damaging the SOC. When there is no DC stress and / or surge stress on the pin of the Type-C port, the connection between the pin of the Type-C port and the SOC is turned on to complete the signal transmission from the pin of the Type-C port to the SOC.

[0139] In some examples, the switch subcircuit 211 can detect by itself whether there is DC stress and / or surge stress on the pin of the Type-C port. Exemplarily, the voltage value corresponding to the DC stress and / or surge stress is large, so the switch subcircuit 211 can determine whether there is DC stress and / or surge stress on the pin of the Type-C port by detecting the voltage at the first end of the switch subcircuit 211.

[0140] When detecting that the voltage at the first end a1 of the switch subcircuit 211 is greater than or equal to a preset threshold, the switch subcircuit 211 determines that there is a DC stress and / or surge stress at the voltage at the first end a1 of the switch subcircuit 211, and disconnects the first end of the switch subcircuit 211 from the second end a2 of the switch subcircuit 211, thereby disconnecting the connection between the pin of the Type-C port and the SOC, isolating the DC stress and / or surge stress from the SOC, and protecting against EOS, thereby preventing EOS from damaging the SOC.

[0141] When detecting that the voltage at the first end a1 of the switch subcircuit 211 is less than a preset threshold, the switch subcircuit 211 determines that there is no DC stress and / or surge stress at the voltage at the first end a1 of the switch subcircuit 211, and maintains conduction between the first end a1 of the switch subcircuit 211 and the second end a2 of the switch subcircuit 211, thereby conducting the connection between the pin of the Type-C port and the SOC, and completing the signal transmission from the pin of the Type-C port to the SOC.

[0142] In other examples, the switch subcircuit 211 can receive control from other units to disconnect the connection between the pin of the Type-C port and the SOC when the switch subcircuit 211 is subject to DC stress and / or surge stress on the pin of the Type-C port, and to connect the connection between the pin of the Type-C port and the SOC when the pin of the Type-C port is not subject to DC stress and / or surge stress.

[0143] For example, Figure 6As shown, the protection circuit 200 may further include a control unit 230. The control unit 230 is coupled to the control terminal a3 of the switch sub-circuit 211. The control unit 230 is configured to provide a control voltage to the control terminal a3 of the switch sub-circuit 211.

[0144] For example, the control unit 230 can detect whether there is DC stress and / or surge stress on the pins of the Type-C port. When there is no DC stress and / or surge stress on the pins of the Type-C port, the control unit 230 can output a first control voltage; when there is DC stress and / or surge stress on the pins of the Type-C port, the control unit 230 can output a second control voltage.

[0145] When the control terminal a3 of the switch subcircuit 211 receives the first control voltage, the first terminal a1 of the switch subcircuit 211 and the second terminal a2 of the switch subcircuit 211 are maintained conductive, thereby conductively connecting the pin of the Type-C port and the SOC, and completing the signal transmission from the pin of the Type-C port to the SOC.

[0146] When the control terminal a3 of the switch sub-circuit 211 receives the second control voltage, the connection between the first terminal a1 of the switch sub-circuit 211 and the second terminal a2 of the switch sub-circuit 211 is disconnected, thereby disconnecting the connection between the pin of the Type-C port and the SOC, isolating the DC stress and / or surge stress from the SOC, and protecting against EOS, thereby preventing EOS from damaging the SOC.

[0147] like Figure 6 As shown, the switch subcircuit 211 includes a transistor T. The first electrode of the transistor T is coupled to the pin of the Type-C port, the second electrode of the transistor T is coupled to the SOC, and the control electrode of the transistor T is coupled to the control unit 230. It can be understood that the first electrode of the transistor T is equivalent to the first terminal a1 of the switch subcircuit 211, the second electrode of the transistor T is equivalent to the second terminal a2 of the switch subcircuit 211, and the control electrode of the transistor T is equivalent to the control terminal a3 of the switch subcircuit 211.

[0148] The transistor T can be a P-channel transistor or an N-channel transistor. The transistor T is an N-channel transistor as an example for explanation. In the case where there is no DC stress and / or surge stress on the pin of the Type-C port, the control unit 230 can output a high voltage signal (first control voltage), and the control terminal a3 of the switch subcircuit 211 receives the high voltage signal, maintaining the conduction between the first terminal a1 of the switch subcircuit 211 and the second terminal a2 of the switch subcircuit 211, thereby conducting the connection between the pin of the Type-C port and the SOC, and completing the signal transmission from the pin of the Type-C port to the SOC. When DC stress and / or surge stress exists on the pin of the Type-C port, the control unit 230 can output a low voltage signal (second control voltage), and the control terminal a3 of the switch subcircuit 211 receives the low voltage signal, disconnecting the connection between the first terminal a1 of the switch subcircuit 211 and the second terminal a2 of the switch subcircuit 211, thereby disconnecting the connection between the pin of the Type-C port and the SOC, isolating the DC stress and / or surge stress from the SOC, and realizing protection against EOS, thereby preventing EOS from damaging the SOC.

