Access detection device for Ra resistor in USB Type-C cable

Abstract

The utility model discloses an access detection device for an Ra resistor in a USB Type-C cable, and relates to the technical field of Ra resistor access detection, the device comprises a comparator module, a logic control module and a driving module, the comparator module compares the voltage on a CC pin with a first threshold voltage and a second threshold voltage to obtain a comparison result, and the logic control module sends the comparison result to the driving module; and when the comparison result is that the voltage on the CC pin is greater than the first threshold voltage and the voltage on the CC pin is less than the second threshold voltage, the logic control module outputs a first opening signal, and the driving module enables the VCONN to supply power to the USB Type-C cable when receiving the first opening signal. According to the application, Ra resistor access and CC pin ground short circuit can be accurately distinguished, false triggering of VCONN work is avoided, and the safety is improved.

Description

A device for detecting the Ra resistor connection in a USB Type-C cable. Technical Field

[0001] This application relates to the field of Ra resistance connection detection technology, and in particular to a device for detecting the Ra resistance connection in a USB Type-C cable. Background Technology

[0002] To standardize market practices and improve the quality and safety of fast charging cables, the USB-IF Association (USB Implementers Forum, a non-profit organization founded by a group of companies developing Universal Serial Bus specifications) released a new standard (or specification) in 2019. According to this standard, when a USB Type-C cable needs to carry a current greater than 3A, support high-speed data transmission or video output functions of USB 3.0 or higher, it must integrate an E-marker (Electrically Marked Cable, an electronic tag for USB Type-C cables). The main function of the E-marker is to store and transmit cable attribute information, communicate with connected devices, and ensure that various parameters of the cable are accurately identified and verified, effectively avoiding various compatibility issues caused by cable problems.

[0003] The power supply end broadcasts its power supply capability through pull-up resistors or pull-up current sources and identifies the voltage on the CC pin to determine the type of connected device. When the voltage on the CC pin is lower than a certain set voltage value, it is determined that the Ra resistor is connected, and the VCONN pin is activated for power supply. However, when the CC pin has extremely low impedance to ground due to foreign object short circuit, interface oxidation, or E-marker chip damage, i.e. when the CC pin is short-circuited to ground, the voltage on the CC pin may also be lower than the set voltage value. This may cause the power supply end to mistakenly identify the Ra resistor as connected and trigger the VCONN voltage output. This abnormal working mode has two hidden dangers: the VCONN current forms an overload current through the abnormally low impedance channel, causing the pin to overheat or even burn out; at the same time, the incorrect power supply output may cause irreversible damage to the cable interface or device circuit, such as conductor melting, semiconductor component breakdown, and other potential faults. Summary of the Invention

[0004] The purpose of this application is to provide a device for detecting the connection of the Ra resistor in a USB Type-C cable, which can accurately distinguish between the Ra resistor connection and the CC pin short circuit to ground, thereby improving safety.

[0005] To achieve the above objectives, this application provides the following solution:

[0006] In a first aspect, this application provides a detection device for the Ra resistor in a USB Type-C cable, the detection device for the Ra resistor in a USB Type-C cable comprising: a comparator module, a logic control module, and a driver module;

[0007] The input terminal of the comparator module is connected to the CC pin of the USB Type-C cable; the comparator module is used to compare the voltage on the CC pin with the first threshold voltage and the second threshold voltage respectively to obtain the comparison result.

[0008] The input terminal of the logic control module is connected to the output terminal of the comparator module; the logic control module is used to receive the comparison result and output a first enable signal or a first disable signal; the first enable signal is the signal output when the voltage on the CC pin is greater than the first threshold voltage and the voltage on the CC pin is less than the second threshold voltage, and the first disable signal is the signal output when the voltage on the CC pin is less than the first threshold voltage;

[0009] The input terminal of the driver module is connected to the output terminal of the logic control module, and the first output terminal of the driver module is connected to the VCONN pin of the power supply terminal; the driver module is used to enable VCONN to supply power to the USB Type-C cable when the first enable signal is received.

[0010] Optionally, the first threshold voltage is the minimum voltage value appearing on the CC pin due to the Ra resistor being connected, and the second threshold voltage is the maximum voltage value appearing on the CC pin due to the Ra resistor being connected, wherein the first threshold voltage is less than the second threshold voltage.

[0011] Optionally, the comparator module is further configured to compare the voltage on the CC pin with a third threshold voltage; the third threshold voltage is the maximum voltage value appearing on the CC pin due to the connection of the Rd resistor, and the third threshold voltage is greater than the second threshold voltage;

[0012] The logic control module is also used to output a second enable signal or a second disable signal; the second enable signal is a signal output when the voltage on the CC pin is greater than the second threshold voltage and the voltage on the CC pin is less than the third threshold voltage, and the second disable signal is a signal output when the voltage on the CC pin is greater than the third threshold voltage;

[0013] The second output terminal of the driving module is connected to the VBUS pin of the power supply terminal; the driving module is used to enable VBUS to supply power to the power receiving terminal when the second enable signal is received.

[0014] Optionally, the comparator module includes a first reference voltage source, a first switch, a second switch, and a first voltage comparator;

[0015] The first output terminal of the first reference voltage source is used to output the first threshold voltage, and the second output terminal of the first reference voltage source is used to output the second threshold voltage.

