High-power all-gallium nitride LED driving power supply circuit

Abstract

The invention discloses a high-power all-gallium nitride LED driving power supply circuit which comprises an EMI filtering and rectifying circuit, a GaN active power factor correction circuit, a GaN half-bridge LLC resonant converter circuit and a GaN synchronous rectifying and filtering circuit. The PFC and LLC combined control module integrates a power factor correction function and a resonance circuit frequency regulation function, the GaN active power factor correction circuit is connected with the PFC and LLC combined control module to realize power factor correction, and the GaN half-bridge LLC resonant converter circuit is connected with the PFC and LLC combined control module to realize output power regulation; and a constant-current voltage-limiting feedback circuit for outputting current and voltage detection feedback is arranged between the GaN synchronous rectification filter circuit and the PFC and LLC combined control module. The advantages of high efficiency of the GaN switching tube and high working frequency of the circuit are utilized, so that power loss and heat dissipation requirements are reduced, and the efficiency and power density of the LED power supply are improved. The invention has the advantages of high efficiency, high power density, high reliability and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit design, and in particular to a high-power all-gallium nitride LED drive power supply circuit. Background Art

[0002] LED has the advantages of high electro-optical conversion efficiency, long service life, environmental protection and energy saving, and small size. While LED is shining, LED driver power supply is the guarantee for the development of the LED industry chain. The quality of LED power supply directly restricts the reliability and market promotion of LED products.

[0003] At present, the power supplies of the LED industry worth hundreds of billions are almost all silicon-based power supplies. The existing traditional silicon-based LED driver power supplies have the following key problems: First, with the increase in LED lighting power, the traditional large-volume, low-efficiency LED power supplies can no longer meet the slim lamp design and the heat dissipation problems in the small space of the lamp. The power supply efficiency is low, the heat is high, and the space heat dissipation is poor, which affects the power supply reliability; secondly, the LED power supply is required to have a longer life, lower current harmonic distortion, higher power factor, and higher power density.

[0004] Traditional silicon-based LED driver power supplies usually use silicon-based MOSFET as the switch tube, and adopt the circuit structure of power factor correction circuit + flyback circuit + output rectifier filter. This technical solution uses silicon-based MOSFET as the main switch tube, and the on-resistance of silicon-based MOSFET is generally large, which will lead to increased conduction loss and reduced power efficiency. At the same time, the flyback circuit structure makes it difficult to increase the operating frequency of the power supply, and the magnetic components such as transformers are large in size, which limits the improvement of the power density of the power supply.

[0005] Traditional silicon-based power electronic devices have gradually approached their theoretical limits, making it difficult to meet the development needs of high-frequency and high-power density LED power supplies, hindering the improvement of power system efficiency. Compared with traditional silicon-based devices, gallium nitride devices have significant advantages in on-resistance and gate charge, and the high-frequency characteristics of gallium nitride devices have been improved by more than ten times. Replacing traditional silicon-based power devices with gallium nitride power devices can solve the heating problem of traditional silicon power supplies and enable the power supply to achieve a smaller size, higher frequency and higher efficiency. The application of gallium nitride power devices in the field of LED driver power supplies has the advantages of being lightweight, miniaturized high-frequency auxiliary magnetic devices, increasing system operating frequency, and improving system efficiency. Therefore, the development of a high-efficiency and high-power-density gallium nitride LED driver power supply has very important application value. Summary of the invention

[0006] The first purpose of the present invention is to solve the problems of low efficiency and high heat generation of traditional silicon-based LED driving power supplies, and to provide a high-power all-gallium nitride LED driving power supply circuit. It is proposed to use gallium nitride devices to replace silicon-based devices in traditional LED power supplies, and to use the advantages of high frequency, high conversion efficiency, and low on-resistance of gallium nitride power devices to solve the heating problem of traditional silicon power supplies.

[0007] The second purpose of the present invention is to solve the problems of low power density caused by low operating frequency and large volume of magnetic components of traditional silicon-based LED driving power supply. The all-gallium nitride LED driving power supply circuit adopts the topology of GaN active power factor correction circuit + GaN half-bridge LLC resonant converter circuit + GaN synchronous rectification filter circuit. By using the half-bridge LLC resonant conversion circuit and the GaN synchronous rectification filter circuit, the operating frequency of the LED driving power supply system can be increased, the switch tube loss can be reduced to improve the power supply efficiency, and the volume of magnetic components can be reduced to improve the power density.