[0149] In other examples, the control unit 230 may provide a constant control voltage to the control terminal a3 of the switch subcircuit 211. For example, the voltage value of the control voltage may be 5V, 6V, 8V, 10V, etc., which is not limited in this application. The transistor T conducts or disconnects the connection between the pin of the Type-C port and the SOC based on the voltage difference between the voltage of the control electrode of the transistor T and the voltage value of the second electrode of the transistor T.

[0150] When there is no DC stress and / or surge stress on the pin of the Type-C port, the voltage difference between the voltage of the control electrode of transistor T and the voltage value of the second electrode of transistor T is greater than zero, and transistor T turns on the connection between the first electrode of transistor T and the second electrode of transistor T, thereby turning on the connection between the pin of the Type-C port and the SOC, completing the signal transmission from the pin of the Type-C port to the SOC.

[0151] In the case where DC stress and / or surge stress exists on the pin of the Type-C port, the voltage of the DC stress and / or surge stress is transmitted to the second electrode of the transistor T, so that the voltage of the second electrode of the transistor T is pulled up, and the voltage difference between the voltage of the control electrode of the transistor T and the voltage value of the second electrode of the transistor T is less than zero, and the transistor T cuts off the connection between the first electrode of the transistor T and the second electrode of the transistor T, thereby disconnecting the connection between the pin of the Type-C port and the SOC, isolating the DC stress and / or surge stress from the SOC, realizing protection against EOS, and preventing EOS from damaging the SOC.

[0152] In some other embodiments, the first protection unit 210 may also include a capacitor. One plate of the capacitor may be coupled to the pin, and the other plate of the capacitor may be coupled to the mobile phone chip. The capacitor can allow AC signals to pass through, and the capacitor can block the transmission of DC stress. That is, the AC signal on the pin can pass through the capacitor and be transmitted to the mobile phone chip, and the DC stress on the pin is blocked by the capacitor and cannot be transmitted to the mobile phone chip.

[0153] In some other embodiments, the first protection unit 210 may also include a switch (e.g., a high-speed switch). The first contact of the switch is used to couple a pin of the Type-C port, and the second contact of the switch is used to couple a mobile phone chip, and the first contact is connected or disconnected with the second contact. The DC stress and / or surge stress of the first end a1 of the first protection unit 210 is isolated from the second end a2 of the first protection unit 210, including: when the voltage of the first contact is greater than or equal to a preset threshold, the first contact is disconnected from the second contact, which is equivalent to disconnecting the connection between the pin of the Type-C port and the SOC, thereby isolating the DC stress and / or surge stress from the SOC, realizing protection against EOS, and preventing EOS from damaging the SOC.

[0154] Of course, the first protection unit 210 may also be other circuit structures that can isolate the mobile phone chip from the DC stress on the pins, and the embodiments of the present application are not limited to this.

[0155] In some embodiments, Figure 5 As shown, the second protection unit 220 may include a first overvoltage protection subcircuit 221. The first end of the first overvoltage protection subcircuit 221 is coupled to the first end a1 of the first protection unit 210, and the second end of the first overvoltage protection subcircuit 221 is coupled to the ground end GND. It can be understood that the first end of the first overvoltage protection subcircuit 221 is equivalent to the first end b1 of the second protection unit 220, and the second end of the first overvoltage protection subcircuit 221 is equivalent to the second end b2 of the second protection unit 220.

[0156] The first overvoltage protection subcircuit 221 includes a protection state and a non-protection state. When the first overvoltage protection subcircuit 221 is in the protection state, the first end b1 of the first overvoltage protection subcircuit 221 and the second end b2 of the first overvoltage protection subcircuit 221 are connected, so that the first end a1 of the first protection unit 210 is connected to the ground terminal GND, thereby pulling down the voltage at the first end a1 of the first protection unit 210. When the first overvoltage protection subcircuit 221 is in the non-protection state, the first end b1 of the first overvoltage protection subcircuit 221 and the second end b2 of the first overvoltage protection subcircuit 221 are disconnected, so that the first end a1 of the first protection unit 210 is disconnected from the ground terminal GND, so that the signal of the pin of the Type-C port is smoothly transmitted to the first protection unit 210.

[0157] Whether the first overvoltage protection subcircuit 221 is in a protection state or a non-protection state may depend on the voltage of the first terminal b1 of the first overvoltage protection subcircuit 221. Exemplarily, when the voltage of the first terminal b1 of the first overvoltage protection subcircuit 221 is greater than or equal to a preset first start-up voltage, the first overvoltage protection subcircuit 221 may be in a protection state; when the voltage of the first terminal b1 of the first overvoltage protection subcircuit 221 is less than the first start-up voltage, the first overvoltage protection subcircuit 221 may be in a non-protection state.

[0158] like Figure 6 As shown, the first overvoltage protection subcircuit 221 may include a first transient voltage suppressor tube TVS1. The first pole of the first transient voltage suppressor tube TVS1 is coupled to the first end a1 of the first protection unit 210, and the second pole of the first transient voltage suppressor tube TVS1 is coupled to the ground end GND. It can be understood that the first pole of the first transient voltage suppressor tube TVS1 is equivalent to the first end b1 of the first overvoltage protection subcircuit 221, and the second pole of the first transient voltage suppressor tube TVS1 is equivalent to the second end b2 of the first overvoltage protection subcircuit 221.

