Switching power supply circuit and power adapter

Abstract

This application relates to a switching power supply circuit and a power adapter, including an input rectifier circuit and a PFC circuit. The first terminal of the input rectifier circuit is connected to an AC power source. The PFC circuit includes a first switching transistor, a second switching transistor, and a drive control circuit. The first terminals of the first and second switching transistors are respectively connected to the second terminal of the input rectifier circuit. The first terminal of the drive control circuit is connected to the control terminal of the first switching transistor, and the second terminal of the drive control circuit is connected to the control terminal of the second switching transistor. The drive control circuit outputs a first drive signal at its first terminal to drive the first switching transistor and outputs a second drive signal at its second terminal to drive the second switching transistor. The waveforms of the first and second drive signals are complementary, and the voltage of the first drive signal is less than the voltage of the second drive signal. Embodiments of this application can improve the efficiency of the PFC circuit.

Description

Technical Field

[0001] This application relates to the field of switching power supply technology, and in particular to a switching power supply circuit and a power adapter. Background Technology

[0002] A switching power supply is a highly efficient power conversion device that regulates the output voltage and current by rapidly switching elements. The input power of a switching power supply is the energy it obtains from the mains or other power sources. When the input power of a switching power supply exceeds 75W, a power factor correction (PFC) circuit is required to improve its power and stability.

[0003] As the output power requirements of switching power supplies increase, the size of the switching power supplies needs to increase accordingly. However, the size of the switching power supply cannot continue to increase with the increase in output power. Therefore, it is necessary to improve the efficiency of the switching power supply to meet the demand for increased output power. However, the efficiency of the PFC circuit in the current switching power supply is not high. Utility Model Content

[0004] Therefore, it is necessary to provide a switching power supply circuit and power adapter that can improve the efficiency of PFC circuit.

[0005] In a first aspect, this application provides a switching power supply circuit, including:

[0006] An input rectifier circuit, wherein the first terminal of the input rectifier circuit is used to connect to an AC power source;

[0007] The PFC circuit includes a first switching transistor, a second switching transistor, and a drive control circuit.

[0008] Wherein, the first terminal of the first switching transistor and the first terminal of the second switching transistor are respectively connected to the second terminal of the input rectifier circuit, the second terminal of the first switching transistor is grounded, and the second terminal of the second switching transistor is connected to the subsequent circuit.

[0009] The first terminal of the drive control circuit is connected to the control electrode of the first switching transistor, and the second terminal of the drive control circuit is connected to the control electrode of the second switching transistor. The drive control circuit is used to output a first drive signal at the first terminal to drive the first switching transistor, and to output a second drive signal at the second terminal to drive the second switching transistor. The waveforms of the first drive signal and the second drive signal are complementary, and the voltage of the first drive signal is less than the voltage of the second drive signal.

[0010] Secondly, this application also provides a power adapter that includes the switching power supply circuit described in the first aspect above.

[0011] The aforementioned switching power supply circuit and power adapter, wherein the switching power supply circuit includes an input rectifier circuit and a PFC circuit, wherein the first terminal of the input rectifier circuit is used to connect to an AC power source, and the PFC circuit includes a first switching transistor, a second switching transistor, and a drive control circuit. The first terminals of the first and second switching transistors are respectively connected to the second terminal of the input rectifier circuit, the second terminal of the first switching transistor is grounded, and the second terminal of the second switching transistor is connected to the subsequent stage circuit. The first terminal of the drive control circuit is connected to the control terminal of the first switching transistor, and the second terminal of the drive control circuit is connected to the control terminal of the second switching transistor. The drive control circuit outputs a first drive signal at its first terminal to drive the first switching transistor, and outputs a second drive signal at its second terminal to drive the second switching transistor. The waveforms of the first and second drive signals are complementary, and the voltage of the first drive signal is less than the voltage of the second drive signal. Thus, the PFC circuit of this application embodiment includes a first switch, a second switch, and a drive control circuit. The drive control circuit can output complementary first and second drive signals to drive the first and second switches. Since the second switch has a smaller on-resistance, the PFC circuit has lower losses and improves the efficiency of the PFC circuit. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 A block diagram of a switching power supply circuit according to one embodiment;

[0014] Figure 2 A block diagram of a PFC circuit according to another embodiment;

[0015] Figure 3 A block diagram of the drive control circuit for another embodiment;

[0016] Figure 4 A block diagram of the driving circuit for another embodiment;

