USB type-C interface circuit in electronic device

Abstract

The invention provides a USB C-type interface circuit in an electronic device. The USB C-type interface circuit comprises a first clamping resistor, a first voltage clamping circuit, a first current discharge circuit, a first resistor switch series unit, a first high-voltage switch tube, a comparator unit and a control signal generation unit. The first end of the first clamping resistor is connected with a first configuration control pin, the first voltage clamping circuit, the first current leakage circuit and the first resistor switch series unit are all connected between the second end of the first clamping resistor and the ground, and the first resistor switch series unit is further connected with a voltage source; the first high-voltage switch tube is connected between the first configuration control pin and the signal transceiving unit, the control end of the first high-voltage switch tube is used for receiving a first switch control signal, the first input end of the comparator unit is connected with the first configuration control pin, and the second input end of the comparator unit is used for receiving a threshold signal; the control signal generation unit is used for outputting a first switch control signal according to the comparison signal output by the comparator unit.

Description

Technical Field

[0001] This application relates to the field of electronics, particularly to the USB Type-C interface circuit in an electronic device. Background Art

[0002] In current electronic systems, USB Type-C cables are often used for power transfer and data transfer between two electronic devices. Cooperating with the USB Type-C cable, an electronic device usually includes a USB Type-C interface. When the sockets at both ends of the USB Type-C cable are inserted into the USB Type-C interface of the electronic device, the two electronic devices perform power transfer and data transfer through the USB Type-C cable.

[0003] For example, if one of the two electronic devices is a power source (such as a power bank) and the other is a device to be charged (such as a mobile phone, or a receiver), the electronic device acting as the power source can charge the electronic device to be charged acting as the receiver through the USB Type-C cable, and ensure the reliability of charging through data transfer between them.

[0004] In actual implementation, the USB Type-C interface of an electronic device includes a corresponding electronic circuit, which we can call the USB Type-C interface circuit. The above-mentioned power transfer and data transfer are implemented through the USB Type-C interface circuit. Therefore, the reliability of the USB Type-C interface circuit is particularly important. At the same time, with the development of power electronics technology, we also hope for the miniaturization and low cost of the USB Type-C interface circuit.

[0005] However, there are still various problems with the current USB Type-C interface circuit. For example, the current USB Type-C interface circuit cannot accurately determine whether the USB Type-C cable has been unplugged from the USB Type-C interface, resulting in incorrect charging stop. For example, the current USB Type-C interface circuit also requires more high-voltage devices, leading to a large size and high cost of the USB Type-C interface. Summary of the Invention

[0006] According to an embodiment, the present application provides a USB Type-C interface circuit in an electronic device, including: a first clamping resistor, a first end of which is configured to be connected to a first configuration control pin; a first voltage clamping circuit configured to be connected between a second end of the first clamping resistor and the ground; a first current discharging circuit configured to be connected between the second end of the first clamping resistor and the ground; a first resistor-switch series unit including a first low-voltage switch tube and a first resistor connected in series, a first end of which is configured to be connected to the second end of the first clamping resistor and a voltage source, and a second end of which is configured to be grounded; a first high-voltage switch tube configured to be connected between the first configuration control pin and a signal transceiver unit, a control end of which is used to receive a first switch control signal; a comparator unit, a first input end of which is configured to be connected to the first configuration control pin, a second input end of which is used to receive a threshold signal, and an output end of which outputs a comparison signal; a control signal generating unit configured to receive the comparison signal and output the first switch control signal according to the comparison signal.

[0007] Further, the first voltage clamping circuit is configured to clamp the second end of the first clamping resistor at a clamping voltage when the first configuration control pin presents a high voltage, and the first current discharging circuit is configured to operate to shunt the current flowing through the first clamping resistor.

[0008] Further, the first voltage clamping circuit includes: a first voltage stabilizing diode, a cathode of the first voltage stabilizing diode being connected to the second end of the first clamping resistor; a second resistor connected between an anode of the first voltage stabilizing diode and the ground.

[0009] Further, the first current discharging circuit includes a second low-voltage switch tube, a first end of the second low-voltage switch tube being configured to be connected to the second end of the first clamping resistor, a second end of which is configured to be grounded, and a control end of which is configured to be connected to a common node of the second resistor and the first voltage stabilizing diode.

[0010] Further, when the first configuration control pin presents a high voltage, the first voltage stabilizing diode is configured to be reversely broken down, and the second low-voltage switch tube is driven to be turned on.

[0011] Further, when the voltage source provides a voltage and the first configuration control pin is connected to a cable, the first low-voltage switch tube is configured to be turned on, and the first configuration control pin generates a first pull-down signal; when the first pull-down signal is greater than the threshold signal, the comparison signal generated by the comparator unit causes the first switch control signal generated by the control signal generating unit to be at a high level.

[0012] Further, it further includes a first dead electricity control circuit, including: a third low-voltage switch tube, whose first end is configured to be connected to the second end of the first clamping resistor, and whose second end is configured to be grounded; a third resistor, connected between the first end of the third low-voltage switch tube and the control end of the third low-voltage switch tube; a fourth low-voltage switch tube, connected between the control end of the third low-voltage switch tube and the ground.

[0013] Further, the first end of the first resistor-switch series unit is further configured to be connected to the voltage source through a fifth low-voltage switch tube, wherein the cathode of the diode connected in parallel with the fifth low-voltage switch tube is connected to the first end of the first resistor-switch series unit, and the anode is connected to the voltage source.

