Buck-boost circuit, charging module and charging device

Abstract

The application discloses a kind of boost-buck circuits, charging module and charging equipment, belong to charging technical field.The circuit includes boost-buck unit, first filter unit, boost-buck unit has first adjustment signal input terminal;First filter unit has second adjustment signal input terminal and first adjustment signal output terminal, first adjustment signal output terminal is connected with first adjustment signal input terminal, and second adjustment signal input terminal is used to input adjustment signal.In the application, noise and interference in adjustment signal can be filtered out by first filter unit, effectively reduce the potential influence of adjustment signal on boost-buck unit, improve the stability of boost-buck unit, and then, reduce the problem of boost-buck circuit failure or performance degradation, so that boost-buck circuit can work normally.

Description

Technical Field

[0001] This application relates to the field of charging technology, and in particular to a buck-boost circuit, a charging module, and a charging device. Background Technology

[0002] With the rapid development of connected cars and smartphones, in-vehicle wireless charging modules are gradually being accepted and promoted by major OEMs due to their superior user convenience and technological innovation. To meet specific voltage and current requirements and ensure efficient and safe charging of devices, these wireless charging modules typically require buck-boost circuits. However, buck-boost circuits may face failure or performance degradation, which could cause them to malfunction. Utility Model Content

[0003] This application provides a buck-boost circuit, a charging module, and a charging device to improve the stability of the buck-boost circuit and mitigate the problem of buck-boost circuit failure or performance degradation affecting normal operation.

[0004] In a first aspect, embodiments of this application provide a buck-boost circuit, the circuit comprising:

[0005] A buck-boost unit, which has a first adjustment signal input terminal;

[0006] The first filtering unit has a second adjustment signal input terminal and a first adjustment signal output terminal. The first adjustment signal output terminal is connected to the first adjustment signal input terminal, and the second adjustment signal input terminal is used to input the adjustment signal.

[0007] This application provides a buck-boost circuit, which includes a buck-boost unit and a first filter unit. The buck-boost unit has a first adjustment signal input terminal; the first filter unit has a second adjustment signal input terminal and a first adjustment signal output terminal. The first adjustment signal output terminal is connected to the first adjustment signal input terminal, and the second adjustment signal input terminal is used to input the adjustment signal. In this application, the first filter unit can filter out noise and interference in the adjustment signal, effectively reducing the potential impact of the adjustment signal on the buck-boost unit, improving the stability of the buck-boost unit, and thus reducing the problem of buck-boost circuit failure or performance degradation, enabling the buck-boost circuit to work normally.

[0008] Secondly, a charging module according to an embodiment of this application includes the above-mentioned buck-boost circuit. Therefore, the charging module can have all the technical features and beneficial effects of the above-mentioned charging module, which will not be repeated here.

[0009] Thirdly, a charging device according to an embodiment of this application includes the above-mentioned buck-boost circuit or charging module. Therefore, the charging device can have all the technical features and beneficial effects of the above-mentioned buck-boost circuit or charging module, which will not be repeated here. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art 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 the structures shown in these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of a buck-boost circuit provided in an embodiment of this application;

[0012] Figure 2 This is a schematic diagram of another structure of the buck-boost circuit provided in the embodiments of this application;

[0013] Figure 3 This is a schematic diagram of another structure of the buck-boost circuit provided in the embodiments of this application;

[0014] Figure 4 This is a schematic diagram of a step-up / step-down circuit provided in the embodiments of this application;

[0015] Figure 5 This is a schematic diagram of a charging module provided in an embodiment of this application;

[0016] Figure 6 This is a schematic diagram of the structure of the charging device provided in the embodiments of this application;

[0017] Figure 7 This is a partial structural diagram of the PCBA board provided in the embodiments of this application.

[0018] Explanation of reference numerals in the attached figures:

[0019] 10. Buck-boost unit; 11. First adjustment signal input terminal; 12. First voltage output terminal;

[0020] 20. First filtering unit; 21. Second adjustment signal input terminal; 22. First adjustment signal output terminal;

[0021] 30. Second filtering unit;

[0022] 40. Digital-to-analog converter; 41. Third adjustment signal input terminal; 42. Second adjustment signal output terminal;

[0023] 50. Charging device; 51. First cover plate; 511. Mounting slot; 52. Second cover plate; 53. PCBA board; 54. Charging coil assembly; 541. Coil bracket; 542. Coil; 55. Heat dissipation assembly; 56. Receiving cavity; 57. Filter board;

[0024] 601. Reverse protection unit; 602. EMI filter; 603. Buck switching regulator; 604. Low dropout linear regulator; 605. Control unit; 606. Wireless charging control chip; 607. Voltage regulation chip; 608. Parallel filter; 609. Charging coil switch; 610. Resonant capacitor; 611. CAN transceiver assembly; 612. NFC controller; 613. PEPS unit; 614. FAN unit; 615. NTC unit; 616. Input connector; 617. Buck-boost circuit; 618. Demodulation unit. Detailed Implementation

[0025] 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 a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0026] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0027] With the rapid development of vehicle-to-everything (V2X) technology and smartphones, in-vehicle wireless charging modules are increasingly favored and promoted by major automakers due to their excellent user-friendliness and technological innovation. To ensure these devices meet specific voltage and current requirements while achieving efficient and safe charging, in-vehicle wireless charging modules generally employ the key technology of buck-boost circuits.