[0017] Figure 5 A block diagram of the input rectifier circuit for another embodiment;

[0018] Figure 6 A block diagram of a rectifier circuit according to another embodiment;

[0019] Figure 7 A block diagram of a rectifier circuit according to another embodiment;

[0020] Figure 8 A block diagram of a filter protection circuit according to another embodiment;

[0021] Figure 9 A block diagram of a rectifier circuit according to another embodiment;

[0022] Figure 10 A block diagram of a filter boost circuit according to another embodiment;

[0023] Figure 11 A block diagram of the first switching transistor in another embodiment;

[0024] Figure 12 A block diagram of the second switching transistor in another embodiment;

[0025] Figure 13 A block diagram of the drive control circuit for another embodiment;

[0026] Figure 14 This is a block diagram of a drive control circuit according to another embodiment.

[0027] Explanation of reference numerals in the attached figures:

[0028] Switching power supply circuit 10; Input rectifier circuit 11; PFC circuit 12;

[0029] First switching transistor 121; Second switching transistor 122; Drive control circuit 123;

[0030] Filter boost circuit 124; Output circuit 125;

[0031] First power management circuit 1231; drive circuit 1232;

[0032] Digital isolation circuit 1232a; isolated power supply circuit 1232b;

[0033] Filter protection circuit 111; Rectifier circuit 112;

[0034] First MOS switch 112a; Second MOS switch 112b;

[0035] The third MOSFET is 112c; the fourth MOSFET is 112d;

[0036] Second power management circuit 112e; Third power management circuit 112f;

[0037] Fourth power management circuit 112g; Fifth power management circuit 112h;

[0038] The first capacitor is 112i; the second capacitor is 112j; the third capacitor is 112k; and the fourth capacitor is 112l. Detailed Implementation

[0039] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0041] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0042] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0043] It is understandable that "at least one" refers to one or more, and "multiple" refers to two or more. "At least a part of an element" refers to part or all of an element.

[0044] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0045] A switching power supply is a highly efficient power conversion device that regulates the output voltage and current by rapidly switching elements. The input power of a switching power supply is the energy it obtains from the mains or other power sources. When the input power of a switching power supply exceeds 75W, a power factor correction (PFC) circuit is required to improve its power and stability.

[0046] As the output power requirements of switching power supplies increase, their size also needs to increase accordingly. However, the size of switching power supplies cannot continue to increase with the increase in output power. Therefore, it is necessary to improve the efficiency of switching power supplies to meet the increased output power requirements. In related technologies, the PFC circuit of a switching power supply includes a switching transistor and a diode. Due to the forward voltage drop of the diode, the circuit loss of the PFC circuit is relatively large. For example, the forward voltage drop of the ultra-fast recovery diode MUR560 is about 1.05V, and the forward voltage drop of the silicon carbide diode C1D05AC is about 1.12V. The current loss of the diode is the product of the forward voltage drop and the current. That is, when the current flowing through the diode is 2A, the current loss is about 2W.

[0047] Therefore, embodiments of this application provide a switching power supply circuit and a power adapter that can improve the efficiency of the PFC circuit.

[0048] like Figure 1 As shown, the switching power supply circuit 10 in this embodiment includes an input rectifier circuit 11 and a PFC circuit 12.

[0049] In this embodiment, the input rectifier circuit 11 is used to convert alternating current (AC) to direct current (DC). Optionally, the input rectifier circuit 11 may include a protection circuit, a rectifier, and a filter circuit. The protection circuit can prevent excessive current in the input rectifier circuit 11 from damaging the circuit components. The rectifier can convert AC to DC, and the filter circuit can smooth the output voltage to ensure that the input rectifier circuit 11 outputs a stable DC signal. The PFC circuit 12 is used to improve the power factor of the switching power supply circuit 10, reduce harmonic distortion, and thus improve energy utilization efficiency.

[0050] The first terminal of the input rectifier circuit 11 is connected to an AC power source. The PFC circuit 12 includes a first switching transistor 121, a second switching transistor 122, and a drive control circuit 123. The first terminal of the first switching transistor 121 and the first terminal of the second switching transistor 122 are respectively connected to the second terminal of the input rectifier circuit 11. The second terminal of the first switching transistor 121 is grounded, and the second terminal of the second switching transistor 122 is connected to the subsequent circuit.