[0016] The first terminal of the first switch is connected to the first output terminal of the first reference voltage source;

[0017] The first terminal of the second switch is connected to the second output terminal of the first reference voltage source;

[0018] The first input terminal of the first voltage comparator is connected to the second terminal of the first switch and the second terminal of the second switch, respectively. The second input terminal of the first voltage comparator is connected to the CC pin of the USB Type-C cable, and the output terminal of the first voltage comparator is connected to the input terminal of the logic control module.

[0019] Optionally, the comparator module further includes a third switch;

[0020] The first terminal of the third switch is connected to the third output terminal of the first reference voltage source, the second terminal of the third switch is connected to the first input terminal of the first voltage comparator, and the third output terminal of the first reference voltage source is used to output the third threshold voltage.

[0021] Optionally, the first input terminal of the first voltage comparator is a non-inverting input terminal, and the second input terminal of the first voltage comparator is an inverting input terminal; or, the first input terminal of the first voltage comparator is an inverting input terminal, and the second input terminal of the first voltage comparator is a non-inverting input terminal.

[0022] Optionally, when the first input terminal of the first voltage comparator is a non-inverting input terminal and the second input terminal of the first voltage comparator is an inverting input terminal, the logic control module includes: a first NOT gate, a second NOT gate, a first NOR gate, a third NOT gate, a second NOR gate, a fourth NOT gate, and a fifth NOT gate. The input terminals of the first NOT gate, the second NOT gate, the first NOR gate, the third NOT gate, the second NOR gate, and the fourth NOT gate are all connected to the output terminal of the first voltage comparator. The output terminal of the first NOT gate is connected to the input terminal of the driving module. The output terminal of the second NOT gate is connected to the second input terminal of the first NOR gate. The output terminal of the first NOR gate is connected to the input terminal of the driving module. The output terminal of the third NOT gate is connected to the second input terminal of the second NOR gate. The output terminal of the second NOR gate is connected to the input terminal of the driving module. The output terminal of the fourth NOT gate is connected to the input terminal of the fifth NOT gate. The output terminal of the fifth NOT gate is connected to the input terminal of the driving module.

[0023] Wherein, the first NOT gate is used to output the second turn-off signal, the first NOR gate is used to output the second turn-on signal, the second NOR gate is used to output the first turn-on signal, and the fifth NOT gate is used to output the first turn-off signal.

[0024] Optionally, when the first input terminal of the first voltage comparator is an inverting input terminal and the second input terminal of the first voltage comparator is a non-inverting input terminal, the logic control module includes: a sixth NOT gate, a seventh NOT gate, an eighth NOT gate, a first AND gate, a ninth NOT gate, a second AND gate, and a tenth NOT gate. The input terminals of the sixth NOT gate, the eighth NOT gate, the first AND gate, the ninth NOT gate, the second AND gate, and the tenth NOT gate are all connected to the output terminal of the first voltage comparator. The output terminal of the sixth NOT gate is connected to the input terminal of the seventh NOT gate. The output terminal of the seventh NOT gate is connected to the input terminal of the driving module. The output terminal of the eighth NOT gate is connected to the second input terminal of the first AND gate. The output terminal of the first AND gate is connected to the input terminal of the driving module. The output terminal of the ninth NOT gate is connected to the second input terminal of the second AND gate. The output terminal of the second AND gate is connected to the input terminal of the driving module. The output terminal of the tenth NOT gate is connected to the input terminal of the driving module.

[0025] The seventh NOT gate is used to output the second turn-off signal, the first AND gate is used to output the second turn-on signal, the second AND gate is used to output the first turn-on signal, and the tenth NOT gate is used to output the first turn-off signal.

[0026] Optionally, the comparator module includes a second reference voltage source, a third reference voltage source, a second voltage comparator, and a third voltage comparator;

[0027] The output terminal of the second reference voltage source is used to output the first threshold voltage;

[0028] The first input terminal of the second voltage comparator is connected to the output terminal of the second reference voltage source, the second input terminal of the second voltage comparator is connected to the CC pin of the USB Type-C cable, and the output terminal of the second voltage comparator is connected to the input terminal of the logic control module.

[0029] The output terminal of the third reference voltage source is used to output the second threshold voltage;

[0030] The first input terminal of the third voltage comparator is connected to the output terminal of the third reference voltage source, the second input terminal of the third voltage comparator is connected to the CC pin of the USB Type-C cable, and the output terminal of the third voltage comparator is connected to the input terminal of the logic control module.

[0031] Optionally, the comparator module further includes a fourth reference voltage source and a fourth voltage comparator;

[0032] The output terminal of the fourth reference voltage source is used to output the third threshold voltage;

[0033] The first input terminal of the fourth voltage comparator is connected to the output terminal of the fourth reference voltage source, the second input terminal of the fourth voltage comparator is connected to the CC pin of the USB Type-C cable, and the output terminal of the fourth voltage comparator is connected to the input terminal of the logic control module.

[0034] According to the specific embodiments provided in this application, this application has the following technical effects:

[0035] This application provides a device for detecting the connection of a Ra resistor in a USB Type-C cable, including a comparator module, a logic control module, and a driver module. The comparator module compares the voltage on the CC pin with a first threshold voltage and a second threshold voltage to obtain a comparison result. When the comparison result shows that the voltage on the CC pin is greater than the first threshold voltage and less than the second threshold voltage, the logic control module outputs a first enable signal. Upon receiving the first enable signal, the driver module enables VCONN to supply power to the USB Type-C cable. By introducing a first threshold voltage and a second threshold voltage, this application compares the voltage on the CC pin with these two threshold voltages. If the voltage on the CC pin is between the first and second threshold voltages, the Ra resistor is connected; if the voltage on the CC pin is lower than the first threshold voltage, the CC pin is short-circuited to ground. This accurately distinguishes between Ra resistor connection and CC pin short-circuit to ground, avoiding false triggering of VCONN and improving safety. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 is a schematic diagram of the connection relationship between the power supply end, the power receiving end, and the USB Type-C cable provided in Embodiment 1 of this application.