[0028] However, in practical applications, the core chip in the buck-boost circuit may fail or experience performance degradation. Once the chip malfunctions, the normal function of the buck-boost circuit will be severely affected, potentially causing the circuit to malfunction and hindering the stable operation of the wireless charging module. This could inconvenience the user experience and even threaten the charging safety and efficiency of the device.

[0029] Please see Figure 1 As shown, Figure 1 This is a schematic diagram of a buck-boost circuit provided in an embodiment of this application.

[0030] This application provides a buck-boost circuit, which includes a buck-boost unit 10 and a first filter unit 20. The buck-boost unit 10 has a first adjustment signal input terminal 11. The first filter unit 20 has a second adjustment signal input terminal 21 and a first adjustment signal output terminal 22. The first adjustment signal output terminal 22 is connected to the first adjustment signal input terminal 11, and the second adjustment signal input terminal 21 is used to input the adjustment signal.

[0031] The step-up / step-down unit 10 is used to increase or decrease the input voltage to meet the voltage requirements of different loads or devices. In this application, the step-up / step-down unit 10 adjusts its output voltage based on the adjustment signal received at the first adjustment signal input terminal 11, enabling it to increase or decrease the input voltage to meet the voltage requirements of different loads or devices. The adjustment signal received at the first adjustment signal input terminal 11 serves as a feedback signal; that is, the adjustment signal represents the output voltage of the step-up / step-down unit 10 being fed back to the unit. Based on this feedback signal, a reference voltage preset within the step-up / step-down unit 10 is compared, and the unit adjusts its output voltage according to the comparison result, resulting in the output voltage of the target voltage.

[0032] In some embodiments, the adjustment signal received by the first adjustment signal input terminal 11 of the buck-boost unit 10 may come from the control unit, such as the MCU. The output voltage can then be dynamically adjusted based on the control unit according to specific requirements. The control unit may monitor the output voltage of the buck-boost unit 10 and send the adjustment signal to the buck-boost unit 10 through the first adjustment signal input terminal 11. The buck-boost unit 10 then adjusts according to this adjustment signal to output the target output voltage.

[0033] In some embodiments, the buck-boost unit 10 further includes a voltage input terminal for inputting a signal to be bucked or boosted. In wireless charging module applications, different devices may require different charging voltages. The buck-boost unit 10 can adjust the power supply voltage input from the voltage input terminal by bucking or boosting it, thereby converting the received power supply voltage into a stable voltage suitable for the target device (such as a smartphone, tablet, or other electronic device).

[0034] The first filtering unit 20 is used to filter out noise and interference in the adjustment signal. That is, before the adjustment signal is input to the first adjustment signal input terminal 11, it first passes through the first filtering unit 20 to filter out noise and interference. This effectively removes or suppresses unwanted components in the adjustment signal, thereby improving the quality of the adjustment signal. A high-quality adjustment signal ensures that the buck-boost unit 10 has higher accuracy and reliability when processing the adjustment signal, and also avoids damage to the buck-boost unit 10 itself. In other words, in some embodiments, the adjustment signal output by the control unit is first filtered by the first filtering unit 20 to remove noise and interference before being input to the first adjustment signal input terminal 11. The buck-boost unit 10 then adjusts its output voltage according to this adjustment signal, causing it to output the target output voltage.

[0035] Understandably, in this application, the first filtering unit 20 can filter out noise and interference in the adjustment signal, effectively reducing the potential impact of the adjustment signal on the buck-boost unit 10, improving the stability of the buck-boost unit 10, and thus reducing the problem of buck-boost circuit failure or performance degradation, so that the buck-boost circuit can work normally.

[0036] In some embodiments, the first filter unit 20 includes: a first resistor, one end of which is connected to the second adjustment signal input terminal 21; a second resistor, one end of which is connected to the first adjustment signal output terminal 22, and the other end of which is connected to the other end of the first resistor; and a first capacitor, one end of which is connected between the first resistor and the second resistor, and the other end of which is grounded.

