Anti-interference LED controller based on gallium nitride chip

Abstract

The utility model relates to the technical field of LED control, in particular to an anti-interference LED controller based on a gallium nitride chip, which comprises a rectifying and filtering unit, a load unit and a transformer T1. The circuit also comprises a starting unit, a PFC unit with an anti-interference capability, and a flyback unit with an anti-interference capability. The starting unit is used for firstly supplying power to start the flyback unit and then delaying power supply to start the PFC unit after the rectifying and filtering unit outputs the current; when the PFC unit and the flyback unit are both started, the flyback unit controls the transformer T to output dimming current to the load unit; the PFC unit is used for filtering common-mode interference generated by coupling of the primary side and the secondary side of the transformer T; the flyback unit is also used for absorbing the instantaneous overvoltage of the primary side of the transformer T; the PFC unit and the flyback unit both adopt gallium nitride chips; and anti-interference design is carried out on each part of the control circuit, so that the stability of dimming current is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of LED control, in particular to an anti-interference LED controller based on a gallium nitride chip. Background Art

[0002] As consumers' demands for energy-saving, environmental protection and intelligent lighting increase, LED lighting products have gradually become the mainstream choice in the market. As a key component of LED lighting products, the market demand for LED controllers has also increased. Especially in the fields of smart home and commercial lighting, LED controllers are increasingly widely used. Therefore, LED controllers need to be able to maintain the stability of circuit operation in different application circuit environments to ensure that the dimming performance remains stable.

[0003] Current LED controllers are often composed of circuit units such as PFC circuits, flyback circuits and auxiliary winding circuits. The PFC circuits, flyback circuits and auxiliary winding circuits require different working power supplies due to different voltage levels, which not only increases the circuit complexity and manufacturing cost of the LED controller but also affects the working circuit to a certain extent due to different voltage levels.

[0004] More importantly, because the PFC circuit and the flyback circuit are powered at the same time, that is, the dimming current is output to the output end at the same time, there is no reserved time for the PFC circuit and the flyback circuit to process the dimming current, which can easily lead to unstable dimming current when the dimming function is turned on, causing the LED to flicker and the dimming to be not smooth. Utility Model Content

[0005] In view of the above-mentioned defects, the purpose of the utility model is to propose an anti-interference LED controller based on a gallium nitride chip, to perform anti-interference design on various parts of the control circuit, and to improve the stability of the dimming current.

[0006] To achieve this purpose, the utility model adopts the following technical solutions:

[0007] A gallium nitride chip-based anti-interference LED controller, comprising a rectifier and filter unit, a load unit and a transformer T1; further comprising a startup unit, a PFC unit with anti-interference capability and a flyback unit with anti-interference capability; the output end of the rectifier and filter unit is electrically connected to the input end of the PFC unit, the output end of the PFC unit and the input end of the flyback unit are both electrically connected to a high-voltage startup pin HV, the power supply end of the PFC unit is electrically connected to the first end of the startup unit, the power supply end of the flyback unit is electrically connected to the second end of the startup unit, the ground end of the PFC unit, the ground end of the startup unit and the ground end of the flyback unit are all grounded, the output end of the flyback unit is electrically connected to the primary side of the transformer T1, the secondary side of the transformer T1 is electrically connected to the input end of the load unit, and the anti-interference end of the PFC unit is electrically connected to the anti-interference end of the load unit;

[0008] The starting unit is used to supply power to start the flyback unit first, and then delay the power supply to start the PFC unit after the rectifying and filtering unit outputs current;

[0009] When the PFC unit and the flyback unit are both started, the flyback unit controls the transformer T1 to output a dimming current to the load unit;

[0010] The PFC unit is used to filter out common-mode interference generated by coupling between the primary side and the secondary side of the transformer T1;

[0011] The flyback unit is also used to absorb the instantaneous overvoltage on the primary side of the transformer T1;

[0012] The PFC unit and the flyback unit both use gallium nitride chips.