[0008] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is as follows: A high-power all-gallium nitride LED drive power supply circuit is characterized by: an EMI filter and rectification circuit, a GaN active power factor correction circuit, a GaN half-bridge LLC resonant converter circuit, and a GaN synchronous rectification filter circuit are connected in sequence from AC input to DC output; a PFC and LLC combined control module integrating power factor correction and resonant circuit frequency adjustment functions is also included, the GaN active power factor correction circuit realizes power factor correction by connecting the PFC and LLC combined control module, and the GaN half-bridge LLC resonant converter circuit realizes output power adjustment by connecting the PFC and LLC combined control module; a constant current and voltage limiting feedback circuit for output current and voltage detection feedback is arranged between the GaN synchronous rectification filter circuit and the PFC and LLC combined control module.

[0009] Optionally, the EMI filtering and rectifying circuit includes a fuse for overcurrent protection connected between the live wire and the neutral wire of the AC input, a Y capacitor for suppressing common-mode interference, a thermistor for limiting surge current, a common-mode inductor for filtering common-mode interference, an X capacitor for suppressing differential-mode interference, a series resistor for discharging the X capacitor, a plug-in rectifier bridge for rectifying the AC input, and a π-type filtering circuit for improving the EMI characteristics of the input end; the π-type filtering circuit is composed of a first filtering capacitor, a filtering inductor and a second filtering capacitor connected in sequence.

[0010] Optionally, the PFC and LLC combination control module includes a PFC / LLC combination controller, a first drive circuit, a first negative voltage drive circuit and a second negative voltage drive circuit; the PFC / LLC combination controller uses a power control chip with integrated power factor correction and resonant circuit frequency adjustment functions; the switch tube of the GaN active power factor correction circuit is connected to the pin of the PFC / LLC combination controller through the first drive circuit; the upper tube of the bridge arm of the GaN half-bridge LLC resonant converter circuit is connected to the first output pin of the PFC / LLC combination controller through the first negative voltage drive circuit, and the lower tube of the bridge arm of the GaN half-bridge LLC resonant converter circuit is connected to the second output pin of the PFC / LLC combination controller through the second negative voltage drive circuit.

[0011] Optionally, the first drive circuit, the first negative voltage drive circuit and the second negative voltage drive circuit all include resistors for adjusting the switching speed of the switch tube, resistors for voltage division, magnetic beads for weakening high-frequency ringing, diodes for providing a fast discharge path, and capacitors for switching acceleration; the first negative voltage drive circuit and the second negative voltage drive circuit also include a Zener diode and a normal diode for clamping the gate voltage, and a capacitor for switching acceleration.

[0012] Optionally, the GaN active power factor correction circuit and the GaN half-bridge LLC resonant converter circuit both include a cascaded gallium nitride power device, the source of the cascaded gallium nitride power device is connected to the gate via a source lead resistor, and the drain of the cascaded gallium nitride power device is connected to the source via a drain lead resistor and a drain lead capacitor.

[0013] Optionally, the switch tube of the GaN active power factor correction circuit adopts a first cascaded gallium nitride power device; the source lead resistor of the first cascaded gallium nitride power device is connected to the pin of the PFC / LLC combination controller through a first drive circuit, and the drain lead inductor of the first cascaded gallium nitride power device is connected to a π-type filter circuit; the first cascaded gallium nitride power device is also connected to a boost inductor and a storage capacitor.

[0014] Optionally, the upper tube of the bridge arm and the lower tube of the bridge arm of the GaN half-bridge LLC resonant converter circuit respectively adopt a second cascade-type gallium nitride power device and a third cascade-type gallium nitride power device; the source lead resistor of the second cascade-type gallium nitride power device is connected to the first output pin of the PFC / LLC combination controller through a first negative voltage drive circuit, and the source lead resistor of the third cascade-type gallium nitride power device is connected to the second output pin of the PFC / LLC combination controller through a second negative voltage drive circuit; the resonant capacitor of the GaN half-bridge LLC resonant converter circuit adopts a high-frequency ceramic capacitor, and the unit of value is nF; the isolation transformer of the GaN half-bridge LLC resonant converter circuit adopts a PCB transformer made by a planar process, and the unit of value is uH.