[0159] The first transient voltage suppressor TVS1 may be a unidirectional transient voltage suppressor or a bidirectional transient voltage suppressor, which is not limited in the embodiments of the present application.

[0160] When the voltage of the first pole of the first transient voltage suppressor TVS1 is greater than or equal to the preset first starting voltage, the first pole of the first transient voltage suppressor TVS1 and the second pole of the first transient voltage suppressor TVS1 are connected, so that the first end a1 of the first protection unit 210 and the ground end GND are connected, thereby pulling down the voltage at the first end a1 of the first protection unit 210.

[0161] When the voltage of the first pole of the first transient voltage suppressor TVS1 is less than the preset first starting voltage, the first pole of the first transient voltage suppressor TVS1 is disconnected from the second pole of the first transient voltage suppressor TVS1, so that the first end a1 of the first protection unit 210 is disconnected from the ground end GND, so that the signal of the pin of the Type-C port is smoothly transmitted to the first protection unit 210.

[0162] It can be understood that the first starting voltage can be understood as the turn-on voltage of the first transient voltage suppressor TVS1. In addition, the first transient voltage suppressor TVS1 also includes a clamping voltage (also called a limiting voltage), which refers to the maximum voltage that the first pole of the first transient voltage suppressor TVS1 allows to continue to transmit to the first end a1 of the first protection unit 210 after the first pole of the first transient voltage suppressor TVS1 and the second pole of the first transient voltage suppressor TVS1 are connected. Among them, the clamping voltage of the first transient voltage suppressor TVS1 is less than the turn-on voltage of the first transient voltage suppressor TVS1.

[0163] In some cases, the first startup voltage is greater than the turn-on voltage of a single transient voltage suppressor. Figure 7 As shown, the first overvoltage protection subcircuit 221 may include a transient voltage suppression tube assembly U-TVS. The first end of the transient voltage suppression tube assembly U-TVS is coupled to the first end a1 of the first protection unit 210, and the second end of the transient voltage suppression tube assembly U-TVS is coupled to the ground terminal GND. It can be understood that the first end of the transient voltage suppression tube assembly U-TVS is equivalent to the first end b1 of the first overvoltage protection subcircuit 221, and the second end of the transient voltage suppression tube assembly U-TVS is equivalent to the second end b2 of the first overvoltage protection subcircuit 221.

[0164] The transient voltage suppressor tube assembly U-TVS may include a plurality of second transient voltage suppressor tubes TVS2 connected in series. The first pole of the first second transient voltage suppressor tube TVS2 among the plurality of second transient voltage suppressor tubes TVS2 is coupled to the first end a1 of the first protection unit 210, the first pole of the second second transient voltage suppressor tube TVS2 is coupled to the second pole of the first second transient voltage suppressor tube TVS2... and so on, until the second pole of the last second transient voltage suppressor tube TVS2 is coupled to the ground terminal GND.

[0165] Multiple second transient voltage suppressor tubes TVS2 are connected in series, so the current passing through each second transient voltage suppressor tube TVS2 is the same. By connecting multiple second transient voltage suppressor tubes TVS2 in series, the sum of the turn-on voltages of each second transient voltage suppressor tube TVS2 can be used as the turn-on voltage of the entire transient voltage suppressor tube assembly U-TVS. Therefore, when a single transient voltage suppressor tube is lower than the first start-up voltage, the turn-on voltage of the transient voltage suppressor tube assembly U-TVS can be equal to the first start-up voltage by connecting multiple transient voltage suppressors in series, thereby achieving the function of overvoltage protection.

[0166] For example, Figure 7 As shown, the transient voltage suppression tube assembly U-TVS may include two second transient voltage suppression tubes TVS2. Of course, in some other examples, the transient voltage suppression tube assembly U-TVS may also include more second transient voltage suppression tubes TVS2.

[0167] In some embodiments, the first startup voltage may be greater than the voltage corresponding to the DC stress. It is understandable that when the pin of the Type-C port has DC stress, since the voltage corresponding to the DC stress is less than the first startup voltage, the second protection unit 220 is not started, and the DC stress is directly transmitted to the first protection unit 210.

[0168] It has been explained before that the duration of occurrence of DC stress is much longer than that of occurrence of electrostatic stress, and the second protection unit 220 can protect against electrostatic stress with a large voltage but a short duration, but may not be able to withstand DC stress with a long duration, so DC stress will damage the second protection unit 220. Therefore, in this embodiment, by designing the first starting voltage to be greater than the voltage corresponding to the DC stress, it is possible to avoid DC stress from starting the second protection unit 220, thereby avoiding DC stress from damaging the second protection unit 220, thereby improving the reliability of the second protection unit 220 and the reliability of the protection circuit 200.

[0169] In some other embodiments, the second protection unit 220 may also include a varistor. One end of the varistor may be coupled to the first end of the first protection unit 210, and the other end of the varistor may be coupled to the ground terminal GND.

[0170] By utilizing the nonlinear characteristics of the varistor, when excessive electrostatic stress and / or surge stress appears on the pin, the varistor can clamp the voltage to a relatively fixed and lower voltage value, thereby reducing the electrostatic stress and / or surge stress at the first end of the first protection unit 210.