[0013] Further, the PFC unit includes a capacitor EC1, a capacitor CB1, a capacitor C2, a capacitor C3, a capacitor C6, a resistor R9, a resistor R29, a resistor R30, a resistor R4, a resistor R18, a resistor R19, a resistor R20, a resistor R2, a resistor R6, a resistor R5, a resistor R3, a resistor R8, an inductor L2, a diode D1, a diode D2, a gallium nitride PFC chip U1 and a first anti-interference circuit; one end and the other end of the capacitor CB1 are both used as the input end of the PFC unit, the positive electrode of the capacitor EC1 is used as the output end of the PFC unit, the negative electrode of the capacitor EC1 is used as the ground end of the PFC unit, the VDD end of the gallium nitride PFC chip U1 is used as the power supply end of the PFC unit, and the first end of the first anti-interference circuit is used as the anti-interference end of the PFC unit;

[0014] One end of the capacitor CB1, one end of the resistor R9, one end of the inductor L2, the anode of the diode D1, and one end of the capacitor C2 are all electrically connected to the second end of the first anti-interference circuit, the other end of the capacitor C2, the cathode of the diode D1, the cathode of the diode D2, and one end of the resistor R3 are all electrically connected to the positive electrode of the capacitor EC1, the other end of the resistor R9 is electrically connected to one end of the resistor R29, the other end of the resistor R29 is electrically connected to one end of the resistor R30, the other end of the resistor R30, one end of the capacitor C3, and one end of the resistor R4 are all electrically connected to the VAC end of the gallium nitride PFC chip U1, the other end of the inductor L2, the cathode of the diode D1, and one end of the resistor R3 are all electrically connected to the positive electrode of the capacitor EC1, the other end of the resistor R9 is electrically connected to one end of the resistor R29, the other end of the resistor R29 is electrically connected to one end of the resistor R30, the other end of the resistor R30, one end of the capacitor C3, and one end of the resistor R4 are all electrically connected to the VAC end of the gallium nitride PFC chip U1, the other end of the inductor L2, the cathode of the diode D2, and one end of the resistor R3 are all electrically connected to the positive electrode of the capacitor EC1, the other end of the resistor R9 is electrically connected to one end of the resistor R29, the other end of the resistor R29 is electrically connected to one end of the resistor R30 The anode of the diode D2 is electrically connected to the DRAIN end of the gallium nitride PFC chip U1, the other end of the resistor R3 is electrically connected to one end of the resistor R8, the other end of the resistor R8 is electrically connected to one end of the resistor R5, the other end of the resistor R5, one end of the resistor R2, one end of the resistor R6, and one end of the capacitor C6 are all electrically connected to the INV end of the gallium nitride PFC chip U1, the other end of the resistor R2, the other end of the resistor R6, the other end of the capacitor C6, the GND end of the gallium nitride PFC chip U1, the other end of the resistor R4, the other end of the capacitor C3, and the other end of the capacitor CB1 are all electrically connected to the negative electrode of the capacitor EC1;

[0015] The first anti-interference circuit is used to filter out common-mode interference generated by coupling between the primary side and the secondary side of the transformer T1.

[0016] Further, the flyback unit includes a capacitor C11, a capacitor C14, a resistor R7, a resistor R16, a resistor R13, a resistor R14, a resistor R15, a resistor R21, an inductor L3, a gallium nitride flyback chip U2 and a second anti-interference circuit; the VDD end of the gallium nitride flyback chip U2 is used as the power supply end of the flyback unit, the HV end of the gallium nitride flyback chip U2 is used as the input end of the flyback unit, one end of the inductor L3 and the first end of the second anti-interference circuit are both used as the output end of the flyback unit, and one end of the resistor R13 is used as the ground end of the flyback unit;

[0017] The HV end of the gallium nitride flyback chip U2 is electrically connected to the second end of the second anti-interference circuit, the DRAIN end of the gallium nitride flyback chip U2, the third end of the second anti-interference circuit, and the other end of the inductor L3 are all electrically connected to one end of the capacitor C14, the other end of the capacitor C14, one end of the resistor R21, one end of the resistor R15, one end of the resistor R14, and the other end of the resistor R13 are all electrically connected to the CS end of the gallium nitride flyback chip U2, the other end of the resistor R21, the other end of the resistor R15, and the other end of the resistor R14 are all electrically connected to one end of the resistor R13, the OVP end of the gallium nitride flyback chip U2, one end of the resistor R7, and one end of the resistor R16 are all electrically connected to one end of the capacitor C11, and the GND end of the gallium nitride flyback chip U2, the other end of the resistor R7, the other end of the resistor R16, and the other end of the capacitor C11 are all grounded;

[0018] The second anti-interference circuit is used to absorb the instantaneous overvoltage on the primary side of the transformer T1.

