Efficient multi-output switching power supply

Abstract

The utility model relates to the technical field of switching power supplies, in particular to a high-efficiency multi-output switching power supply, which comprises at least two analog constant-current output modules. The efficient primary side loop is electrically connected with a primary side winding of the transformer T1, a secondary side winding of the transformer T1 is electrically connected with the secondary side filtering module, and the secondary side filtering module is electrically connected with the analog constant current output module; the microcontroller is electrically connected with the analog constant-current output module, so that the analog constant-current output module receives a PWM signal and a protection action signal of the microcontroller; a secondary side auxiliary winding of the transformer T1 is electrically connected with the analog constant-current output module, and provides a voltage reduction bias power supply for the analog constant-current output module; the first detection module and the second detection module are electrically connected between the analog constant current output module and the microcontroller and between the secondary side filtering module and the microcontroller respectively and are used for signal feedback; the problems of working efficiency and stability of a switching power supply with multiple outputs are solved.

Description

Technical Field

[0001] This utility model relates to the field of switching power supply technology, and in particular to a high-efficiency multi-output switching power supply. Background Technology

[0002] The working principle of a switching power supply is to transfer energy when the switching transistor is off. When the switching transistor is on, the primary and secondary coils of the transformer cannot transfer energy due to their opposite winding directions and the unidirectional conductivity of the diodes; the primary coil of the transformer acts as an inductor storing energy. When the switching transistor is off, the current in the primary coil decreases, generating a reverse electromotive force that induces a voltage in the secondary coil. The transformer then transfers the energy stored in the primary coil to the subsequent circuit. In this operating mode, traditional switching power supplies typically have only one output due to limitations imposed by their operating principle, voltage and current output characteristics, transient control characteristics, transformer design constraints, and cost and efficiency considerations. However, setting multiple outputs is a complex technical issue, requiring comprehensive consideration of voltage and current regulation, cross-regulation, efficiency and power consumption tradeoffs, and circuit stability; otherwise, the efficiency and stability of the switching power supply will decrease significantly.

[0003] However, as the application scenarios of lighting systems become more and more complex, the number of switching power supplies required to make up the lighting system is increasing, resulting in system redundancy and making installation and debugging difficult; therefore, there is an urgent need for a single switching power supply to be able to expand multiple outputs to reduce the complexity of the overall lighting system. Utility Model Content

[0004] To address the aforementioned shortcomings, the purpose of this invention is to propose a high-efficiency multi-output switching power supply, which solves the problems of working efficiency and stability of switching power supplies with multiple outputs.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] A high-efficiency multi-output switching power supply includes a high-efficiency primary circuit, a transformer T1, a secondary-side filter module, a microcontroller, a first detection module, a second detection module, and at least two analog constant current output modules; the high-efficiency primary circuit is electrically connected to the primary winding of the transformer T1, the secondary winding of the transformer T1 is electrically connected to the secondary-side filter module, and the secondary-side filter module is electrically connected to each of the analog constant current output modules;

[0007] The microcontroller is electrically connected to the analog constant current output module, and the analog constant current output module receives the PWM signal and protection action signal from the microcontroller.

[0008] The secondary auxiliary winding of the transformer T1 is electrically connected to the analog constant current output module, and the secondary auxiliary winding of the transformer T1 provides a step-down bias power supply for the analog constant current output module.

[0009] The first detection module is electrically connected between the analog constant current output module and the microcontroller, and is used to feed back the output voltage signal of the analog constant current output module to the microcontroller;

[0010] The second detection module is electrically connected between the secondary-side filter module and the microcontroller, and is used to feed back the output voltage signal of the secondary-side filter module to the microcontroller.

[0011] Furthermore, the high-efficiency primary circuit includes an input rectifier module and a high power factor constant voltage drive module; the input rectifier module, the high power factor constant voltage drive module, and the primary winding of the transformer T1 are sequentially electrically connected, and the high power factor constant voltage drive module is electrically connected to the primary auxiliary winding of the transformer T1; the high power factor constant voltage drive module receives voltage feedback from the primary auxiliary winding of the transformer T1.

[0012] The high power factor constant voltage drive module is equipped with a gallium nitride MOS transistor Q1; the high power factor constant voltage drive module drives the gallium nitride MOS transistor Q1 to achieve constant voltage output.

[0013] Furthermore, the analog constant current output module includes an analog constant current driver chip U2, a constant current output processing circuit, and a current detection circuit; the voltage detection terminal of the analog constant current driver chip U2 is electrically connected to the constant current output processing circuit; the constant current output processing circuit is connected to the SGND ground terminal through the current detection circuit, and the current detection terminal of the analog constant current driver chip U2 is electrically connected to the current detection circuit.

[0014] The first detection module and the constant current output processing circuit are electrically connected; the enable terminal, analog signal drive terminal and fault terminal of the analog constant current drive chip U2 are all electrically connected to the microcontroller.

[0015] The step-down bias power supply terminal of the analog constant current drive chip U2 is electrically connected to the secondary auxiliary winding of the transformer T1.

[0016] The secondary-side filter module, after passing through the constant current output processing circuit, is electrically connected to the drain terminal of the internal MOS transistor of the analog constant current driver chip U2; the source terminal of the internal MOS transistor of the analog constant current driver chip U2 is connected to the load after passing through the constant current output processing circuit.

[0017] Furthermore, the analog constant current output module also includes a diode D18, a capacitor EC6, a resistor R10, and a capacitor C36; the opposite-named terminal of the secondary auxiliary winding of the transformer T1 is connected to the SGND ground terminal, and the same-named terminal of the secondary auxiliary winding of the transformer T1 is electrically connected to the anode of the diode D18; the cathode of the diode D18 is connected in series with the resistor R10 and then electrically connected to the step-down bias power supply terminal of the analog constant current drive chip U2; the capacitor C36 is connected in parallel between the step-down bias power supply terminal of the analog constant current drive chip U2 and the SGND ground terminal; the cathode of the diode D18 and the SGND ground terminal are respectively electrically connected to the positive and negative terminals of the capacitor EC6.