[0037] Understandably, the first filtering unit 20 includes an RC filter consisting of two resistors and one capacitor. The first filtering unit 20 can filter out high-frequency noise and interference components in the adjustment signal, thereby improving the quality of the adjustment signal and ensuring that the buck-boost unit 10 has higher accuracy and reliability when processing signals. Furthermore, the first filtering unit 20 can reduce harmful noise and interference components to a safe range that the buck-boost unit 10 can withstand, thus protecting the chip from damage. Moreover, the filtered signal is purer and more stable, which helps the buck-boost unit 10 to better perform its function. Therefore, after the filtered adjustment signal enters the buck-boost unit 10, the buck-boost unit 10 can make precise adjustments to the output voltage based on these signals, ensuring that the output voltage accurately meets the requirements.

[0038] Please see Figure 2 As shown, Figure 2 This is another schematic diagram of the buck-boost circuit provided in the embodiments of this application. In some embodiments, the buck-boost unit 10 further has a first voltage output terminal 12, and the buck-boost circuit further includes a second filter unit 30, which is connected to the first voltage output terminal 12.

[0039] Understandably, the first voltage output terminal 12 is used to output the voltage adjusted by the buck-boost unit 10 according to the adjustment signal. Although the first filter unit 20 has already filtered the adjustment signal, new high-frequency noise and interference may still be generated at the output terminal of the buck-boost unit 10 due to factors such as circuit nonlinearity. Therefore, the second filter unit 30 can further filter out these high-frequency noises and interferences, making the output voltage purer and more stable, and protecting the related circuits from damage.

[0040] In some embodiments, the second filter unit 30 includes a second capacitor, one end of which is connected to the first voltage output terminal 12, and the other end of which is grounded.

[0041] Understandably, the second capacitor smooths out fluctuations in the output voltage, making it more stable. Furthermore, the second capacitor enhances the circuit's anti-interference capability, enabling it to maintain stable operation when subjected to external interference.

[0042] In some embodiments, the capacitance value of the second capacitor is between 0.8μF and 1.2μF. It is understood that the capacitance value directly affects its filtering effect. In the circuit, the capacitor smooths voltage fluctuations and filters out high-frequency noise through the charging and discharging process. The capacitance value range of 0.8μF to 1.2μF is a limitation imposed on the capacitance value while ensuring a certain filtering effect, so that the capacitance value within this range can meet the filtering requirements. The capacitance value of the second capacitor being between 0.8μF and 1.2μF means that the capacitance value of the second capacitor can be any capacitance value among 0.8μF, 0.9μF, 1.0μF, 1.1μF, and 1.2μF, or a range between any two capacitance values. It is understood that the capacitance value of the second capacitor is related to the characteristics of the chip itself in the buck-boost unit 10.

[0043] Please see Figure 3 As shown, Figure 3 This is another schematic diagram of the buck-boost circuit provided in the embodiments of this application. In some embodiments, the circuit further includes: a digital-to-analog converter unit 40, which has a third adjustment signal input terminal 41 and a second adjustment signal output terminal 42. The second adjustment signal output terminal 42 is connected to the second adjustment signal input terminal 21, and the third adjustment signal input terminal 41 is used to input the adjustment signal.

[0044] In some embodiments, the control unit outputs a digital signal, and the control unit is connected to the third adjustment signal input terminal 41 to input the digital signal adjustment signal into the digital-to-analog converter 40. After the digital-to-analog converter 40 obtains the analog signal adjustment signal, it passes through the first filter unit 20 and is then input from the first adjustment signal to the buck-boost unit 10. The buck-boost unit 10 adjusts according to this adjustment signal to achieve the desired target output voltage.

[0045] Understandably, the buck-boost unit 10 requires a continuous analog signal to precisely control the output voltage. Therefore, when the adjustment signal is a digital signal, a digital-to-analog converter (DAC) 40 is needed to convert the digital signal into an analog signal, enabling the continuous adjustment signal to be provided to the buck-boost unit 10. Furthermore, the DAC 40 allows the adjustment signal to be sent to the buck-boost unit 10 with higher precision; the resolution (i.e., bit depth) of the digital signal determines the precision of the analog output signal. A high-resolution DAC can provide a finer analog output, thereby achieving more precise control.

[0046] The following is an exemplary description of the operation of a buck-boost circuit proposed in this application:

[0047] First, if the adjustment signal is a digital signal, the adjustment signal is sent to the digital-to-analog converter 40;

[0048] Then, the digital-to-analog converter 40 converts the adjustment signal from a digital signal to an analog signal, and then sends the converted adjustment signal to the first filter unit 20;

[0049] Then, the adjustment signal is sent to the buck-boost unit 10 after passing through the first filter unit 20;

[0050] Finally, the buck-boost unit 10 compares the feedback of the feedback adjustment signal with a preset reference voltage within the buck-boost unit 10. Based on this comparison result, the buck-boost unit 10 adjusts its output voltage to achieve the target output voltage. The final output voltage signal is then filtered by the second filtering unit 30.