[0019] Further, the startup unit includes a capacitor C1, a capacitor C7, a capacitor C10 and a resistor R23; one end of the capacitor C7 is used as a first end of the startup unit, and one end of the capacitor C10 is used as a second end of the startup unit;

[0020] One end of the resistor R23 is electrically connected to one end of the capacitor C10, the other end of the resistor R23 and one end of the capacitor C1 are electrically connected to one end of the capacitor C7, and the other end of the capacitor C1, the other end of the capacitor C7 and the other end of the capacitor C10 are grounded.

[0021] Further, the second anti-interference circuit includes a capacitor C5, a resistor R10, a resistor R11, a resistor R12, a resistor R17 and a diode D3; one end of the capacitor C5 is used as a first end of the second anti-interference circuit, one end of the resistor R11 is used as a second end of the second anti-interference circuit, and an anode of the diode D3 is used as a third end of the second anti-interference circuit;

[0022] One end of the resistor R11 and one end of the resistor R12 are electrically connected to one end of the capacitor C5, the other end of the resistor R11, the other end of the resistor R12, one end of the resistor R10, and one end of the resistor R17 are electrically connected to the other end of the capacitor C5, and the other end of the resistor R10 and the other end of the resistor R17 are electrically connected to the cathode of the diode D3.

[0023] Furthermore, the first anti-interference circuit includes a capacitor CY1; one end of the capacitor CY1 is used as a first end of the first anti-interference circuit, and the other end of the capacitor CY1 is used as a second end of the first anti-interference circuit.

[0024] Furthermore, a MOS tube is integrated inside the GaN flyback chip U2.

[0025] The technical solution provided by the utility model may include the following beneficial effects: when the circuits of the PFC unit and the flyback unit themselves have a certain anti-interference ability, they respectively have the ability to filter out the common-mode interference generated by the coupling between the primary side and the secondary side of the transformer T and the ability to absorb the instantaneous overvoltage of the primary side of the transformer T; and the two share a power supply terminal and the PFC unit replaces the original auxiliary winding circuit to continuously supply power to the flyback unit in the working state, thereby reducing the circuit complexity and the working voltage level, and reducing the impact of circuits with different voltage levels on the LED controller; at the same time, the dimming current output method of starting the flyback unit first and then starting the PFC unit can further ensure the stability of the dimming current, and eliminate the interference of the coordination problem of the PFC unit and the flyback unit on the dimming current. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a circuit diagram of an anti-interference LED controller based on a gallium nitride chip in one embodiment of the present utility model.

[0027] Wherein: PFC unit 1, startup unit 2, flyback unit 3, rectifier filter unit 4, load unit 5, transformer T1, capacitor EC1, capacitor CB1, capacitor C2, capacitor C3, capacitor C6, resistor R9, resistor R29, resistor R30, resistor R4, resistor R18, resistor R19, resistor R20, resistor R2, resistor R6, resistor R5, resistor R3, resistor R8, inductor L2, diode D1, diode D2, gallium nitride PFC chip U1, first anti-interference circuit 11, capacitor C11, capacitor C14, resistor R7, resistor R16, resistor R13, resistor R14, resistor R15, resistor R21, inductor L3, gallium nitride flyback chip U2, second anti-interference circuit 31, capacitor C1, capacitor C7, capacitor C10, resistor R23, capacitor C5, resistor R10, resistor R11, resistor R12, resistor R17, diode D3, capacitor CY1. DETAILED DESCRIPTION

[0028] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0029] In the description of the embodiments of the present invention, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0030] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0031] Combine the following Figure 1 , describing an anti-interference LED controller based on a gallium nitride chip in an embodiment of the utility model.

[0032] A gallium nitride chip-based anti-interference LED controller comprises a rectifier filter unit 4, a load unit 5 and a transformer T1; further comprising a start-up unit 2, a PFC unit 1 with anti-interference capability and a flyback unit 3 with anti-interference capability; the output end of the rectifier filter unit 4 is electrically connected to the input end of the PFC unit 1, the output end of the PFC unit 1 and the input end of the flyback unit 3 are both electrically connected to a high-voltage start-up pin HV, the power supply end of the PFC unit 1 is electrically connected to the first end of the start-up unit 2, the power supply end of the flyback unit 3 is electrically connected to the second end of the start-up unit 2, the ground end of the PFC unit 1, the ground end of the start-up unit 2 and the ground end of the flyback unit 3 are all grounded, the output end of the flyback unit 3 is electrically connected to the primary side of the transformer T1, the secondary side of the transformer T1 is electrically connected to the input end of the load unit 5, and the anti-interference end of the PFC unit 1 is electrically connected to the anti-interference end of the load unit 5;