[0014] Further, it further includes: a second clamping resistor, whose first end is configured to be connected to the second configuration control pin; a second voltage clamping circuit, configured to be connected between the second end of the second clamping resistor and the ground; a second current discharging circuit, configured to be connected between the second end of the second clamping resistor and the ground; a second resistor-switch series unit, including a sixth low-voltage switch tube and a fifth resistor connected in series, whose first end is configured to be connected to the second end of the second clamping resistor and the voltage source, and whose second end is configured to be grounded; a second high-voltage switch tube, whose first end is configured to be connected to the second configuration control pin, whose second end is configured to be used to connect the signal transceiver unit, and whose control end is used to receive a second switch control signal; wherein the comparator unit further includes a third input terminal, the third input terminal is connected to the second configuration control pin, and the comparator unit is further configured to output a comparison signal at its output terminal according to the first pull-down signal received from the first configuration control pin, the second pull-down signal received from the second configuration control pin, and the threshold signal, and the control signal generating unit outputs the first switch control signal and the second switch control signal according to the comparison signal.

[0015] Further, the second voltage clamping circuit includes: a second zener diode, the cathode of the second zener diode is connected to the second end of the second clamping resistor; a sixth resistor, the first end of the sixth resistor is connected to the anode of the second zener diode, and the second end of the sixth resistor is grounded; the second current discharging circuit includes a seventh low-voltage switch tube, the first end of the seventh low-voltage switch tube is configured to be connected to the second end of the second clamping resistor, the second end is configured to be grounded, and the control end is configured to be connected to the common node of the sixth resistor and the second zener diode.

[0016] The features and technical advantages of the present disclosure have been outlined rather extensively above so that the following detailed description of the disclosure may be better understood. Additional features and advantages of the disclosure will be described hereinafter, which form the subject matter of the claims of the disclosure. Those skilled in the art should understand that the disclosed concepts and specific embodiments can be readily used as a basis for modifying or designing other structures or processes for achieving the same purposes of the present disclosure. Those skilled in the art should also recognize that such equivalent structures do not depart from the spirit and scope of the present disclosure as set forth in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] To more fully understand the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which:

[0018] Figure 1 FIG. shows a schematic diagram of a typical pin layout of a USB Type-C interface in an electronic device;

[0019] Figure 2 FIG. shows a schematic diagram of a USB Type-C interface circuit in an electronic device according to an embodiment of the present application;

[0020] Figure 3 FIG. shows a schematic diagram of a USB Type-C interface circuit in an electronic device according to a specific embodiment of the present application;

[0021] Figure 4 FIG. shows a schematic diagram of a USB Type-C interface circuit in an electronic device according to another embodiment of the present application;

[0022] Figure 5 FIG. shows a schematic diagram of a USB Type-C interface circuit in an electronic device according to a specific embodiment of the present application;

[0023] Figure 6 FIG. shows a schematic diagram of another typical pin layout of a USB Type-C interface in an electronic device;

[0024] Figure 7 FIG. shows a schematic diagram of a USB Type-C interface circuit in an electronic device according to another embodiment of the present application;

[0025] Figure 8 FIG. shows a schematic diagram of a circuit of a second interface control circuit according to an embodiment of the present application.

[0026] Unless otherwise noted, corresponding numbers and symbols in different figures generally refer to corresponding parts. These figures are drawn to clearly illustrate relevant aspects of various embodiments and are not necessarily drawn to scale. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The technical solutions in the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the scope of protection of the present application.

[0028] Specifically, please refer to Figure 1 the schematic diagram of a typical USB Type-C interface pin layout in the electronic device shown. The VBUS pins (A4 and A9) therein can provide a DC power supply of up to dozens of volts (such as 24V) for power transmission. The first configuration control pin CC1 (A5) is used to dock with the configuration control pin CC in the USB Type-C cable socket to configure the attributes of the USB Type-C cable through data transmission, and can also provide a power supply of several volts (such as about 5V) to power the integrated circuit in the electronically marked USB Type-C cable. Other pins in the USB Type-C interface are all conventional settings and will not be elaborated here.

[0029] As described above, the first configuration control pin CC1 is defined as a low-voltage signal, and VBUS is defined as a high-voltage signal. In practical applications, the size of the USB Type-C interface is small, the distance between pins is small, and as Figure 1 shown, the VBUS pin (A4) and the first configuration control pin CC1 (A5) are physically adjacent, then it may be caused by a fault (such as a metal foreign object or a liquid foreign object) that the VBUS pin (A4) is short-circuited with the first configuration control pin CC1 (A5), resulting in the first configuration control pin CC1 (A5) being subjected to the high voltage of VBUS. If the circuit connected to the first configuration control pin CC1 (A5) is not protected against high voltage, the circuit will also be subjected to high voltage and burned out; or in order to make the circuit work normally, devices with high withstand voltage can be selected, such as a switching tube with high withstand voltage, however this results in a large circuit volume and high cost. Of course, the first configuration control pin CC1 (A5) may also be subjected to high voltage due to other reasons.

