A water ingress protection circuit for a vehicle-mounted USB fast charging port that is resistant to high voltage breakdown

Abstract

This utility model claims protection for a water ingress protection circuit for a vehicle-mounted USB fast charging interface that resists high-voltage breakdown. The circuit comprises a charging chip and an output port. The input pin of the charging chip is used to connect to the vehicle battery for power, and the output pin of the charging chip is connected to the output port. The signal pin of the charging chip is connected to the output port through a thermistor, and one end of the thermistor connected to the signal pin is grounded through a Zener diode. The output port is used for charging mobile phones. This application adds a thermistor and a Zener diode to the signal pin of the vehicle-mounted fast charging interface. When water enters the output port, causing a short circuit between the output pin and the signal pin of the charging chip, the current will flow to ground through the Zener diode. During this grounding process, the temperature rises, increasing the resistance of the thermistor and reducing the current, thus preventing the charging chip from burning out even after prolonged water ingress.

Description

Technical Field

[0001] This utility model relates to the field of vehicle charging connector technology, specifically a water ingress protection circuit for a vehicle USB fast charging interface that is resistant to high voltage breakdown. Background Technology

[0002] The USB ports on motorcycles, electric scooters, and other vehicles are typically exposed. While conventional fast-charging USB chips have water ingress protection, triggering a protection state through impedance changes or other water detection methods, during riding in rain or when the USB port is submerged, using the USB for fast charging at 5V or higher (e.g., 9V, 12V, 15V, 20V) can cause a short circuit. This is because the USB female connector (TYPE-A USB) and female connector (TYPE-C) are connected to the chip's pin circuitry. The fast-charging signal identification pin DP / DM typically only has a withstand voltage of -0.3-6V. Water ingress can cause all pins of the interface to short-circuit, especially the output pins short-circuiting to the DP / DM pin. The high voltage can then damage the USB chip by breaking down its internal components through the DP / DM pin. Therefore, preventing the fast-charging signal identification pin of the vehicle charger from being short-circuited is the technical problem this application aims to solve. Utility Model Content

[0003] To address the shortcomings of existing technologies, this invention proposes a water ingress protection circuit for a vehicle-mounted USB fast charging interface that is resistant to high-voltage breakdown. A thermistor and a Zener diode are installed on the fast charging signal pin to prevent water ingress and short circuits in the vehicle charger.

[0004] The technical solution of this utility model is as follows: A water ingress protection circuit for a vehicle-mounted USB fast charging interface that is resistant to high voltage breakdown is characterized by including a charging chip and an output socket; The input pins of the charging chip are used to connect to the vehicle battery to obtain power. The output pins of the charging chip are connected to the output port. The signal pins of the charging chip are connected to the output port through a thermistor. One end of the thermistor connected to the signal pin is grounded through a Zener diode. The output port is used to connect and charge mobile phones.

[0005] In summary, the above technical solution has the following beneficial effects: This application adds a thermistor and a Zener diode to the signal pin of the vehicle fast charging interface. When water enters the output port and causes a short circuit between the output pin and the signal pin of the charging chip, the current will be grounded through the Zener diode. The short circuit causes a temperature rise, which will increase the resistance of the thermistor, thereby reducing the current and preventing the charging chip from being burned out even after a long period of water ingress, thus providing resistance to high voltage breakdown. Attached Figure Description

[0006] Figure 1A schematic diagram of a USB Type-C charging chip for a water ingress protection circuit for a vehicle-mounted USB fast charging interface that is resistant to high voltage breakdown. Figure 2 A schematic diagram of a USB Type-A charging chip for a water ingress protection circuit for a vehicle-mounted USB fast charging interface that is resistant to high voltage breakdown. Figure 3 This is a schematic diagram of the power supply circuit for a water ingress protection circuit for a vehicle-mounted USB fast charging interface that is resistant to high voltage breakdown.