[0033] The start-up unit 2 is used to supply power to start the flyback unit 3 first, and then delay the supply of power to start the PFC unit 1 after the rectifier filter unit 4 outputs current;

[0034] When the PFC unit 1 and the flyback unit 3 are both started, the flyback unit 3 controls the transformer T1 to output a dimming current to the load unit 5;

[0035] The PFC unit 1 is used to filter out the common mode interference generated by the coupling between the primary side and the secondary side of the transformer T1;

[0036] The flyback unit 3 is also used to absorb the transient overvoltage on the primary side of the transformer T1;

[0037] The PFC unit 1 and the flyback unit 3 both use gallium nitride chips.

[0038] The utility model proposes a preferred embodiment of an anti-interference LED controller based on a gallium nitride chip, such as Figure 1 As shown, after the LED controller is powered on, the output current processed by the rectifier and filter unit 4 enters the switching power supply circuit composed of the PFC unit 1 and the flyback unit 3, wherein the PFC unit 1 has the function of filtering out the common-mode interference generated by the coupling between the primary side and the secondary side of the transformer T1 in addition to the basic functions of its own circuit having anti-interference ability and being used to correct the input current into a sine wave with the same phase as the input voltage and without distortion, improving the power factor, improving the energy utilization efficiency, reducing harmonics, and improving the circuit stability; the flyback unit 3 has the ability to absorb instantaneous overvoltage in addition to the basic functions of its own circuit having anti-interference ability and being used to store the electric energy boosted by the PFC unit 1 and improve the energy conversion efficiency and stably output it to the subsequent LED. On the basis of the above, the PFC unit 1 replaces the original auxiliary winding circuit to continuously provide electric energy for the flyback unit 3. The flyback unit 3 has the switching capability to determine whether the dimming current on the secondary side of the transformer T1 is output; therefore, after the rectifier and filter unit 4 outputs the current, it flows through the PFC unit 1 and the flyback unit 3, and the start-up unit 2 obtains the high-voltage starting electric energy through the flyback unit 3 to first supply power to start the flyback unit 3, while the PFC unit 1 also stores electric energy, and then starts the PFC unit 1 after a delay. At this time, the PFC unit 1 has stored enough electric energy, and can continuously provide a smooth and stable high voltage to the flyback unit 3 and the transformer T1, so that the flyback unit 3 can continuously obtain electric energy from the PFC unit 1. At this time, the flyback unit 3 controls the transformer T1 to release energy to output to the load unit 5, so as to meet the current demand of the load unit 5 and reduce the current fluctuation of the load unit 5, so as to obtain a stable dimming current.

[0039] More importantly, gallium nitride (GaN) chips have excellent anti-interference performance. Gallium nitride chips are used in the circuits constituting the PFC unit 1 and the flyback unit 3, which greatly improves the anti-interference performance of the chip itself. This is mainly due to the excellent physical properties of the gallium nitride material itself and the optimization of the chip design. First, gallium nitride has a high breakdown electric field strength and a high electron saturation mobility, which enables the gallium nitride chip to maintain stable performance under high voltage, high frequency and high power density working environment. This stability helps to reduce interference caused by changes in the external environment or fluctuations in the internal circuit. Secondly, the design of gallium nitride chips usually includes advanced noise suppression technology and electromagnetic shielding measures. These technologies can effectively reduce the impact of external noise and electromagnetic interference on chip performance and ensure the stable operation of the chip in a complex electromagnetic environment. In addition, gallium nitride chips also usually have a wide operating temperature range and high reliability, which enables them to work normally in various harsh working environments without being disturbed by external factors such as temperature and humidity.

[0040] In summary, when the PFC unit 1 and the flyback unit 3 have certain anti-interference capabilities, they have the ability to filter out the common-mode interference generated by the coupling between the primary and secondary sides of the transformer T1 and the ability to absorb the instantaneous overvoltage on the primary side of the transformer T1; and the two share a common power supply terminal, and the PFC unit 1 replaces the original auxiliary winding circuit to continuously supply power to the flyback unit 3 in the working state, which reduces the circuit complexity and the working voltage level, and reduces the impact of circuits with different voltage levels on the LED controller; at the same time, the dimming current output method of starting the flyback unit 3 first and then starting the PFC unit 1 can further ensure the stability of the dimming current, and eliminate the interference of the coordination problem of the PFC unit 1 and the flyback unit 3 on the dimming current.