[0018] Furthermore, the constant current output processing circuit includes inductor L3, inductor L10, capacitor C14, capacitor C35, capacitor C48, capacitor CE3, resistor R34, resistor R26, resistor R57, resistor R58, resistor R33, diode D3, and common mode inductor LF5; the source terminal of the internal MOS transistor of the analog constant current drive chip U2, one end of capacitor C14, the cathode of diode D3, and one end of inductor L3 are all electrically connected; the other end of capacitor C14 is electrically connected to one end of resistor R34; and the other end of resistor R34 and the anode of diode D3 are both connected to SGND ground.

[0019] The secondary side filter module and one end of the capacitor C35 are both electrically connected to one end of the inductor L10, and the other end of the inductor L10 is electrically connected to the drain terminal of the internal MOS transistor of the analog constant current drive chip U2.

[0020] The first detection module, the other end of the capacitor C35, one end of the capacitor C48, the positive terminal of the capacitor CE3, and one end of the resistor R57 are all electrically connected to the input terminal of the first winding of the common mode inductor LF5, and the other end of the capacitor C48 is connected to the SGND ground terminal.

[0021] The output voltage detection terminal of the analog constant current drive chip U2, the other end of the resistor R57, one end of the resistor R26, and one end of the resistor R58 are all electrically connected.

[0022] The second winding input terminal of the common mode inductor LF5, the other end of the resistor R26, the other end of the resistor R58, and the negative terminal of the capacitor CE3 are connected together and then connected to the SGND ground terminal through the current detection circuit.

[0023] The resistor R33 is connected in parallel between the first winding output terminal and the second winding output terminal of the common mode inductor LF5, and then connected to the load.

[0024] Furthermore, the current detection circuit includes resistors R80, R22, R38, R39, R40, and capacitor C4; the constant current output processing circuit is connected in series with resistor R40 and then connected to the SGND ground terminal; resistors R22, R38, and R39 are connected in parallel between the two ends of resistor R40; the common connection point of the constant current output processing circuit and resistor R40 is connected in series with resistor R80 and then electrically connected to the current detection terminal of the analog constant current drive chip U2; capacitor C4 is connected in parallel between the current detection terminal of the analog constant current drive chip U2 and the SGND ground terminal.

[0025] Furthermore, the high power factor constant voltage drive module also includes resistors R14, R17, R19, and R36, MOSFET Q2, capacitor C11, diode D1, capacitor C2, capacitor C4, capacitor C9, high power factor drive chip U3, RCD snubber circuit, power supply circuit, voltage detection circuit, and first drive and current detection circuit; the output terminal of the input rectifier module is electrically connected to the same-name terminal of the primary winding of the transformer T1, and the RCD snubber circuit is connected in parallel between the same-name terminal and the opposite-name terminal of the primary winding of the transformer T1;

[0026] The output terminal of the input rectifier module is connected to the gate of the MOSFET Q2 after being connected in series with resistors R14 and R17. The output terminal of the input rectifier module is connected to the drain of the MOSFET Q2 after being connected in series with resistors R36 and R19. The gate of the MOSFET Q2 is connected to the VIN terminal of the high power factor driver chip U3. The capacitor C11 is connected in parallel between the gate of the MOSFET Q2 and the GND terminal. The source of the MOSFET Q2 is connected to the anode of the diode D1. The VCC terminal of the high power factor driver chip U3 is connected to the cathode of the diode D1. The capacitor C2 is connected in parallel between the VCC terminal and the GND terminal of the high power factor driver chip U3. The capacitor C4 is connected in parallel between the VDD terminal and the GND terminal of the high power factor driver chip U3. The GND terminal of the high power factor driver chip U3 is connected to the GND terminal.

[0027] The opposite-named end of the primary auxiliary winding of the transformer T1 is connected to the GND ground terminal, and the same-named end of the primary auxiliary winding of the transformer T1 is electrically connected to the VCC terminal of the high power factor drive chip U3 through the power supply circuit.

[0028] The VSNS terminal of the high power factor drive chip U3 is electrically connected to the same-name terminal of the primary auxiliary winding of the transformer T1 via the voltage detection circuit.

[0029] The opposite terminal of the primary winding of the transformer T1 is electrically connected to the drain of the gallium nitride MOS transistor Q1. The capacitor C9 is connected in parallel between the drain and source of the gallium nitride MOS transistor Q1. The OUT terminal and ISNS terminal of the high power factor driver chip U3 are electrically connected to the drive terminal and feedback terminal of the first drive and current detection circuit, respectively. The output terminal and input terminal of the first drive and current detection circuit are electrically connected to the gate and source of the gallium nitride MOS transistor Q1, respectively.

[0030] Furthermore, the first driving and current detection circuit includes resistors R2 and R5, diode D9, resistors R6 and R7, capacitor C6, resistor R49, resistor R50, resistor R3, resistor R4, resistor R16, and capacitor C7; the cathode of diode D9 and one end of resistor R5 are electrically connected to the OUT terminal of the high power factor driving chip U3, the anode of diode D9 is electrically connected to one end of resistor R2, and the other ends of resistors R5, R2, R6, and R7 are all electrically connected to the gate of the gallium nitride MOSFET Q1. The other end is electrically connected to one end of the capacitor C6. The other end of the capacitor C6, the other end of the resistor R6, one end of the resistor R49, one end of the resistor R50, one end of the resistor R3, one end of the resistor R4, and one end of the resistor R16 are all electrically connected to the source of the gallium nitride MOS transistor Q1. The other end of the resistor R16 and one end of the capacitor C7 are all electrically connected to the ISNS terminal of the high power factor driver chip U3. The other ends of the resistor R49, the other ends of the resistor R50, the other ends of the resistor R3, the other ends of the resistor R4, and the other ends of the capacitor C7 are all connected to the GND ground terminal.