[0007] Figure reference numerals: 10, charging chip; 20, thermistor; 30, Zener diode. Detailed Implementation

[0008] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Identical components are indicated by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "upper," and "lower" used in the following description refer to directions in the accompanying drawings, and the terms "bottom surface," "top surface," "inner," and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0009] like Figures 1-3 As shown, a water ingress protection circuit for a vehicle-mounted USB fast charging interface with high-voltage breakdown protection is disclosed. It includes a charging chip 10 and an output socket. The input pins of the charging chip 10 are connected to the vehicle battery for power, and the output pins of the charging chip 10 are connected to the output socket. The signal pins of the charging chip 10 are connected to the output socket via a thermistor 20, and one end of the thermistor 20 connected to the signal pin is grounded via a Zener diode 30. The output socket is used for charging mobile phones. This application adds a thermistor 20 and a Zener diode 30 to the signal pins of the vehicle-mounted fast charging interface. When water enters the output socket, causing a short circuit between the output pins and the signal pins of the charging chip 10, the current will flow to ground through the Zener diode 30. The short circuit causes a temperature rise, increasing the resistance of the thermistor 20, thus reducing the current and preventing the charging chip 10 from burning out even after prolonged water ingress, thereby providing high-voltage breakdown protection.

[0010] Specifically, the input pin VIN of the charging chip 10 is connected to the vehicle's onboard charging port. The onboard charging port contains positive and negative electrode plates, which are connected to the positive and negative terminals of the vehicle's battery, thereby obtaining power from the vehicle's battery.

[0011] The charging chip 10 includes signal pins DP and DM. Signal pins DP and DM are each connected to the output port via a thermistor 20. The ends of the thermistors 20 connected to the charging chip 10 are connected to the negative terminals of Zener diodes 30, and the positive terminals of the Zener diodes 30 are grounded. Generally, the output port connected to the fast charging chip 10 has a positive terminal, a negative terminal, and two signal terminals. Under normal circumstances, after the output port is connected to the mobile phone, the communication current is small, the resistance of the thermistor 20 is also small, and the Zener diodes 30 are in the off state. The mobile phone communicates with the charging chip 10 through the two signal terminals, and then charges the mobile phone through the positive and negative terminals according to the fast charging protocol. If water gets into the output port, causing a short circuit between the signal terminal and the positive terminal, the current generated by the short circuit will cause the Zener diode 30 to conduct through the thermistor 20, thereby grounding the short circuit current and preventing a large voltage from damaging the two signal pins of the charging chip 10. After the short circuit current flows for a period of time, the temperature rises, causing the resistance of the thermistor 20 to increase, thereby reducing the short circuit current and preventing the temperature from continuing to rise. The charging chip 10 will not provide a large voltage if it does not receive a fast charging signal, thus protecting the charging chip 10 and allowing the output port to remain undamaged for a longer period of time after water gets in.

[0012] Charging chip 10 is a USB Type-C charging chip 10, and the output port is a USB Type-C output port. For example... Figure 1 As shown, the USB Type-C charging chip 10 is the U2 chip in the attached diagram. The USB Type-C output port is represented by a node in the attached diagram.

[0013] The charging chip 10 is a USB Type-A charging chip 10, and the output port is a USB Type-A output port. For example... Figure 2 As shown, the USB Type-A charging chip 10 is the U3 chip in the attached diagram. The USB Type-A output port is represented by a node in the attached diagram.

[0014] There are two charging chips 10: a USB Type-C charging chip 10 and a USB Type-A charging chip 10. The USB Type-C charging chip 10 is connected to the USB Type-C output port, and the USB Type-A charging chip 10 is connected to the USB Type-A output port. The vehicle charging interface of this application can be either a USB Type-C output interface or a USB Type-A output port; preferably, both types of output interfaces are provided, giving users more choices. The USB Type-C charging chip 10, in addition to its positive and negative power supply terminals, two signal terminals, and connections to the output interface, also has its CC1 and CC2 pins connected to the output interface as detection pins, and its RP pin connected to the output interface as ground. The output interface connected to the USB Type-A charging chip 10 only has two positive and negative charging terminals and two signal terminals.