[0051] If the adjustment signal is an analog signal, it can be directly sent to the first filter unit 20; otherwise, the adjustment signal can come from the output voltage of the buck-boost unit 10 monitored by the control unit, or from the output voltage of the buck-boost unit 10 monitored by other external sensors.

[0052] For further details, please refer to Figure 4 As shown, Figure 4 This is a schematic diagram of a step-up / step-down circuit provided in an embodiment of this application.

[0053] For example, the chip U1 in the boost / buck unit 10 can use a TPS55288 chip to increase or decrease the input voltage to meet the voltage requirements of different loads or devices. The 14 pins of the TPS55288 chip are... In this application, pin 14 of the TPS55288 chip serves as the first adjustment signal input terminal 11, used to receive feedback of the adjustment signal. The first filter unit 20 includes resistors R1 and R2, and capacitor C1. Resistor R1 acts as the first resistor, resistor R2 as the second resistor, and capacitor C1 as the first capacitor. One end of resistor R1 is connected to terminal A, which is the second adjustment signal input terminal 21. Terminal A is connected to the digital-to-analog converter unit 40, which can be connected to the control unit. One end of resistor R2 is connected to pin 14 of the TPS55288 chip, and the other end of resistor R1 is connected to the other end of resistor R2. One end of capacitor C1 is connected between resistors R1 and R2, and the other end of capacitor C1 is grounded. Thus, the adjustment signal passes through the RC filter circuit composed of resistors R1, R2, and C1, and is then input to the TPS55288 chip through pin 14. The TPS55288 chip then adjusts the signal according to the input signal. The feedback of the adjustment signal received by the pin is used to adjust the output voltage, enabling the buck-boost unit 10 to increase or decrease the input voltage to meet the voltage requirements of different loads or devices. Additionally, one end of resistor R2 is connected to one end of resistor R7 and one end of resistor R8. The other end of resistor R7 is connected to pin 13 of the TPS55288 chip, which is the ISN pin. The other end of resistor R8 is grounded. Resistors R7 and R8 form a resistor divider, feeding a portion of the output voltage back to the FB pin. By adjusting the ratio of R7 and R8, the feedback voltage can be set, thereby setting the output voltage. Resistor R7 is connected to the ISN pin, which is the negative input of the current-sense amplifier in the chip. Therefore, the chip can connect to the resistor divider based on the ISN pin to perform current monitoring and achieve functions such as overcurrent protection.

[0054] Pin 11 of the TPS55288 chip is the VOUT pin, serving as the first voltage output terminal 12. The second filter unit 30 includes capacitor C5, which acts as the second capacitor. One end of capacitor C5 is connected to pin 11 of the TPS55288 chip, and the other end is grounded. Furthermore, pin 11 of the TPS55288 chip is also connected to one end of capacitors C2, C3, C4, and C6, respectively. The other ends of capacitors C2, C3, C4, and C6 are grounded. It's important to understand that pin 11 of the TPS55288 chip is sequentially connected to one end of capacitors C2, C3, C4, C5, and C6. For example, capacitors C2, C3, and C4 have a capacitance of 10uF, capacitor C5 has a capacitance of 1uF, and capacitor C6 has a capacitance of 220uF. Furthermore, the first voltage output terminal 12, based on multiple capacitors, can cover a wider frequency range and provide a more comprehensive filtering effect, thereby improving the stability, filtering performance, and transient response capability of the output voltage, ensuring the reliability and efficiency of the system. It should be noted that the values ​​of the capacitors connected to the first voltage output terminal 12 in this application can be set according to the actual scheme requirements. Additionally, the distance between capacitor C5 and pin 11 of the TPS55288 chip will affect the parasitic inductance, which may cause voltage fluctuations and instability in the buck-boost chip.

[0055] In some embodiments, in the application of the wireless charging module, the output voltage of the first voltage output terminal 12 of the buck-boost unit 10 can be powered externally through a voltage regulation chip. The voltage regulation chip can be a NU8040 full-bridge power stage chip, which can communicate with the control unit via an I2C interface. The chip integrates a full-bridge FET and driver, bootstrap circuit, 5V integrated DC / DC power supply, 3.3V LDO, and lossless current sensing, conforming to the AEC-Q100 standard. A built-in proprietary current sensing circuit provides for FOD (Foreign Object Detection), power measurement, Q-factor detection, and digital demodulation. It supports input undervoltage lockout, overvoltage protection, overcurrent protection, and thermal shutdown protection functions. These protections further improve the reliability of the overall external power supply. Furthermore, pin 11 of the TPS55288 chip is connected to one end of resistor R5 and one end of resistor R3. The other end of resistor R3 is connected to one end of resistor R4 and one end of capacitor C17. The other ends of resistor R4 and capacitor C17 are grounded. The two ends O1 and O2 of resistor R5 are connected to the voltage regulator chip, and then the voltage regulator chip provides power to the outside.