[0030] To solve the above problems and achieve miniaturization and low cost of the USB Type-C interface circuit, an embodiment of the present application provides a USB Type-C interface circuit in an electronic device. Please refer to Figure 2 the schematic diagram of the USB Type-C interface circuit in an electronic device according to an embodiment of the present application shown, which includes:

[0031] A first clamping resistor Rc1, the first end of which is configured to be connected to the first configuration control pin CC1;

[0032] A first voltage clamping circuit 110, configured to be connected between the second end of the first clamping resistor Rc1 and the ground GND;

[0033] The first current discharge circuit 120 is configured to be connected between the second end of the first clamping resistor Rc1 and the ground GND;

[0034] The first resistor-switch series unit 130 includes a first low-voltage switch tube M1 and a first resistor R1 connected in series. Its first end is configured to be connected to the second end of the first clamping resistor Rc1 and the voltage source VDD, and its second end is configured to be grounded to GND;

[0035] The first high-voltage switch tube S1 is configured to be connected between the first configuration control pin CC1 and the signal transceiver unit 300, and its control end is used to receive the first switch control signal Cs1;

[0036] The comparator unit 400 has its first input terminal configured to be connected to the first configuration control pin CC1, its second input terminal for receiving the threshold signal Vref, and its output terminal outputs the comparison signal sc;

[0037] The control signal generation unit 500 is used to receive the comparison signal sc and output the first switch control signal Cs1 according to the comparison signal sc.

[0038] As Figure 2 shown, in this application, by configuring the first voltage clamping circuit 110 and the first current discharge circuit 120, when the first configuration control pin CC1 presents a high voltage (such as 24V), the first voltage clamping circuit 110 clamps the second end of the first clamping resistor Rc1 at the clamping voltage Vc1 (such as between 6V and 8V), and the first current discharge circuit 120 operates to shunt (or discharge) the current flowing through the first clamping resistor Rc1. In this way, the first voltage clamping circuit 110 plays a role of high-voltage isolation, which can prevent the devices in the subsequent circuits (such as the first current discharge circuit 120 and the first resistor-switch series unit 130) connected to the second end of the first clamping resistor Rc1 from also bearing the high voltage, that is, it can prevent the devices inside from being damaged due to bearing the high voltage, and can also enable the switch tubes and resistors inside to use devices with a low withstand voltage rating, which not only has low cost and small volume, but also has high reliability.

[0039] In actual implementation, the clamping voltage Vc1 is much smaller than the high voltage presented by the first configuration control pin CC1. For example, in an embodiment, the clamping voltage Vc1 is between 6V and 8V, and the high voltage presented by the first configuration control pin CC1 is 24V, then the clamping voltage Vc1 is about 1 / 4 of the high voltage presented by the first configuration control pin CC1. Of course, the specific value of this application is not limited, and different devices in the first voltage clamping circuit 110 can be selected according to the circuit design requirements to achieve different clamping voltages Vc1.

[0040] In a specific embodiment, please refer to Figure 3Schematic diagram of the USB Type-C interface circuit in the electronic device according to a specific embodiment of the present application. The first voltage clamping circuit 110 includes: a first voltage stabilizing diode D1, the cathode of the first voltage stabilizing diode D1 is connected to the second end of the first clamping resistor Rc1; a second resistor R2, connected between the anode of the first voltage stabilizing diode D1 and the ground GND.

[0041] Furthermore, as Figure 3 shown, the first current discharging circuit 120 includes a second low-voltage switching transistor M2. The first end of the second low-voltage switching transistor M2 is configured to be connected to the second end of the first clamping resistor Rc1, the second end is configured to be grounded GND, and the control end is configured to be connected to the common node of the second resistor R2 and the first voltage stabilizing diode D1.

[0042] In actual implementation, when the first configuration control pin CC1 presents a high voltage (such as 24V), the first voltage stabilizing diode D1 is configured to be reversely broken down, and the second low-voltage switching transistor M2 is driven to conduct.

[0043] Specifically, refer to Figure 3 , when the first configuration control pin CC1 presents a high voltage (such as 24V), the first voltage stabilizing diode D1 is reversely broken down, and the current flowing through the first voltage stabilizing diode D1 forms a second resistor voltage drop in the second resistor R2. Then the second end of the first clamping resistor Rc1 (i.e., the clamping voltage Vc1) is clamped at the sum of the voltage of the first voltage stabilizing diode D1 and the second resistor voltage drop. In actual implementation, the current that can flow through the first voltage stabilizing diode D1 is very small, generally only at the microamp level, such as one or two hundred microamps. When the resistance value of the second resistor R2 is selected to be at the kiloohm level, such as 100KΩ, the current flowing through the first voltage stabilizing diode D1 forms a second resistor voltage drop of about 1V in the second resistor R2. At the same time, when the first voltage stabilizing diode D1 with a stable voltage of 7V is selected, the clamping voltage Vc1 is clamped at about 8V. As described above, the first voltage stabilizing diode D1 and the second resistor R2 can be selected according to the circuit design requirements to achieve different clamping voltages Vc1.

[0044] As described above, when the first configuration control pin CC1 presents a high voltage of 24V and the first voltage clamping circuit 110 is designed such that the clamping voltage Vc1 is clamped at about 8V, if the first clamping resistor Rc1 is selected to be 1KΩ, the current flowing through the first clamping resistor Rc1 is at the milliamp level, such as 16 milliamps. However, only a microamp-level current can flow through the first voltage stabilizing diode D1. At this time, a shunt circuit is required to shunt (or discharge) the current flowing through the first clamping resistor Rc1.