[0015] The VIN pin of the USB Type-C charging chip 10 is used to connect to the positive terminal of the vehicle battery; the VOUT pin is connected to the VOUTC terminal of the USB Type-C output port; the SW pin is connected to the first terminal of inductor L2 and one terminal of capacitor C5; the second terminal of inductor L2 is connected to one terminal of capacitor C6, the positive terminal of electrolytic capacitor C4, and the VOUTC terminal of the USB Type-C output port; the other terminal of capacitor C16 and the negative terminal of electrolytic capacitor C4 are grounded together; the BST pin is connected to the other terminal of capacitor C5. The positive terminal of the vehicle battery is represented as VCC in the attached diagram. The EP pin of the USB Type-C charging chip 10 is grounded; the CC2 pin is connected to the CC2 terminal of the USB Type-C output port; the CC1 pin is connected to the CC1 terminal of the USB Type-C output port; the DP pin is connected to one end of the thermistor 20F2 and the negative terminal of the Zener diode 30D3 respectively, and the other end of the thermistor 20F2 is connected to the PCD+ terminal of the USB Type-C output port as a fast charging signal, and the positive terminal of the Zener diode 30D3 is grounded; the DM pin is connected to one end of the thermistor 20F4 and the negative terminal of the Zener diode 30D5 respectively, and the other end of the thermistor 20F4 is connected to the PCD- terminal of the USB Type-C output port as a fast charging signal, and the positive terminal of the Zener diode 30D5 is grounded.

[0016] The VIN pin of the USB Type-A charging chip 10 is used to connect to the positive terminal of the vehicle battery; the VOUT pin is connected to the VOUTA terminal of the USB Type-A output port; the SW pin is connected to one end of inductor L1 and one end of capacitor C3, the second end of inductor L1 is connected to one end of resistor R7, one end of electrolytic capacitor C2, and the VOUTA terminal of the USB Type-A output port, and the other end of resistor R7 and the negative terminal of electrolytic capacitor C2 are grounded together; the BST pin is connected to the other end of capacitor C3. The positive terminal of the vehicle battery is represented as VCC in the attached diagram. The DND pin of the USB Type-A charging chip 10 is grounded; the DP pin is connected to one end of the thermistor 20F3 and the negative terminal of the Zener diode 30D4, respectively. The other end of the thermistor 20F3 is connected to the PAD+ terminal of the USB Type-C output port as a fast charging signal, and the positive terminal of the Zener diode 30D4 is grounded; the DM pin is connected to one end of the thermistor 20F5 and the negative terminal of the Zener diode 30D6, respectively. The other end of the thermistor 20F5 is connected to the PAD- terminal of the USB Type-C output port as a fast charging signal, and the positive terminal of the Zener diode 30D6 is grounded.

[0017] like Figure 3 As shown, the input pin VIN of the charging chip 10 is connected to the vehicle battery through a power supply circuit. Specifically, the input pin VIN of the charging chip 10 is connected to one end of the thermistor 20F1. The other end of the thermistor 20F1 is connected to the VCC terminal of the vehicle battery, one end of resistor R1, one end of transient voltage suppressor diode TVS1, the positive terminal of electrolytic capacitor U1, and one end of capacitor C1. The other ends of resistor R1 and transient voltage suppressor diode TVS1 are connected to the negative terminal of diode D1. The negative terminal of electrolytic capacitor U1 and the other end of capacitor C1 are connected to the positive terminal of diode D1. The negative terminal of diode D1 is also connected to the negative terminal of diode D2 and ground, and the positive terminal of diode D1 is connected to the positive terminal of diode D2 and ground. The charging chip 10 obtains power from the positive terminal of the vehicle battery through the above circuit, thereby performing current filtering and other optimizations. Preferably, diodes D1 and D2 are Schottky diodes.

