Vehicle-mounted charging circuit with data transmission function

Abstract

The utility model discloses a vehicle-mounted charging circuit with a data transmission function, which relates to the technical field of automotive electronics and comprises a voltage conversion circuit, a protection circuit and a serial port conversion circuit. The input end of the voltage conversion circuit is connected with the output end of the protection circuit, and the output end of the voltage conversion circuit is connected with the output end of the serial port switching circuit; the voltage conversion circuit comprises a main control chip U1, a first filter circuit, a second filter circuit, a feedback circuit and a voltage division circuit. The first filter circuit is connected with the input end of the main control chip, the second filter circuit is connected with the output end of the main control chip, one end of the feedback circuit is connected with the main control chip U1, the other end of the feedback circuit is connected with the second filter circuit, and the voltage division circuit is connected with the input end of the main control chip U1; the beneficial effects of the utility model are that: can provide stable voltage output, satisfy fast charge demand, effectively protect equipment safety, strengthen the compatibility with other equipment.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of automobile electronic technology more specifically, the utility model relates to a vehicle-mounted charging circuit with data transmission function. BACKGROUND

[0002] With the rapid development of mobile internet technology and smart phones, smart devices have become an indispensable device in people's daily life. The types and quantities of vehicle-mounted electronic devices are increasing, such as vehicle-mounted navigation, vehicle-mounted audio, vehicle-mounted recorders, smart phones and other portable electronic devices, etc. These devices have higher requirements for the power supply performance of vehicle-mounted power supply. During driving, smart phones are usually widely used for navigation, music playing, communication and other functions. However, due to the high frequency of use of smart phones, the power consumption is large, especially when navigating or running applications for a long time, the problem of insufficient power of the phone is increasingly prominent. It is particularly important to have a fully charged phone during driving. Drivers may encounter various emergencies, such as vehicle failure, accidents or getting lost, etc., at which time it is particularly important to communicate with the outside world in time. In the case of long-distance driving or business travel, the driver's phone may be quickly consumed due to frequent use. Therefore, vehicle-mounted phone charging devices have emerged as one of the important configurations of modern cars.

[0003] Traditional vehicle-mounted power charging devices usually have problems such as unstable output voltage, low charging efficiency and imperfect protection function, which are difficult to meet the needs of modern vehicle-mounted device diversification and high performance. In vehicle-mounted charging applications, due to the unstable voltage output by the car battery and the influence of external environment such as high temperature, low temperature, vibration, etc., the voltage stabilizing performance of the circuit becomes one of the key technologies. In addition, vehicle-mounted charging devices need to have overvoltage protection, overcurrent protection, short circuit protection and other safety functions to ensure the safety of vehicle-mounted devices and users. However, most of the vehicle-mounted charging devices on the market lack effective protection circuit design, which cannot provide reliable protection in abnormal conditions, and is easy to cause equipment damage and even safety accidents. At the same time, with the widespread popularity of fast charging technology, users' demand for fast charging of vehicle-mounted charging devices has significantly increased. The existing vehicle-mounted charging devices lack support for mainstream fast charging protocols, cannot be compatible with multiple fast charging devices, resulting in slow charging speed and poor user experience. In addition, vehicle-mounted charging devices also have deficiencies in multi-device compatibility. Traditional design is difficult to support communication and conversion between USB interface and serial port devices at the same time, limiting its application range. SUMMARY

[0004] In order to overcome the prior art, a vehicle-mounted charging circuit with data transmission function can not only provide stable voltage output to meet the fast charging demand, but also effectively protect the safety of the equipment and enhance the compatibility with other equipment, so as to meet the diversified use scenarios of modern vehicle-mounted electronic equipment.

[0005] The utility model discloses a vehicle-mounted charging circuit with data transmission function, and the improvement lies in comprising voltage conversion circuit, protection circuit and serial port conversion circuit.

[0006] The input end of the voltage conversion circuit is connected with the output end of the protection circuit, and the output end of the voltage conversion circuit is connected with the output end of the serial port switching circuit.

[0007] The voltage conversion circuit comprises a main control chip U1, a first filter circuit, a second filter circuit, a feedback circuit and a voltage dividing circuit.

[0008] In the above structure, the main control chip U1 of the voltage conversion circuit is MPQ4241.

[0009] In the above structure, the first filter circuit comprises capacitors C1, C2, C3, C4, C5, C6 and an inductor L1.

[0010] In the above structure, the second filter circuit comprises capacitors C7, C8, C9, C10 and C11.