[0031] Furthermore, the power supply circuit includes a resistor R79, a diode D2, and a capacitor EC1; the primary auxiliary winding of the transformer T1 is electrically connected to the anode of the diode D2, the cathode of the diode D2 is connected in series with the resistor R79, and then electrically connected to the VCC terminal of the high power factor drive chip U3 and the positive terminal of the capacitor EC1, and the negative terminal of the capacitor EC1 is connected to the GND ground terminal.

[0032] Furthermore, the first detection module and the second detection module have the same circuit structure;

[0033] The first detection module includes resistor R64, resistor R70, and capacitor C31; the secondary filtering module or the analog constant current output module is electrically connected to one end of resistor R64, and the other end of resistor R64, one end of resistor R70, and one end of capacitor C31 are all electrically connected to the microcontroller, and the other end of resistor R70 and the other end of capacitor C31 are both connected to the SGND ground terminal.

[0034] The technical solution provided by this utility model can include the following beneficial effects: the main circuit of the constant voltage switching power supply is composed of a high-efficiency primary circuit, transformer T1 and secondary filter module, and multiple constant current outputs driven by the microcontroller using PWM signal are composed of an analog constant current output module. It can realize multiple functions such as multi-channel dimming, multi-channel color adjustment or complementary dimming and color adjustment output. Therefore, when applied to the lighting system, it can greatly reduce the complexity of the lighting system.

[0035] Meanwhile, based on the use of a high-efficiency primary circuit and a step-down bias power supply (SVIN_33V) that obtains analog constant current output modules from the secondary auxiliary winding of transformer T1 (instead of the secondary winding), the working efficiency of multiple outputs is ensured, and the no-load loss of transformer T1 is reduced.

[0036] Furthermore, since analog constant current output modules use analog signal control, the related chips typically lack self-protection (fault protection) capabilities and have poor stability. Therefore, the first and second detection modules monitor the voltages on the front and rear sides of the analog constant current output module and feed them back to the microcontroller. The microcontroller then determines whether the analog constant current output module is overvoltage, unloaded, or overloaded, and uses protection action signals to control the analog constant current output module to execute relevant protection actions, thereby improving the stability of multiple outputs. Alternatively, if the analog constant current output module has self-protection capabilities, adding protection logic programmed into the microcontroller (such as an MCU) further improves the stability of multiple outputs. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of a high-efficiency multi-output switching power supply according to one embodiment of the present invention.

[0038] Figure 2 Is it like this? Figure 1 The circuit diagram shows a high-efficiency multi-output switching power supply. Figure 1 .

[0039] Figure 3 Is it like this? Figure 1 The circuit diagram shows a high-efficiency multi-output switching power supply. Figure 2 .

[0040] Figure 4 Is it like this? Figure 1The circuit diagram shows a high-efficiency multi-output switching power supply. Figure 3 .

[0041] Figure 5 Is it like this? Figure 1 The circuit diagram of the first detection module or the second detection module is shown.

[0042] The circuit includes: a high-efficiency primary circuit 8, a transformer T1, a secondary filter module 3, a microcontroller 5, a first detection module 6, a second detection module 7, an analog constant current output module 4, an input rectification module 1, a high power factor constant voltage drive module 2, a gallium nitride MOSFET Q1, an analog constant current drive chip U2, a constant current output processing circuit 41, a current detection circuit 42, a diode D18, a capacitor EC6, a resistor R10, a capacitor C36, an inductor L3, an inductor L10, a capacitor C14, a capacitor C35, a capacitor C48, a capacitor CE3, a resistor R34, a resistor R26, a resistor R57, a resistor R58, a resistor R33, a diode D3, a common mode inductor LF5, a resistor R80, and a resistor R2. 2. Resistors R38, R39, R40, C4, R14, R17, R19, R36, MOSFET Q2, C11, D1, C2, C4, C9, high power factor driver chip U3, RCD snubber circuit 21, power supply circuit 22, voltage detection circuit 23, first drive and current detection circuit 24, resistors R2, R5, D9, R6, R7, C6, R49, R50, R3, R4, R16, C7, R79, D2, EC1, R64, R70, C30. Detailed Implementation

[0043] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0044] In the description of embodiments of this utility model, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of embodiments of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0045] In the description of the embodiments of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this utility model according to the specific circumstances.

[0046] The following is combined with Figures 1 to 5 This describes an embodiment of a high-efficiency multi-output switching power supply.

[0047] A high-efficiency multi-output switching power supply includes a high-efficiency primary circuit 8, a transformer T1, a secondary filter module 3, a microcontroller 5, a first detection module 6, a second detection module 7, and at least two analog constant current output modules 4; the high-efficiency primary circuit 8 is electrically connected to the primary winding of the transformer T1, the secondary winding of the transformer T1 is electrically connected to the secondary filter module 3, and the secondary filter module 3 is electrically connected to the analog constant current output modules 4 respectively;

[0048] The microcontroller 5 is electrically connected to the analog constant current output module 4, which receives the PWM signal and protection action signal from the microcontroller 5.

[0049] The secondary auxiliary winding of transformer T1 is electrically connected to the analog constant current output module 4, and the secondary auxiliary winding of transformer T1 provides a step-down bias power supply for the analog constant current output module 4.