[0171] Of course, the second protection unit 220 can also be other circuit structures that can reduce electrostatic stress and / or surge stress, such as a buck circuit that can step down the voltage corresponding to electrostatic stress and / or surge stress, etc. The embodiments of the present application are not limited to this.

[0172] Figure 8 A schematic diagram of the structure of another protection circuit in a mobile phone is shown.

[0173] like Figure 8 As shown, the protection circuit 200 may further include a third protection unit 240. A first terminal c1 of the third protection unit 240 is coupled to a second terminal a2 of the first protection unit 210, and a second terminal c2 of the third protection unit 240 is coupled to a ground terminal GND.

[0174] In some embodiments, in order to prevent DC stress from damaging the second protection unit 220, the startup voltage of the second protection unit 220 is increased, which will cause the clamping voltage of the second protection unit 220 to also increase, resulting in the clamping voltage of the second protection unit 220 being higher than the safety voltage of the SOC.

[0175] Therefore, the third protection unit 240 can further protect the surge stress and / or electrostatic stress protected by the second protection unit 220 to ensure that the surge stress and / or electrostatic stress protected by the third protection unit 240 is less than or equal to the safety voltage of the SOC, thereby improving the protection performance of the protection circuit 200 to the SOC.

[0176] In other embodiments, even if the clamping voltage of the second protection unit 220 is less than or equal to the safety voltage of the SOC, the third protection unit 240 can further improve the performance of the protection circuit 200 in protecting against surge stress and / or electrostatic stress.

[0177] When there is no surge stress and / or electrostatic stress on the pin of the Type-C port, or when there is surge stress and / or electrostatic stress on the pin of the Type-C port and the second protection unit 220 reduces the voltage of the surge stress and / or electrostatic stress to less than the preset second starting voltage, the voltage of the first end c1 of the third protection unit 240 is less than the preset second starting voltage, the first end c1 of the third protection unit 240 and the second end c2 of the third protection unit 240 are disconnected, so that the second end a2 of the first protection unit 210 is disconnected from the ground terminal GND, so that the signal output from the second end a2 of the first protection unit 210 is smoothly transmitted to the SOC and provided to the SOC.

[0178] In the case where surge stress and / or electrostatic stress exists on the pin of the Type-C port and the second protection unit 220 reduces the voltage of the surge stress and / or electrostatic stress but is still greater than or equal to the second startup voltage, the voltage of the first end c1 of the third protection unit 240 is greater than or equal to the second startup voltage, and the first end c1 of the third protection unit 240 and the second end c2 of the third protection unit 240 are conductively connected, so that the second end a2 of the first protection unit 210 is conductively connected to the ground terminal GND, thereby pulling down the voltage of the second end a2 of the first protection unit 210, so as to ensure that the surge stress and / or electrostatic stress protected by the third protection unit 240 is less than or equal to the safety voltage of the SOC, thereby improving the protection performance of the protection circuit for the SOC.

[0179] It should be clear that the second startup voltage corresponding to the third protection unit 240 is less than the first startup voltage corresponding to the second protection unit 220. Exemplarily, the second startup voltage corresponding to the third protection unit 240 is less than the clamping voltage corresponding to the second protection unit 220. In addition, the output voltage corresponding to the second terminal c2 of the third protection unit 240 may be less than or equal to the safety voltage of the SOC.

[0180] like Fig. 9 As shown, the third protection unit 240 may include a second overvoltage protection subcircuit 241. The connection relationship between the second overvoltage protection subcircuit 241 and the third protection unit 240 may refer to the connection relationship between the first overvoltage protection subcircuit 221 and the second protection unit 220; similarly, the working process of the second overvoltage protection subcircuit 241 may refer to the working process of the first overvoltage protection subcircuit 221; this application will not repeat this.

[0181] like Fig.10 As shown, the second overvoltage protection subcircuit 241 may include a third transient voltage suppressor tube TVS3. The connection relationship between the third transient voltage suppressor tube TVS3 and the second overvoltage protection subcircuit 241 can refer to the connection relationship between the third transient voltage suppressor tube TVS3 and the second overvoltage protection subcircuit 241; similarly, the working process of the third transient voltage suppressor tube TVS3 can refer to the working process of the first transient voltage suppressor tube TVS1; this application will not repeat it in detail.

[0182] In some other examples, the second overvoltage protection subcircuit 241 may also include multiple transient voltage suppression tubes. In the case where the second overvoltage protection subcircuit 241 includes multiple transient voltage suppression tubes, the connection relationship and working principle of the multiple transient voltage suppression tubes can refer to the connection relationship and working principle of the multiple second transient voltage suppression tubes TVS2 in the transient voltage suppression tube assembly U-TVS, which will not be repeated here.

[0183] Fig.11 Shows Fig.10The protection circuit shown is applied to the D+ pin and D- pin of the Type-C port.

[0184] In some examples, the protection circuit 200 is coupled to the D+ pin and the D- pin in the Type-C port. Fig.11 As shown, an inductor L1 may be included between the D-pin and the protection circuit 200a, and an inductor L2 may be included between the D+pin and the protection circuit 200b. The first end d1 of the inductor L1 is coupled to the D-pin, and the second end d2 of the inductor L1 is coupled to the first end b1 of the second protection unit 220 in the protection circuit 200a. The first end d3 of the inductor L2 is coupled to the D+pin, and the second end d4 of the inductor L2 is coupled to the first end b1 of the second protection unit 220 in the protection circuit 200b.