[0038] Figure 2 is a circuit diagram of the Ra resistor access detection device in the USB Type-C cable provided in Embodiment 1 of this application.

[0039] Figure 3 is a schematic diagram of the voltage comparison process provided in Embodiment 1 of this application.

[0040] Figure 4 is a schematic diagram of the working timing waveform of the threshold gating switch provided in Embodiment 1 of this application.

[0041] Figure 5 is a schematic diagram of a logic control module provided in Embodiment 1 of this application.

[0042] Figure 6 is a schematic diagram of another structure of the logic control module provided in Embodiment 1 of this application. Detailed Implementation

[0043] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0044] Example 1

[0045] Figure 1 shows the connection relationship between the power supply end, the power receiving end, and the USB Type-C cable. In Figure 1, VCC is the power supply voltage of the power supply end, VBUS and VCONN are both power supply pins of the power supply end, VBUS supplies power to the power receiving end, VCONN supplies power to the USB Type-C cable, Rp is the pull-up resistor or pull-up current source of the power supply end, Rd is the pull-down resistor of the power receiving end, VCONN1 and VCONN2 are pins of the E-marker chip in the USB Type-C cable, VCONN1 is connected to the power supply end, VCONN2 is connected to the power receiving end, Ra is the ground connection resistor in the USB Type-C cable, and CC1, CC, and CC2 are all pins. Figure 1 has bidirectional power supply and reversible plug power supply functions. Bidirectional power supply means that the power supply end can become the power receiving end, and the power receiving end can become the power supply end. Reversible plug power supply means that CC1 of the power supply end can be used as the detection connection pin, and CC2 of the power supply end can be used as the VCONN output pin to supply power to the USB Type-C cable, or CC1 of the power supply end can be used as the VCONN output pin to supply power to the USB Type-C cable. The Type-C cable provides power, and the CC2 pin on the power supply side is used as a connection detection pin.

[0046] According to the USB Type-C protocol, the connection / disconnection thresholds for the power supply and power receiving ends are shown in Table 1.

[0047] Table 1 Connection / Disconnection Thresholds for Power Supply and Receiving Terminals

[0048] 0.5A@5V 1.5A@5V 3.0A@5V USB Type-C Cable (vRa) 0.2V 0.4V 0.8V Power Receiver (vRd) 1.6V 1.6V 2.6V surface

[0049] The power supply end broadcasts its power supply capacity through a pull-up resistor or a pull-up current source, that is, broadcasts whether it is a 0.5A, 1.5A or 3A current capacity, and judges the type of connected device by identifying the voltage on the CC pin. Taking the broadcast of 3A current capacity as an example, when the voltage on the CC pin is between 0.8V and 2.6V, it is determined that the Rd resistor is connected, that is, the power receiving end is connected, and at this time, VBUS is activated to supply power to the power receiving end; when the voltage on the CC pin is lower than 0.8V, it is determined that the Ra resistor is connected, that is, a USB Type-C cable containing an E-marker chip is connected, and at this time, VCONN is activated to supply power to the USB Type-C cable. However, when the CC pin has a very low impedance to the ground due to foreign object short circuit, interface oxidation or damage of the E-marker chip, the voltage on the CC pin may also be lower than 0.8V, resulting in the power supply end misidentifying it as the Ra resistor connected and triggering the VCONN power supply, which poses a safety hazard.

[0050] Obviously, the traditional solution only relies on a single threshold (0.8V when broadcasting 3A current capacity) to judge the connection of the Ra resistor, and cannot distinguish between the connection of the Ra resistor (1kΩ) and the short circuit of the CC pin to the ground. It may misjudge the short circuit of the CC pin to the ground as the connection of the Ra resistor, mistakenly think that the USB Type-C cable is connected, and thus supply power through VCONN, resulting in dangers such as excessive current and overheating and burning of the chip. To solve this problem, this embodiment proposes a dual-threshold voltage detection mechanism. On the basis of detecting and distinguishing the connection of the Rd resistor and the non-Rd resistor by pulling down, by adding a lower threshold voltage, it accurately distinguishes the connection of the Ra resistor and the short circuit fault of the CC pin to the ground. When broadcasting 3A current capacity, the upper threshold voltage is set to 0.8V (compatible with the existing protocol), and the newly added lower threshold voltage is set to 0.2V. The value of 0.2V here is only the value of a specific embodiment and does not limit the newly added lower threshold voltage. When the voltage V_cc on the CC pin satisfies 0.2V < V_cc < 0.8V, it is determined that the Ra resistor is connected and the VCONN power supply is triggered. When V_cc < 0.2V, it is determined that the CC pin is shorted to the ground and the VCONN power supply is prohibited, avoiding the risk of hardware damage caused by mis-triggering the VCONN power supply.