[0011] In the above structure, the feedback circuit comprises resistors R1, R2, R3 and capacitor C12; the resistors R1, R2 and R3 are connected in series, one common end of the series connection of the resistors R1, R2 and R3 is connected to the FB pin of the master chip U1, the other common end of the series connection of the resistors R1, R2 and R3 is connected to the second filter circuit, one end of the capacitor C12 is connected to the common end of the resistors R1 and R2, and the other end of the capacitor is connected to the common end of the resistors R2 and R3.

[0012] In the above structure, the voltage dividing circuit comprises resistors R4 and R5; the resistor R4 is connected to the FLT pin of the master chip U1, and the resistor R5 is connected to the FREQ pin of the master chip U1.

[0013] In the above structure, the protection circuit comprises a relay J1, a PMOS tube Q1, a bidirectional breakdown diode D1, a voltage stabilizing diode D2 and a resistor R6.

[0014] One end of the relay is connected to the drain of the PMOS tube Q1, the other end of the relay is grounded, the gate of the PMOS tube Q1 is connected to the anode of the voltage stabilizing diode D2, the source of the PMOS tube Q1 is connected to the anode of the voltage stabilizing diode D2, one end of the resistor R6 is connected to the common end of the source of the PMOS tube Q1 and the anode of the voltage stabilizing diode D2, the other end of the resistor R6 is grounded, and the bidirectional breakdown diode D1 is connected across the relay J1.

[0015] In the above structure, the serial port conversion circuit comprises a master chip U2, the model of the master chip U2 is 1186-11X10-23A, USB signals are converted into serial port signals to communicate with various serial port devices.

[0016] In the above structure, the vehicle-mounted charging circuit further comprises a signal filtering circuit GT17, which comprises a four-pin connector, a capacitor C13, a resistor R7 and a resistor R8.

[0017] The fourth pin of the four-pin connector GT17 is grounded, the second pin of the four-pin connector GT17 is connected with the DM_OUT pin of the chip U1, the third pin of the four-pin connector GT17 is connected with the DP_OUT pin of the chip U1, one end of the resistor R7 is connected with the second pin of the four-pin connector GT17, the other end of the resistor R7 is connected with the DM_OUT pin of the chip U1, one end of the resistor R8 is connected with the third pin of the four-pin connector GT17, and the other end of the resistor R7 is connected with the DP_OUT pin of the chip U1; one end of the capacitor C13 is connected with the second pin of the four-pin connector GT17, and the other end of the capacitor C13 is connected with the third pin of the four-pin connector GT17.

[0018] In the above structure, the vehicle-mounted charging circuit with data transmission function supports the PD3.0 fast charging protocol.

[0019] The vehicle-mounted charging circuit with data transmission function has the advantages that stable voltage output can be provided to meet fast charging requirements, equipment safety can be effectively protected, compatibility with other equipment is enhanced, and diversified use scenarios of modern vehicle-mounted electronic equipment are met. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 A schematic diagram of the vehicle-mounted charging circuit with data transmission function of the utility model;

[0021] Figure 2 A circuit diagram of the voltage conversion circuit of the vehicle-mounted charging circuit with data transmission function of the utility model;

[0022] Figure 3 A circuit diagram of the protection circuit of the vehicle-mounted charging circuit with data transmission function of the utility model;

[0023] Figure 4 A circuit diagram of the serial port conversion circuit of the vehicle-mounted charging circuit with data transmission function of the utility model;

[0024] Figure 5 A circuit diagram of the signal filtering circuit of the vehicle-mounted charging circuit with data transmission function of the utility model. DETAILED DESCRIPTION

[0025] The utility model is further described below in combination with the drawings and examples.

[0026] The concept, specific structure and generated technical effects of the utility model will be clearly and completely described below in combination with the embodiments and drawings, so as to fully understand the purpose, features and effects of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments, and other embodiments obtained by the person skilled in the art without creative labor based on the embodiments of the utility model all belong to the protection scope of the utility model. In addition, all the coupling / connection relations involved in the patent do not mean that the components directly connect, but means that a better coupling structure can be formed by adding or reducing coupling auxiliary components according to the specific implementation situation. The various technical features in the utility model creation can be interactively combined without mutual contradiction and conflict.

[0027] In addition, if the description of "first", "second" and the like is involved in the embodiments of the utility model, the description of "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one feature. Secondly, the technical solutions of various embodiments can be combined with each other, but it must be based on the fact that the person skilled in the art can realize it, when the combination of technical solutions appears mutual contradiction or cannot be realized, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope required by the utility model.