[0015] Optionally, the resonant frequency range of the GaN half-bridge LLC resonant converter circuit is 100KHz-300KHz; the ratio range of the excitation inductance and the resonant inductance of the isolation transformer is 4-10, and the full-load quality factor Q ranges from 0.2-0.6.

[0016] Optionally, the GaN synchronous rectification and filtering circuit includes a synchronous rectification circuit and a filtering circuit; the synchronous rectification circuit rectifies the AC value transmitted from the primary to the secondary of the GaN half-bridge LLC resonant converter circuit; the filtering circuit is connected to the synchronous rectification circuit, and filtering is performed to obtain a stable DC output; the MOS tube of the synchronous rectification circuit adopts a gallium nitride power device.

[0017] Optionally, the constant current and voltage limiting feedback circuit includes a resistor sampling circuit, a comparison amplifier circuit, and an optocoupler feedback circuit; the resistor sampling circuit is connected to the output end of the GaN synchronous rectification and filtering circuit to sample the DC voltage and current output values, and the resistor sampling circuit uses a high-precision chip alloy resistor; the comparison amplifier circuit is connected to the output end of the resistor sampling circuit to compare the sampled value with a preset reference value; the optocoupler feedback circuit is connected to the output end of the comparison amplifier circuit, generates a feedback signal according to the change of the output value of the comparison circuit, and is connected to the feedback control pin of the PFC and LLC combination control module.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1. The high-power all-gallium nitride LED driving power supply circuit proposed in the present invention adopts the topology of GaN active power factor correction circuit + GaN half-bridge LLC resonant converter circuit + GaN synchronous rectification filter circuit, which effectively improves the power density of the LED power supply by increasing the operating frequency of the power supply and reducing the volume of magnetic components.

[0019] 2. The present invention adopts a PFC / LLC combination controller that integrates power factor correction and resonant circuit frequency adjustment functions. The combination controller combines two independent devices, power factor correction and resonant circuit frequency adjustment, into one, and simultaneously outputs control signals of an active power factor correction circuit and a half-bridge LLC resonant converter circuit. One chip is used to complete the functions of two chips, and the circuit structure is simple, the number of peripheral components is reduced, the power supply cost is greatly reduced, and it is beneficial to improve production efficiency and effectively improve the reliability of LED power supply.

[0020] 3. The present invention adopts gallium nitride MOS tubes to replace traditional silicon-based MOS tubes, thereby increasing the operating frequency of the power supply and solving the problem of difficulty in improving the system power density due to low switching frequency. It can achieve high frequency and high power density while ensuring high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0022] FIG. 1 is a block diagram of the overall circuit structure of a high-power all-gallium nitride LED driving power supply circuit provided in an embodiment of the present application.

[0023] FIG. 2 is a schematic diagram of an EMI filtering and rectification circuit provided in an embodiment of the present application.

[0024] Figure 3 A schematic diagram of a GaN active power factor correction circuit provided in an embodiment of the present application.

[0025] Figure 4 Schematic diagram of a GaN half-bridge LLC resonant converter circuit and a GaN synchronous rectification filter circuit provided in an embodiment of the present application.

[0026] Figure 5 This is a comparison chart of the efficiency of the high-power all-gallium nitride LED drive power circuit provided in the embodiment of the present application and the traditional silicon-based LED drive power circuit. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. At the same time, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0028] In order to solve the problems of low efficiency, high heat generation, low operating frequency and low power density caused by large volume of magnetic components of traditional silicon-based LED driving power supplies, the embodiment of the present application provides a high-power all-gallium nitride LED driving power supply circuit. The driving power supply circuit adopts a topology structure of GaN active power factor correction circuit + GaN half-bridge LLC resonant converter circuit + GaN synchronous rectification filter circuit. By using the half-bridge LLC resonant conversion circuit and the GaN synchronous rectification filter circuit, the operating frequency of the LED driving power supply system can be increased, the switching tube loss can be reduced to improve the power supply efficiency, the volume of magnetic components can be reduced to improve the power density.