[0185] Among them, the ring between the inductor L1 and the inductor L2 represents the magnetic ring shared by the inductor L1 and the inductor L2. The inductor L1, the inductor L2 and the magnetic ring together constitute the common mode inductor DL. The common mode inductor DL ​​can filter the common mode electromagnetic interference signal. It can be understood that the inductor L1 can filter the electromagnetic interference signal of the D- pin in the Type-C port; similarly, the inductor L2 can filter the electromagnetic interference signal of the D+ pin in the Type-C port. In this way, the reliability of the signal transmission of the Type-C port can be improved.

[0186] Fig.12 A schematic diagram showing a structure in which there is no protection circuit between the pin of the Type-C port and the SOC in a mobile phone; Fig.13 A schematic diagram of a structure including a second protection unit but not including a first protection unit between a pin of a Type-C port and a SOC in a mobile phone is shown; Fig.14 for Fig.13 Schematic diagram of the structure of the D+ pin of the Type-C port in the circuit application; Fig.15 A schematic diagram of a structure including a first protection unit but not including a second protection unit between a pin of a Type-C port in a mobile phone and a SOC is shown.

[0187] The following is a comparison of the protection effects of various circuits between a pin of the Type-C port in a mobile phone and the SOC.

[0188] Fig.12 One pin of the Type-C port is directly coupled to the SOC, without the first protection unit or the second protection unit. In this way, electrostatic stress, surge stress and DC stress can be directly transmitted from the pin to the SOC, causing damage to the SOC.

[0189] Fig.13One pin of the Type-C port is directly coupled to the SOC, where Fig.13 The second protection unit 220 is also included, and the first protection unit 210 is not included.

[0190] When the turn-on voltage of the second protection unit 220 is greater than the voltage corresponding to the DC stress (less than the voltage corresponding to the surge stress and the voltage corresponding to the electrostatic stress), the surge stress and / or DC stress can turn on the second protection unit 220, and the second protection unit 220 can conduct the surge stress and / or electrostatic stress to the ground terminal GND, thereby pulling down the voltage corresponding to the surge stress and / or electrostatic stress, thereby realizing protection against surge stress and / or electrostatic stress on the pins of the Type-C port, and preventing surge stress and / or electrostatic stress from damaging the SOC.

[0191] However, the DC stress does not activate the second protection unit 220 , and the DC stress may be directly transmitted from the pins of the Type-C port to the SOC, causing damage to the SOC.

[0192] When the start-up voltage of the second protection unit 220 is less than the voltage corresponding to the DC stress (less than the voltage corresponding to the surge stress and the voltage corresponding to the electrostatic stress), the DC stress can start the second protection unit 220, but the second protection unit 220 cannot withstand the DC stress for a long time and is damaged. The DC stress can still be directly transmitted from the pin of the Type-C port to the SOC, causing damage to the SOC. And because the second protection unit 220 is damaged, the subsequent second protection unit 220 can no longer continue to protect the pin of the Type-C port from surge stress and / or electrostatic stress.

[0193] In some examples, the protection circuit 200 is coupled to the D+ pin in the Type-C port. Fig.14 As shown, an inductor L2 may be further included between the D+ pin and the protection circuit 200 . A first end d3 of the inductor L2 is coupled to the D+ pin, and a second end d4 of the inductor L2 is coupled to a first end b1 of the second protection unit 220 .

[0194] When the start-up voltage of the second protection unit 220 is lower than the voltage corresponding to the DC stress (also lower than the voltage corresponding to the surge stress and / or the electrostatic stress), the DC stress can activate the second protection unit 220, wherein one of the inductor L2 and the second protection unit 220 may be damaged due to being unable to withstand the DC stress for a long time.

[0195] If the inductor coil L2 is damaged due to DC stress, it will cause a short circuit between the D+ pin and the SOC. Subsequently, the Type-C port may lose its fast charging, data transmission and other functions, affecting the normal use of the Type-C port.

[0196] If the second protection unit 220 is damaged due to DC stress, the second protection unit 220 may no longer be able to protect the pins of the Type-C port from surge stress and / or electrostatic stress.

[0197] Fig.15 One pin of the Type-C port is directly coupled to the SOC, where Fig.15 A first protection unit is also included and a second protection unit is not included.

[0198] In the case of DC stress on the pins of the Type-C port, the first protection unit 210 can cut off the connection between the pins of the Type-C port and the SOC, thereby protecting the pins of the Type-C port from DC stress. Similarly, in the case of surge stress on the pins of the Type-C port, the first protection unit 210 can also cut off the connection between the pins of the Type-C port and the SOC, thereby protecting the pins of the Type-C port from surge stress.

[0199] However, when electrostatic stress occurs on the pins of the Type-C port, since the electrostatic stress occurs for a very short time and the voltage corresponding to the electrostatic stress is very high, the electrostatic stress can be directly transmitted from the pins of the Type-C port to the SOC, causing damage to the SOC.