[0051] The AC power supply can be 220V AC mains power. The first terminal of the input rectifier circuit 11 is connected to the AC power supply, and the second terminal of the input rectifier circuit 11 is connected to the first terminal of the first switching transistor 121 and the first terminal of the second switching transistor 122. Optionally, the first switching transistor 121 can be a MOS (Metal-Oxide-Semiconductor Field-Effect Transistor) or a GAN (Gallium Nitride Field-Effect Transistor). The second switching transistor 122 can be either a MOS or a GAN. MOS switches have low on-resistance and high-speed switching characteristics, and can include both N-channel and P-channel types, which can be selected according to the actual circuit design. GAN switches have high efficiency and high-speed switching characteristics, which can significantly reduce energy loss in the circuit. The first terminal of the first switching transistor 121 and the first terminal of the second switching transistor 122 can be the drain (D), and the second terminal of the first switching transistor 121 and the second terminal of the second switching transistor 122 can be the source (S).

[0052] Optionally, taking the use of a GAN switch as the second switch 122 as an example, the current loss of the PFC circuit 12 using the second switch 122 is the product of the internal resistance Rds(on) of the second switch 122, i.e., the on-resistance and the square of the current. When the internal resistance of the GAN switch is 0.15Ω, the current loss = 0.15Ω x 2. 2 =0.6W. It can be seen that the PFC circuit 12 using the second switching transistor 122 has a lower loss of 2W than the PFC circuit 12 using a diode; therefore, the PFC circuit 12 is more efficient.

[0053] The drive control circuit 123 is used to drive the first switch 121 and the second switch 122 to work. The subsequent circuit may include an isolation circuit and a load.

[0054] The first terminal of the drive control circuit 123 is connected to the control electrode of the first switching transistor 121, and the second terminal of the drive control circuit 123 is connected to the control electrode of the second switching transistor 122. The drive control circuit 123 is used to output a first drive signal at the first terminal of the drive control circuit 123 to drive the first switching transistor 121, and to output a second drive signal at the second terminal of the drive control circuit 123 to drive the second switching transistor 122. The waveforms of the first drive signal and the second drive signal are complementary, and the voltage of the first drive signal is less than the voltage of the second drive signal.

[0055] In the embodiments of this application, the first driving signal and the second driving signal can be pulse width modulation (PWM) signals. The waveforms of the first driving signal and the second driving signal are complementary; that is, when the first driving signal output is high, the second driving signal output is low, and vice versa. The first terminal of the drive control circuit 123 outputs a first driving signal to control the operation of the first switching transistor 121. Since the second terminal of the first switching transistor 121 is grounded, the first switching transistor 121 can be driven using a lower voltage; therefore, the voltage of the first driving signal can be a low-voltage signal. The second terminal of the drive control circuit 123 outputs a second control signal to control the operation of the second switching transistor 122. The second terminal of the second switching transistor 122 is connected to the subsequent circuit. The second switching transistor 122 requires a higher voltage to be driven; therefore, the voltage of the second driving signal needs to be a high-voltage signal.

[0056] In the above embodiment, the switching power supply circuit 10 includes an input rectifier circuit 11 and a PFC circuit 12. The first terminal of the input rectifier circuit 11 is connected to an AC power source. The PFC circuit 12 includes a first switching transistor 121, a second switching transistor 122, and a drive control circuit 123. The first terminals of the first switching transistor 121 and the second switching transistor 122 are respectively connected to the second terminal of the input rectifier circuit 11. The second terminal of the first switching transistor 121 is grounded, and the second terminal of the second switching transistor 122 is connected to the subsequent stage circuit. The first terminal of the drive control circuit 123 is connected to the control terminal of the first switching transistor 121, and the second terminal of the drive control circuit 123 is connected to the control terminal of the second switching transistor 122. The drive control circuit 123 outputs a first drive signal at its first terminal to drive the first switching transistor 121 and outputs a second drive signal at its second terminal to drive the second switching transistor 122. The waveforms of the first and second drive signals are complementary, and the voltage of the first drive signal is less than the voltage of the second drive signal. Thus, the PFC circuit 12 of this application embodiment includes a first switch 121, a second switch 122, and a drive control circuit 123. The drive control circuit 123 can output complementary first drive signals and second drive signals to drive the first switch 121 and the second switch 122. Since the second switch 122 has a smaller on-resistance, the PFC circuit 12 has lower losses and improves the efficiency of the PFC circuit 12.