[0045] This application provides a second low-voltage switch tube M2 as a current discharge circuit. As described above, when the first configuration control pin CC1 presents a high voltage of 24V, the voltage drop of about 1V across the second resistor automatically drives the second low-voltage switch tube M2 to conduct. Then, the current that cannot pass through the first voltage clamping circuit 110 on the first clamping resistor Rc1 will be discharged through the second low-voltage switch tube M2 to maintain the clamping voltage Vc1. And when the first configuration control pin CC1 presents a high voltage of 24V, the drive signal of the second low-voltage switch tube M2 is automatically high. Therefore, no dedicated control circuit is required, making the control simple and highly reliable.

[0046] As described above, when the first configuration control pin CC1 presents a high voltage of 24V, the clamping voltage Vc1 is clamped at about 8V. Thus, it can be seen that the USB Type-C interface circuit provided by this application can protect the subsequent circuits from being damaged even if the first configuration control pin CC1 presents a high voltage due to a fault. Generally, the voltage source VDD is between 2.7V and 5.5V. Then, the second low-voltage switch tube M2, the first low-voltage switch tube M1, and the first resistor R1 can all select devices with a breakdown voltage slightly higher than the clamping voltage Vc1, such as low-voltage devices with a breakdown voltage of about 10V.

[0047] In an actual embodiment, when the voltage source VDD provides a voltage (such as between 2.7V and 5.5V) and the first configuration control pin CC1 is connected to a USB Type-C cable, the first low-voltage switch tube M1 is configured to conduct, and the first configuration control pin CC1 generates a first pull-down signal Vcc1. When the first pull-down signal Vcc1 is greater than the threshold signal Vref, the comparison signal sc generated by the comparator unit 400 causes the first switch control signal Cs1 generated by the control signal generation unit 500 to be at a high level.

[0048] Specifically, please refer to Figure 3 As shown, when the voltage source VDD provides a voltage (such as between 2.7V and 5.5V) and the first configuration control pin CC1 is connected to a USB Type-C cable, the first low-voltage switch tube M1 is configured to conduct, and the first clamping resistor Rc1 and the first resistor R1 form a series resistor branch. Then, a first pull-down signal Vcc1 is generated at the first configuration control pin CC1. The first input terminal of the comparator unit 400 receives the first pull-down signal Vcc1. When the first pull-down signal Vcc1 is greater than the threshold signal Vref, the comparison signal sc output by the comparator unit 400 flips, and the first switch control signal Cs1 output by the control signal generation unit 500 according to the comparison signal sc at this time is at a high level, and the first high-voltage switch tube S1 is driven to conduct, so that the signal transceiver unit 300 is connected to the first configuration control pin CC1.

[0049] At this time, the electronic devices on both sides of the USB TYPE-C cable can perform power transmission and data transmission through the conducting first high-voltage switching transistor S1 and the signal transceiver unit 300. For example, the device to be charged transmits its acceptable current or voltage to the power source. In fact, when a first pull-down signal Vcc1 is generated on the first configuration control pin CC1, it means that the first configuration control pin CC1 has been connected to the USB TYPE-C cable, and normal power transmission and data transmission can be carried out.

[0050] During actual operation, the drive signal of the first low-voltage switching transistor M1 is pre-stored in the USB Type-C interface circuit. When the USB Type-C interface circuit is in a normal operating state, that is, when the voltage source VDD provides a voltage (such as between 2.7V and 5.5V), the drive signal of the first low-voltage switching transistor M1 is set high, that is, the first low-voltage switching transistor M1 will be in a conducting state. When the USB Type-C interface circuit is in a dead power state, the drive signal of the first low-voltage switching transistor M1 is floating, and the first low-voltage switching transistor M1 automatically turns off.

[0051] Moreover, according to the operating principles of the first voltage clamping circuit 110 and the first current discharging circuit 120, when there is no abnormality or fault, the first voltage clamping circuit 110 and the first current discharging circuit 120 do not work. At this time, only the first low-voltage switching transistor M1 is conducting, and the first clamping resistor Rc1 and the first resistor R1 form a series resistor branch.

[0052] In actual implementation, when the first configuration control pin CC1 is connected to the USB TYPE-C cable, it is equivalent to a current source being connected to the first configuration control pin CC1, and a voltage signal of about 0.4V to 1.8V will be applied to the first configuration control pin CC1. At this time, the first clamping resistor Rc1 and the first resistor R1 form a series resistor branch, and a first pull-down signal Vcc1 will be generated on the first configuration control pin CC1. When the first pull-down signal Vcc1 is greater than the threshold signal Vref, the first high-voltage switching transistor S1 is driven to conduct, and power transmission and data transmission can be carried out. If the first configuration control pin CC1 is not connected to the USB TYPE-C cable, the first configuration control pin CC1 will not carry a voltage signal, and a pull-down signal close to 0V (or it can be said that no pull-down signal is generated) will be generated on the first configuration control pin CC1, and the first high-voltage switching transistor S1 turns off, and power transmission and data transmission cannot be carried out. It can be seen that the USB Type-C interface circuit provided by this application can accurately detect whether a cable is connected when its voltage source VDD provides a voltage (that is, in normal operation).

[0053] And as Figure 3As shown, during normal operation, the branch that forms the first pull-down signal Vcc1 only includes the first clamping resistor Rc1, the first resistor R1, and the first low-voltage switch tube M1. The first low-voltage switch tube M1 is a low-voltage switch tube, which is driven by a pre-stored drive signal in the USB Type-C interface circuit. That is, as long as the voltage source VDD provides voltage, the first low-voltage switch tube M1 can be reliably turned on. The on-impedance of it is certain and has nothing to do with the magnitude of the voltage source VDD. Therefore, the USB Type-C interface circuit provided by this application will not stop power transmission due to the increase in the on-impedance of the switch tube caused by the too low voltage provided by the voltage source VDD, resulting in misdetection that the USB Type-C cable has been unplugged, improving the reliability.