[0050] The first detection module 6 is electrically connected between the analog constant current output module 4 and the microcontroller 5, and is used to feed back the output voltage signal of the analog constant current output module 4 to the microcontroller 5.

[0051] The second detection module 7 is electrically connected between the secondary filter module 3 and the microcontroller 5, and is used to feed back the output voltage signal of the secondary filter module 3 to the microcontroller 5.

[0052] This utility model proposes a preferred embodiment of a high-efficiency multi-output switching power supply, such as... Figure 1 As shown, the main circuit of the constant voltage switching power supply is composed of the high-efficiency primary circuit 8, the transformer T1 and the secondary filter module 3. The analog constant current output module 4 is composed of multiple constant current outputs driven by the microcontroller 5 using PWM signals. It can realize multiple functions such as multi-channel dimming, multi-channel color adjustment or complementary dimming and color adjustment output. Therefore, when applied to the lighting system, it can greatly reduce the complexity of the lighting system.

[0053] Meanwhile, based on the adoption of a high-efficiency primary circuit 8 and a step-down bias power supply (SVIN_33V) for analog constant current output module 4 obtained from the secondary auxiliary winding (instead of the secondary winding) of transformer T1, the working efficiency of multiple outputs is guaranteed, and the no-load loss of transformer T1 is reduced.

[0054] Furthermore, since the analog constant current output module 4 uses analog signal control, the related chips used typically lack self-protection (fault protection) capabilities and have poor stability. Therefore, the first detection module 6 and the second detection module 7 monitor the voltages on the front and rear sides of the analog constant current output module 4 and feed them back to the microcontroller 5. The microcontroller 5 then determines whether the analog constant current output module 4 is overvoltage, unloaded, or overloaded, and controls the analog constant current output module 4 to perform relevant protection actions with protection action signals, thereby improving the stability of multiple outputs. Alternatively, if the analog constant current output module 4 has self-protection capabilities, the microcontroller 5 (such as an MCU) can be programmed with protection logic to further improve the stability of multiple outputs.

[0055] It should be noted that the secondary filter module 3 is typically as follows: Figure 2 and 3 As shown, the secondary signal of transformer T1 is rectified and filtered by inductor L6, RCD absorption circuit and filter inductor and then output (VBUS) to analog constant current output module 4. The specific circuit is not limited here.

[0056] Furthermore, the high-efficiency primary circuit 8 includes an input rectifier module 1 and a high power factor constant voltage drive module 2; the input rectifier module 1, the high power factor constant voltage drive module 2 and the primary winding of the transformer T1 are electrically connected in sequence, and the high power factor constant voltage drive module 2 is electrically connected to the primary auxiliary winding of the transformer T1, and the high power factor constant voltage drive module 2 receives voltage feedback from the primary auxiliary winding of the transformer T1.

[0057] The high power factor constant voltage drive module 2 is equipped with a gallium nitride MOSFET Q1; the high power factor constant voltage drive module 2 drives the gallium nitride MOSFET Q1 to achieve constant voltage output.

[0058] In this embodiment, as Figure 2 As shown, to improve the working efficiency of the high-efficiency primary-side circuit 8, it needs to be composed of an input rectifier module 1 and a high power factor constant voltage drive module 2. The high power factor constant voltage drive module 2 uses a gallium nitride MOSFET Q1 to achieve constant voltage output. By utilizing the low power consumption and high frequency switching characteristics of the gallium nitride MOSFET Q1 and the high working efficiency of the high power factor constant voltage drive module 2, the response speed of the switching power supply is greatly improved.

[0059] Furthermore, the analog constant current output module 4 includes an analog constant current driver chip U2, a constant current output processing circuit 41, and a current detection circuit 42; the voltage detection terminal of the analog constant current driver chip U2 is electrically connected to the constant current output processing circuit 41; the constant current output processing circuit 41 is connected to the SGND ground terminal via the current detection circuit 42, and the current detection terminal of the analog constant current driver chip U2 is electrically connected to the current detection circuit 42.

[0060] The first detection module 6 and the constant current output processing circuit 41 are electrically connected; the enable terminal, analog signal drive terminal and fault terminal of the analog constant current drive chip U2 are all electrically connected to the microcontroller 5.

[0061] The step-down bias power supply terminal of the analog constant current drive chip U2 is electrically connected to the secondary auxiliary winding of transformer T1;

[0062] After passing through the constant current output processing circuit 41, the secondary-side filter module 3 is electrically connected to the drain terminal of the internal MOS transistor of the analog constant current driver chip U2; the source terminal of the internal MOS transistor of the analog constant current driver chip U2 is connected to the load after passing through the constant current output processing circuit 41.

[0063] In this embodiment, as Figure 4 As shown, the analog constant current output module 4 is composed of an analog constant current driver chip U2 and its peripheral circuits. The main function is to utilize the constant current output processing circuit 41 to receive the output voltage (VBUS) from the secondary-side filter module 3. Under the PWM signal drive of the microcontroller 5, the power MOSFET built into the analog constant current driver chip U2 is switched. The constant current output processing circuit 41 outputs a dimming or color-tuning signal to the load, realizing one output path of the switching power supply. The current detection circuit 42 feeds back the current status of this output path to the analog constant current driver chip U2, and the constant current output processing circuit 41 feeds back the voltage status (VSNS_1) of this output path to the analog constant current driver chip U2, enabling the analog constant current driver chip U2 to self-regulate and maintain output stability. The constant current output processing circuit 41 also feeds back the voltage status (V0_1) of this output path to the microcontroller 5 for status judgment, and the protection action signal (FAULT_1) controls the analog constant current driver chip U2 to execute relevant protection actions.