[0028] Referring to Figure 1 and Figure 2 , the utility model provides a kind of vehicle-mounted charging circuit with data transmission function, including voltage conversion circuit, protection circuit and serial port conversion circuit;

[0029] The input end of the voltage conversion circuit is connected with the output end of the protection circuit, and the output end of the voltage conversion circuit is connected with the output end of the serial port switching circuit;

[0030] The voltage conversion circuit includes main control chip U1, first filter circuit, second filter circuit, feedback circuit and voltage dividing circuit;The input end of the first filter circuit is connected with the main control chip, and the output end of the second filter circuit is connected with the main control chip;One end of the feedback circuit is connected with the main control chip U1, and the other end of the feedback circuit is connected with the second filter circuit;The input end of the voltage dividing circuit is connected with the main control chip circuit U1.The vehicle-mounted charging circuit with data transmission function supports PD3.0 fast charging protocol.The vehicle-mounted charging circuit supporting PD3.0 protocol can automatically adjust output voltage and current according to the charging demand of different equipment, so as to realize more efficient and safer charging.

[0031] In the embodiment, referring to Figure 2As shown, the main control chip U1 of the voltage conversion circuit is MPQ4241. The brake motor power supply circuit includes a switching power supply control circuit, a capacitor C1, an electrolytic capacitor C2, a non-polar capacitor C3, a feedback circuit, and a filter circuit. The first filter circuit includes capacitors C1, C2, C3, C4, C5, C6, and inductor L1. Capacitors C1, C2, C3, C4, C5, and C6 are connected in parallel with the IN pin of the main control chip U1. One end of the inductor L1 is connected to the capacitor C2, and the other end of the inductor L1 is connected to the capacitor C3. The design of the main control chip U1 (MPQ4241) can efficiently regulate the input voltage, so that the voltage output always remains within a stable range, which is particularly important for sensitive vehicle-mounted devices, avoiding the risk of device damage or abnormal function caused by unstable voltage. By using multiple capacitors (such as capacitors C1, C2, C3, C4, C5, and C6) in parallel, high-frequency noise and fluctuations in the input voltage can be effectively reduced, ensuring stable power supply. The combination of inductor L1 and capacitors C2 and C3 further improves the smoothness of the power supply, preventing current spikes or fluctuations from affecting system operation.

[0032] The second filter circuit includes capacitors C7, C8, C9, C10, and C11. Capacitors C7, C8, C9, C10, and C11 are connected in parallel, and one common end of capacitors C7, C8, C9, C10, and C11 is connected to the OUT pin of the main control chip U1. The other common end of capacitors C7, C8, C9, C10, and C11 of the second filter circuit is grounded. The parallel connection of multiple capacitors in this place can effectively filter out high-frequency noise and clutter in the output voltage, ensuring smooth voltage output and reducing interference. This is particularly important for vehicle charging circuits, as electromagnetic interference is common in vehicle environments, and high-frequency noise can affect the stability and performance of charging devices. By connecting capacitors of different values in parallel, a wide frequency range can be covered, effectively suppressing noise signals of multiple frequencies and ensuring the purity of the output voltage.

[0033] Further, the feedback circuit comprises resistors R1, R2, R3 and capacitor C12; the resistors R1, R2 and R3 are connected in series, one common end of the series connection of the resistors R1, R2 and R3 is connected to the FB pin of the master chip U1, the other common end of the series connection of the resistors R1, R2 and R3 is connected to the second filter circuit, one end of the capacitor C12 is connected to the common end of the resistors R1 and R2, the other end of the capacitor is connected to the common end of the resistors R2 and R3. The resistors R1, R2 and R3 guide part of the output voltage of the second filter circuit to the FB pin of the master chip U1 through voltage division. The master chip U1 compares the feedback voltage with its internal reference voltage and dynamically adjusts the output voltage to ensure that it always remains within the set range, thereby achieving precise voltage stabilization function. By adjusting the resistance ratio of R1, R2 and R3, the target value of the output voltage can be flexibly set. This feature makes the circuit suitable for the power supply needs of various vehicle-mounted electronic devices. The addition of the capacitor C12 forms an RC network, which can filter out high-frequency signals in the feedback signal, preventing these signals from being transmitted to the FB pin of the master chip U1, thereby enhancing the stability and anti-interference ability of the system.

[0034] As shown in Figure 3 The protection circuit comprises a relay J1, a PMOS tube Q1, a bidirectional breakdown diode D1, a voltage stabilizing diode D2 and a resistor R6.