[0018] The above are merely preferred embodiments of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are within its protection scope. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should also be considered within its protection scope.

Claims

1. A water ingress protection circuit for a vehicle-mounted USB fast charging interface resistant to high voltage breakdown, characterized in that, Includes a charging chip (10) and an output port; The input pin of the charging chip (10) is used to connect to the vehicle battery to obtain power. The output pin of the charging chip (10) is connected to the output port. The signal pin of the charging chip (10) is connected to the output port through the thermistor (20). One end of the thermistor (20) connected to the signal pin is grounded through the Zener diode (30). The output port is used to connect and charge mobile phones. The charging chip (10) includes a signal pin DP and a signal pin DM. The signal pin DP and the signal pin DM are respectively connected to the output port through a thermistor (20). The two thermistors (20) and the charging chip (10) are respectively connected to the negative terminal of the Zener diode (30). The positive terminals of the two Zener diodes (30) are respectively grounded. The input pin VIN of the charging chip (10) is connected to one end of the thermistor (20) F1, and the other end of the thermistor (20) F1 is connected to the VCC terminal of the vehicle battery, one end of the resistor R1, one end of the transient suppression diode TVS1, the positive terminal of the electrolytic capacitor U1 and one end of the capacitor C1 respectively. The other end of resistor R1 and transient suppression diode TVS1 is connected to the negative terminal of diode D1. The negative terminal of electrolytic capacitor U1 and the other end of capacitor C1 are connected to the positive terminal of diode D1. The negative terminal of diode D1 is also connected to the negative terminal of diode D2 and ground. The positive terminal of diode D1 is connected to the positive terminal of diode D2 and ground.

2. The water ingress protection circuit for a vehicle-mounted USB fast charging interface resistant to high voltage breakdown as described in claim 1, characterized in that, The charging chip (10) is a USB Type-C charging chip (10), and the output port is a USB Type-C output port.

3. The water ingress protection circuit for a vehicle-mounted USB fast charging interface resistant to high voltage breakdown as described in claim 1, characterized in that, The charging chip (10) is a USB Type-A charging chip (10), and the output port is a USB Type-A output port.

4. The water ingress protection circuit for a vehicle-mounted USB fast charging interface resistant to high voltage breakdown according to claim 1, characterized in that, There are two charging chips (10), namely a USB Type-C charging chip (10) and a USB Type-A charging chip (10). The USB Type-C charging chip (10) is connected to the USB Type-C output port, and the USB Type-A charging chip (10) is connected to the USB Type-A output port.

5. A water ingress protection circuit for a vehicle-mounted USB fast charging interface resistant to high-voltage breakdown as described in claim 2 or 4, characterized in that, The VIN pin of the USB Type-C charging chip (10) is used to connect to the positive terminal of the vehicle's battery; The VOUT pin is connected to the VOUTC terminal of the USB Type-C output port; The SW pin is connected to the first end of inductor L2 and one end of capacitor C5. The second end of inductor L2 is connected to one end of capacitor C6, the positive terminal of electrolytic capacitor C4, and the VOUTC terminal of the USB Type-C output port. The other end of capacitor C16 and the negative terminal of electrolytic capacitor C4 are grounded together. The BST pin is connected to the other end of capacitor C5.

6. A water ingress protection circuit for a vehicle-mounted USB fast charging interface resistant to high-voltage breakdown as described in claim 3 or 4, characterized in that, The VIN pin of the USB Type-A charging chip (10) is used to connect to the positive terminal of the vehicle's battery; The VOUT pin is connected to the VOUTA terminal of the USB Type-A output port; The SW pin is connected to the first end of inductor L1 and one end of capacitor C3. The second end of inductor L1 is connected to one end of resistor R7, one end of electrolytic capacitor C2 and the VOUTA end of USB Type-A output port, respectively. The other end of resistor R7 and the negative terminal of electrolytic capacitor C2 are grounded together. The BST pin is connected to the other end of capacitor C3.

Images