[0057] In one embodiment, based on Figure 1 The illustrated embodiment can be found in [reference]. Figure 2 The PFC circuit 12 also includes a filter boost circuit 124 and an output circuit 125.

[0058] The filter boost circuit 124 can be used to convert low voltage to high voltage. The filter boost circuit 124 may include a filter circuit and a boost inductor. The filter circuit smooths the input voltage, and then the boost inductor boosts the voltage to the desired output voltage level. The filter circuit may consist of an inductor and a capacitor, effectively removing noise and fluctuations in the input voltage and ensuring the stability of the boost process.

[0059] The first terminal of the filter boost circuit 124 is connected to the second terminal of the input rectifier circuit 11, the second terminal of the filter boost circuit 124 is connected to the first terminal of the first switching transistor 121 and the first terminal of the second switching transistor 122 respectively, and the third terminal of the filter boost circuit 124 is connected to the third terminal of the drive control circuit 123.

[0060] In the embodiments of this application, the first terminal of the filter boost circuit 124 is connected to the second terminal of the input rectifier circuit 11, receiving the voltage signal output by the input rectifier circuit 11. After filtering and boosting the voltage signal, the filter boost circuit 124 outputs the signal to the first terminal of the first switching transistor 121 and the first terminal of the second switching transistor 122. The third terminal of the filter boost circuit 124 is connected to the third terminal of the drive control circuit 123, providing voltage to the drive control circuit 123.

[0061] The first terminal of the output circuit 125 is connected to the second terminal of the second switching transistor 122 and the fourth terminal of the drive control circuit 123, respectively. The first terminal of the output circuit 125 is also used to connect to the subsequent circuit, and the second terminal of the output circuit 125 is grounded.

[0062] Optionally, the output circuit 125 may include an output capacitor and a grounding resistor. The output capacitor stores electrical energy and releases it when the subsequent circuit changes, thereby maintaining a stable output, smoothing voltage fluctuations, and ensuring a stable power supply when the switching power supply circuit 10 is connected to the subsequent circuit. The grounding resistor can effectively guide interference signals in the circuit to ground, thereby reducing noise and electromagnetic interference and improving the circuit's anti-interference capability.

[0063] In the above embodiments, the efficient operation and stability of the switching power supply circuit 10 are ensured by the coordinated operation of the filter boost circuit 124 and the output circuit 125.

[0064] In the embodiments of this application, such as Figure 3As shown, the drive control circuit 123 includes a first power management circuit 1231 and a drive circuit 1232. The first terminal of the first power management circuit 1231 is connected to the control electrode of the first switching transistor 121; the second terminal of the first power management circuit 1231 is connected to the third terminal of the input rectifier circuit 11; the third terminal of the first power management circuit 1231 is connected to the third terminal of the filter boost circuit 124; the fourth terminal of the first power management circuit 1231 is used to connect to subsequent circuits; and the first power management circuit 1231 outputs a first drive signal from its first terminal.

[0065] The first power management circuit 1231 may include an integrated controller chip for power management. The first terminal of the first management circuit is connected to the control electrode of the first switching transistor 121, and outputs a first drive signal to control the operation of the first switching transistor 121. The integrated controller chip may include multiple functional pins, and each pin is connected to the input rectifier circuit 11, the filter boost circuit 124, and the subsequent circuits according to their functions.

[0066] The first terminal of the driving circuit 1232 is connected to the fifth terminal of the first power management circuit 1231, the second terminal of the driving circuit 1232 is connected to the first terminal of the output circuit 125, and the third terminal of the driving circuit 1232 is connected to the control electrode of the second switching transistor 122. The first power management circuit 1231 is also used to output a reverse driving signal at its fifth terminal. The waveform of the reverse driving signal is complementary to the waveform of the first driving signal. The driving circuit 1232 is used to amplify the output voltage at the first terminal of the output circuit 125, and output a second driving signal at its third terminal based on the amplified output voltage and the reverse driving signal.

[0067] The driving circuit 1232 may include a digital isolation module and an isolation power supply module. The digital isolation module and the isolation power supply module may be circuits or integrated chips. The driving circuit 1232 can isolate the input and output signals through the digital isolation module and the isolation power supply module, thereby achieving signal isolation technology to prevent interference and protect the circuit.

[0068] In the embodiments of this application, such as Figure 4 As shown, the driving circuit 1232 includes a digital isolation circuit 1232a and an isolation power supply circuit 1232b.