[0054] In an actual implemented embodiment, the USB Type-C interface circuit requires the resistance value of the pull-down signal generation branch to be about 5.1 KΩ. For this application, it means that the resistance value of the resistor series branch formed by the first clamping resistor Rc1 and the first resistor R1 is 5.1 KΩ. For this reason, in the above embodiment of this application, the resistance value of the first clamping resistor Rc1 is selected to be 1 KΩ, and the resistance value of the first resistor R1 is 4.1 KΩ. The above values can fluctuate within ±50%. Of course, this application does not limit the specific values of the first clamping resistor Rc1 and the first resistor R1.

[0055] The signal transceiver unit 300 is the physical layer of the transmission protocol, responsible for processing the physical signals of the transmission, mainly used for negotiating the transmission voltage and current. Therefore, it can also be called the physical layer signal transceiver unit. As Figure 3 shown, it includes an output driver and an input comparator. However, this application does not make specific limitations on the signal transceiver unit 300. It is a conventional circuit and will not be elaborated here.

[0056] Please refer to Figure 4 the schematic diagram of the USB Type-C interface circuit in the electronic device of another embodiment of this application shown in Figure 4As shown, the USB Type-C interface circuit in the electronic device further includes a first dead power control circuit 140. The first dead power control circuit 140 is connected between the second end of the first clamping resistor Rc1 and the ground GND. It is configured to generate a first pull-down signal at the first configuration control pin CC1 when the voltage source VDD provides a voltage approximately equal to zero (i.e., the USB Type-C interface circuit is in the dead power state, or the circuit is not powered), and the first configuration control pin CC1 is connected to the USB Type-C cable. When the first pull-down signal is greater than the threshold signal Vref, the comparison signal sc generated by the flip of the comparator unit 400 causes the first switch control signal Cs1 generated by the control signal generation unit 500 to be at a high level. Then, similarly, the electronic devices on both sides of the USB Type-C cable can perform power transfer and data transfer through the conducting first high-voltage switch tube S1 and the signal transceiver unit 300. For example, the device to be charged transfers its acceptable current or voltage to the power source.

[0057] It can be seen that when the USB Type-C interface circuit is in the dead power state, as long as the first configuration control pin CC1 is connected to the USB Type-C cable, the first pull-down signal Vcc1 can still be generated at the first configuration control pin CC1 through the first dead power control circuit 140, enabling power transfer and data transfer between the two electronic devices. At this time, the power supply (such as Vbus) in the electronic device can be used as the power source for the USB Type-C interface circuit, enabling the USB Type-C interface circuit to work.

[0058] In implementation, the first dead power control circuit 140 is further configured not to work when the voltage source VDD provides a voltage, that is, during normal power supply.

[0059] More specifically, please refer to Figure 5 the schematic diagram of the USB Type-C interface circuit in the electronic device of a specific embodiment of the present application shown. The first dead power control circuit 140 includes: a third low-voltage switch tube M3, whose first end is configured to be connected to the second end of the first clamping resistor Rc1, and whose second end is configured to be grounded GND; a third resistor R3, connected between the first end of the third low-voltage switch tube M3 and the control end of the third low-voltage switch tube M3; a fourth low-voltage switch tube M4, connected between the control end of the third low-voltage switch tube M3 and the ground GND.

[0060] Similar to the driving of the first low-voltage switch tube M1, when the USB Type-C interface circuit is in the dead power state, the driving signal of the fourth low-voltage switch tube M4 is floating, and when the USB Type-C interface circuit is in the normal power supply state, that is, when there is a power source, the driving signal of the first low-voltage switch tube M1 is set high.

[0061] When the voltage source VDD provides a voltage approximately equal to zero, that is, in the dead power state, and the first configuration control pin CC1 is connected to the USB TYPE-C cable, the fourth low-voltage switch M4 is configured to be turned off. Then, the third low-voltage switch M3 provides the inter-pole voltage between its control terminal and the second terminal, and the first configuration control pin CC1 generates a first pull-down signal that is the sum of the first clamping resistor voltage drop and the inter-pole voltage. Similarly, when the first pull-down signal is greater than the threshold signal Vref, the first switch control signal Cs1 is at a high level, which causes the signal transceiver unit 300 to be connected to the first configuration control pin CC1, enabling power transfer and data transfer between the two electronic devices.

[0062] As described above, at this time, the first low-voltage switch M1 is configured to be turned off, and the resistor branch formed by the first resistor R1 is disconnected. Since the fourth low-voltage switch M4 is configured to be turned off, it is equivalent to a very large impedance, so the third resistor R3 is equivalent to being very small. The voltage between the g pole and the d pole of the third low-voltage switch M3 (when the third low-voltage switch M3 is a MOSFET) is similar. At this time, the voltage on the third low-voltage switch M3 is equivalent to VGS, and the voltage at the second end of the first clamping resistor Rc1 is also VGS.

[0063] In actual implementation, if the first configuration control pin CC1 is not connected to the USB TYPE-C cable at this time, this pin receives a voltage source, and the first configuration control pin CC1 presents a stable voltage signal instead of a pull-down signal. Then, the comparison signal output by the comparator unit 400 causes the control signal generation unit 500 to generate a low-level first switch control signal Cs1, turning off the first high-voltage switch S1.