[0051] Specifically, when the charging current is above 3A, a USB Type-C cable with an E-marker chip is required. According to the USB Type-C protocol, the pull-up current of the CC pin, which broadcasts a 3A current capability, is 330uA±8%. At this time, the power supply determines that the high threshold voltage connected to the Rd resistor is 2.6V, and the upper threshold voltage is 0.8V. The resistance value of the Rd resistor is 5.1kohm±20%, meaning that when the charging current is 3A, the voltage range connected to the Rd resistor is 1.24V~2.18V, between the high and upper threshold voltages. The resistance value of the Ra resistor is 1kohm±20%, meaning that when the charging current is 3A, the voltage range connected to the Ra resistor is 0.24V~0.43V, within the upper threshold range. Based on the voltage limit, this embodiment further introduces a lower threshold voltage. In this case, the three threshold voltages for detecting the CC pin are 2.6V, 0.8V, and 0.2V. When the voltage on the CC pin is greater than 2.6V, it is determined that no device is connected. When the voltage on the CC pin is between 0.8V and 2.6V, it is determined that resistor Rd is connected. When the voltage on the CC pin is between 0.2V and 0.8V, it is determined that resistor Ra is connected. When the voltage on the CC pin is less than 0.2V, it is determined that the CC pin is short-circuited to ground, and VCONN is not powered.

[0052] Based on the above principle, this embodiment specifically designs a detection device for the Ra resistor in a USB Type-C cable, as shown in Figure 2. In Figure 2, VCC and Rp form a pull-up circuit for the USB Type-C cable. The function of the pull-up circuit is to output a pull-up current to the CC pin, which facilitates the detection of the voltage on the CC pin. The detection device for the Ra resistor in the USB Type-C cable includes a comparator module, a logic control module, and a driver module.

[0053] The comparator module's input is connected to the CC pin of the USB Type-C cable. The comparator module compares the voltage on the CC pin with a first threshold voltage and a second threshold voltage to obtain the comparison result. The first threshold voltage is the minimum voltage value appearing on the CC pin due to the Ra resistor being connected, for example, 0.2V. The second threshold voltage is the maximum voltage value appearing on the CC pin due to the Ra resistor being connected, for example, 0.8V when broadcasting a 3A current capability. The first threshold voltage is less than the second threshold voltage.

[0054] The input terminal of the logic control module is connected to the output terminal of the comparator module. The logic control module is used to receive the comparison result and output a first enable signal or a first disable signal. The first enable signal is the signal output when the voltage on the CC pin is greater than the first threshold voltage and less than the second threshold voltage. The first disable signal is the signal output when the voltage on the CC pin is less than the first threshold voltage.

[0055] The input terminal of the driver module is connected to the output terminal of the logic control module, and the first output terminal of the driver module is connected to the VCONN pin of the power supply terminal. The driver module is used to enable VCONN to supply power to the USB Type-C cable when it receives the first enable signal. Specifically, it can control the closing of the switch used to connect the VCONN pin and the USB Type-C cable, so that VCONN supplies power to the USB Type-C cable.

[0056] In addition to implementing the Ra resistor connection detection function and the CC pin short circuit to ground detection function, this embodiment can also implement the Rd resistor connection detection function. In this case, the comparator module is also used to compare the voltage on the CC pin with the third threshold voltage. The third threshold voltage is the maximum voltage value that appears on the CC pin due to the Rd resistor connection, such as 2.6V when broadcasting a 3A current capability. The third threshold voltage is greater than the second threshold voltage.

[0057] The logic control module is also used to output a second enable signal or a second disable signal. The second enable signal is the signal output when the voltage on the CC pin is greater than the second threshold voltage and the voltage on the CC pin is less than the third threshold voltage. The second disable signal is the signal output when the voltage on the CC pin is greater than the third threshold voltage.

[0058] The second output terminal of the driver module is connected to the VBUS pin of the power supply terminal. When the driver module receives the second enable signal, it enables VBUS to supply power to the power receiving terminal. Specifically, it can control the switch used to connect the VBUS pin and the power receiving terminal to close, so that VBUS supplies power to the power receiving terminal.

[0059] The comparator module in this embodiment includes a reference voltage source and a voltage comparator. The function of the reference voltage source is to provide three threshold voltages (i.e., a first threshold voltage, a second threshold voltage, and a third threshold voltage) to the voltage comparator. Specifically, a threshold selection switch can be introduced. By controlling the on / off state of the threshold selection switch, one of the three threshold voltages from the reference voltage source is dynamically selected, and the selected threshold voltage is transmitted to the voltage comparator. The voltage comparator compares the voltage V_cc on the CC pin with the three threshold voltages in real time, thereby establishing a precise voltage state and obtaining the comparison result; alternatively, it can also be set to... One reference voltage source corresponds to one threshold voltage and one voltage comparator. The reference voltage source directly transmits the threshold voltage to the voltage comparators. The three voltage comparators compare the voltage V_cc on the CC pin with the three threshold voltages in real time, thereby establishing a precise voltage state and obtaining the comparison result. Alternatively, one reference voltage source can be set to correspond to three voltage comparators. The reference voltage source directly transmits the three threshold voltages to the three voltage comparators respectively. The three voltage comparators compare the voltage V_cc on the CC pin with the three threshold voltages in real time, thereby establishing a precise voltage state and obtaining the comparison result. The logic control module generates an Rd detection signal (i.e., identifying Rd resistor connection), an Ra detection signal (i.e., identifying Ra resistor connection), or a CC pin short-circuit fault signal to ground (i.e., identifying CC pin short-circuit to ground) based on the comparison result output by the comparator module. When the driver module receives the Rd detection signal, it is controlled by the Rd detection signal and outputs the VBUS voltage. When it receives the Ra detection signal, it is controlled by the Ra detection signal and outputs the VCONN voltage.