[0029] For example, some embodiments of the present application provide a high-power all-gallium nitride LED driving power supply circuit, including: EMI filtering and rectification circuit, GaN active power factor correction circuit, GaN half-bridge LLC resonant converter circuit, GaN synchronous rectification filter circuit connected in sequence from AC input to DC output; also including a PFC and LLC combined control module integrating power factor correction and resonant circuit frequency adjustment functions, the GaN active power factor correction circuit realizes power factor correction by connecting the PFC and LLC combined control module, and the GaN half-bridge LLC resonant converter circuit realizes output power adjustment by connecting the PFC and LLC combined control module; a constant current and voltage limiting feedback circuit for output current and voltage detection feedback is arranged between the GaN synchronous rectification filter circuit and the PFC and LLC combined control module.

[0030] like Figure 1As shown, FIG1 is a block diagram of the overall circuit structure of the all-gallium nitride LED driving power supply circuit provided by an embodiment of the present application. The high-power all-gallium nitride LED driving power supply circuit includes: an EMI filter and rectifier circuit, a GaN active power factor correction circuit, a GaN half-bridge LLC resonant converter circuit, and a GaN synchronous rectifier filter circuit, which are sequentially connected in the direction from AC input to DC output. The EMI filter and rectifier circuit, the GaN active power factor correction circuit, and the GaN half-bridge LLC resonant converter circuit are also connected to the PFC and LLC combined control module. A constant current limiting voltage feedback circuit for output voltage and current detection feedback is also provided between the GaN synchronous rectifier filter circuit and the PFC and LLC combined control module. The PFC and LLC combined control module integrates power factor correction and resonant circuit frequency adjustment functions, and the GaN active power factor correction circuit and the GaN half-bridge LLC resonant converter circuit realize power factor correction and adjust output power by connecting the PFC and LLC combined control module.

[0031] In some embodiments of the present application, Figure 2 As shown, the EMI filtering and rectifying circuit includes a fuse MOV connected between the live wire and the neutral wire of the AC input for overcurrent protection, a Y capacitor CY1 and a Y capacitor CY2 for suppressing common-mode interference, a thermistor NTC for limiting surge current, a common-mode inductor L1 and a common-mode inductor L2 for filtering common-mode interference, an X capacitor CX1 for suppressing differential-mode interference, series resistors RC1-RC2 and series resistors RC3-RC4 for discharging the X capacitor CX1, a plug-in rectifier bridge DB1 for rectifying the AC input, and a π-type filter circuit for improving the EMI characteristics of the input end.

[0032] In some embodiments of the present application, Figure 2 As shown, the π-type filter circuit is a π-type filter circuit in the form of a capacitor-inductor-capacitor (CLC), including a first filter capacitor C1, a filter inductor L3 and a second filter capacitor C2. The π-type filter circuit is connected to the GaN active power factor correction circuit, and the filter capacitors C1 and C2 provide a ground loop for the high-frequency harmonic components in the GaN active power factor correction circuit to filter out the high-order harmonics in the input voltage, and the filter inductor L3 suppresses the high-frequency harmonic components in the input current.

[0033] In some embodiments of the present application, Figure 3 , 4 As shown, the PFC and LLC combination control module includes a PFC / LLC combination controller U1, a first drive circuit, a first negative voltage drive circuit and a second negative voltage drive circuit. The first drive circuit is connected to a GaN active power factor correction circuit, and the first negative voltage drive circuit and the second negative voltage drive circuit are connected to a GaN half-bridge LLC resonant converter circuit.

[0034] The PFC / LLC combination controller U1 combines the two independent control chips of power factor correction function and resonant circuit frequency adjustment function into one, and can simultaneously output the control signals of the active power factor correction circuit and the half-bridge LLC resonant conversion circuit. Using one chip to complete the functions of two chips has a simple circuit structure, reduces the number of peripheral components, greatly reduces the power cost, is conducive to improving production efficiency and effectively improves the reliability of the power supply.