[0041] It should be noted that the anti-interference end of the load unit 5 can be the positive end, negative end or positive end of the secondary side of the transformer T1, etc., so as to achieve the purpose of electrically connecting the primary side and the secondary side of the transformer T1 to filter out common-mode interference.

[0042] Further, the PFC unit 1 includes a capacitor EC1, a capacitor CB1, a capacitor C2, a capacitor C3, a capacitor C6, a resistor R9, a resistor R29, a resistor R30, a resistor R4, a resistor R18, a resistor R19, a resistor R20, a resistor R2, a resistor R6, a resistor R5, a resistor R3, a resistor R8, an inductor L2, a diode D1, a diode D2, a gallium nitride PFC chip U1 and a first anti-interference circuit 11; one end and the other end of the capacitor CB1 are both used as an input end of the PFC unit 1, the positive electrode of the capacitor EC1 is used as an output end of the PFC unit 1, the negative electrode of the capacitor EC1 is used as a ground end of the PFC unit 1, the VDD end of the gallium nitride PFC chip U1 is used as a power supply end of the PFC unit 1, and the first end of the first anti-interference circuit 11 is used as an anti-interference end of the PFC unit 1;

[0043] One end of capacitor CB1, one end of resistor R9, one end of inductor L2, the anode of diode D1, and one end of capacitor C2 are all electrically connected to the second end of the first anti-interference circuit 11, the other end of capacitor C2, the cathode of diode D1, the cathode of diode D2, and one end of resistor R3 are all electrically connected to the positive electrode of capacitor EC1, the other end of resistor R9 is electrically connected to one end of resistor R29, the other end of resistor R29 is electrically connected to one end of resistor R30, the other end of resistor R30, one end of capacitor C3, and one end of resistor R4 are all electrically connected to the VAC end of gallium nitride PFC chip U1, the other end of inductor L2, the cathode of diode D1, and one end of resistor R2 are all electrically connected to the positive electrode of capacitor EC1, the other end of resistor R9 is electrically connected to one end of resistor R29, the other end of resistor R29 is electrically connected to one end of resistor R30, the other end of resistor R30, one end of capacitor C3, and one end of resistor R4 are all electrically connected to the VAC end of gallium nitride PFC chip U1, the other end of inductor L2, The anode of the pole tube D2 is electrically connected to the DRAIN terminal of the gallium nitride PFC chip U1, the other end of the resistor R3 is electrically connected to one end of the resistor R8, the other end of the resistor R8 is electrically connected to one end of the resistor R5, the other end of the resistor R5, one end of the resistor R2, one end of the resistor R6, and one end of the capacitor C6 are all electrically connected to the INV terminal of the gallium nitride PFC chip U1, the other end of the resistor R2, the other end of the resistor R6, the other end of the capacitor C6, the GND terminal of the gallium nitride PFC chip U1, the other end of the resistor R4, the other end of the capacitor C3, and the other end of the capacitor CB1 are all electrically connected to the negative electrode of the capacitor EC1;

[0044] The first anti-interference circuit 11 is used to filter out common-mode interference generated by coupling between the primary side and the secondary side of the transformer T1 .