[0060] As one implementation method, as shown in Figure 2, when implementing the Ra resistor connection detection function and the CC pin short-circuit detection function, the comparator module in this embodiment includes a first reference voltage source, a first switch (denoted as se10p2v in Figure 2, representing 0.2V when the first switch is closed), a second switch (denoted as se10p8v in Figure 2, representing 0.8V when the second switch is closed, taking a broadcast current capability of 3A as an example), and a first voltage comparator. The first output terminal of the first reference voltage source is used to output a first threshold voltage, and the second output terminal of the first reference voltage source is used to output a second threshold voltage. The first terminal of the first switch is connected to the first output terminal of the first reference voltage source. The first terminal of the second switch is connected to the second output terminal of the first reference voltage source. The first input terminal of the first voltage comparator (denoted as comp in Figure 2) is connected to the second terminal of the first switch and the second terminal of the second switch, respectively. The second input terminal of the first voltage comparator is connected to the CC pin of the USB Type-C cable, and the output terminal of the first voltage comparator is connected to the input terminal of the logic control module.

[0061] At this time, when implementing the Rd resistor connection detection function, the comparator module in this embodiment also includes a third switch (denoted as se12p6v in Figure 2, representing that when the third switch is closed, 2.6V is selected, taking the broadcast current capability of 3A as an example). The first end of the third switch is connected to the third output terminal of the first reference voltage source, the second end of the third switch is connected to the first input terminal of the first voltage comparator, and the third output terminal of the first reference voltage source is used to output the third threshold voltage.

[0062] As shown in Figures 3 and 4, the specific working process is as follows: While waiting for the device to connect at the power supply end, the voltage comparator opens the first and second switches and closes the third switch, selecting 2.6V as the comparison threshold. It detects whether the voltage on the CC pin is pulled down. When the voltage on the CC pin is detected to be lower than 2.6V, it opens the first and third switches and closes the second switch, switching the comparison threshold to 0.8V. It further detects whether the reason for the voltage pull-down on the CC pin is the connection of resistor Rd. If the voltage on the CC pin is greater than 0.8V, it is determined that resistor Rd is connected. If the voltage on the CC pin is less than 0.8V, it opens the second and third switches and closes the first switch, switching the comparison threshold to 0.2V. It further detects whether the reason for the voltage pull-down on the CC pin is the connection of resistor Ra. If the voltage on the CC pin is greater than 0.2V, it is determined that resistor Ra is connected. If the voltage on the CC pin is less than 0.2V, it is determined to be an abnormal short circuit, that is, a short circuit to ground at the CC pin. The three comparison thresholds can be switched back and forth in the same voltage comparator circuit via a threshold gating switch, so there is no need to add a voltage comparator circuit, making the circuit simple.

[0063] During testing, the voltage comparator's output can be collected at different comparison thresholds by using a round-robin method. Then, the logic control module can determine which range the voltage on the CC pin is in, thereby determining the current connection status of the CC pin.

[0064] In this embodiment, the first input terminal of the first voltage comparator is a non-inverting input terminal, and the second input terminal of the first voltage comparator is an inverting input terminal; or, the first input terminal of the first voltage comparator is an inverting input terminal, and the second input terminal of the first voltage comparator is a non-inverting input terminal, as long as the voltage magnitude can be compared.

[0065] The first switch, the second switch, and the third switch can all be connected to the logic control module for control of their on / off states.

[0066] In another implementation, when implementing the Ra resistor connection detection function and the CC pin short-circuit detection function, the comparator module in this embodiment includes a second reference voltage source, a third reference voltage source, a second voltage comparator, and a third voltage comparator. The output of the second reference voltage source is used to output a first threshold voltage. The first input of the second voltage comparator is connected to the output of the second reference voltage source, the second input of the second voltage comparator is connected to the CC pin of the USB Type-C cable, and the output of the second voltage comparator is connected to the input of the logic control module. The output of the third reference voltage source is used to output a second threshold voltage. The first input of the third voltage comparator is connected to the output of the third reference voltage source, the second input of the third voltage comparator is connected to the CC pin of the USB Type-C cable, and the output of the third voltage comparator is connected to the input of the logic control module.

[0067] In implementing the Rd resistor connection detection function, the comparator module in this embodiment further includes a fourth reference voltage source and a fourth voltage comparator. The output of the fourth reference voltage source is used to output the third threshold voltage. The first input of the fourth voltage comparator is connected to the output of the fourth reference voltage source, the second input of the fourth voltage comparator is connected to the CC pin of the USB Type-C cable, and the output of the fourth voltage comparator is connected to the input of the logic control module.

[0068] In this embodiment, the first input terminal of the second voltage comparator is a non-inverting input terminal, and the second input terminal of the second voltage comparator is an inverting input terminal, or the first input terminal of the second voltage comparator is an inverting input terminal, and the second input terminal of the second voltage comparator is a non-inverting input terminal. The first input terminal of the third voltage comparator is a non-inverting input terminal, and the second input terminal of the third voltage comparator is an inverting input terminal, or the first input terminal of the third voltage comparator is an inverting input terminal, and the second input terminal of the third voltage comparator is a non-inverting input terminal. The first input terminal of the fourth voltage comparator is a non-inverting input terminal, and the second input terminal of the fourth voltage comparator is an inverting input terminal, or the first input terminal of the fourth voltage comparator is an inverting input terminal, and the second input terminal of the fourth voltage comparator is a non-inverting input terminal.