[0035] In some embodiments of the present application, Figure 3 As shown, the first driving circuit includes a resistor R3 for adjusting the opening speed of the switch tube, a resistor R4 for voltage division, a magnetic bead R5 for reducing high-frequency ringing, a diode D2 for providing a fast discharge path, and a capacitor C3 for switching acceleration. The resistor R3, the resistor R4 and the magnetic bead R5 are connected in series, the diode D2 is connected in parallel at both ends of the resistor R3, and the capacitor C3 is connected in parallel at both ends of the resistor R4. The resistor R3 is connected to the pin SUPREG of the PFC / LLC combination controller U1, and the magnetic bead R5 is connected to the switch tube of the GaN active power factor correction circuit.

[0036] In some embodiments of the present application, Figure 4 As shown, the first negative voltage driving circuit includes a resistor R7 for adjusting the opening speed of the switch tube, a resistor R8 for voltage division, a magnetic bead R9 for weakening high-frequency ringing, a diode D3 for providing a fast discharge path, a voltage regulator diode D6 for clamping the gate voltage, a common diode D5 and a capacitor C7 for switching acceleration. The resistor R7, the resistor R8, the magnetic bead R9, the common diode D5 and the voltage regulator diode D6 are connected in series, the diode D3 is connected in parallel at both ends of the resistor R7, and the capacitor C7 is connected in parallel at both ends of the resistor R8. The resistor R7 is connected to the first output pin GATEHS of the PFC / LLC combination controller U1, and the magnetic bead R9 and the voltage regulator diode D6 are connected to the upper tube of the bridge arm of the GaN half-bridge LLC resonant converter circuit. The negative voltage of the first negative voltage driving circuit can improve the reliability of the drive, avoid the direct-through phenomenon caused by interference of the cascaded gallium nitride power device, and improve the drive reliability.

[0037] The second negative voltage driving circuit includes a resistor R12 for adjusting the switching speed of the switch tube, a resistor R13 for voltage division, a magnetic bead R14 for reducing high-frequency ringing, a diode D4 for providing a fast discharge path, a voltage regulator diode D8 for clamping the gate voltage, a common diode D7 and a capacitor C8 for switching acceleration. The resistor R12, the resistor R13, the magnetic bead R14, the common diode D7 and the voltage regulator diode D8 are connected in series, the diode D4 is connected in parallel at both ends of the resistor R12, and the capacitor C8 is connected in parallel at both ends of the resistor R13. The resistor R12 is connected to the second output pin GATELS of the PFC / LLC combination controller U1, and the magnetic bead R14 and the voltage regulator diode D8 are connected to the lower tube of the bridge arm of the GaN half-bridge LLC resonant converter circuit. The negative voltage of the second negative voltage driving circuit can improve the reliability of the drive, avoid the direct-through phenomenon caused by interference of the cascaded gallium nitride power device, and improve the drive reliability.

[0038] In some embodiments of the present application, Figure 3 As shown, the GaN active power factor correction circuit uses the first cascaded gallium nitride power device Q1 as a switch tube. The cascaded gallium nitride power device has a lower on-resistance than the traditional silicon MOSFET, which effectively reduces the switching loss of the active power factor correction circuit and improves the system efficiency.

[0039] The source of the first cascaded gallium nitride power device Q1 is connected to the gate through the source lead resistor R6, and the drain of the first cascaded gallium nitride power device Q1 is connected to the source through the drain lead resistor R2 and the drain lead capacitor C5. The source lead resistor R6 of the first cascaded gallium nitride power device Q1 is connected to the pin SUPREG of the PFC / LLC combination controller U1 through the first drive circuit. The drain lead inductor L4 of the first cascaded gallium nitride power device Q1 is connected to the π-type filter circuit. The inductor L4 leads the boost diode D1 to the positive electrode of the electrolytic capacitor C6, and the resistor R1 and the capacitor C4 set in series are connected in parallel at both ends of the boost diode D1. The circuit can correct the phase difference between the current and voltage at the input end, and effectively reduce the additional loss caused by the current and voltage phase difference of the AC mains input. The GaN active power factor correction circuit uses the inductor L4 and the cascaded gallium nitride power device Q1 to complete the power factor correction of the AC mains.