[0045] In this embodiment, after the rectifier filter unit 4 outputs current, the PFC unit 1 is not started, and the current is stored in the inductor L2 and supplies power to the capacitor EC1 and the subsequent circuit through the diode D2, waiting for the capacitor EC1 to be fully charged and have sufficient voltage to ensure that the current fluctuation is small after startup; after waiting for the startup unit 2 to supply power to the PFC unit 1, the circuit detection module and constant voltage controller built into the chip form this output voltage following function, and the VAC terminal is connected to the resistor voltage division between the input line and the ground to obtain the voltage of R4 after the voltage division, and the circuit of the gallium nitride PFC chip U1 (such as the OB3674 chip) The detection module will sample the voltage peak value of the VAC terminal and obtain a reference voltage to follow, which is recorded as Vac_pk. The INV terminal is connected to the resistor voltage divider between the output line and the ground, and the INV terminal voltage is compared with Vac_pk+0.22V to adjust the output voltage of the built-in CV constant voltage module. The upper limit of the clamping voltage of Vac_pk is 2.28V, and the lower limit is 1.05V. Usually, the GaN PFC chip U1 boosts the voltage to obtain a 410V output high voltage. The chip has a built-in reference voltage of 2.5V. When the Vac_pk terminal is floating, the Vac_pk terminal voltage is set The output voltage is set to 2.28V, and the output voltage following function is disabled. By comparison, it is not difficult to find that when the VAC terminal is left unconnected, Vac_pk+0.22V, that is, 2.28+0.22V, is exactly 2.5V, which is the internal reference voltage of the normal GaN PFC chip U1. This also means that when the VAC pin of the GaN PFC chip in the circuit in the figure is 2.28V, the output voltage is 410V, which has reached the high-voltage output of the input voltage upper limit, and the output voltage following will not continue to increase. On the contrary, if the VAC terminal is less than 2.28V, this circuit will adjust the output voltage following to decrease, and the output voltage of the PFC is Voutput=k*(Vac_pk+0.22V), where k is the ratio of the INV terminal resistance. According to the output voltage follower, the GaN PFC chip U1 does not need to be boosted to 410V. When the input voltage is low, the output voltage of the PFC is relatively reduced to reduce the power loss of the internal boost of the chip, avoid overheating, affect the stability and performance of the chip, and avoid long-term high voltage state causing electrical noise inside the chip, causing interference to signal transmission and processing, thereby improving the anti-interference ability of the PFC unit 1 during the working process.

[0046] Further, the flyback unit 3 includes a capacitor C11, a capacitor C14, a resistor R7, a resistor R16, a resistor R13, a resistor R14, a resistor R15, a resistor R21, an inductor L3, a gallium nitride flyback chip U2, and a second anti-interference circuit 31; the VDD end of the gallium nitride flyback chip U2 is used as the power supply end of the flyback unit 3, the HV end of the gallium nitride flyback chip U2 is used as the input end of the flyback unit 3, one end of the inductor L3 and the first end of the second anti-interference circuit 31 are both used as the output end of the flyback unit 3, and one end of the resistor R13 is used as the ground end of the flyback unit 3;

[0047] The HV end of the gallium nitride flyback chip U2 is electrically connected to the second end of the second anti-interference circuit 31, the DRAIN end of the gallium nitride flyback chip U2, the third end of the second anti-interference circuit 31, and the other end of the inductor L3 are all electrically connected to one end of the capacitor C14, the other end of the capacitor C14, one end of the resistor R21, one end of the resistor R15, one end of the resistor R14, and the other end of the resistor R13 are all electrically connected to the CS end of the gallium nitride flyback chip U2, the other end of the resistor R21, the other end of the resistor R15, and the other end of the resistor R14 are all electrically connected to one end of the resistor R13, the OVP end of the gallium nitride flyback chip U2, one end of the resistor R7, and one end of the resistor R16 are all electrically connected to one end of the capacitor C11, and the GND end of the gallium nitride flyback chip U2, the other end of the resistor R7, the other end of the resistor R16, and the other end of the capacitor C11 are all grounded;

[0048] The second anti-interference circuit 31 is used to absorb the instantaneous overvoltage on the primary side of the transformer T1.

[0049] In this embodiment, when power is turned on, the HV end is directly started with high voltage, and the HV end is internally connected to the VDD end. The startup unit 2 at the VDD end of the gallium nitride flyback chip U2 (for example, the OB8652 chip) is first charged through the HV end high voltage startup. When the voltage provided to the VDD end by the startup unit 2 is higher than the UVLO (OFF), the chip is started, and the startup unit 2 is charged for the second time to power the PFC unit 1. After the PFC unit 1 and the flyback unit 3 are started at the same time, the power module built into the gallium nitride PFC chip U1 will continue to supply VCC power to the gallium nitride flyback chip U2, replacing the original auxiliary winding circuit. At this time, the gallium nitride flyback chip U2 outputs overvoltage protection and C through the OVP end. The constant current control at the S end can detect the high voltage at the DRAIN end, so it is no longer limited by the influence of the original auxiliary winding. If there is an auxiliary winding, because the auxiliary winding and the secondary winding are positively correlated, when the load voltage increases or decreases, the load winding voltage also increases or decreases, and the voltage range adjusted according to the load winding is also relatively limited. Usually, the load capacity of the power supply with an auxiliary winding can only be from half load to full load, and the voltage adjustment range of the VDD end of the gallium nitride flyback chip U2 is larger; therefore, since the voltage adjustment range can be adjusted to a lower level, when the voltage demand of the load unit 5 is low, compared with the original auxiliary winding, the secondary side voltage of the transformer T1 can be adjusted to a lower level (that is, the turns ratio is reduced) to maintain the stability of the load unit 5.