[0064] Specifically, the analog constant current driver chip U2 can be the SY87596 chip, which has the above functions. The enable terminal corresponds to the EN pin, the analog signal drive terminal corresponds to the PWM pin, the fault terminal corresponds to the FAULT pin, the buck bias power supply terminal corresponds to the SVIN pin, the drain terminal of the internal MOSFET corresponds to the PVIN pin, the source terminal of the internal MOSFET corresponds to the LX pin, the voltage detection terminal corresponds to the VSEN pin, and the current detection terminal corresponds to the ISEN pin.

[0065] Furthermore, the analog constant current output module 4 also includes diode D18, capacitor EC6, resistor R10, and capacitor C36; the opposite-named terminal of the secondary auxiliary winding of transformer T1 is connected to the SGND ground terminal, and the same-named terminal of the secondary auxiliary winding of transformer T1 is electrically connected to the anode of diode D18; the cathode of diode D18 is connected in series with resistor R10 and then electrically connected to the step-down bias power supply terminal of analog constant current drive chip U2; capacitor C36 is connected in parallel between the step-down bias power supply terminal of analog constant current drive chip U2 and the SGND ground terminal; the cathode of diode D18 and the SGND ground terminal are electrically connected to the positive and negative terminals of capacitor EC6, respectively.

[0066] In this embodiment, as Figure 3 and 4 As shown, in order to ensure that the analog constant current drive chip U2 can stably receive the buck bias power supply (SVIN_33V), diode D18 and capacitor EC6 are set on the auxiliary winding side of the secondary side of transformer T1, and resistor R10 and capacitor C36 are set on the buck bias power supply side of analog constant current drive chip U2 to filter and conduct the buck bias power supply in one direction.

[0067] Furthermore, the constant current output processing circuit 41 includes inductors L3 and L10, capacitors C14, C35, C48, CE3, resistors R34, R26, R57, R58, R33, diode D3, and common-mode inductor LF5. The source terminal of the internal MOS transistor of the analog constant current drive chip U2, one end of capacitor C14, and the cathode of diode D3 are all electrically connected to one end of inductor L3. The other end of capacitor C14 is electrically connected to one end of resistor R34. The other end of resistor R34 and the anode of diode D3 are both connected to the SGND ground terminal.

[0068] The secondary-side filter module 3 and one end of capacitor C35 are both electrically connected to one end of inductor L10, and the other end of inductor L10 is electrically connected to the drain terminal of the internal MOS transistor of analog constant current drive chip U2.

[0069] The other end of the first detection module 6, the other end of capacitor C35, one end of capacitor C48, the positive terminal of capacitor CE3, and one end of resistor R57 are all electrically connected to the input terminal of the first winding of common mode inductor LF5, and the other end of capacitor C48 is connected to the SGND ground terminal.

[0070] The output voltage detection terminal of the analog constant current drive chip U2, the other end of resistor R57, one end of resistor R26, and one end of resistor R58 are all electrically connected.

[0071] After the input terminal of the second winding of the common mode inductor LF5, the other end of resistor R26, the other end of resistor R58, and the negative terminal of capacitor CE3 are connected together, they are connected to the SGND ground terminal through the current detection circuit 42.

[0072] A resistor R33 is connected in parallel between the first winding output terminal and the second winding output terminal of the common mode inductor LF5, and then the load is connected.

[0073] In this embodiment, the preferred circuit structure of the constant current output processing circuit 41 is as follows: Figure 4 As shown, the output receiving circuit (VBUS) of the secondary-side filter module 3 is composed of inductor L10, capacitor C35, and capacitor C48; the dimming signal or color tone signal output processing circuit of the analog constant current drive chip U2 is composed of inductor L3, capacitor C14, capacitor C48, capacitor CE3, resistor R34, resistor R26, resistor R57, resistor R58, resistor R33, diode D3, and common-mode inductor LF5. The voltage signals VO_1 and VSNS_1 are obtained from the end of this circuit and fed back to the microcontroller 5 and the analog constant current drive chip U2, respectively; and the current signal is obtained from the ground terminal of this circuit and fed back to the analog constant current drive chip U2.

[0074] Furthermore, the current detection circuit 42 includes resistors R80, R22, R38, R39, R40, and capacitor C4; the constant current output processing circuit 41 is connected to the SGND ground terminal after series with resistor R40; resistors R22, R38, and R39 are connected in parallel between the two ends of resistor R40; the common contact of the constant current output processing circuit 41 and resistor R40 is connected in series with resistor R80 and electrically connected to the current detection terminal of the analog constant current drive chip U2; capacitor C4 is connected in parallel between the current detection terminal of the analog constant current drive chip U2 and the SGND ground terminal.

[0075] In this embodiment, the preferred circuit structure of the current detection circuit 42 is as follows: Figure 4 As shown, the current acquisition circuit is mainly composed of multiple resistors connected in parallel.

[0076] Furthermore, the high power factor constant voltage drive module 2 also includes resistors R14, R17, R19, and R36, MOSFET Q2, capacitor C11, diode D1, capacitor C2, capacitor C4, capacitor C9, high power factor drive chip U3, RCD absorption circuit 21, power supply circuit 22, voltage detection circuit 23, and first drive and current detection circuit 24; the output terminal of the input rectifier module 1 is electrically connected to the same-name terminal of the primary winding of transformer T1, and the RCD absorption circuit 21 is connected in parallel between the same-name terminal and the opposite-name terminal of the primary winding of transformer T1;

[0077] The output terminal of the input rectifier module 1 is connected to the gate of MOSFET Q2 after being connected in series with resistors R14 and R17. The output terminal of the input rectifier module 1 is connected to the drain of MOSFET Q2 after being connected in series with resistors R36 and R19. The gate of MOSFET Q2 is connected to the VIN terminal of high power factor driver chip U3. A capacitor C11 is connected in parallel between the gate of MOSFET Q2 and GND. The source of MOSFET Q2 is connected to the anode of diode D1. The VCC terminal of high power factor driver chip U3 is connected to the cathode of diode D1. A capacitor C2 is connected in parallel between the VCC terminal of high power factor driver chip U3 and GND. A capacitor C4 is connected in parallel between the VDD terminal of high power factor driver chip U3 and GND. The GND terminal of high power factor driver chip U3 is connected to GND.