[0069] Digital isolation circuit 1232a: its first terminal is connected to the fifth terminal of the first power management circuit 1231; its second terminal is connected to the control electrode of the second switching transistor 122; and its third terminal is connected to the first terminal of the output circuit 125. Isolation power supply circuit 1232b: its first terminal is connected to the first terminal of the output circuit 125; its second terminal is connected to the fourth terminal of the digital isolation circuit 1232a and the power supply terminal of the second switching transistor 122, respectively. Isolation power supply circuit 1232b amplifies the output voltage at the first terminal of the output circuit 125 and outputs a boost voltage signal at its second terminal based on the amplified output voltage. Digital isolation circuit 1232a outputs a second drive signal at its second terminal based on the boost voltage signal and the reverse drive signal.

[0070] As can be seen from the above, the fifth terminal of the first power management circuit 1231 can output a drive signal that is opposite to that of the first terminal. The first power management circuit 1231 outputs the reverse drive signal from the fifth terminal to the first terminal of the drive circuit 1232, that is, the first terminal of the digital isolation circuit 1232a. The isolation power supply circuit 1232b amplifies the output voltage of the first terminal of the output circuit 125 and outputs a boost voltage signal to the digital isolation circuit 1232a. Then, the digital isolation circuit 1232a outputs a second drive signal according to the reverse drive signal and the boost voltage signal, and outputs it to the second switching transistor 122 through the third terminal of the drive circuit 1232 to drive the second switching transistor 122 to work.

[0071] In the above embodiment, a second driving signal that is opposite to the first driving signal is generated by the digital isolation circuit 1232a and the isolation power supply circuit 1232b of the driving circuit 1232 to drive the second switching transistor 122 to work.

[0072] In the embodiments of this application, please refer to Figure 5 The input rectifier circuit 11 includes a filter protection circuit 111 and a rectifier circuit 112. The first terminal of the filter protection circuit 111 is connected to the AC power supply. The first terminal of the rectifier circuit 112 is connected to the second terminal of the filter protection circuit 111, and the second terminal of the rectifier circuit 112 is connected to the first terminal of the filter boost circuit 124.

[0073] The filter protection circuit 111 can be a fuse. When the current input to the rectifier circuit 11 exceeds the safety limit, the filter protection circuit 111 disconnects, thereby cutting off the current and preventing damage to other circuits. The rectifier circuit 112 is used to convert alternating current to direct current and can be composed of diodes, transistors, or other semiconductor devices. The rectifier circuit 112 can be a bridge rectifier circuit or a half-wave rectifier circuit.

[0074] Optional, such as Figure 6 As shown, the rectifier circuit 112 includes a first bridge arm and a second bridge arm connected in parallel. The first bridge arm includes a first MOS switch 112a and a second MOS switch 112b connected in series, and the second bridge arm includes a third MOS switch 112c and a fourth MOS switch 112d connected in series.

[0075] In traditional switching power supply circuits, the rectifier circuit typically uses a bridge rectifier composed of four diodes. However, this method results in significant current loss due to the large forward voltage drop of the diodes. For example, a bridge rectifier composed of GBU1006 diodes has a forward voltage drop of 1V. In one cycle, current flows through two diodes. When the current is 5A, the current loss is 1V x 2 x 5A = 10W.

[0076] Therefore, to improve circuit efficiency and reduce current loss in rectifier circuit 112, a MOS switch with lower internal resistance can be used to replace the diode in rectifier circuit 112, resulting in the following: Figure 6 The rectifier circuit 112 is shown. At this time, the internal resistance of the MOS switch is 0.099Ω. In one cycle, when the current is 5A, the current loss = 2 x internal resistance Rds(on) x the square of the current I. 2 =2 x 0.099 Ω x 5 A x 5 A x 1.5 = 7.4 W. Where 1.5 is the thermal resistance of the MOSFET at high temperature. Therefore, the rectifier circuit 112 using the MOSFET reduces current loss by 2.6 W compared to the rectifier circuit 112 using a diode.

[0077] In the above embodiment, the rectifier circuit 112 includes a first bridge arm and a second bridge arm connected in parallel. Each bridge arm includes two MOS switches connected in series. Since the MOS switches have a smaller internal resistance, the current loss is less than that of the rectifier circuit 112 composed of diodes, thus improving the efficiency of the circuit.