[0040] In some embodiments of the present application, Figure 4As shown, the GaN half-bridge LLC resonant converter circuit uses the second cascaded gallium nitride power device Q2 as the upper tube of the bridge arm, and the third cascaded gallium nitride power device Q3 as the lower tube of the bridge arm. The GaN half-bridge LLC resonant converter circuit also includes: a resonant capacitor Cr, a resonant inductor Lr and an isolation transformer T1. The resonant inductor Lr is connected to the midpoint of the bridge arm formed by the second cascaded gallium nitride power device Q2 and the third cascaded gallium nitride power device Q3, and the other end of the resonant inductor Lr is connected to the isolation transformer T1. The other end of the isolation transformer T1 is connected to the resonant capacitor Cr, and the resonant capacitor Cr is connected to the third cascaded gallium nitride power device Q3 to the ground to form a closed resonant loop. The isolation transformer T1 of the GaN half-bridge LLC resonant converter circuit adopts a PCB transformer made by a planar process, and the value unit is uH. The resonant capacitor Cr adopts a high-frequency ceramic capacitor, and the value unit is nF. The GaN half-bridge LLC resonant converter circuit uses the resonance principle to transfer and convert energy, realizing the zero voltage turn-on of the second cascaded GaN power device Q2 and the third cascaded GaN power device Q3 and the zero current turn-off of the GaN power device Q4 and the GaN power device Q5 in the GaN synchronous rectification filter circuit, effectively reducing device switching losses and improving LED power supply efficiency.

[0041] In some embodiments of the present application, Figure 4 As shown, the source of the second cascaded GaN power device Q2 is connected to the gate through the source lead resistor R10, and the drain of the second cascaded GaN power device Q2 is connected to the source through the drain lead resistor R11 and the drain lead capacitor C9. The two ends of the source lead resistor R10 are connected in parallel with the ordinary diode D5 and the voltage regulator diode D6 connected in series in the first negative voltage drive circuit. The source lead resistor R10 of the second cascaded GaN power device Q2 is connected to the first output pin GATEHS of the PFC / LLC combination controller U1 through the first negative voltage drive circuit.

[0042] The source of the third cascaded gallium nitride power device Q3 is connected to the gate through the source lead resistor R15, and the drain of the third cascaded gallium nitride power device Q3 is connected to the source through the drain lead resistor R16 and the drain lead capacitor C10. The two ends of the source lead resistor R15 are connected in parallel with the ordinary diode D7 and the voltage regulator diode D8 connected in series in the second negative voltage drive circuit. The source lead resistor R15 of the third cascaded gallium nitride power device Q3 is connected to the second output pin GATELS of the PFC / LLC combination controller U1 through the second negative voltage drive circuit.

[0043] Specifically, the resonant frequency range of the GaN half-bridge LLC resonant converter circuit is 100 KHz-300 KHz; the ratio range of the excitation inductance and the resonant inductance of the isolation transformer is 4-10, and the value range of the full-load quality factor Q is 0.2-0.6.

[0044] In some embodiments of the present application, Figure 4 As shown, the GaN synchronous rectification and filtering circuit includes a synchronous rectification circuit and a filtering circuit; the synchronous rectification circuit includes a secondary coil of an isolation transformer T1, a gallium nitride power device Q4 and a gallium nitride power device Q5, the drain of the gallium nitride power device Q4 and the drain of the gallium nitride power device Q5 are respectively connected to the two ends of the secondary coil of the isolation transformer T1, the source of the gallium nitride power device Q4 and the source of the gallium nitride power device Q5 are connected and then grounded, and a current sampling resistor R17 is led out to connect to the DC voltage output negative line VO-, and the center tap of the isolation transformer T1 leads out a path connected to the DC voltage output positive line VO+, and the synchronous rectification circuit rectifies the AC value transmitted from the primary to the secondary of the GaN half-bridge LLC resonant converter circuit. The filtering circuit includes output filter capacitors C11, C12, C13 and a filter inductor L5 arranged on the output positive line VO+ and the DC voltage output negative line VO- in sequence, and the filtering circuit is connected to the synchronous rectification circuit to obtain a stable DC output.