[0035] The relay J1 is an actuator in the circuit, controlling the on-off of the main circuit. Under normal circumstances, the relay is powered to maintain closure, allowing the circuit to work normally; when an abnormal situation (such as overvoltage or overcurrent) is detected, the PMOS tube is closed, the relay is powered off and opened, thereby protecting the subsequent circuit from damage. One end of the relay is connected to the drain of the PMOS tube Q1, the other end of the relay is grounded, the gate of the PMOS tube Q1 is connected to the positive electrode of the zener diode D2, the source of the PMOS tube Q1 is connected to the positive electrode of the zener diode D2, and one end of the resistor R6 is connected to the common end of the source of the PMOS tube Q1 and the positive electrode of the zener diode D2, which functions to limit the voltage at the gate of the PMOS tube. The PMOS tube Q1 here acts as a main switching element, controlling the on-off of the relay J1. Under normal working conditions, the PMOS tube is in the on state, allowing the relay to work normally; when an abnormality (such as overvoltage or overcurrent) is detected, the PMOS tube quickly closes, thereby cutting off the working circuit of the relay J1, protecting the subsequent equipment from damage. Whether the PMOS tube is on or off is determined by the gate voltage. When the voltage difference between the gate and the source meets the on condition, the PMOS tube is turned on; when the gate voltage rises (above a certain threshold, such as an overvoltage condition), the PMOS tube is turned off. Under normal working conditions, D2 stabilizes the gate voltage within a safe range, keeping the PMOS tube in the on state. If the input voltage exceeds the zener voltage of the zener diode D2, the zener diode begins to conduct, raising the gate voltage of the PMOS tube, causing the PMOS tube to turn off and thereby cutting off the relay circuit, protecting the load. The other end of the resistor R6 is grounded, and the two ends of the bidirectional breakdown diode D1 are connected to the two ends of the relay J1. It is used to protect the PMOS tube and the zener diode D2 from being directly impacted by excessive current.

[0036] As shown in Figure 4 The model of the master chip U2 is 1186-11X10-23A, which is a USB-to-serial conversion chip commonly used to convert USB signals to serial signals for communication with various serial devices. The chip contains multiple pins, such as power pins (GND, VBUS), data pins (TX1+, TX1-, RX1+, RX2+, etc.), and control pins (SBU1, SBU2, etc.), which are connected to USB devices through the USB_OUT interface and connected to external circuits through these pins, realizing data transmission and power management functions.

[0037] As shown in Figure 5 The vehicle-mounted charging circuit further includes a signal filtering circuit GT17, which includes a four-pin connector, a capacitor C13, a resistor R7, and a resistor R8.

[0038] The fourth pin of the four-pin connector GT17 is grounded, the second pin of the four-pin connector GT17 is connected with the DM_OUT pin of the chip U1, and is used for receiving the signal output from the DM_OUT (data line negative end) of the chip U1. The third pin of the four-pin connector GT17 is connected with the DP_OUT pin of the chip U1, and is used for receiving the signal output from the DP_OUT (data line positive end) of the chip U1. One end of the resistor R7 is connected with the second pin of the four-pin connector GT17, and the other end of the resistor R7 is connected with the DM_OUT pin of the chip U1, so as to play a current limiting effect, and meanwhile, the signal transmission quality is improved through appropriate voltage division and impedance matching. One end of the resistor R8 is connected with the third pin of the four-pin connector GT17, and the other end of the resistor R7 is connected with the DP_OUT pin of the chip U1. One end of the capacitor C13 is connected with the second pin of the four-pin connector GT17, and the other end of the capacitor C13 is connected with the third pin of the four-pin connector GT17. When the chip U1 outputs a differential signal through the DM_OUT and DP_OUT pins, the signal is transmitted to the second and third pins of the four-pin connector GT17 through the resistors R7 and R8. The parallel connection of the capacitor C13 forms a low-pass filter, so that the high-frequency noise components are filtered out, the signal transmitted to the subsequent circuit is more smooth and stable, and the interference caused by the noise is reduced.

[0039] The utility model discloses a device that can provide a car machine interaction and fast charging for the user in the cockpit, and the device realizes Carplay and hicar functions through CDP protocol and car machine interaction, supports PD3.0 protocol, and increases fast charging function. In the process that the user frequently interacts with the car machine, the mobile phone is fast charged synchronously, and the mobile phone power is increased.

[0040] The above is a specific description of the preferred embodiment of the utility model, but the utility model creation is not limited to the described embodiment, and those skilled in the art can make various equivalent modifications or replacements without departing from the spirit of the utility model, and these equivalent modifications or replacements are all included in the range defined by the claims of the present application.