[0056] Additionally, a capacitor C7 is connected between pins 12 and 13 (ISN pin) of the TPS55288 chip. Pin 12 is the ISP pin. One end of capacitor C7 connected to pin 12 of the TPS55288 chip is connected to one end of resistor R2, and the other end of resistor R2 is connected to one end of resistor R5. One end of capacitor C7 connected to pin 13 of the TPS55288 chip is connected to one end of resistor R62, and the other end of resistor R6 is connected to the other end of resistor R5. The ISP pin is the positive input of the current sensing amplifier in the chip. The voltage difference across resistor R5 can be detected at the ISP pin and the ISN pin. The current value flowing through resistor R5 is obtained through the chip's internal operational amplifier circuit. If the detected voltage difference across resistor R5 reaches the current limit setting value in the chip register, the voltage between the ISP pin and the ISN pin will be adjusted to achieve overcurrent protection. Additionally, the TPS55288 chip has pin 1, which is the DR1L pin. The DR1L pin is used to drive the gate of the low-side MOSFET on the buck side. Pin 1 is connected to one end of resistor R14, and the other end of resistor R14 is connected to the gate of field-effect transistor Q2. The source of field-effect transistor Q2 is grounded, and the drain of field-effect transistor Q2 is connected to one end of inductor L1. The TPS55288 chip also has pin 2, which is the DR1H pin. The DR1H pin is used to drive the gate of the high-side MOSFET on the buck side. Pin 2 is connected to one end of resistor R13, and the other end of resistor R13 is connected to the gate of the high-side MOSFET on the buck side. The gate of the field-effect transistor Q1 is connected to the circuit, the source of the field-effect transistor Q1 is connected to one end of the inductor L1, and the drain of the field-effect transistor Q1 is connected to pin 3 of the TPS55288 chip. The TPS55288 chip also has a 3-pin circuit, which is the VIN pin. Pin 3 is connected to the signal to be stepped up or down. In the figure, the V1 terminal represents the signal to be stepped up or down, which can be the power supply voltage. The other 3 pins are also connected to one end of capacitor C13, one end of capacitor C14, one end of capacitor C15, and one end of capacitor C16, respectively. The other ends of capacitors C13, C14, C15, and C16 are grounded. The TPS55288 chip also has 4 pins, which are the EN / UVLO pins. These 4 pins are connected to the control unit and one end of resistor R15, with the other end of resistor R15 grounded. The EN / UVLO pins are used to enable (EN) logic inputs or programmable input voltage undervoltage lockout (UVLO) inputs. The TPS55288 chip also has 5 pins, which are the SCL pins and are connected to the control unit. The TPS55288 chip also has 6 pins, which are the SCA pins and are connected to the control unit. Furthermore, terminals B, C, and D in the diagram are all connected to the control unit.The TPS55288 chip also has a 7-pin connector, which is the DITH / SYNC pin. Pin 7 is connected to one end of resistor R16, and the other end of resistor R16 is grounded. The DITH / SYNC pin is used for jitter frequency setting (DITH) or synchronization clock input (SYNC). The TPS55288 chip also has an 8-pin connector, which is the FSW pin. The FSW pin is used for switching frequency setting. Pin 8 is connected to one end of resistor R17, and the other end of resistor R17 is grounded. The TPS55288 chip also has a 9-pin connector, which is the PGND pin, i.e., power ground. The TPS55288 chip also has a 10-pin AGND pin, which is analog ground. Pin 10 is connected to the other end of resistor R17. The TPS55288 chip also has a 15-pin MOOE pin. Different operating modes can be selected based on the resistor connected between this pin and ground. Pin 15 is connected to one end of resistor R9, and the other end of resistor R9 is grounded. The TPS55288 chip also has a 16-pin CDC pin. The CDC pin is used to set the output voltage compensation function. By connecting a resistor between this pin and ground, the output voltage can be adjusted to compensate for the voltage loss. Due to the voltage drop caused by the cable resistance, pin 16 is connected to one end of resistor R10, and the other end of resistor R10 is grounded. The TPS55288 chip also has pin 17, which is the ILIM pin. The ILIM pin is used to set the average inductor current limit. By connecting an external resistor between this pin and the ground pin, the current limit threshold can be adjusted. Pin 17 is connected to one end of resistor R11, and the other end of resistor R11 is grounded. The TPS55288 chip also has pin 18, which is the COMP pin. The COMP pin is used to connect to the loop compensation network in the chip. By connecting an external resistor between the COMP pin and ground... Connecting an appropriate compensation network (usually composed of resistors and capacitors) can stabilize the control loop and optimize the dynamic response of the system. Pin 18 is connected to one end of capacitor C8 and one end of resistor R12, with the other end of capacitor C8 grounded. The other end of resistor R12 is connected to one end of capacitor C9, with the other end of capacitor C9 grounded. The TPS55288 chip also has pin 19, which is the VCC pin. Pin 19 is connected to a preset power supply voltage, which can be 5.2V. This means that the V2 terminal can input a 5.2V power supply voltage. Pin 19 is also connected to one end of capacitor C10, with the other end of capacitor C10 grounded.The TPS55288 chip also has a 20-pin connector, which is the BOOT2 pin. Pin 20 is connected to one end of capacitor C11, and the other end of capacitor C11 is connected to pin 21 of the TPS55288 chip. Pin 21 is the SW2 pin, and the connection point between capacitor C11 and pin 21 is also connected to the other end of inductor L1. BOOT2 is used to power the gate of the high-side MOSFET on the boost side, and SW2 is the switching node pin on the boost side. The TPS55288 chip also has a 22-pin connector, which is the BOOT1 pin. Pin 22 is connected to one end of capacitor C12, and the other end of capacitor C12 is connected to pin 23 of the TPS55288 chip. Pin 23 is the SW1 pin, and the connection point between capacitor C12 and pin 23 is also connected to one end of inductor L1. The BOOT1 pin is used to power the gate of the high-side MOSFET on the buck side, and the SW1 pin is the switching node pin on the buck side. The TPS55288 chip also has a pin 24, which is the PGND pin, i.e., power ground. Pin 25 of the TPS55288 chip is the SW2 pin, and pin 25 is connected to the other end of inductor L1. The TPS55288 chip also has a pin 26, which is the VOUT pin. Pin 26 of the TPS55288 chip can also output a voltage signal adjusted by the buck-boost unit 10 based on the O3 terminal. It should be noted that the usage and pin functions of the TPS55288 chip can be found in the chip's product datasheet. Additionally, the field-effect transistor in this application is a power MOSFET. The source of a power MOSFET may have multiple pins, which typically need to be connected together to ensure that the current is evenly distributed and passes through all pins.