[0200] Figure 4 The mobile phone includes both a first protection unit and a second protection unit.

[0201] When the start-up voltage of the second protection unit 220 is less than the voltage corresponding to the DC stress (less than the voltage corresponding to the surge stress and / or electrostatic stress), the DC stress can start the second protection unit 220, but the second protection unit 220 cannot withstand the DC stress for a long time and is damaged. The first protection unit 210 can cut off the connection between the pins of the Type-C port and the SOC, thereby realizing the protection of the DC stress on the pins of the Type-C port. However, since the DC stress causes damage to the second protection unit 220, the subsequent second protection unit 220 can no longer continue to protect the pins of the Type-C port from surge stress and / or electrostatic stress.

[0202] When the start-up voltage of the second protection unit 220 is greater than the voltage corresponding to the DC stress (less than the voltage corresponding to the electrostatic stress), the DC stress does not start the second protection unit 220. The first protection unit 210 can cut off the connection between the pin of the Type-C port and the SOC, thereby realizing the protection of the pin of the Type-C port from DC stress. Similarly, when the start-up voltage of the second protection unit 220 is greater than the voltage corresponding to the surge stress, the first protection unit 210 can also cut off the connection between the pin of the Type-C port and the SOC, and can also realize the protection of the pin of the Type-C port from surge stress.

[0203] Furthermore, the second protection unit 220 can conduct the electrostatic stress with the ground terminal GND, thereby pulling down the voltage corresponding to the electrostatic stress of the first end a1 of the first protection unit 210, thereby protecting the pins of the Type-C port from electrostatic stress. Similarly, when the start-up voltage of the second protection unit 220 is less than the voltage corresponding to the surge stress, the second protection unit 220 can conduct the surge stress with the ground terminal GND, thereby pulling down the voltage corresponding to the surge stress of the first end a1 of the first protection unit 210, thereby protecting the pins of the Type-C port from surge stress.

[0204] However, since the turn-on voltage of the second protection unit 220 is relatively large, the clamping voltage corresponding to the second protection unit 220 may also be relatively large and exceed the safety voltage of the SOC. In this way, the voltage corresponding to the surge stress and / or electrostatic stress after protection by the second protection unit 220 may be greater than the safety voltage of the SOC, thereby causing damage to the SOC.

[0205] Figure 8 The first protection unit, the second protection unit and the third protection unit are also included.

[0206] The opening voltage of the second protection unit 220 is greater than the voltage corresponding to the DC stress, and the clamping voltage of the second protection unit 220 is greater than the safety voltage of the SOC. The opening voltage of the third protection unit 240 is less than the opening voltage of the second protection unit 220 and less than the clamping voltage of the second protection unit 220, and the clamping voltage of the third protection unit 240 is less than or equal to the safety voltage of the SOC.

[0207] When electrostatic stress appears on the pin of the Type-C port, the second protection unit 220 can be activated, so that the second protection unit 220 pulls down the voltage corresponding to the electrostatic stress of the first end a1 of the first protection unit 210 (the voltage is greater than the safety voltage of the SOC). After that, the electrostatic stress after the pull-down is transmitted to the second end a2 of the first protection unit 210, and the third protection unit 240 is activated, so that the third protection unit 240 pulls down the voltage corresponding to the electrostatic stress of the second end a2 of the first protection unit 210, so that the voltage corresponding to the electrostatic stress after the second pull-down is less than the safety voltage of the SOC. In this way, the protection of the electrostatic stress on the pin of the Type-C port can be achieved, and the damage of the SOC to the electrostatic stress can be avoided.

[0208] When surge stress occurs on the pins of the Type-C port:

[0209] If the voltage corresponding to the surge stress is greater than the start-up voltage of the second protection unit 220, the second protection unit 220 can be started, so that the second protection unit 220 pulls down the voltage corresponding to the surge stress of the first end a1 of the first protection unit 210 (the voltage is greater than the safety voltage of the SOC). After that, the surge stress that has been pulled down once is transmitted to the second end a2 of the first protection unit 210, and the third protection unit 240 is started, so that the third protection unit 240 pulls down the voltage corresponding to the surge stress of the second end a2 of the first protection unit 210, so that the voltage corresponding to the surge stress after the second pull-down is less than the safety voltage of the SOC. In this way, the protection of the surge stress on the pin can be achieved, and the damage to the SOC caused by the surge stress can be avoided.

[0210] If the voltage corresponding to the surge stress is less than the start-up voltage of the second protection unit 220, the second protection unit 220 is not started. The surge stress is transmitted to the second end a2 of the first protection unit 210, and the first protection unit 210 is started. The first protection unit 210 can cut off the connection between the pin of the Type-C port and the SOC, so that the surge stress is isolated from the SOC, and the surge stress is prevented from being transmitted to the SOC, thereby realizing the protection of the surge stress on the pin of the Type-C port and preventing the damage of the SOC to the SOC by the surge stress.

[0211] When DC stress appears on the pin, the first protection unit 210 is started. The first protection unit 210 can cut off the connection between the pin of the Type-C port and the SOC, so that the DC stress is isolated from the SOC and the DC stress is prevented from being transmitted to the SOC, thereby protecting the pin from DC stress and preventing the SOC from being damaged by the DC stress.

