High-energy-efficiency quick charging circuit and device

Abstract

The embodiment of the utility model relates to the field of charging, in particular to a charging circuit and device. A power supply input end of the charging circuit is connected with an AC / DC conversion module, the AC / DC conversion module comprises a surge protection circuit unit, a filter circuit unit, a rectification circuit unit and a boost circuit unit, and the boost circuit unit comprises an inductor-diode boost circuit and an MOS switch circuit connected with the inductor-diode boost circuit. The inductor-diode boost circuit comprises a boost inductor L1, a boost inductor L2 and a diode D3 which are sequentially connected in series, and a diode D1 which is connected with the boost inductor L2 and the diode D3 in parallel; the PWM and PFC control circuit unit comprises a PFCDRV pin and a PFCSZCD pin, and the PFCDRV pin and the PFCSZCD pin are connected with the MOS switching circuit. According to the charging circuit, the power factor of the whole machine is improved by using the boosted circuit unit, so that the power factor is greatly improved and can reach more than 0.95, the heating value is reduced, and the charging efficiency is improved.

Description

Technical Field

[0001] The present utility model relates to the field of charging, and in particular to charging circuits and devices. Background Art

[0002] With the advancement of battery technology and the increasing demand for laptop battery life, the capacity of current laptop batteries has gradually increased, and with it, the demand for fast charging. Otherwise, it takes a considerable amount of time to fully charge the laptop battery. Existing laptop manufacturers often use different fast charging protocols to meet the fast charging requirements of their products according to their own design requirements.

[0003] Moreover, there are now various types of electronic devices such as mobile phones, tablets, and laptops, and products of different specifications from the same manufacturer often use different fast charging powers. In order to avoid each electronic device using a dedicated charger to achieve fast charging, the chargers that are randomly provided by existing manufacturers or third-party compatible chargers often need to meet the charging needs of multiple charging powers under multiple protocols. In order to achieve such usage requirements, the complexity of the existing charging circuit is more complicated than that of the ordinary single-protocol single-power charging circuit. In order to achieve output power control and regulation, there are generally more nonlinear load circuits and components, which makes its power factor relatively low, generally around 0.7, resulting in low power conversion efficiency and high heat generation. Utility Model Content

[0004] In a first aspect, embodiments of the present application disclose a high-efficiency fast charging circuit that solves problems such as low power factor and low power conversion efficiency in existing multi-protocol charging circuits.

[0005] The charging circuit of the embodiment of the present application includes:

[0006] It includes a power input terminal for connecting to the mains, wherein the power input terminal is connected to an AC-DC conversion module, and the AC-DC conversion module includes:

[0007] A surge protection circuit unit is connected to the power input terminal;

[0008] A filter circuit unit connected to the output section of the surge protection unit;

[0009] A rectifier circuit unit connected to the output section of the filter circuit unit;

[0010] a boost circuit unit connected to the output section of the rectifier circuit unit, comprising an inductor-diode boost circuit and a MOS switch circuit connected to the inductor-diode boost circuit, wherein the inductor-diode boost circuit comprises a boost inductor L1, a boost inductor L2, and a diode D3 connected in series, and a diode D1 connected in parallel with the boost inductor L2 and the diode D3;

[0011] The PWM and PFC control circuit unit includes a PFCDRV pin and a PFCSZCD pin, and the PFCDRV pin and the PFCSZCD pin are connected to the MOS switch circuit.

[0012] Due to the adoption of the above-mentioned technical solution, the charger circuit of the present application improves the power factor of the circuit through the cooperation of the boost circuit unit with the PWM and PFC control circuit units, thereby significantly improving the power factor to above 0.95. In addition, the boost circuit unit can realize the segmented function of the PFC voltage, thereby achieving compatibility of circuit functions, simplifying the circuit design, reducing the circuit scale, reducing heat generation, and improving charging efficiency.