[0069] As another implementation, when implementing the Ra resistor connection detection function and the CC pin short-circuit detection function, the comparator module in this embodiment includes a fifth reference voltage source, a fourth switch, a fifth switch, a fifth voltage comparator, and a sixth voltage comparator. The first output terminal of the fifth reference voltage source is used to output a first threshold voltage, and the second output terminal of the fifth reference voltage source is used to output a second threshold voltage. The first terminal of the fourth switch is connected to the first output terminal of the fifth reference voltage source. The first terminal of the fifth switch is connected to the second output terminal of the fifth reference voltage source. The first input terminal of the fifth voltage comparator is connected to the second terminal of the fourth switch, the second input terminal of the fifth voltage comparator is connected to the CC pin of the USB Type-C cable, and the output terminal of the fifth voltage comparator is connected to the input terminal of the logic control module. The first input terminal of the sixth voltage comparator is connected to the second terminal of the fifth switch, the second input terminal of the sixth voltage comparator is connected to the CC pin of the USB Type-C cable, and the output terminal of the sixth voltage comparator is connected to the input terminal of the logic control module.

[0070] At this point, when implementing the Rd resistor connection detection function, the comparator module in this embodiment also includes a sixth switch and a seventh voltage comparator. The first terminal of the sixth switch is connected to the third output terminal of the fifth reference voltage source, and the third output terminal of the fifth reference voltage source is used to output the third threshold voltage. The first input terminal of the seventh voltage comparator is connected to the second terminal of the sixth switch, the second input terminal of the seventh voltage comparator is connected to the CC pin of the USB Type-C cable, and the output terminal of the seventh voltage comparator is connected to the input terminal of the logic control module.

[0071] In this embodiment, the first threshold voltage can be dynamically adjusted based on the power supply capacity. According to the power supply capacity broadcast by the power supply end, 3A corresponds to I_cc = 330uA, 1.5A corresponds to I_cc = 180uA, and 0.5A corresponds to I_cc = 80uA. The first threshold voltage is dynamically adjusted, and the calculation formula is as follows:

[0072] V_th_low=I_cc×(Ra||R_short_max);

[0073] Where V_th_low is the first threshold voltage; I_cc is the current value on the CC pin; Ra is the Ra resistance value, which can be 0.8kΩ to 1.2kΩ; || is parallel connection; R_short_max is the upper limit of short-circuit impedance (generally below 200Ω, which can be determined according to experience and requirements).

[0074] The second and third threshold voltages can be dynamically adjusted based on the power supply capacity. According to the power supply capacity broadcast by the power supply end, at 3A, the second threshold voltage is 0.8V and the third threshold voltage is 2.6V; at 1.5A, the second threshold voltage is 0.4V and the third threshold voltage is 1.6V; and at 0.5A, the second threshold voltage is 0.2V and the third threshold voltage is 1.6V.

[0075] Based on the identification result of the CC pin connection status, different control responses are made. For example, when the Rd resistor is detected to be connected, the VBUS voltage is output; when the Ra resistor is detected to be connected, the VCONN voltage is output; when the CC pin is detected to be short-circuited to ground, the corresponding abnormal protection strategy is adopted, including not outputting the VCONN voltage and reporting an abnormal warning.

[0076] As shown in Figures 5 and 6, when the comparator module includes a first reference voltage source, a first switch, a second switch, a third switch, and a first voltage comparator, the output signal of the first voltage comparator is denoted as flg2p6v when 2.6V is selected as the comparison threshold, flg0p8v when 0.8V is selected as the comparison threshold, and flg0p2v when 0.2V is selected as the comparison threshold. The output signal of the first voltage comparator is output to the VBUS driver module and the VCONN driver module in the driver module through logic combination: a first enable signal (turn on VCONN), a first disable signal (turn off VCONN), a second enable signal (turn on VBUS), or a second disable signal (turn off VBUS). When the above signals are high (i.e., "1" in digital logic), they represent valid signals.

[0077] When the first input terminal of the first voltage comparator is the non-inverting input terminal and the second input terminal of the first voltage comparator is the inverting input terminal, as shown in Figure 5, when the voltage at the non-inverting input terminal is greater than the voltage at the inverting input terminal, flg2p6v, flg0p8v, and flg0p2v are high. When V_cc < 0.2V, flg0p2v is "1", otherwise flg0p2v is "0"; when V_cc < 0.8V, flg0p8v is "1", otherwise flg0p8v is "0"; when V_cc < 2.6V, flg2p6v is "1", otherwise flg2p6v is "0". When flg0p2v is "1", the first turn-off signal is "1"; when flg0p2v is "0" and flg0p8v is "1", the first turn-on signal is "1"; when flg0p8v is "0" and flg2p6v is "1", the second turn-on signal is "1"; when flg2p6v is "0", the second turn-off signal is "1".

[0078] At this time, as shown in Figure 5, when the first input terminal of the first voltage comparator is the non-inverting input terminal and the second input terminal of the first voltage comparator is the inverting input terminal, the logic control module includes: a first NOT gate, a second NOT gate, a first NOR gate, a third NOT gate, a second NOR gate, a fourth NOT gate, and a fifth NOT gate. The input terminals of the first NOT gate, the second NOT gate, the first NOR gate, the third NOT gate, the first NOR gate, and the fourth NOT gate are all connected to the output terminal of the first voltage comparator. The output terminal of the first NOT gate is connected to the input terminal of the drive module. The output terminal of the second NOT gate is connected to the second input terminal of the first NOR gate. The output terminal of the first NOR gate is connected to the input terminal of the drive module. The output terminal of the third NOT gate is connected to the second input terminal of the second NOR gate. The output terminal of the second NOR gate is connected to the input terminal of the drive module. The output terminal of the fourth NOT gate is connected to the input terminal of the fifth NOT gate. The output terminal of the fifth NOT gate is connected to the input terminal of the drive module. Among them, the first NOT gate is used to output the second turn-off signal, the first NOR gate is used to output the second turn-on signal, the second NOR gate is used to output the first turn-on signal, and the fifth NOT gate is used to output the first turn-off signal.