[0078] Since the MOS switch requires a control circuit to control its operation, in order to achieve control of the first MOS switch 112a and the second MOS switch 112b, as follows: Figure 7As shown, the first bridge arm further includes: a second power management circuit 112e, the first terminal of which is connected to the control electrode of the first MOS switch 112a, the second terminal of which is connected to the first electrode of the first MOS switch 112a, the third terminal of which is connected to the second electrode of the first MOS switch 112a, and the fourth terminal of which is connected to the second electrode of the first MOS switch 112a through a first capacitor; and a third power management circuit 112f, the first terminal of which is connected to the control electrode of the second MOS switch 112b, the second terminal of which is connected to the first electrode of the second MOS switch 112b, the third terminal of which is connected to the second electrode of the second MOS switch 112b, and the fourth terminal of which is connected to the second electrode of the second MOS switch 112b through a second capacitor.

[0079] In this embodiment, the second power management circuit 112e and the third power management circuit 112f can be power management chips. The second terminal of the second power management circuit 112e is connected to the first terminal (drain D) of the first MOS switch 112a, and the third terminal of the second power management circuit 112e is connected to the second terminal (source S) of the first MOS switch 112a. The operation of the first MOS switch 112a is controlled by detecting the voltage difference between the drain D and the source S. For example, detecting a drain-source voltage difference of -105mV controls the operation of the first MOS switch 112a, and detecting a drain-source voltage difference of +1mV controls the first MOS switch to stop operating. The second power management circuit 112e can be self-powered through the first capacitor; therefore, the second power management circuit 112e can operate on either the low-side or high-side. The operating principle of the third power management circuit 112f is the same as that of the second power management circuit 112e. The size of the second capacitor can be the same as that of the first capacitor.

[0080] To control the third MOSFET 112c and the fourth MOSFET 112d, please refer to [the relevant documentation / reference]. Figure 7The second bridge arm also includes: a fourth power management circuit 112g, the first terminal of which is connected to the control electrode of the third MOS switch 112c, the second terminal of which is connected to the first electrode of the third MOS switch 112c, the third terminal of which is connected to the second electrode of the third MOS switch 112c, and the fourth terminal of which is connected to the second electrode of the third MOS switch 112c through a third capacitor; and a fifth power management circuit 112h, the first terminal of which is connected to the control electrode of the fourth MOS switch 112d, the second terminal of which is connected to the first electrode of the fourth MOS switch 112d, the third terminal of which is connected to the second electrode of the fourth MOS switch 112d, and the fourth terminal of which is connected to the second electrode of the fourth MOS switch 112d through a fourth capacitor.

[0081] In this embodiment, the fourth power management circuit 112g and the fifth power management circuit 112h operate on the same principle as the second power management circuit 112e described above. The sizes of the third and fourth capacitors can be the same as the size of the first capacitor.

[0082] Optionally, the first power management circuit 1231, the second power management circuit 112e, the third power management circuit 112f, the fourth power management circuit 112g, and the fifth power management circuit 112h are integrated.

[0083] By integrating the first power management circuit 1231, the second power management circuit 112e, the third power management circuit 112f, the fourth power management circuit 112g, and the fifth power management circuit 112h, such as by packaging them into a single chip, the size and weight of the circuit board can be significantly reduced, making the switching power supply device lighter and more portable. Simultaneously, the integrated design also improves the stability and reliability of the circuit because the reduced number of connection points and solder joints lowers the likelihood of failure. Furthermore, the integrated design simplifies the circuit design and manufacturing process, provides better heat dissipation, and facilitates maintenance and upgrades.

[0084] In the embodiments of this application, such as Figure 8 The diagram shown is an example of the circuit structure of the filter protection circuit 111 of the switching power supply circuit 10. The L and N terminals of the filter protection circuit 111 are connected to the AC input. Figure 9The diagram shows the circuit structure of rectifier circuit 112, which is connected to filter protection circuit 111. The first MOSFET 112a is Q1, the second MOSFET 112b is Q2, the third MOSFET 112c is Q3, and the fourth MOSFET 112d is Q4. The second power management circuit 112e is IC2, the third power management circuit 112f is IC3, the fourth power management circuit 112g is IC4, and the fifth power management circuit 112h is IC5. Replacing diodes with MOSFETs and power management circuits in rectifier circuit 112 reduces current loss.