[0013] In one possible implementation, the MOS switch circuit includes a switch tube Q1 connected to the boost inductor L2, the gate of the switch tube Q1 is connected to the PFCDRV pin, the drain of the switch tube Q1 is connected to the boost inductor L2, and the source of the switch tube Q1 is connected to the PFCSZCD pin via a series-parallel resistor circuit.

[0014] In one possible implementation, the output section of the inductor-diode boost circuit is connected to a primary RCD peak pulse absorption circuit, the output section of the primary RCD peak pulse absorption circuit is connected to a transformer circuit, the primary RCD peak pulse absorption circuit includes a parallel circuit of a resistor R4 and a capacitor C4 and a parallel circuit of a resistor R11 and a capacitor C7 connected in sequence, and is connected to a parallel resistance circuit consisting of a resistor R17, a resistor R18, and a resistor R19, and the parallel resistance circuit is connected in series with a diode D6.

[0015] In one possible implementation, the PWM and PFC control circuit unit further includes a VIN pin for IC startup power supply, the VIN pin is connected to a linear voltage regulator circuit, the linear voltage regulator circuit includes a voltage regulator transistor Q3, a resistor R51 is connected in parallel between the collector and base of the voltage regulator transistor Q3, the base of the voltage regulator transistor Q3 is connected to a voltage regulator diode ZD1, and the emitter of the voltage regulator transistor Q3 is connected in series with a diode D8 and then connected to the VIN pin.

[0016] In one possible implementation, the surge protection circuit unit is a common-mode inductor circuit, comprising a varistor RV1, a common-mode inductor LF1, and a common-mode inductor LF2 connected sequentially between the neutral line and the live line of the mains, and a thermistor RT1 connected in series on the live line;

[0017] In one possible implementation, the filtering circuit unit includes an X capacitor CX1 connected in parallel between the common-mode inductor LF1 and the common-mode inductor LF2, and a discharge resistance circuit connected in parallel with the output section of the common-mode inductor LF2, wherein the discharge resistance circuit includes multiple groups of connected parallel resistors.

[0018] In a possible implementation, the rectifier circuit unit is connected to the output section of the common-mode inductor LF2 and includes a rectifier bridge.

[0019] In a possible implementation, the PWM and PFC control circuit unit is an IC of model LD7798ODGS1.

[0020] In one possible implementation, the secondary side of the transformer circuit is connected to the charging output interface through a synchronous rectifier module, and the synchronous rectifier module includes an LD8526GL model IC; the charging output interface includes a device identification pin, and the device identification pin is connected to a protocol chip circuit, and the protocol chip circuit includes an LD6612GQMW model IC.

[0021] In a second aspect, an embodiment of the present application further discloses a charging device, comprising any one of the charging circuits of the first aspect described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the module structure of the first embodiment;

[0023] Figure 2 This is a circuit diagram of an AC / DC conversion module according to a second embodiment;

[0024] Figure 3 Schematic diagram of the specific circuit structure of the synchronous rectification module of the second embodiment;

[0025] Figure 4 FIG. 2 is a schematic diagram of a specific circuit structure of a protocol chip circuit according to the second embodiment. DETAILED DESCRIPTION

[0026] To make the purpose, technical solutions, and advantages of this application more clear, the technical solutions of this application will be described in detail below through implementation methods with reference to the accompanying drawings in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. In the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0027] Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of this application.

[0028] It should be noted that, in the description of this application, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, movable, or detachable connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0029] like Figure 1 As shown, the charging circuit of the first embodiment of the present application includes:

[0030] The power input terminals L and N are used to connect to the mains, with L connected to the live wire of the mains and N connected to the neutral wire of the mains. The power input terminal is connected to an AC / DC conversion module 1, which converts the AC power of the mains into DC power for the charging circuit and performs a series of processing on the AC and DC power. In this embodiment, the AC / DC conversion module 1 includes:

[0031] The surge protection circuit unit 11 is connected to the power input terminal and is used to smooth out the surge current when lightning strikes or when the mains power is initially connected;

[0032] The filter circuit unit 12 is connected to the output section of the surge protection unit and filters the input AC power to make it have a stable waveform;

[0033] The rectifier circuit unit 13 is connected to the output section of the filter circuit unit and converts the input AC power into DC power output;

[0034] The boost circuit unit 14 is connected to the output section of the rectifier circuit unit and includes an inductor-diode boost circuit and a Q1 MOS switch circuit connected to the inductor-diode boost circuit; it boosts the input DC power, mainly for improving the power factor of the circuit.