[0078] The opposite-named terminal of the primary auxiliary winding of transformer T1 is connected to the GND ground terminal, and the same-named terminal of the primary auxiliary winding of transformer T1 is electrically connected to the VCC terminal of the high power factor drive chip U3 through the power supply circuit 22.

[0079] The VSNS terminal of the high power factor drive chip U3 is electrically connected to the same terminal of the primary auxiliary winding of transformer T1 via voltage detection circuit 23.

[0080] The opposite terminal of the primary winding of transformer T1 is electrically connected to the drain of gallium nitride MOSFET Q1. A capacitor C9 is connected in parallel between the drain and source of gallium nitride MOSFET Q1. The OUT terminal and ISNS terminal of high power factor driver chip U3 are electrically connected to the drive terminal and feedback terminal of the first drive and current detection circuit 24, respectively. The output terminal and input terminal of the first drive and current detection circuit 24 are electrically connected to the gate and source of gallium nitride MOSFET Q1, respectively.

[0081] In this embodiment, as Figure 2 As shown, the input rectifier module 1 typically consists of a safety circuit (the input circuit of the rectifier bridge BD1), the rectifier bridge BD1, and a Π-type filter (capacitor CB7, inductor L5, resistor R80, and capacitor CB8) to achieve AC to DC rectification and filtering. When the output voltage of the input rectifier module 1 is increased to a certain level, the MOSFET Q2 is turned on and transmitted to the high power factor driver chip U3 to achieve efficient operation.

[0082] Taking the XP3359G chip as an example, the high power factor drive chip U3 uses the voltage received at its VCC and VIN terminals to determine whether it starts up and to ensure operational stability. Its digital core analyzes the waveform of the primary auxiliary winding of transformer T1 in real time to control the gallium nitride MOSFET Q1, achieving primary-side control of transformer T1. Phase compensation is performed internally, ensuring loop stability under any input / output conditions without the need for external compensation components. Furthermore, based on its real-time monitoring of the voltage of the primary auxiliary winding of transformer T1 and the current of gallium nitride MOSFET Q1, excellent power factor (PF) / thunder factor (THD) can be achieved regardless of the transformer inductance value. In addition, the chip's digital core performs reverse phase shift adjustment of the flyback through internal calculations to reduce the impact of EMI capacitors on PF / THD, greatly improving the chip's driving efficiency for gallium nitride MOSFET Q1 and thus increasing the response speed of the switching power supply.

[0083] It should be noted that the RCD absorption circuit 21 is mainly used to absorb high-frequency oscillations on the primary side of transformer T1, and its circuit structure can be as follows: Figure 2 As shown, other RCD absorption circuit structures are also possible and are not limited here. In addition, the specific circuit structure of the voltage detection circuit 23 is not limited. It can be composed of resistor R15, resistor R21, resistor R22, diode D10 and capacitor C12 to sample the voltage of the primary auxiliary winding and provide voltage regulation and filtering feedback to the high power factor driver chip U3.

[0084] Furthermore, the first driving and current detection circuit 24 includes resistors R2 and R5, diode D9, resistors R6 and R7, capacitor C6, resistors R49, R50, R3, R4, R16, and capacitor C7. The cathode of diode D9 and one end of resistor R5 are electrically connected to the OUT terminal of the high power factor driving chip U3. The anode of diode D9 is electrically connected to one end of resistor R2. The other ends of resistors R5, R2, R6, and R7 are all electrically connected to the gate of gallium nitride MOSFET Q1. The other end of resistor R7 is electrically connected to one end of capacitor C6. The other end of capacitor C6, the other end of resistor R6, one end of resistor R49, one end of resistor R50, one end of resistor R3, one end of resistor R4, and one end of resistor R16 are all electrically connected to the source of gallium nitride MOSFET Q1. The other end of resistor R16 and one end of capacitor C7 are both electrically connected to the ISNS terminal of high power factor driver chip U3. The other ends of resistor R49, resistor R50, resistor R3, resistor R4, and capacitor C7 are all connected to GND ground.

[0085] In this embodiment, the first driving and current detection circuit 24 consists of resistors R2 and R5, diode D9, resistors R6 and R7, and capacitor C6, which form a driving circuit to directly drive the gallium nitride MOS transistor Q1. The current detection circuit consists of resistors R49, R50, R3, R4, R16, and capacitor C7, which feeds back the current signal to the high power factor driving chip U3.

[0086] Furthermore, the power supply circuit 22 includes a resistor R79, a diode D2, and a capacitor EC1; the primary auxiliary winding of the transformer T1 is electrically connected to the anode of the diode D2, the cathode of the diode D2 is connected to the VCC terminal of the high power factor drive chip U3 and the positive terminal of the capacitor EC1 after being connected in series with the resistor R79, and the negative terminal of the capacitor EC1 is connected to the GND ground terminal.

[0087] In this embodiment, after the high power factor drive chip U3 starts up and stabilizes, it is powered by the primary auxiliary winding. Based on this, it is preferable to use a power supply circuit 22 composed of resistor R79, diode D2 and capacitor EC1 to obtain a unidirectional stable voltage. Only after the high power factor drive chip U3 starts up and stabilizes can diode D2 conduct forward to supply power.