[0212] From the above comparison, it can be known that only when the protection circuit 200 includes at least the first protection unit 210 and the second protection unit 220 at the same time, the protection circuit 200 can fully protect the electrostatic stress, surge stress and DC stress in the EOS, thereby preventing the EOS appearing on the pins of the Type-C port from damaging the SOC.

[0213] In addition, by adding the third protection unit 240 , the protection circuit 200 can increase the start-up voltage of the second protection unit 220 while ensuring the protection circuit 200 's EOS protection effect, thereby preventing DC stress from damaging the second protection unit 220 , thereby improving the reliability of the protection circuit 200 .

[0214] Fig.16 A schematic structural diagram of a mobile phone is shown; Fig.17 A structural schematic diagram of another mobile phone is shown.

[0215] The mobile phone may include at least one circuit board. For example, the mobile phone may include one circuit board (such as a main board), or the mobile phone may include multiple circuit boards.

[0216] In some examples, such as Fig.16 As shown, the above protection circuit 200 is located on this circuit board (circuit board 2). In addition, the pins and SOC on the Type-C port can also be located on the circuit board. It can be understood that the pins on the Type-C port, the SOC, and the protection circuit 200 respectively connected to the pins and the SOC are all located on the same circuit board (circuit board 2).

[0217] In other examples, the mobile phone may include two circuit boards. The mobile phone may include circuit board 1 and circuit board 2. The area of ​​circuit board 1 may be smaller than the area of ​​circuit board 2, or may be equal to or larger than the area of ​​circuit board 2, which is not limited in the present application.

[0218] For example, Fig.16 As shown, the pins on the Type-C port can be located on circuit board 1, and the above-mentioned protection circuits are all located on circuit board 2.

[0219] For example, Fig.17 As shown, the second protection unit 220 can be located on the circuit board 1, and the first protection unit 210 can be located on the circuit board 2. In addition, the pins on the Type-C port can be located together with the second protection unit 220 on the circuit board 1, and the SOC can be located together with the first protection unit 210 on the circuit board 2.

[0220] like Fig.16 and Fig.17As shown, the mobile phone may further include a flexible printed circuit (FPC) 300. The FPC 300 may connect two circuit boards, for example, the FPC may connect the circuit board 1 and the circuit board 2 respectively.

[0221] The FPC 300 may include a plurality of signal lines, each of which may be coupled to a signal interface on two adjacent circuit boards, so that the signal is transmitted outside the two circuit boards, thereby realizing signal transmission across the circuit boards. In addition, due to the flexibility of the FPC, the FPC does not limit the layout position of the two connected circuit boards, which facilitates the space design inside the mobile phone.

[0222] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A protection circuit, applied to an electronic device having an external port and a processing chip, characterized in that: The protection circuit comprises: a first protection unit and a second protection unit; The first end of the first protection unit is used to couple a pin of the external port, and the second end of the first protection unit is used to couple the processing chip; the first protection unit is configured to isolate the DC stress and / or surge stress of the first end of the first protection unit from the second end of the first protection unit; The first end of the second protection unit is coupled to the first end of the first protection unit, and the second end of the second protection unit is coupled to the ground end; the second protection unit is configured to reduce surge stress and / or electrostatic stress at the first end of the first protection unit.

2. The protection circuit according to claim 1, characterized in that: The first protection unit includes a switch subcircuit; a first end of the switch subcircuit is used to couple a pin of the external port, and a second end of the switch subcircuit is used to couple the processing chip; The step of isolating the DC stress and / or surge stress at the first end of the first protection unit from the second end of the first protection unit includes isolating the first end of the switch sub-circuit from the second end of the switch sub-circuit.

3. The protection circuit according to claim 2, characterized in that: The method of isolating the DC stress and / or surge stress at the first end of the first protection unit from the second end of the first protection unit includes: when the voltage at the first end of the switch subcircuit is greater than or equal to a preset threshold, isolating the first end of the switch subcircuit from the second end of the switch subcircuit.

4. The protection circuit according to claim 2 or 3, characterized in that: The protection circuit further comprises a control unit; the switch subcircuit comprises a transistor; The first electrode of the transistor is used to couple to a pin of the external port, the second electrode of the transistor is used to couple to the processing chip, and the control electrode of the transistor is coupled to the control unit; The isolating the first end of the switch subcircuit from the second end of the switch subcircuit includes: isolating the first electrode of the transistor from the second electrode of the transistor.

5. The protection circuit according to claim 1, characterized in that: The first protection unit includes a capacitor; a first plate of the capacitor is used to couple a pin of the external port, and a second plate of the capacitor is used to couple the processing chip; The step of isolating the DC stress and / or surge stress at the first end of the first protection unit from the second end of the first protection unit includes: isolating the DC stress at the first plate of the capacitor from the second plate of the capacitor.

6. The protection circuit according to claim 1, characterized in that: The first protection unit includes a switch; a first contact of the switch is used to couple a pin of the external port, a second contact of the switch is used to couple the processing chip, and the first contact is connected or disconnected with the second contact; The method of isolating the DC stress and / or surge stress at the first end of the first protection unit from the second end of the first protection unit includes: when the voltage of the first contact is greater than or equal to a preset threshold, the first contact is disconnected from the second contact, and the DC stress and / or surge stress of the first contact is isolated from the second contact.