[0035] The PWM and PFC control circuit unit 15 includes a PFCDRV pin and a PFCSZCD pin, which are connected to the Q1 MOS switch circuit. In this embodiment, the PWM and PFC control circuit unit is implemented using a PWM integrated circuit chip with a PFC processing circuit. To improve the power factor of the circuit in conjunction with the boost circuit unit 14, the PFCDRV and PFCSZCD pins are provided. The PFCDRV pin is connected to the Q1 MOS switch circuit. In this embodiment, the PWM and PFC control circuit unit 15 is connected to a transformer.

[0036] The charger circuit of this embodiment incorporates PFC processing into a traditional PWM control unit. This, in conjunction with a boost circuit unit, significantly improves the power factor of the entire device, significantly increasing it to approximately 90%. Furthermore, the boost circuit unit enables segmented PFC voltage control, achieving circuit functional compatibility, simplifying circuit design, reducing circuit size, reducing heat generation, and improving charging efficiency.

[0037] The PFC (Power Factor Correction) voltage segmentation function adjusts the PFC circuit's output voltage into multiple stages or intervals based on varying input voltage and load conditions, optimizing power supply performance and efficiency. For example, when the input voltage is low, lowering the PFC voltage can effectively reduce component losses. When the input voltage is high or the load is heavy, increasing the PFC voltage appropriately ensures stable circuit operation and a good power factor.

[0038] The second embodiment of the present application provides a specific circuit implementation method, such as Figure 2 As shown, in the second embodiment, the inductor-diode boost circuit includes a boost inductor L1, a boost inductor L2 and a diode D3 connected in series, and a diode D1 connected in parallel with the boost inductor L2 and the diode D3.

[0039] In this embodiment, the Q1 MOS switch circuit includes a switch tube Q1 connected to the boost inductor L2, the gate of the switch tube Q1 is connected to the PFCDRV pin, the drain of the switch tube Q1 is connected to the boost inductor L2, and the source of the switch tube Q1 is connected to the PFCSZCD pin via a series-parallel resistor circuit.

[0040] The Q1 MOS switch circuit primarily functions to activate and deactivate the boost circuit unit in conjunction with the output power determination of the rear side. This activates the boost circuit unit when the output reaches a certain wattage threshold, and deactivates it otherwise, reducing circuit losses and improving charging efficiency under low loads. In this embodiment, to control the activation and deactivation of the Q1 MOS switch circuit, the Q1 MOS switch circuit is controlled to activate when the output power is greater than or equal to 35W.

[0041] This embodiment further includes a Q2 MOS switch circuit, which serves as an output control switch. When the Q1 MOS switch circuit operates normally, the negative segment of the diode D1 has a high voltage signal. The PWM and PFC control circuit unit 15 detects the high voltage signal and outputs a high voltage signal to rapidly open the Q2 MOS switch circuit. When the Q2 MOS switch circuit is open, current flows from the input end to the downstream transformer.

[0042] In this embodiment, in order to absorb the peak voltage generated by the leakage inductance of the transformer when the transformer is connected, the output section of the inductor-diode boost circuit is connected to a primary RCD peak pulse absorption circuit, and the output section of the primary RCD peak pulse absorption circuit is connected to the transformer circuit. The primary RCD peak pulse absorption circuit includes a parallel circuit of a resistor R4 and a capacitor C4 and a parallel circuit of a resistor R11 and a capacitor C7 connected in sequence, and is connected to a parallel resistance circuit consisting of a resistor R17, a resistor R18, and a resistor R19. The parallel resistance circuit is connected in series with a diode D6.