[0064] In this way, the USB C-type interface circuit provided by this application can make it possible to generate a first pull-down signal at the first configuration control pin CC1 as long as the USB TYPE-C cable is reliably connected to the interface, regardless of whether the USB C-type interface circuit is in the dead power state, enabling power transfer and data transfer between the electronic devices on both sides of the USB TYPE-C cable. In fact, when the first pull-down signal Vcc1 is generated at the first configuration control pin CC1, it means that the first configuration control pin CC1 has been connected to the USB TYPE-C cable, and normal power transfer and data transfer can be carried out.

[0065] Specifically, when the voltage source VDD provides a voltage, that is, when the USB C-type interface circuit is normally powered, the fourth low-voltage switch M4 will be driven to conduct, and the drive terminal of the third low-voltage switch M3 will be pulled low and be in the off state, so the dead power circuit does not work.

[0066] In an embodiment of the present application, the first end of the first resistor-switch series unit 130 is further configured to be connected to the voltage source VDD through the fifth low-voltage switch tube M5, wherein the cathode of the diode connected in parallel with the fifth low-voltage switch tube M5 is connected to the first end of the first resistor-switch series unit 130, and the anode is connected to the voltage source VDD.

[0067] During actual operation, its drive signal is similar to that of the first low-voltage switch tube M1 and the fourth low-voltage switch tube M4 and is pre-stored by the USB Type-C interface circuit. Then when the USB Type-C interface circuit is in a normal working state, that is, there is a power supply, the fifth low-voltage switch tube M5 will be in a conducting state, and the power supply VDD can supply power to the USB Type-C interface circuit normally; when the USB Type-C interface circuit is in a dead power state, the drive signal of the fifth low-voltage switch tube M5 is floating, and the fifth low-voltage switch tube M5 automatically turns off.

[0068] During actual implementation, the voltage source VDD is approximately between 2.7V and 5V. When the first configuration control pin CC1 is charged with high voltage due to a fault (such as 24V), as described above, the second end of the first clamping resistor Rc1 is clamped at a clamping voltage Vc1 of approximately 8V. To avoid the voltage source VDD being unstable due to the current flowing from the 8V clamping voltage Vc1 to the voltage source VDD, the second end of the first clamping resistor Rc1 needs to be isolated from the voltage source VDD. Then when the first configuration control pin CC1 is charged with high voltage due to a fault, the fifth low-voltage switch tube M5 is also driven to turn off, and at this time, the diode connected in parallel with it is reverse cut-off, and the second end of the first clamping resistor Rc1 can be decoupled from the voltage source VDD.

[0069] During actual implementation, the resistance value of the second resistor R2 is 100KΩ, and the resistance value of the third resistor R3 is 2MΩ. And the above values can fluctuate within ±50%.

[0070] Please refer to Figure 6 Another typical USB Type-C interface pin layout schematic diagram in the shown electronic device. During actual implementation, there is usually only one CC signal terminal on the USB Type-C cable. In order to improve the user experience, the USB Type-C interface pins on the electronic device usually include two configuration control pins, that is, the first configuration control pin CC1 and the second configuration control pin CC2, and the relative position is that when the USB Type-C cable is inserted correctly, it is connected to one of the first configuration control pin CC1 and the second configuration control pin CC2, and when it is inserted reversely, it is connected to the other.

[0071] Therefore, during actual implementation, the second configuration control pin CC2 needs to be configured with the same circuit as the first configuration control pin CC1. Such as Figures 2 to 5As shown in the figure, the first clamping resistor Rc1 connected to the first configuration control pin CC1, the first voltage clamping circuit 110, the first current discharging circuit 120, the first resistor-switch series unit 130, the first dead-time control circuit 140, and the fifth low-voltage switch tube M5 are referred to as the first interface control circuit 100. The second configuration control pin CC2 is also connected to an interface control circuit with the same structure and function as the first interface control circuit 100, which can be called the second interface control circuit 200.

[0072] Specifically, please refer to Figure 7 the schematic diagram of the USB Type-C interface circuit in the electronic device according to another embodiment of the present application shown in Figures 2 to 5 the basis of the USB Type-C interface circuit in the electronic device shown in the figure includes: a second configuration control pin CC2, a second high-voltage switch tube S2, and a second interface control circuit 200. The second high-voltage switch tube S2 is connected between the second configuration control pin CC2 and the signal transceiver unit 300. The second configuration control pin CC2 is also connected to the third input terminal of the comparator unit 400, and transmits the second pull-down signal Vcc2 representing the second configuration control pin CC2 to the third input terminal of the comparator unit 400. The comparator unit 400 is further configured to output a comparison signal sc at its output terminal according to the first pull-down signal Vcc1 received from the first configuration control pin CC1, the second pull-down signal Vcc2 received from the second configuration control pin CC2, and the threshold signal Vref. The control signal generation unit 500 outputs a first switch control signal Cs1 and a second switch control signal Cs2 according to the comparison signal sc.