[0057] Secondly, embodiments of this application provide a charging module, including the buck-boost circuit described in the above embodiments.

[0058] Please see Figure 5 As shown, Figure 5 This is a schematic diagram of a charging module provided in an embodiment of this application.

[0059] The charging module can be used to convert external power to supply external devices. In the charging module, the external power can sequentially pass through the reverse protection unit 601 and the EMI (Electromagnetic Interference) filter 602, and then sequentially supply power to the control unit 605 through the buck switching regulator 603 and the low dropout linear regulator 604; another path supplies power to subsequent circuits through the buck-boost circuit 617, which performs buck-boosting under the control of the adjustment signal of the control unit 605. The wireless charging control chip 606 and the voltage regulation chip 607 receive power from the buck-boost circuit 617, and the voltage regulation chip 607 supplies power to the coil 542 under the control of the control unit 605 and the wireless charging control chip 606. A parallel filter 608 is also connected between the voltage regulation chip 607 and the coil 542, and a charging coil switch 609 is provided between the parallel filter 608 and the coil 542. The charging coil switch 609 can be controlled to open or close by a charging enable signal issued by the control unit 605 or the wireless charging control chip 606. When three charging coils 542 are included, a corresponding charging coil switch 609 is provided between the parallel filter 608 and the positive terminal of each of the three charging coils 542, i.e., there are three charging coil switches 609. The charging coil switch 542 device can be a MOSFET. Furthermore, a corresponding resonant capacitor 610 is provided between the parallel filter 608 and the negative terminal of each of the three charging coils 542, i.e., there are three resonant capacitors 610. In addition, during the charging process of the charging device through the charging coils 542, the receiving coil in the charging device modulates the ASK carrier signal of the modulation signal onto the coil waveform of the wireless charging through load modulation. Then, the demodulation unit 618 performs detection and low-pass filtering through diodes and a low-pass filter circuit. The resulting signal is sent to the NU8040 chip for demodulation and also to the control unit 605 for processing and decoding, allowing the control unit 605 to perform corresponding subsequent operations based on the decoded information. Furthermore, in the charging module, the control unit is also connected to the CAN transceiver component 611, the NFC controller 612, the PEPS unit 613, the FAN unit 614, and the NTC unit 615. The CAN transceiver unit 611 is connected to the input connector 616 and the control unit 605, respectively, and is used to receive signals sent from the vehicle's central control unit and forward them to the control unit 605. The NFC controller 612 is connected to the control unit 605 and is used to poll and read the NFC card to wake up the wireless charging module. The PEPS (Passive Entry Passive Start) unit 613 is connected to the input connector 616 and the control unit 605, respectively, and is used for the vehicle's keyless entry and start system.The NTC (Negative Temperature Coefficient) unit 615 refers to a negative temperature coefficient thermistor. The NTC unit 615 is connected to the control unit 605 and can be configured in multiple locations for applications such as temperature measurement, temperature compensation, and current limiting. The FAN unit 614, also connected to the control unit, refers to a fan unit used for cooling. The input connector 616 is an interface component used to connect an external power supply or signal source to a circuit board or device. Its main function is to provide a reliable physical and electrical connection point so that electrical energy or signals can be smoothly transmitted to the circuit system. The design and type of the input connector can vary depending on the specific application requirements.