[0045] In some embodiments of the present application, Figure 4 As shown, the constant current and voltage limiting feedback circuit includes a resistor sampling circuit, a comparison amplifier circuit, and an optocoupler feedback circuit. The resistor sampling circuit is connected to the output end of the GaN synchronous rectification filter circuit to sample the DC voltage and current output values; the comparison amplifier circuit is connected to the output end of the resistor sampling circuit to compare the sampled value with a preset reference value; the optocoupler feedback circuit is connected to the output end of the comparison amplifier circuit to generate a feedback signal according to the change of the output value of the comparison circuit, and is connected to the feedback control pin FB of the PFC / LLC combination controller U1. Example

[0046] The specific circuit of this embodiment is as follows Figure 1-4As shown, the PFC / LLC combination controller U1 uses the TEA2016 control chip, the cascaded gallium nitride power device Q1 used in the GaN active power factor correction circuit is G1N65R150TA, the inductor L4 uses an EQ25 skeleton and a JPP-95 material core. The resonant frequency of the GaN half-bridge LLC resonant converter circuit is set to 110KHz; the ratio of the excitation inductance Lm and the resonant inductance Lr of the isolation transformer T1 is 8, the full-load quality factor Q is 0.38, the resonant capacitor Cr is 26nF, the resonant inductor Lr is 81uH, and the excitation inductance Lm of the isolation transformer T1 is 648uH. The isolation transformer TI uses a PCB transformer made of planar technology, the value unit is uH, using an EQ25 skeleton and a JPP-5A material core, and the resonant inductor Lr uses an EPC17 skeleton and a JPP-95P material core. The gallium nitride power device Q4 and the gallium nitride power device Q5 both use low-voltage gallium nitride devices, whose model is INN150LA070A, the synchronous rectification circuit control chip whose model is MP6924, and the current sampling resistor R17 has a resistance of 5mΩ.

[0047] The high-power all-gallium nitride LED driving power supply circuit provided in this embodiment can realize AC-DC conversion from 180V~264V AC voltage to 51V DC voltage output, with an output current of 4.2A, an output power of 200W, and a conversion efficiency of 95%.

[0048] like Figure 5 As shown in the figure, a curve diagram showing the relationship between the load and efficiency of the high-power all-gallium nitride LED driving power supply circuit provided in this embodiment is shown. When the input voltage is the same, it can be seen that the high-power all-gallium nitride LED driving power supply circuit provided in this embodiment has good efficiency performance under different levels of load. Compared with the silicon-based power supply with the same output power, the full-load efficiency is improved by 2.24% year-on-year.

[0049] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A high-power all-gallium nitride LED drive power supply circuit, characterized in that: include: The invention sequentially connects the following circuits from AC input to DC output: an EMI filter and rectifier circuit, a GaN active power factor correction circuit, a GaN half-bridge LLC resonant converter circuit, and a GaN synchronous rectifier filter circuit; further includes a PFC and LLC combined control module integrating power factor correction and resonant circuit frequency adjustment functions; the GaN active power factor correction circuit realizes power factor correction by connecting the PFC and LLC combined control module; the GaN half-bridge LLC resonant converter circuit realizes output power adjustment by connecting the PFC and LLC combined control module; and a constant current and voltage limiting feedback circuit for output current and voltage detection feedback is arranged between the GaN synchronous rectifier filter circuit and the PFC and LLC combined control module.

2. The high-power all-gallium nitride LED driving power supply circuit according to claim 1, characterized in that: The EMI filtering and rectifying circuit includes a fuse for overcurrent protection connected between the live wire and the neutral wire of the AC input, a Y capacitor for suppressing common mode interference, a thermistor for limiting surge current, a common mode inductor for filtering common mode interference, an X capacitor for suppressing differential mode interference, a series resistor for discharging the X capacitor, a plug-in rectifier bridge for rectifying the AC input, and a π-type filtering circuit for improving the EMI characteristics of the input end; the π-type filtering circuit is composed of a first filtering capacitor, a filtering inductor and a second filtering capacitor connected in sequence.

3. The high-power all-gallium nitride LED driving power supply circuit according to claim 1, characterized in that: The PFC and LLC combination control module comprises a PFC / LLC combination controller, a first drive circuit, a first negative voltage drive circuit and a second negative voltage drive circuit; the PFC / LLC combination controller adopts a power control chip with integrated power factor correction and resonant circuit frequency adjustment functions; the switch tube of the GaN active power factor correction circuit is connected to the pin of the PFC / LLC combination controller through the first drive circuit; the upper tube of the bridge arm of the GaN half-bridge LLC resonant converter circuit is connected to the first output pin of the PFC / LLC combination controller through the first negative voltage drive circuit, and the lower tube of the bridge arm of the GaN half-bridge LLC resonant converter circuit is connected to the second output pin of the PFC / LLC combination controller through the second negative voltage drive circuit.