[0079] When the first input terminal of the first voltage comparator is the inverting input terminal and the second input terminal of the first voltage comparator is the non-inverting input terminal, as shown in Figure 6, when V_cc > 0.2V, flg0p2v is "1", otherwise flg0p2v is "0"; when V_cc > 0.8V, flg0p8v is "1", otherwise flg0p8v is "0"; when V_cc > 2.6V, flg2p6v is "1", otherwise flg2p6v is "0". When flg0p2v is "0", the first turn-off signal is "1"; when flg0p2v is "1" and flg0p8v is "0", the first turn-on signal is "1"; when flg0p8v is "1" and flg2p6v is "0", the second turn-on signal is "1"; when flg2p6v is "1", the second turn-off signal is "1".

[0080] As shown in Figure 6, when the first input terminal of the first voltage comparator is the inverting input terminal and the second input terminal of the first voltage comparator is the non-inverting input terminal, the logic control module includes: a sixth NOT gate, a seventh NOT gate, an eighth NOT gate, a first AND gate, a ninth NOT gate, a second AND gate, and a tenth NOT gate. The input terminals of the sixth NOT gate, the eighth NOT gate, the first AND gate, the ninth NOT gate, the second AND gate, and the tenth NOT gate are all connected to the output terminal of the first voltage comparator. The output terminal of the sixth NOT gate is connected to the input terminal of the seventh NOT gate, and the output terminal of the seventh NOT gate is connected to the input terminal of the driver module. The output terminal of the eighth NOT gate is connected to the second input terminal of the first AND gate, and the output terminal of the first AND gate is connected to the input terminal of the driver module. The output terminal of the ninth NOT gate is connected to the second input terminal of the second AND gate, and the output terminal of the second AND gate is connected to the input terminal of the driver module. The output terminal of the tenth NOT gate is connected to the input terminal of the driver module. Specifically, the seventh NOT gate outputs a second turn-off signal, the first AND gate outputs a second turn-on signal, the second AND gate outputs a first turn-on signal, and the tenth NOT gate outputs a first turn-off signal.

[0081] This embodiment relates to the field of USB Type-C interface technology, specifically to a Ra resistor access identification circuit based on dual-threshold voltage detection. This significantly reduces the risk of false triggering caused by a short circuit to ground on the CC pin, improves interface security, is compatible with existing USB Type-C protocols, requires no modification to the device or cable design, has low hardware implementation costs, and is suitable for mobile devices, chargers, docking stations, and other scenarios. By introducing a dual-threshold voltage detection mechanism, this embodiment effectively distinguishes between Ra resistor access and a short circuit to ground on the CC pin, significantly reducing safety hazards, and is suitable for high-reliability industrial equipment, vehicle charging systems, and other fields.

[0082] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0083] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0084] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A device for detecting the Ra resistance in a USB Type-C cable, characterized in that, The device for detecting the Ra resistor connection in the USB Type-C cable includes: a comparator module, a logic control module, and a driver module; the input terminal of the comparator module is connected to the CC pin of the USB Type-C cable; the comparator module is used to compare the voltage on the CC pin with a first threshold voltage and a second threshold voltage respectively to obtain a comparison result; the input terminal of the logic control module is connected to the output terminal of the comparator module; the logic control module is used to receive the comparison result and output a first enable signal or a first disable signal; the first enable signal is the signal output when the voltage on the CC pin is greater than the first threshold voltage and less than the second threshold voltage, and the first disable signal is the signal output when the voltage on the CC pin is less than the first threshold voltage; the input terminal of the driver module is connected to the output terminal of the logic control module, and the first output terminal of the driver module is connected to the VCONN pin of the power supply terminal; the driver module is used to supply power to the USB Type-C cable via VCONN when the first enable signal is received.

2. The device for detecting the Ra resistance in a USB Type-C cable according to claim 1, characterized in that, The first threshold voltage is the minimum voltage value that appears on the CC pin due to the connection of the Ra resistor, and the second threshold voltage is the maximum voltage value that appears on the CC pin due to the connection of the Ra resistor. The first threshold voltage is less than the second threshold voltage.

3. The device for detecting the Ra resistance in a USB Type-C cable according to claim 2, characterized in that, The comparator module is further configured to compare the voltage on the CC pin with a third threshold voltage; the third threshold voltage is the maximum voltage value appearing on the CC pin due to the connection of the Rd resistor, and the third threshold voltage is greater than the second threshold voltage; the logic control module is further configured to output a second enable signal or a second disable signal; the second enable signal is the signal output when the voltage on the CC pin is greater than the second threshold voltage and less than the third threshold voltage, and the second disable signal is the signal output when the voltage on the CC pin is greater than the third threshold voltage; the second output terminal of the driver module is connected to the VBUS pin of the power supply terminal; the driver module is configured to enable VBUS to supply power to the power receiving terminal when the second enable signal is received.