[0060] Understandably, the NU8040 is a highly integrated full-bridge power management chip for wireless charging transmitters. It achieves DC-AC conversion by alternately switching four MOSFETs within the chip using PWM control. A single NU8040 does not support 50W charging; to achieve 50W charging capability, two NU8040 chips can be used, with their inputs and outputs connected in parallel. Furthermore, a buck switching regulator 603 and a low-dropout linear regulator 604 can convert the power supply voltage to 5V or 3.3V to power other chips and devices.

[0061] The charging module of this application supports wireless charging for mobile phones using the latest 50W proprietary charging protocol, such as Xiaomi and Huawei. Furthermore, this application supports the Qi 1.3 wireless charging protocol. In this embodiment, the wireless charging control chip 606 can be a CPSQ8100, the voltage regulation chip 607 is a full-bridge power stage chip of model NU8040, the control unit 605 can be an S32K114, the CAN transceiver component 611 can be a TJA1042, the NFC controller 612 can be an ST25R3914, and the chip in the buck-boost circuit 617 can be a TPS55288.

[0062] It is understood that a charging module according to an embodiment of this application includes the above-described buck-boost circuit, and therefore the charging module can have all the technical features and beneficial effects of the above-described charging module, which will not be repeated here.

[0063] Thirdly, embodiments of this application provide a charging device, including the buck-boost circuit in the above embodiments, or the charging module in the above embodiments.

[0064] Please see Figure 6 As shown, Figure 6 This is a schematic diagram of the charging device provided in the embodiments of this application.

[0065] In some embodiments, the charging device 50 further includes:

[0066] The first cover plate 51 and the second cover plate 52 are arranged opposite to each other, and the first cover plate 51 and the second cover plate 52 are connected to form a receiving cavity 56;

[0067] PCBA board 53 is located inside receiving cavity 56; PCBA board 53 is provided with buck-boost circuit, or PCBA board 53 is provided with charging module.

[0068] The charging coil assembly 54 is disposed on the side of the PCBA board 53 facing the first cover plate 51, and the charging coil assembly 54 is electrically connected to the PCBA board 53.

[0069] The heat dissipation component 55 is located on the side of the second cover plate 52 away from the first cover plate 51, and the heat dissipation component 55 is connected to the second cover plate 52 and electrically connected to the PCBA board 53.

[0070] In some embodiments, the charging coil assembly 54 includes a coil 542 bracket and three parallel charging coils 542. The charging coils 542 are fixed to the coil 542 bracket and are respectively connected to the PCBA board 53. Multiple charging coils 542 allow for a greater positional tolerance of the device, eliminating the need to precisely place the device in a specific location to begin charging. Furthermore, the control unit 605 can activate the coil 542 that first successfully hands off via the charging coil switch 609, and deactivate the other coils 542, effectively selecting the charging coil 542 closest to the device 50 to be charged, thus improving charging efficiency.

[0071] In some embodiments, the heat dissipation assembly 55 includes a fan and a fan cover. The fan is connected to a second cover plate 52, and the fan cover is disposed on the fan and connected to the second cover plate 52. The fan is connected to the PCBA board 53, i.e., the FAN unit 614 includes a fan and is connected to the control unit 605. The heat dissipation assembly 55 can be used to cool the vehicle-mounted wireless charging device and the device 50 to be charged, effectively improving charging efficiency and safety performance, shortening charging time, and preventing long-term overheating and device aging.

[0072] In addition, a filter plate 57 is provided on the first cover plate 51 of this application. Furthermore, the first cover plate 51 is provided with a mounting groove 511 that cooperates with the filter plate 57 for mounting the filter plate 57. It is understood that the filter plate 57 can effectively filter out EMI radiation from wireless charging, especially EMI radiation in the low-frequency band, and better meet the EMI requirements put forward by various car manufacturers.