[0073] It can be referred to Figure 8 the circuit schematic diagram of the second interface control circuit according to an embodiment of the present application shown in the figure, and in combination with Figures 2 to 5 and Figure 7 the second interface control circuit 200 includes: a second clamping resistor Rc2, the first end of which is configured to be connected to the second configuration control pin CC2; a second voltage clamping circuit 210, configured to be connected between the second end of the second clamping resistor Rc2 and the ground GND; a second current discharging circuit 220, configured to be connected between the second end of the second clamping resistor Rc2 and the ground GND; a second resistor-switch series unit 230, including a sixth low-voltage switch tube M6 and a fifth resistor R5 connected in series, the first end of which is configured to be connected to the second end of the second clamping resistor Rc2 and the voltage source VDD, and the second end of which is configured to be grounded to GND.

[0074] Specifically, as Figure 8As shown, the second voltage clamping circuit 210 therein includes: a second zener diode D2, the cathode of the second zener diode D2 is connected to the second end of the second clamping resistor Rc2; a sixth resistor R6, the first end of the sixth resistor R6 is connected to the anode of the second zener diode D2, and the second end of the sixth resistor R6 is grounded. The second current discharging circuit 220 includes a seventh low-voltage switching transistor M7, the first end of the seventh low-voltage switching transistor M7 is configured to be connected to the second end of the second clamping resistor Rc2, the second end is configured to be grounded to GND, and the control end is configured to be connected to the common node of the sixth resistor R6 and the second zener diode D2.

[0075] Furthermore, the second interface control circuit 200 further includes a second dead-time control circuit 240, as Figure 8 shown, the second dead-time control circuit 240 includes: an eighth low-voltage switching transistor M8, its first end is configured to be connected to the second end of the second clamping resistor Rc2, and its second end is configured to be grounded to GND; a seventh resistor R7, connected between the first end of the eighth low-voltage switching transistor M8 and its control end; a ninth low-voltage switching transistor M9, connected between the control end of the eighth low-voltage switching transistor M8 and the ground GND.

[0076] Furthermore, the second interface control circuit 200 further includes a tenth low-voltage switching transistor M10, and the first end of the second resistor-switch series unit 230 is further configured to be connected to the voltage source VDD through the tenth low-voltage switching transistor M10, wherein the cathode of the diode connected in parallel with the tenth low-voltage switching transistor M10 is connected to the first end of the second resistor-switch series unit 230, and the anode is connected to the voltage source VDD.

[0077] The structure, the control signals of the corresponding switching transistors, and the working principle of the second interface control circuit 200 are completely the same as those of the first interface control circuit 200, and will not be elaborated here.

[0078] In an embodiment of the actual implementation, when the USB TYPE-C cable socket is inserted into the USB C-type interface of the electronic device, the CC signal terminal of the USB TYPE-C cable is connected to the first configuration control pin CC1 or the second configuration control pin CC2. When the CC signal terminal of the SB TYPE-C cable is connected to the first configuration control pin CC1, the first pull-down signal Vcc1 is greater than zero, and the second pull-down signal Vcc2 is approximately equal to zero. At this time, the first switch control signal Cs1 output by the control signal generation unit 500 according to the comparison signal sc is at a high level, and the second switch control signal Cs2 is at a low level. When the CC signal terminal of the USB TYPE-C cable is connected to the second configuration control pin CC2, the second pull-down signal Vcc2 is greater than zero, and the first pull-down signal Vcc1 is approximately equal to zero. At this time, the second switch control signal Cs2 output by the control signal generation unit 500 according to the comparison signal sc is at a high level, and the first switch control signal Cs1 is at a low level. That is, when one of the first switch control signal Cs1 and the second switch control signal Cs2 is at a high level, the other is at a low level. Therefore, whether the USB TYPE-C cable is inserted correctly or reversely, power transmission and data transmission can be performed between the two electronic devices. Of course, the present application does not limit that the first switch control signal Cs1 and the second switch control signal Cs2 must be opposite. As long as the high-voltage switch tube of the path connected to the CC signal terminal of the SB TYPE-C cable is turned on, power transmission and data transmission can be performed.

[0079] Furthermore, the present application does not limit the withstand voltage of the first high-voltage switch tube S1 and the second high-voltage switch tube S2. As long as it exceeds the high voltage brought by the failure of the first configuration control pin CC1 and the second configuration control pin CC2, such as exceeding 24V. Selecting the first high-voltage switch tube S1 and the second high-voltage switch tube S2 as high-voltage switch tubes can prevent the devices in the signal transceiver unit 300 from also bearing high voltage, that is, it avoids the damage of the devices therein due to bearing high voltage.

[0080] The present application does not limit the specific values of the first pull-down signal Vcc1 and the second pull-down signal Vcc2.

[0081] In actual implementation, the present application does not limit the specific structure of the comparator unit 400. For example, it may include one or more comparators, as long as it can achieve the above functions.

[0082] Similarly, the present application does not limit the specific structure of the control signal generation unit 500, as long as it can achieve the above functions.

[0083] Furthermore, the first end of the first resistor-switch series unit 130 is also connected to the voltage source VDD through the fourth resistor R4, and the first end of the second resistor-switch series unit 230 is also connected to the voltage source VDD through the eighth resistor R8.

[0084] Although the embodiments of the present disclosure and their advantages have been described in detail, it should be understood that various changes, substitutions, and alterations can be made herein without departing from the spirit and scope of the present disclosure as defined by the appended claims.