[0085] Figure 10 This is a schematic diagram of the filter boost circuit 124 of the PFC circuit 12. Figure 11 This is a schematic diagram of the structure of the first switching transistor 121 (U3) in the PFC circuit 12. Figure 12 This is a schematic diagram of the second switch 122 (U4) and the output circuit 125 of the PFC circuit 12. Figure 10 Pin 4 of the boost inductor T2.1 is connected to Figure 11 The D-pole of U3 and Figure 12 The drain (D) terminal of U4 is connected.

[0086] Figure 13 and Figure 14 The circuit structure diagram of the drive control circuit 123 is shown. The drive control circuit 123 includes a first power management circuit 1231 and a drive circuit 1232. The first power management circuit 1231 includes IC1. The drive circuit 1232 includes a digital isolation circuit 1232a and an isolation power supply circuit 1232b. The digital isolation circuit 1232a includes U1 and the isolation power supply circuit 1232b includes U2.

[0087] U3's S pin is grounded, and D pin is connected to... Figure 10 In the boost inductor T2.1, pin S of U4 is connected to the positive terminal of the large capacitor, and pin D is connected to... Figure 10 In the boost inductor T2.1, pin 1 of IC1 is connected to pin 8 of U3, providing a 12V first drive signal, which is a PWM signal. Pin 8 of IC1 outputs a PWM waveform opposite to that of pin 1, which is connected to pin 2 of U1. Pin 5 of U1 and pins 2, 3, and 4 of U2 are connected to the positive terminals of the capacitors. Pins 5, 6, and 7 of U2 are connected to pin 8 of U1 and pin 27 of U4. U2 uses the positive voltage of the capacitor as a reference and adds VCC to achieve amplification, outputting BOOST-VDD to U1 and U4. U1 outputs a second drive signal from pin 7, which is a PWM signal with a magnitude of 380-400V to drive pin 8 of U4, thereby driving the first and second switching transistors of PFC circuit 12 to work.

[0088] In an embodiment of this application, a power adapter is also provided, including the switching power supply circuit described in the above embodiments.

[0089] Power adapters are widely used in various electronic devices. They provide a stable power supply to portable electronic devices, ensuring their normal operation. For example, power adapters can be used in devices such as laptops, smartphones, tablets, and game consoles. By regulating voltage and current, they ensure that these devices can operate safely and stably under different voltage environments. Power adapters can also be used in mobile workstations, portable projectors, medical devices, industrial automation systems, and communication equipment.

[0090] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0091] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0092] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A switching power supply circuit, characterized by comprising: include: An input rectifier circuit, wherein the first terminal of the input rectifier circuit is used to connect to an AC power source; The PFC circuit includes a first switching transistor, a second switching transistor, and a drive control circuit. Wherein, the first terminal of the first switching transistor and the first terminal of the second switching transistor are respectively connected to the second terminal of the input rectifier circuit, the second terminal of the first switching transistor is grounded, and the second terminal of the second switching transistor is connected to the subsequent circuit. The first terminal of the drive control circuit is connected to the control electrode of the first switching transistor, and the second terminal of the drive control circuit is connected to the control electrode of the second switching transistor. The drive control circuit is used to output a first drive signal at the first terminal to drive the first switching transistor, and to output a second drive signal at the second terminal to drive the second switching transistor. The waveforms of the first drive signal and the second drive signal are complementary, and the voltage of the first drive signal is less than the voltage of the second drive signal.

2. The switching power supply circuit according to claim 1, characterized in that, The PFC circuit also includes: A filter boost circuit is provided, wherein the first terminal of the filter boost circuit is connected to the second terminal of the input rectifier circuit, the second terminal of the filter boost circuit is connected to the first terminal of the first switching transistor and the first terminal of the second switching transistor respectively, and the third terminal of the filter boost circuit is connected to the third terminal of the drive control circuit. The output circuit has its first terminal connected to the second terminal of the second switching transistor and the fourth terminal of the drive control circuit, and its first terminal is also used to connect to the subsequent stage circuit. The second terminal of the output circuit is grounded.