[0050] At the same time, the switch function of the flyback unit 3 is realized by the GaN flyback chip U2 used as an output switch from the primary side to the secondary side of the transformer T1, which is based on the sensing and adjustment of the primary side of the transformer. When the GaN flyback chip U2 itself is turned on, the current passing through the transformer T1 will store energy in the primary side of the transformer T1. When the GaN flyback chip U2 itself is turned off, the energy stored in the transformer T1 is transmitted and output to the load unit 5 in the form of high-frequency pulses.

[0051] Further, the start-up unit 2 includes a capacitor C1, a capacitor C7, a capacitor C10 and a resistor R23; one end of the capacitor C7 is used as a first end of the start-up unit 2, and one end of the capacitor C10 is used as a second end of the start-up unit 2;

[0052] One end of the resistor R23 is electrically connected to one end of the capacitor C10, the other end of the resistor R23 and one end of the capacitor C1 are electrically connected to one end of the capacitor C7, and the other end of the capacitor C1, the other end of the capacitor C7 and the other end of the capacitor C10 are grounded.

[0053] In this embodiment, the startup unit 2 has two startup terminals, the first startup terminal is composed of capacitor C10, and the second startup terminal is composed of capacitors C1 and C7. The first startup terminal and the second startup terminal are used to start the flyback unit 3 and the PFC unit 1 respectively, that is, after high-voltage startup, the VH terminal of the gallium nitride flyback chip U2 is internally connected to the VDD terminal to charge the capacitor C10 first, and wait until the voltage provided by the capacitor C10 to the VDD terminal is higher than UVLO (OFF) to start the gallium nitride flyback chip U2, and then charge the capacitors C1 and C7 to supply power to the gallium nitride PFC chip U1. It should be noted that the charging time of the capacitors C10, C1 and C7 is the delayed startup time of the PFC unit 1.

[0054] Further, the second anti-interference circuit 31 includes a capacitor C5, a resistor R10, a resistor R11, a resistor R12, a resistor R17 and a diode D3; one end of the capacitor C5 is used as a first end of the second anti-interference circuit 31, one end of the resistor R11 is used as a second end of the second anti-interference circuit 31, and an anode of the diode D3 is used as a third end of the second anti-interference circuit 31;

[0055] One end of the resistor R11 and one end of the resistor R12 are electrically connected to one end of the capacitor C5, the other end of the resistor R11, the other end of the resistor R12, one end of the resistor R10, and one end of the resistor R17 are electrically connected to the other end of the capacitor C5, and the other end of the resistor R10 and the other end of the resistor R17 are electrically connected to the cathode of the diode D3.

[0056] In this embodiment, the second anti-interference circuit 31 is composed of an RCD absorption circuit, which can absorb the instantaneous overvoltage on the primary side of the transformer T1 to ensure the voltage stability on the primary side.

[0057] Furthermore, the first anti-interference circuit 11 includes a capacitor CY1 ; one end of the capacitor CY1 is used as a first end of the first anti-interference circuit 11 , and the other end of the capacitor CY1 is used as a second end of the first anti-interference circuit 11 .

[0058] In this embodiment, since there is parasitic capacitance between each coil winding of the transformer T1, a voltage is formed during operation, which becomes a noise source. A capacitor is connected across the primary side and the secondary side of the transformer T1 to filter out the common-mode disturbance generated by the coupling between the primary and secondary sides. Therefore, the first anti-interference circuit 11 uses the capacitor CY1 as a decoupling capacitor, because in addition to the mutual inductance flux coupling to transfer power between the primary and secondary sides of the high-frequency transformer (transformer T1), there is also distributed capacitance coupling between the coils. If the loop formed by the distributed capacitance coupling is not connected, there will be high-frequency interference on all secondary groups. After the capacitor CY1 is connected, the high-frequency interference on the secondary winding due to the distributed capacitance will be "short-circuited" back through CY1, so that the high-frequency interference is short-circuited.