[0085] Moreover, the scope of the present application is not intended to be limited to the specific embodiments of the processes, machines, manufactures, compositions of matter, devices, methods, and steps described in the specification. As will be readily understood by those of ordinary skill in the art from the disclosure of the present disclosure, processes, machines, manufactures, compositions of matter, means, methods, or steps that perform substantially the same function, whether currently existing or later to be developed or implemented, can achieve substantially the same results as the corresponding embodiments described herein that are available according to the present disclosure. Accordingly, the appended claims are intended to include such processes, machines, manufactures, compositions of matter, devices, methods, or steps within their scope.

Claims

1. A USB Type-C interface circuit in an electronic device, characterized in that, Comprising: A first clamping resistor, the first end of which is configured to be connected to a first configuration control pin; A first voltage clamping circuit, configured to be connected between the second end of the first clamping resistor and ground; A first current discharging circuit, configured to be connected between the second end of the first clamping resistor and ground; A first resistor-switch series unit, including a first low-voltage switch tube and a first resistor connected in series, the first end of which is configured to be connected to the second end of the first clamping resistor and a voltage source, and the second end of which is configured to be grounded; A first high-voltage switch tube, configured to be connected between the first configuration control pin and a signal transceiver unit, and the control end of which is used to receive a first switch control signal; A comparator unit, the first input end of which is configured to be connected to the first configuration control pin, the second input end of which is used to receive a threshold signal, and the output end of which outputs a comparison signal; A control signal generating unit, configured to receive the comparison signal and output the first switch control signal according to the comparison signal.

2. The USB Type-C interface circuit in the electronic device according to claim 1, wherein The first voltage clamping circuit is configured to clamp the second end of the first clamping resistor at a clamping voltage when the first configuration control pin presents a high voltage, and the first current discharging circuit is configured to operate to shunt the current flowing through the first clamping resistor.

3. The USB Type-C interface circuit in the electronic device according to claim 2, wherein, The first voltage clamping circuit includes: A first voltage stabilizing diode, the cathode of the first voltage stabilizing diode is connected to the second end of the first clamping resistor; A second resistor, connected between the anode of the first voltage stabilizing diode and ground.

4. The USB Type-C interface circuit in the electronic device according to claim 3, characterized in that The first current discharging circuit includes a second low-voltage switch tube, the first end of the second low-voltage switch tube is configured to be connected to the second end of the first clamping resistor, the second end of which is configured to be grounded, and the control end of which is configured to be connected to the common node of the second resistor and the first voltage stabilizing diode.

5. The USB Type-C interface circuit in the electronic device according to claim 4, wherein When the first configuration control pin presents a high voltage, the first voltage stabilizing diode is configured to be reversely broken down, and the second low-voltage switch tube is driven to conduct.

6. The USB Type-C interface circuit in the electronic device according to claim 1, wherein When the voltage source provides a voltage and the first configuration control pin is connected to a cable, The first low-voltage switch tube is configured to conduct, and the first configuration control pin generates a first pull-down signal; When the first pull-down signal is greater than the threshold signal, the comparison signal generated by the comparator unit causes the first switch control signal generated by the control signal generating unit to be at a high level.

7. The USB Type-C interface circuit in the electronic device according to claim 1, wherein It further includes a first dead-time control circuit, including: A third low-voltage switch tube, the first end of which is configured to be connected to the second end of the first clamping resistor, and the second end of which is configured to be grounded; A third resistor, connected between the first end of the third low-voltage switch tube and the control end of the third low-voltage switch tube; A fourth low-voltage switch tube, connected between the control end of the third low-voltage switch tube and ground.

8. The USB Type-C interface circuit in the electronic device according to claim 1, wherein The first end of the first resistor-switch series unit is further configured to be connected to the voltage source through a fifth low-voltage switch tube, wherein the cathode of the diode in parallel with the fifth low-voltage switch tube is connected to the first end of the first resistor-switch series unit, and the anode is connected to the voltage source.

9. The USB Type-C interface circuit in the electronic device according to any one of claims 1 to 8, characterized in that, It further includes: A second clamping resistor, the first end of which is configured to be connected to a second configuration control pin; A second voltage clamping circuit, configured to be connected between the second end of the second clamping resistor and the ground; A second current discharging circuit, configured to be connected between the second end of the second clamping resistor and the ground; A second resistor-switch series unit, including a sixth low-voltage switching transistor and a fifth resistor connected in series, the first end of which is configured to be connected to the second end of the second clamping resistor and a voltage source, and the second end of which is configured to be grounded; A second high-voltage switching transistor, the first end of which is configured to be connected to the second configuration control pin, the second end of which is configured to be connected to the signal transceiver unit, and the control end of which is configured to receive a second switching control signal; Wherein the comparator unit further includes a third input terminal, the third input terminal is connected to the second configuration control pin, and the comparator unit is further configured to output a comparison signal at its output terminal according to a first pull-down signal received from the first configuration control pin, a second pull-down signal received from the second configuration control pin, and the threshold signal, and the control signal generating unit outputs the first switching control signal and the second switching control signal according to the comparison signal.

10. The USB Type-C interface circuit in the electronic device according to claim 9, wherein The second voltage clamping circuit includes: A second zener diode, the cathode of the second zener diode is connected to the second end of the second clamping resistor; A sixth resistor, the first end of the sixth resistor is connected to the anode of the second zener diode, and the second end of the sixth resistor is grounded; The second current discharging circuit includes a seventh low-voltage switching transistor, the first end of the seventh low-voltage switching transistor is configured to be connected to the second end of the second clamping resistor, the second end of which is configured to be grounded, and the control end of which is configured to be connected to the common node of the sixth resistor and the second zener diode.

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