[0073] Please see Figure 7 As shown, Figure 7This is a partial structural schematic diagram of the PCBA board provided in the embodiments of the present application. In some embodiments, on the PCBA board 53, the distance L between the first voltage output terminal 12 of the buck-boost unit 10 and the second filtering unit 30 satisfies: 0 mm < L ≤ 1 mm. It can be understood that the distance L needs to satisfy 0 mm < L to prevent the second filtering unit 30 from overlapping and fitting with the buck-boost unit 10, which may affect the welding process. The distance L needs to satisfy L ≤ 1 mm because the distance between the second filtering unit 30 and the first voltage output terminal 12 of the buck-boost unit 10 will affect the parasitic inductance, which may cause voltage mutations and instability of the chip in the buck-boost unit 10. Therefore, the closer the distance between the second filtering unit 30 and the first voltage output terminal 12 of the buck-boost unit 10, the better the filtering effect and the more stable the chip. It can reduce parasitic inductance and capacitance, thereby improving the response speed and efficiency of the circuit. Moreover, an appropriate distance helps to maintain signal integrity and reduce signal reflection and interference. It should be noted that the distance between the first voltage output terminal 12 of the buck-boost unit 10 and the second filtering unit 30 refers to the distance between the welding positions of the second capacitor and the pin of the first voltage output terminal 12 of the corresponding chip of the buck-boost unit 10 on the PCBA board.

[0074] A charging device 50 according to an embodiment of the present application includes the above-mentioned buck-boost circuit or charging module. Therefore, the charging device 50 can have all the technical features and beneficial effects of the above-mentioned buck-boost circuit or charging module, which will not be elaborated here. Additionally, due to the use of a fan to cool the mobile phone, the fast charging time becomes longer.

[0075] The above are only optional embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structural transformation made under the application concept of the present application by using the content of the specification and drawings of the present application, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present application.

Claims

1. A step-up / step-down circuit, characterized in that, include: A boost / buck unit (10) has a first adjustment signal input terminal (11); The first filtering unit (20) has a second adjustment signal input terminal (21) and a first adjustment signal output terminal (22). The first adjustment signal output terminal (22) is connected to the first adjustment signal input terminal (11), and the second adjustment signal input terminal (21) is used to input the adjustment signal.

2. The step-up / step-down circuit according to claim 1, characterized in that, The first filtering unit (20) includes: A first resistor, one end of which is connected to the second adjustment signal input terminal (21); The second resistor has one end connected to the first adjustment signal output terminal (22) and the other end connected to the other end of the first resistor. A first capacitor, one end of which is connected between the first resistor and the second resistor, and the other end of which is grounded.

3. The step-up / step-down circuit according to claim 1, characterized in that, The buck-boost unit (10) also has a first voltage output terminal (12), and the buck-boost circuit further includes: The second filter unit (30) is connected to the first voltage output terminal (12).

4. The step-up / step-down circuit according to claim 3, characterized in that, The second filtering unit (30) includes: The second capacitor has one end connected to the first voltage output terminal (12) and the other end grounded.

5. The step-up / step-down circuit according to claim 4, characterized in that, The capacitance value of the second capacitor is between 0.8μF and 1.2μF.

6. The buck-boost circuit according to claim 1, characterized in that, Also includes: The digital-to-analog converter (40) has a third adjustment signal input terminal (41) and a second adjustment signal output terminal (42). The second adjustment signal output terminal (42) is connected to the second adjustment signal input terminal (21). The third adjustment signal input terminal (41) is used to input the adjustment signal.

7. A charging module, characterized in that, Includes the buck-boost circuit as described in any one of claims 1 to 6.

8. A charging device, characterized in that, It includes the buck-boost circuit as described in any one of claims 1 to 6, or the charging module as described in claim 7.

9. The charging device according to claim 8, characterized in that, Also includes: A first cover plate (51) and a second cover plate (52) are arranged opposite to each other, and the first cover plate (51) and the second cover plate (52) are connected to form a receiving cavity (56); A PCBA board (53) is disposed within the receiving cavity (56); the PCBA board (53) is provided with the buck-boost circuit, or the PCBA board (53) is provided with the charging module; A charging coil assembly (54) is disposed on the side of the PCBA board (53) facing the first cover plate (51), and the charging coil assembly (54) is electrically connected to the PCBA board (53); A heat dissipation component (55) is disposed on the side of the second cover plate (52) away from the first cover plate (51), and the heat dissipation component (55) is connected to the first cover plate (51) and electrically connected to the PCBA board (53).

10. The charging device according to claim 9, characterized in that, On the PCBA board (53), the distance L between the first voltage output terminal (12) of the buck-boost unit (10) and the second filter unit (30) satisfies: 0mm < L ≤ 1mm.

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