4. The device for detecting the Ra resistance in a USB Type-C cable according to claim 3, characterized in that, The comparator module includes a first reference voltage source, a first switch, a second switch, and a first voltage comparator; the first output terminal of the first reference voltage source is used to output the first threshold voltage, and the second output terminal of the first reference voltage source is used to output the second threshold voltage. The first terminal of the first switch is connected to the first output terminal of the first reference voltage source; The first terminal of the second switch is connected to the second output terminal of the first reference voltage source; the first input terminal of the first voltage comparator is connected to the second terminal of the first switch and the second terminal of the second switch respectively; the second input terminal of the first voltage comparator is connected to the CC pin of the USB Type-C cable; and the output terminal of the first voltage comparator is connected to the input terminal of the logic control module.

5. The device for detecting the Ra resistance in a USB Type-C cable according to claim 4, characterized in that, The comparator module further includes a third switch; the first end of the third switch is connected to the third output terminal of the first reference voltage source, the second end of the third switch is connected to the first input terminal of the first voltage comparator, and the third output terminal of the first reference voltage source is used to output the third threshold voltage.

6. The device for detecting the Ra resistance in a USB Type-C cable according to claim 5, characterized in that, The first input terminal of the first voltage comparator is a non-inverting input terminal, and the second input terminal of the first voltage comparator is an inverting input terminal; or, the first input terminal of the first voltage comparator is an inverting input terminal, and the second input terminal of the first voltage comparator is a non-inverting input terminal.

7. The device for detecting the Ra resistance in a USB Type-C cable according to claim 6, characterized in that, When the first input terminal of the first voltage comparator is a non-inverting input terminal and the second input terminal of the first voltage comparator is an inverting input terminal, the logic control module includes: a first NOT gate, a second NOT gate, a first NOR gate, a third NOT gate, a second NOR gate, a fourth NOT gate, and a fifth NOT gate. The input terminals of the first NOT gate, the second NOT gate, the first NOR gate, the third NOT gate, the first NOR gate, and the fourth NOT gate are all connected to the output terminal of the first voltage comparator. The output terminal of the first NOT gate is connected to the input terminal of the driving module, and the output terminal of the second NOT gate is connected to... The first NOT gate is connected to the second input terminal of the first NOR gate, the output terminal of the first NOR gate is connected to the input terminal of the driving module, the output terminal of the third NOT gate is connected to the second input terminal of the second NOR gate, the output terminal of the second NOR gate is connected to the input terminal of the driving module, the output terminal of the fourth NOT gate is connected to the input terminal of the fifth NOT gate, and the output terminal of the fifth NOT gate is connected to the input terminal of the driving module; wherein, the first NOT gate is used to output the second turn-off signal, the first NOR gate is used to output the second turn-on signal, the second NOR gate is used to output the first turn-on signal, and the fifth NOT gate is used to output the first turn-off signal.

8. The device for detecting the Ra resistance in a USB Type-C cable according to claim 6, characterized in that, When the first input terminal of the first voltage comparator is an inverting input terminal and the second input terminal of the first voltage comparator is a non-inverting input terminal, the logic control module includes: a sixth NOT gate, a seventh NOT gate, an eighth NOT gate, a first AND gate, a ninth NOT gate, a second AND gate, and a tenth NOT gate. The input terminals of the sixth NOT gate, the eighth NOT gate, the first AND gate, the ninth NOT gate, the second AND gate, and the tenth NOT gate are all connected to the output terminal of the first voltage comparator. The output terminal of the sixth NOT gate is connected to the input terminal of the seventh NOT gate. The output terminal of the seventh NOT gate... The input terminal of the driving module is connected, the output terminal of the eighth NOT gate is connected to the second input terminal of the first AND gate, the output terminal of the first AND gate is connected to the input terminal of the driving module, the output terminal of the ninth NOT gate is connected to the second input terminal of the second AND gate, the output terminal of the second AND gate is connected to the input terminal of the driving module, and the output terminal of the tenth NOT gate is connected to the input terminal of the driving module; wherein, the seventh NOT gate is used to output the second turn-on signal, the first AND gate is used to output the second turn-on signal, the second AND gate is used to output the first turn-on signal, and the tenth NOT gate is used to output the first turn-off signal.

9. The device for detecting the Ra resistance in a USB Type-C cable according to claim 3, characterized in that, The comparator module includes a second reference voltage source, a third reference voltage source, a second voltage comparator, and a third voltage comparator; the output of the second reference voltage source is used to output the first threshold voltage. The first input terminal of the second voltage comparator is connected to the output terminal of the second reference voltage source, the second input terminal of the second voltage comparator is connected to the CC pin of the USB Type-C cable, and the output terminal of the second voltage comparator is connected to the input terminal of the logic control module; the output terminal of the third reference voltage source is used to output the second threshold voltage; the first input terminal of the third voltage comparator is connected to the output terminal of the third reference voltage source, the second input terminal of the third voltage comparator is connected to the CC pin of the USB Type-C cable, and the output terminal of the third voltage comparator is connected to the input terminal of the logic control module.

10. The device for detecting the Ra resistance in a USB Type-C cable according to claim 9, characterized in that, The comparator module further includes a fourth reference voltage source and a fourth voltage comparator; the output of the fourth reference voltage source is used to output the third threshold voltage; the first input of the fourth voltage comparator is connected to the output of the fourth reference voltage source, the second input of the fourth voltage comparator is connected to the CC pin of the USB Type-C cable, and the output of the fourth voltage comparator is connected to the input of the logic control module.

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