[0088] Furthermore, the circuit structures of the first detection module 6 and the second detection module 7 are the same;

[0089] The first detection module 6 includes resistors R64 and R70 and capacitor C31; the secondary filter module 3 or the analog constant current output module 4 is electrically connected to one end of resistor R64, and the other end of resistor R64, one end of resistor R70, and one end of capacitor C31 are all electrically connected to microcontroller 5. The other end of resistor R70 and the other end of capacitor C31 are both connected to the SGND ground terminal.

[0090] In this embodiment, as Figure 5 As shown, the voltage divider circuit composed of resistors R64 and R70 collects the output voltage signal of the secondary filter module 3 or the output voltage signal of the analog constant current output module 4 and transmits it to the microcontroller 5 for reading.

[0091] Other configurations and operations of a high-efficiency multi-output switching power supply according to embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0092] In this specification, the terms "embodiment," "example," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0093] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A high efficiency multiple output switching power supply characterized by: The high-efficiency primary side loop, the transformer T1, the secondary side filter module, the microcontroller, the first detection module, the second detection module and at least two analog constant current output modules are included; the high-efficiency primary side loop and the primary winding of the transformer T1 are electrically connected; the secondary winding of the transformer T1 and the secondary side filter module are electrically connected; the secondary side filter module is electrically connected with the analog constant current output module respectively; The microcontroller is electrically connected with the analog constant current output module respectively; the analog constant current output module receives the PWM signal and the protection action signal of the microcontroller; The secondary side auxiliary winding of the transformer T1 is electrically connected with the analog constant current output module respectively; the secondary side auxiliary winding of the transformer T1 provides the voltage reduction bias power supply for the analog constant current output module; The first detection module is electrically connected between the analog constant current output module and the microcontroller, and is used for feeding back the output voltage signal of the analog constant current output module to the microcontroller; The second detection module is electrically connected between the secondary side filter module and the microcontroller, and is used for feeding back the output voltage signal of the secondary side filter module to the microcontroller.

2. The high efficiency multiple output switching power supply of claim 1 wherein: The high-efficiency primary side loop includes an input rectification module and a high-power factor constant voltage driving module; the input rectification module, the high-power factor constant voltage driving module and the primary winding of the transformer T1 are electrically connected in sequence, and the high-power factor constant voltage driving module and the primary auxiliary winding of the transformer T1 are electrically connected; the high-power factor constant voltage driving module receives the voltage feedback of the primary auxiliary winding of the transformer T1; The high-power factor constant voltage driving module is provided with a gallium nitride MOS tube Q1; The high-power factor constant voltage driving module drives the gallium nitride MOS tube Q1 to realize constant voltage output.

3. The high efficiency multiple output switching power supply of claim 2 wherein: The analog constant current output module includes an analog constant current driving chip U2, a constant current output processing circuit and a current detection circuit; the voltage detection end of the analog constant current driving chip U2 and the constant current output processing circuit are electrically connected; the constant current output processing circuit is connected to the SGND ground end through the current detection circuit; the current detection end of the analog constant current driving chip U2 and the current detection circuit are electrically connected; The first detection module and the constant current output processing circuit are electrically connected; the enable end, the analog signal driving end and the fault end of the analog constant current driving chip U2 are electrically connected with the microcontroller; The voltage reduction bias power supply end of the analog constant current driving chip U2 and the secondary side auxiliary winding of the transformer T1 are electrically connected; The secondary side filter module is electrically connected with the internal MOS tube drain end of the analog constant current driving chip U2 through the constant current output processing circuit; the internal MOS tube source end of the analog constant current driving chip U2 is connected to the load through the constant current output processing circuit.

4. The high efficiency multiple output switching power supply of claim 3 wherein: The analog constant current output module further comprises a diode D18, a capacitor EC6, a resistor R10 and a capacitor C36; the auxiliary winding of the secondary side of the transformer T1 is connected to the SGND ground end at the non-identical end, and the identical end of the auxiliary winding of the secondary side of the transformer T1 is electrically connected to the anode of the diode D18; the cathode of the diode D18 is electrically connected to the voltage reduction bias power supply end of the analog constant current drive chip U2 in series with the resistor R10; the capacitor C36 is connected in parallel between the voltage reduction bias power supply end of the analog constant current drive chip U2 and the SGND ground end; the cathode of the diode D18 and the SGND ground end are electrically connected to the positive electrode and the negative electrode of the capacitor EC6 respectively.

5. A high-efficiency multi-output switching power supply according to claim 3, characterized in that: The constant current output processing circuit comprises an inductor L3, an inductor L10, a capacitor C14, a capacitor C35, a capacitor C48, a capacitor CE3, a resistor R34, a resistor R26, a resistor R57, a resistor R58, a resistor R33, a diode D3 and a common mode inductor LF5; the source end of the internal MOS transistor of the analog constant current drive chip U2, one end of the capacitor C14 and the cathode of the diode D3 are electrically connected to one end of the inductor L3, the other end of the capacitor C14 is electrically connected to one end of the resistor R34, and the other end of the resistor R34 is connected to the anode of the diode D3 at the SGND ground end; The auxiliary winding of the secondary side and one end of the capacitor C35 are electrically connected to one end of the inductor L10, and the other end of the inductor L10 is electrically connected to the drain end of the internal MOS transistor of the analog constant current drive chip U2; The first detection module, the other end of the capacitor C35, one end of the capacitor C48, the positive electrode of the capacitor CE3 and one end of the resistor R57 are electrically connected to the first winding input end of the common mode inductor LF5, and the other end of the capacitor C48 is connected to the SGND ground end; The output voltage detection end of the analog constant current drive chip U2, the other end of the resistor R57 and one end of the resistor R26 are electrically connected to one end of the resistor R58; The second winding input end of the common mode inductor LF5, the other end of the resistor R26, the other end of the resistor R58 and the negative electrode of the capacitor CE3 are connected in common, and then connected to the SGND ground end through the current detection circuit; The resistor R33 is connected in parallel between the first winding output end and the second winding output end of the common mode inductor LF5, and then connected to the load.