[0043] In this embodiment, the PWM and PFC control circuit unit also includes a VIN pin for powering the IC. This VIN pin is connected to a linear voltage regulator circuit. This linear voltage regulator circuit includes a voltage regulator transistor Q3. A resistor R51 is connected in parallel between the collector and base of the voltage regulator transistor Q3. The base of the voltage regulator transistor Q3 is connected to a voltage regulator diode ZD1. The emitter of the voltage regulator transistor Q3 is connected in series with a diode D8 and then to the VIN pin. The VIN pin provides voltage and current to the IC at startup. After the circuit is started, the VIN pin automatically shuts down the linear voltage regulator circuit, and the IC's operating current is supplied by the VCC pin. In this embodiment, by incorporating a transistor linear voltage regulator circuit into the power supply circuit, the IC's supply voltage within the pin's voltage tolerance range is ensured under full input and output voltage conditions, preventing the IC's overvoltage protection from being triggered.

[0044] In terms of the specific circuit settings of the auxiliary circuit, some examples are also provided in this embodiment. Since there are many circuit forms for realizing corresponding functions, one circuit implementation is provided below, and the description of alternative situations is not expanded. During specific implementation, relevant functional circuits can be selected as replacements according to actual conditions.

[0045] Optionally, in this embodiment, the surge protection circuit unit is a common-mode inductor circuit, comprising a varistor RV1, a common-mode inductor LF1, and a common-mode inductor LF2 sequentially connected between the neutral line and the live line of the mains, and a thermistor RT1 connected in series on the live line;

[0046] Optionally, in this embodiment, the filtering circuit unit includes an X capacitor CX1 connected in parallel between the common-mode inductor LF1 and the common-mode inductor LF2, and a discharge resistance circuit connected in parallel with the output section of the common-mode inductor LF2, and the discharge resistance circuit includes multiple groups of connected parallel resistors.

[0047] Optionally, in this embodiment, the rectifier circuit is connected to the output section of the common-mode inductor LF2 and includes a rectifier bridge.

[0048] Optionally, the PWM and PFC control circuit unit described in this embodiment is the LD7798ODGS1 IC. Tongjia's LD7798ODGS1 IC is a highly efficient control chip integrating PFC and PWM. It uses a conventional SOP-16 package, facilitating debugging and production process control, reducing overall size and area, and improving energy efficiency.

[0049] like Figure 3 As shown, in terms of component selection, the secondary side of the transformer described in this embodiment is optionally connected to the charging output interface via a synchronous rectifier module. The synchronous rectifier module includes the LD8526GL IC. Tongjia's LD8526GL IC features compact size and high energy efficiency, making it suitable for miniaturized, high-conversion-rate, and low-heat charging circuit solutions.

[0050] like Figure 4 As shown, optionally, in terms of component selection, the charging output interface described in this embodiment includes a device identification pin, and the device identification pin is connected to a protocol chip circuit, and the protocol chip circuit includes an LD6612GQMW model IC.

[0051] Optionally, in terms of component selection, the charging output interface in this embodiment is a TYPE-C interface, having pins such as CC1 and CC2 for conducting electrical signal handshake communication with the charged device. The device identification pin described in this embodiment is the CC2 pin of the TYPE-C interface.

[0052] Since the circuit improvement in this embodiment is mainly located in the specific circuit of the AC-DC conversion module, the pin definitions of the synchronous rectification module, the protocol chip circuit, and the charging output interface are only exemplified in conjunction with the drawings and will not be further explained.

[0053] The third embodiment of the present application further discloses a charging device, which includes the charging circuit described in detail in the first and second embodiments above.