7. The protection circuit according to any one of claims 1 to 6, characterized in that: The second protection unit includes a first overvoltage protection subcircuit; A first end of the first overvoltage protection subcircuit is coupled to a first end of the first protection unit, and a second end of the first overvoltage protection subcircuit is coupled to the ground end; The method of reducing the surge stress and / or electrostatic stress at the first end of the first protection unit includes: when the voltage at the first end of the first overvoltage protection subcircuit is greater than or equal to a preset first starting voltage, the first end of the first overvoltage protection subcircuit is connected to the second end of the first overvoltage protection subcircuit to reduce the voltage at the first end of the first protection unit.

8. The protection circuit according to claim 7, characterized in that: The first overvoltage protection subcircuit includes a first transient voltage suppression tube; a first electrode of the first transient voltage suppression tube is coupled to a first end of the first protection unit, and a second electrode of the first transient voltage suppression tube is coupled to the ground end; The first end of the first overvoltage protection subcircuit is connected to the second end of the first overvoltage protection subcircuit, including: connecting the first pole of the first transient voltage suppression tube to the second pole of the first transient voltage suppression tube.

9. The protection circuit according to claim 7, characterized in that: The first overvoltage protection subcircuit includes a transient voltage suppression tube assembly; a first end of the transient voltage suppression tube assembly is coupled to a first end of the first protection unit, and a second end of the transient voltage suppression tube assembly is coupled to the ground end; The transient voltage suppression tube assembly includes a plurality of second transient voltage suppression tubes connected in series.

10. The protection circuit according to any one of claims 1 to 9, characterized in that: The protection circuit also includes a third protection unit; The first end of the third protection unit is coupled to the second end of the first protection unit, and the second end of the third protection unit is coupled to the ground end; the third protection unit is configured to reduce the surge stress and / or the electrostatic stress of the second end of the first protection unit.

11. The protection circuit according to claim 10, characterized in that: The third protection unit includes a second overvoltage protection subcircuit; The first end of the second overvoltage protection subcircuit is coupled to the second end of the first protection unit, and the second end of the second overvoltage protection subcircuit is coupled to the ground end; The reducing the surge stress and / or the electrostatic stress at the second end of the first protection unit includes: when the voltage at the first end of the second overvoltage protection subcircuit is greater than or equal to a preset second starting voltage, the first end of the second overvoltage protection subcircuit is connected to the second end of the second overvoltage protection subcircuit to reduce the voltage at the second end of the first protection unit.

12. The protection circuit according to claim 11, characterized in that: The protection circuit also includes a first overvoltage protection subcircuit; The second startup voltage corresponding to the second overvoltage protection subcircuit is lower than the first startup voltage corresponding to the first overvoltage protection subcircuit.

13. The protection circuit according to claim 11 or 12, characterized in that: The second overvoltage protection subcircuit includes a third transient voltage suppression tube; a first electrode of the third transient voltage suppression tube is coupled to the second end of the first protection unit, and a second electrode of the third transient voltage suppression tube is coupled to the ground end; The first end of the second overvoltage protection subcircuit is connected to the second end of the second overvoltage protection subcircuit, including: connecting the first pole of the third transient voltage suppression tube to the second pole of the third transient voltage suppression tube.

14. An electronic device, characterized in that: include: An external port, a processing chip, and a protection circuit coupled to the external port and the processing chip respectively; The protection circuit is the protection circuit according to any one of claims 1 to 13.

15. The electronic device according to claim 14, characterized in that: The external port includes a plurality of pins; One of the pins is coupled to the protection circuit and coupled to the processing chip through the protection circuit; or, The plurality of pins are respectively coupled to different protection circuits, and each pin is coupled to the processing chip by using the connected protection circuits.

16. The electronic device according to claim 14 or 15, characterized in that: The external port includes at least one of a universal serial bus (USB) port, a high-definition multimedia interface (HDMI), and a network card interface.

17. The electronic device according to any one of claims 14 to 16, characterized in that: The processing chip includes a system-on-chip (SOC) or a microcontroller unit (MCU).

18. The electronic device according to any one of claims 14 to 17, characterized in that: The electronic device comprises at least one circuit board; The first protection unit and the second protection unit in the protection circuit are located on the same circuit board; or, The first protection unit and the second protection unit in the protection circuit are respectively located on different circuit boards.

19. The electronic device according to any one of claims 14 to 18, characterized in that: The external port includes a Type-C port, and the Type-C port includes a D+ pin and a D- pin; The electronic device further includes a common mode inductor, which includes a magnetic ring, and a first inductor coil and a second inductor coil respectively wound around the magnetic ring; a first end of the first inductor coil is coupled to the D- pin, and a first end of the second inductor coil is coupled to the D+ pin; The electronic device also includes two protection circuits; in one protection circuit, the first end of the first protection unit is coupled to the second end of the first inductor coil, and the second end of the first protection unit is coupled to the processing chip; in the other protection circuit, the first end of the first protection unit is coupled to the second end of the second inductor coil, and the second end of the first protection unit is coupled to the processing chip.

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