Claims

1. A vehicle-mounted charging circuit with data transmission function, characterized in that, Includes voltage conversion circuit, protection circuit, and serial port conversion circuit; The input terminal of the voltage conversion circuit is connected to the output terminal of the protection circuit, and the output terminal of the voltage conversion circuit is connected to the output terminal of the serial port conversion circuit. The voltage conversion circuit includes a main control chip U1, a first filter circuit, a second filter circuit, a feedback circuit, and a voltage divider circuit. The first filter circuit is connected to the input terminal of the main control chip, the second filter circuit is connected to the output terminal of the main control chip, one end of the feedback circuit is connected to the main control chip U1, the other end of the feedback circuit is connected to the second filter circuit, and the voltage divider circuit is connected to the input terminal of the main control chip circuit U1.

2. The on-board charging circuit with data transmission function according to claim 1, characterized in that, The main control chip U1 of the voltage conversion circuit is model MPQ4241.

3. The on-board charging circuit with data transmission function according to claim 2, characterized in that, The first filter circuit includes capacitors C1, C2, C3, C4, C5, and C6, as well as inductor L1. Capacitors C1, C2, C3, C4, C5, and C6 are connected in parallel and then connected to the IN pin of the main control chip U1. One end of inductor L1 is connected to capacitor C2, and the other end of inductor L1 is connected to capacitor C3.

4. The on-board charging circuit with data transmission function according to claim 2, characterized in that, The second filter circuit includes capacitors C7, C8, C9, C10, and C11; capacitors C7, C8, C9, C10, and C11 are connected in parallel, one common terminal of capacitors C7, C8, C9, C10, and C11 is connected to the OUT pin of the main control chip U1, and the other common terminal of capacitors C7, C8, C9, C10, and C11 in the second filter circuit is grounded.

5. A vehicle-mounted charging circuit with data transmission function according to claim 2, characterized in that, The feedback circuit includes resistors R1, R2, and R3, and capacitor C12. Resistors R1, R2, and R3 are connected in series. One common terminal of the series resistors R1, R2, and R3 is connected to the FB pin of the main control chip U1, and the other common terminal of the series resistors R1, R2, and R3 is connected to the second filter circuit. One end of capacitor C12 is connected to the common terminal of resistors R1 and R2, and the other end of capacitor is connected to the common terminal of resistors R2 and R3.

6. The on-board charging circuit with data transmission function according to claim 1, characterized in that, The voltage divider circuit includes resistors R4 and R5; resistor R4 is connected to the FLT pin of the main control chip U1, and resistor R5 is connected to the FREQ pin of the main control chip U1.

7. The on-board charging circuit with data transmission function according to claim 1, characterized in that, The protection circuit includes a relay J1, a PMOS transistor Q1, a bidirectional breakdown diode D1, a Zener diode D2, and a resistor R6. One end of the relay is connected to the drain of the PMOS transistor Q1, and the other end of the relay is grounded. The gate of the PMOS transistor Q1 is connected to the anode of the Zener diode D2, and the source of the PMOS transistor Q1 is connected to the anode of the Zener diode D2. One end of the resistor R6 is connected to the common terminal of the source of the PMOS transistor Q1 and the anode of the Zener diode D2, and the other end of the resistor R6 is grounded. The two ends of the bidirectional breakdown diode D1 are connected to the two ends of the relay J1.

8. The on-board charging circuit with data transmission function according to claim 1, characterized in that, The serial port conversion circuit includes a main control chip U2, model number 1186-11X10-23A, which converts USB signals into serial port signals for communication with various serial port devices.

9. A vehicle-mounted charging circuit with data transmission function according to claim 2, characterized in that, The on-board charging circuit also includes a signal filtering circuit GT17, which includes a four-pin connector, a capacitor C13, a resistor R7, and a resistor R8. The fourth pin of the four-pin connector GT17 is grounded; the second pin of the four-pin connector GT17 is connected to the DM_OUT pin of chip U1; the third pin of the four-pin connector GT17 is connected to the DP_OUT pin of chip U1; one end of resistor R7 is connected to the second pin of the four-pin connector GT17; the other end of resistor R7 is connected to the DM_OUT pin of chip U1; one end of resistor R8 is connected to the third pin of the four-pin connector GT17; the other end of resistor R7 is connected to the DP_OUT pin of chip U1; one end of capacitor C13 is connected to the second pin of the four-pin connector GT17; the other end of capacitor C13 is connected to the third pin of the four-pin connector GT17.

10. A vehicle-mounted charging circuit with data transmission function according to claim 1, characterized in that, The aforementioned on-board charging circuit with data transmission function supports the PD3.0 fast charging protocol.

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