[0054] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the description and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A high-efficiency fast charging circuit, including a power input terminal for connecting to mains power, characterized in that: The power input terminal is connected to an AC / DC conversion module, and the AC / DC conversion module includes: A surge protection circuit unit is connected to the power input terminal; A filter circuit unit connected to the output section of the surge protection unit; A rectifier circuit unit connected to the output section of the filter circuit unit; a boost circuit unit connected to the output section of the rectifier circuit unit, comprising an inductor-diode boost circuit and a MOS switch circuit connected to the inductor-diode boost circuit, wherein the inductor-diode boost circuit comprises a boost inductor L1, a boost inductor L2, and a diode D3 connected in series, and a diode D1 connected in parallel with the boost inductor L2 and the diode D3; The PWM and PFC control circuit unit includes a PFCDRV pin and a PFCSZCD pin, and the PFCDRV pin and the PFCSZCD pin are connected to the MOS switch circuit.

2. The high-performance fast charging circuit according to claim 1, wherein: The MOS switch circuit includes a switch tube Q1 connected to the boost inductor L2, the gate of the switch tube Q1 is connected to the PFCDRV pin, the drain of the switch tube Q1 is connected to the boost inductor L2, and the source of the switch tube Q1 is connected to the PFCSZCD pin via a series-parallel resistor circuit.

3. The high-performance fast charging circuit according to claim 2, wherein: The output section of the inductor-diode boost circuit is connected to a primary RCD peak pulse absorption circuit, and the output section of the primary RCD peak pulse absorption circuit is connected to a transformer circuit. The primary RCD peak pulse absorption circuit includes a parallel circuit of a resistor R4 and a capacitor C4 and a parallel circuit of a resistor R11 and a capacitor C7 connected in sequence, and is connected to a parallel resistance circuit consisting of a resistor R17, a resistor R18, and a resistor R19, and the parallel resistance circuit is connected in series with a diode D6.

4. The high-efficiency fast charging circuit according to any one of claims 1 to 3, wherein: The PWM and PFC control circuit unit also includes a VIN pin for IC startup power supply. The VIN pin is connected to a linear voltage regulator circuit. The linear voltage regulator circuit includes a voltage regulator transistor Q3. A resistor R51 is connected in parallel between the collector and base of the voltage regulator transistor Q3. The base of the voltage regulator transistor Q3 is connected to a voltage regulator diode ZD1. The emitter of the voltage regulator transistor Q3 is connected in series with a diode D8 and then connected to the VIN pin.

5. The high-performance fast charging circuit according to claim 1, wherein: The surge protection circuit unit is a common mode inductor circuit, including a varistor RV1, a common mode inductor LF1, and a common mode inductor LF2 connected in sequence between the neutral line and the live line of the mains, and a thermistor RT1 is connected in series to the live line.

6. The high-performance fast charging circuit according to claim 1, wherein: The filter circuit unit includes an X capacitor CX1 connected in parallel between the common mode inductor LF1 and the common mode inductor LF2 and a discharge resistance loop connected in parallel with the output section of the common mode inductor LF2. The discharge resistance loop includes multiple groups of parallel resistors.

7. The high-efficiency fast charging circuit as claimed in claim 6, wherein: The rectifier circuit unit is connected to the output section of the common mode inductor LF2 and includes a rectifier bridge.

8. The high-efficiency fast charging circuit as claimed in claim 4, wherein: The PWM and PFC control circuit unit is an IC of model LD7798ODGS1.

9. The high-performance fast charging circuit according to claim 3, wherein: The secondary side of the transformer circuit is connected to the charging output interface through a synchronous rectifier module, and the synchronous rectifier module includes an LD8526GL model IC; the charging output interface includes a device identification pin, and the device identification pin is connected to a protocol chip circuit, and the protocol chip circuit includes an LD6612GQMW model IC.

10. High-efficiency fast charging device, characterized in that: The charging circuit comprises any one of claims 1 to 9.

Images