4. The high-power all-gallium nitride LED driving power supply circuit according to claim 3, characterized in that: The first drive circuit, the first negative voltage drive circuit and the second negative voltage drive circuit all include resistors for adjusting the switching speed of the switch tube, resistors for voltage division, magnetic beads for reducing high-frequency ringing, diodes for providing a fast discharge path, and capacitors for switching acceleration; the first negative voltage drive circuit and the second negative voltage drive circuit also include a voltage regulator diode and a common diode for clamping the gate voltage, and a capacitor for switching acceleration.

5. The high-power all-gallium nitride LED driving power supply circuit according to any one of claims 1 to 4, characterized in that: The GaN active power factor correction circuit and the GaN half-bridge LLC resonant converter circuit both include a cascaded gallium nitride power device, the source of the cascaded gallium nitride power device is connected to the gate via a source lead resistor, and the drain of the cascaded gallium nitride power device is connected to the source via a drain lead resistor and a drain lead capacitor.

6. The high-power all-gallium nitride LED driving power supply circuit according to claim 5, characterized in that: The switch tube of the GaN active power factor correction circuit adopts a first cascaded gallium nitride power device; the source lead resistor of the first cascaded gallium nitride power device is connected to the pin of the PFC / LLC combination controller through a first drive circuit, and the drain lead inductor of the first cascaded gallium nitride power device is connected to a π-type filter circuit; the first cascaded gallium nitride power device is also connected to a boost inductor and an energy storage capacitor.

7. The high-power all-gallium nitride LED driving power supply circuit according to claim 5, characterized in that: The upper tube of the bridge arm and the lower tube of the bridge arm of the GaN half-bridge LLC resonant converter circuit respectively adopt a second cascaded gallium nitride power device and a third cascaded gallium nitride power device; the source lead resistor of the second cascaded gallium nitride power device is connected to the first output pin of the PFC / LLC combination controller through a first negative voltage drive circuit, and the source lead resistor of the third cascaded gallium nitride power device is connected to the second output pin of the PFC / LLC combination controller through a second negative voltage drive circuit; the resonant capacitor of the GaN half-bridge LLC resonant converter circuit adopts a high-frequency ceramic capacitor, and the unit of value is nF; the isolation transformer of the GaN half-bridge LLC resonant converter circuit adopts a PCB transformer made by a planar process, and the unit of value is uH.

8. The high-power all-gallium nitride LED driving power supply circuit according to claim 7, characterized in that: The resonant frequency range of the GaN half-bridge LLC resonant converter circuit is 100KHz-300KHz; the ratio range of the excitation inductance and the resonant inductance of the isolation transformer is 4-10, and the value range of the full-load quality factor Q is 0.2-0.

6.

9. The high-power all-gallium nitride LED driving power supply circuit according to claim 1, characterized in that: The GaN synchronous rectification and filtering circuit comprises a synchronous rectification circuit and a filtering circuit; the synchronous rectification circuit rectifies the AC value transmitted from the primary to the secondary of the GaN half-bridge LLC resonant converter circuit; the filtering circuit is connected to the synchronous rectification circuit, and filtering obtains a stable DC output; the MOS tube of the synchronous rectification circuit adopts a gallium nitride power device.

10. The high-power all-gallium nitride LED driving power supply circuit according to claim 1, characterized in that: The constant current and voltage limiting feedback circuit includes a resistance sampling circuit, a comparison amplifier circuit, and an optocoupler feedback circuit; the resistance sampling circuit is connected to the output end of the GaN synchronous rectification and filtering circuit to sample the DC voltage and current output values, and the resistance sampling circuit uses a high-precision chip alloy resistor; The comparison amplifier circuit is connected to the output end of the resistor sampling circuit to compare the sampled value with a preset reference value; The optocoupler feedback circuit is connected to the output end of the comparison amplifier circuit, generates a feedback signal according to the change of the output value of the comparison circuit, and is connected to the feedback control pin of the PFC and LLC combination control module.

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