6. The high-efficiency multi-output switching power supply according to claim 3, characterized in that: The current detection circuit comprises a resistor R80, a resistor R22, a resistor R38, a resistor R39, a resistor R40 and a capacitor C4; the constant current output processing circuit is connected to the SGND ground end in series with the resistor R40; the resistor R22, the resistor R38 and the resistor R39 are connected in parallel between the two ends of the resistor R40; the common connection point of the constant current output processing circuit and the resistor R40 is connected to the current detection end of the analog constant current drive chip U2 in series with the resistor R80; the capacitor C4 is connected in parallel between the current detection end of the analog constant current drive chip U2 and the SGND ground end.

7. The high-efficiency multi-output switching power supply according to claim 2, characterized in that: The high-power-factor constant-voltage driving module further comprises a resistor R14, a resistor R17, a resistor R19, a resistor R36, a MOS tube Q2, a capacitor C11, a diode D1, a capacitor C2, a capacitor C4, a capacitor C9, a high-power-factor driving chip U3, an RCD absorption circuit, a power supply circuit, a voltage detection circuit and a first driving and current detection circuit; the output end of the input rectifying module is electrically connected with the same-named end of the primary winding of the transformer T1, and the RCD absorption circuit is connected in parallel between the same-named end and the different-named end of the primary winding of the transformer T1. The output end of the input rectifying module is electrically connected with the gate of the MOS tube Q2 after being connected in series with the resistor R14 and the resistor R17 in sequence; the output end of the input rectifying module is electrically connected with the drain of the MOS tube Q2 after being connected in series with the resistor R36 and the resistor R19 in sequence; the gate of the MOS tube Q2 is electrically connected with the VIN end of the high-power-factor driving chip U3, the capacitor C11 is connected in parallel between the gate of the MOS tube Q2 and the GND ground end, the source of the MOS tube Q2 is electrically connected with the anode of the diode D1, the VCC end of the high-power-factor driving chip U3 is electrically connected with the cathode of the diode D1, the capacitor C2 is connected in parallel between the VCC end and the GND ground end of the high-power-factor driving chip U3, the capacitor C4 is connected in parallel between the VDD end and the GND ground end of the high-power-factor driving chip U3, and the GND end of the high-power-factor driving chip U3 is connected with the GND ground end; The different-named end of the primary auxiliary winding of the transformer T1 is connected with the GND ground end, and the same-named end of the primary auxiliary winding of the transformer T1 is electrically connected with the VCC end of the high-power-factor driving chip U3 through the power supply circuit; The VSNS end of the high-power-factor driving chip U3 is electrically connected with the same-named end of the primary auxiliary winding of the transformer T1 through the voltage detection circuit; The different-named end of the primary winding of the transformer T1 is electrically connected with the drain of the gallium nitride MOS tube Q1, the capacitor C9 is connected in parallel between the drain and the source of the gallium nitride MOS tube Q1, the OUT end and the ISNS end of the high-power-factor driving chip U3 are respectively electrically connected with the driving end and the feedback end of the first driving and current detection circuit, and the output end and the input end of the first driving and current detection circuit are respectively electrically connected with the gate and the source of the gallium nitride MOS tube Q1.

8. A high-efficiency multi-output switching power supply according to claim 7, characterized in that: The first driving and current detecting circuit comprises resistors R2, R5, a diode D9, resistors R6, R7, a capacitor C6, resistors R49, R50, resistors R3, R4, a resistor R16 and a capacitor C7; the cathode of the diode D9 and one end of the resistor R5 are electrically connected to the OUT end of the high-power-factor driving chip U3, the anode of the diode D9 is electrically connected to one end of the resistor R2, the other end of the resistor R5, the other end of the resistor R2, one end of the resistor R6, one end of the resistor R7 are electrically connected to the gate of the gallium nitride MOS tube Q1, the other end of the resistor R7 is electrically connected to one end of the capacitor C6, the other end of the capacitor C6, the other end of the resistor R6, one end of the resistor R49, one end of the resistor R50, one end of the resistor R3, one end of the resistor R4, one end of the resistor R16 are electrically connected to the source of the gallium nitride MOS tube Q1, the other end of the resistor R16 and one end of the capacitor C7 are electrically connected to the ISNS end of the high-power-factor driving chip U3, the other end of the resistor R49, the other end of the resistor R50, the other end of the resistor R3, the other end of the resistor R4 and the other end of the capacitor C7 are electrically connected to the GND ground end.

9. A high-efficiency multi-output switching power supply according to claim 7, characterized in that: The power supply circuit comprises a resistor R79, a diode D2 and a capacitor EC1; the same end of the primary auxiliary winding of the transformer T1 is electrically connected to the anode of the diode D2, the cathode of the diode D2 is electrically connected to the VCC end of the high-power-factor driving chip U3 and the positive electrode of the capacitor EC1 after being connected in series with the resistor R79, and the negative electrode of the capacitor EC1 is electrically connected to the GND ground end.

10. A high-efficiency multi-output switching power supply according to claim 1, characterized in that: The first detection module and the second detection module have the same circuit structure; The first detection module comprises a resistor R64, a resistor R70 and a capacitor C31; One end of the resistor R64 of the secondary side filtering module or the analog constant current output module is electrically connected to the resistor R64, the other end of the resistor R64, one end of the resistor R70 and one end of the capacitor C31 are electrically connected to the microcontroller, and the other end of the resistor R70 and the other end of the capacitor C31 are electrically connected to the SGND ground end.

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