3. The switching power supply circuit according to claim 2, characterized in that, The drive control circuit includes: A first power management circuit, wherein a first terminal of the first power management circuit is connected to the control electrode of the first switching transistor, a second terminal of the first power management circuit is connected to the third terminal of the input rectifier circuit, a third terminal of the first power management circuit is connected to the third terminal of the filter boost circuit, a fourth terminal of the first power management circuit is used to connect to the subsequent stage circuit, and the first power management circuit is used to output the first drive signal at the first terminal of the first power management circuit. A driving circuit, wherein the first terminal of the driving circuit is connected to the fifth terminal of the first power management circuit, the second terminal of the driving circuit is connected to the first terminal of the output circuit, and the third terminal of the driving circuit is connected to the control electrode of the second switching transistor. The first power management circuit is further configured to output a reverse drive signal at the fifth terminal of the first power management circuit. The waveform of the reverse drive signal is complementary to the waveform of the first drive signal. The drive circuit is configured to amplify the output voltage at the first terminal of the output circuit and output the second drive signal at the third terminal of the drive circuit based on the amplified output voltage and the reverse drive signal.

4. The switching power supply circuit according to claim 3, characterized in that, The driving circuit includes: A digital isolation circuit, wherein a first terminal of the digital isolation circuit is connected to a fifth terminal of the first power management circuit, a second terminal of the digital isolation circuit is connected to the control electrode of the second switching transistor, and a third terminal of the digital isolation circuit is connected to a first terminal of the output circuit. An isolated power supply circuit is provided, wherein a first terminal of the isolated power supply circuit is connected to a first terminal of the output circuit, a second terminal of the isolated power supply circuit is connected to a fourth terminal of the digital isolation circuit and a power supply terminal of the second switching transistor, the isolated power supply circuit is used to amplify the output voltage of the first terminal of the output circuit, and outputs a boost voltage signal at the second terminal of the isolated power supply circuit based on the amplified output voltage, and the digital isolation circuit is used to output the second driving signal at the second terminal of the digital isolation circuit according to the boost voltage signal and the reverse driving signal.

5. The switching power supply circuit according to claim 1, characterized in that, The first switch is a MOS switch or a GAN switch, and the second switch is a MOS switch or a GAN switch.

6. The switching power supply circuit according to any one of claims 2-4, characterized in that, The input rectifier circuit includes: A filter protection circuit, wherein the first terminal of the filter protection circuit is connected to the AC power supply; A rectifier circuit, wherein the first terminal of the rectifier circuit is connected to the second terminal of the filter protection circuit, and the second terminal of the rectifier circuit is connected to the first terminal of the filter boost circuit.

7. The switching power supply circuit according to claim 6, characterized in that, The rectifier circuit includes a first bridge arm and a second bridge arm connected in parallel. The first bridge arm includes a first MOS switch and a second MOS switch connected in series, and the second bridge arm includes a third MOS switch and a fourth MOS switch connected in series.

8. The switching power supply circuit according to claim 7, characterized in that, The first bridge arm also includes: The second power management circuit has a first terminal connected to the control electrode of the first MOS switch, a second terminal connected to the first electrode of the first MOS switch, a third terminal connected to the second electrode of the first MOS switch, and a fourth terminal connected to the second electrode of the first MOS switch through a first capacitor. The third power management circuit has a first terminal connected to the control electrode of the second MOS switch, a second terminal connected to the first electrode of the second MOS switch, a third terminal connected to the second electrode of the second MOS switch, and a fourth terminal connected to the second electrode of the second MOS switch through a second capacitor.

9. The switching power supply circuit according to claim 7, characterized in that, The second bridge arm also includes: A fourth power management circuit, wherein the first terminal of the fourth power management circuit is connected to the control electrode of the third MOS switch, the second terminal of the fourth power management circuit is connected to the first electrode of the third MOS switch, the third terminal of the fourth power management circuit is connected to the second electrode of the third MOS switch, and the fourth terminal of the fourth power management circuit is connected to the second electrode of the third MOS switch through a third capacitor. A fifth power management circuit is provided, wherein the first terminal of the fifth power management circuit is connected to the control electrode of the fourth MOS switch, the second terminal of the fifth power management circuit is connected to the first electrode of the fourth MOS switch, the third terminal of the fifth power management circuit is connected to the second electrode of the fourth MOS switch, and the fourth terminal of the fifth power management circuit is connected to the second electrode of the fourth MOS switch through a fourth capacitor.

10. The switching power supply circuit according to claim 9, characterized in that, The first power management circuit, the second power management circuit, the third power management circuit, the fourth power management circuit, and the fifth power management circuit are integrated into one unit.

11. A power adapter, characterized in that, Includes the switching power supply circuit according to any one of claims 1 to 10.

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