[0059] Furthermore, a MOS tube is integrated inside the GaN flyback chip U2.

[0060] In this embodiment, because the gallium nitride flyback chip U2 is used as an output switch from the primary side to the secondary side of the transformer T1, the gallium nitride flyback chip U2 with an internally integrated MOS tube is selected to more easily realize the conduction or shutdown of the chip itself, simplifying the circuit complexity of the LED controller, and the MOS tube integrated inside the chip is tightly integrated with the chip circuit, which can reduce the loss in the signal transmission and energy conversion process, thereby improving the energy efficiency of the flyback unit 3.

[0061] Other structures and operations of the anti-interference LED controller based on the gallium nitride chip according to the embodiment of the utility model are known to ordinary technicians in the field and will not be described in detail here.

[0062] In the description of this specification, the description with reference to the terms "embodiment", "example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0063] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An anti-interference LED controller based on a gallium nitride chip, comprising a rectifier filter unit, a load unit and a transformer T1; characterized in that: It also includes a startup unit, a PFC unit with anti-interference capability, and a flyback unit with anti-interference capability; the output end of the rectifier and filter unit is electrically connected to the input end of the PFC unit, the output end of the PFC unit and the input end of the flyback unit are both electrically connected to a high-voltage startup pin HV, the power supply end of the PFC unit is electrically connected to the first end of the startup unit, the power supply end of the flyback unit is electrically connected to the second end of the startup unit, the ground end of the PFC unit, the ground end of the startup unit, and the ground end of the flyback unit are all grounded, the output end of the flyback unit is electrically connected to the primary side of the transformer T1, the secondary side of the transformer T1 is electrically connected to the input end of the load unit, and the anti-interference end of the PFC unit is electrically connected to the anti-interference end of the load unit; The starting unit is used to supply power to start the flyback unit first, and then delay the power supply to start the PFC unit after the rectifying and filtering unit outputs current; When the PFC unit and the flyback unit are both started, the flyback unit controls the transformer T1 to output a dimming current to the load unit; The PFC unit is used to filter out common-mode interference generated by coupling between the primary side and the secondary side of the transformer T1; The flyback unit is also used to absorb the instantaneous overvoltage on the primary side of the transformer T1; The PFC unit and the flyback unit both use gallium nitride chips.

2. The anti-interference LED controller based on a gallium nitride chip according to claim 1, characterized in that: The PFC unit includes a capacitor EC1, a capacitor CB1, a capacitor C2, a capacitor C3, a capacitor C6, a resistor R9, a resistor R29, a resistor R30, a resistor R4, a resistor R18, a resistor R19, a resistor R20, a resistor R2, a resistor R6, a resistor R5, a resistor R3, a resistor R8, an inductor L2, a diode D1, a diode D2, a gallium nitride PFC chip U1 and a first anti-interference circuit; one end and the other end of the capacitor CB1 are both used as the input end of the PFC unit, the positive electrode of the capacitor EC1 is used as the output end of the PFC unit, the negative electrode of the capacitor EC1 is used as the ground end of the PFC unit, the VDD end of the gallium nitride PFC chip U1 is used as the power supply end of the PFC unit, and the first end of the first anti-interference circuit is used as the anti-interference end of the PFC unit; One end of the capacitor CB1, one end of the resistor R9, one end of the inductor L2, the anode of the diode D1, and one end of the capacitor C2 are all electrically connected to the second end of the first anti-interference circuit, the other end of the capacitor C2, the cathode of the diode D1, the cathode of the diode D2, and one end of the resistor R3 are all electrically connected to the positive electrode of the capacitor EC1, the other end of the resistor R9 is electrically connected to one end of the resistor R29, the other end of the resistor R29 is electrically connected to one end of the resistor R30, the other end of the resistor R30, one end of the capacitor C3, and one end of the resistor R4 are all electrically connected to the VAC end of the gallium nitride PFC chip U1, the other end of the inductor L2, the cathode of the diode D1, and one end of the resistor R3 are all electrically connected to the positive electrode of the capacitor EC1, the other end of the resistor R9 is electrically connected to one end of the resistor R29, the other end of the resistor R29 is electrically connected to one end of the resistor R30, the other end of the resistor R30, one end of the capacitor C3, and one end of the resistor R4 are all electrically connected to the VAC end of the gallium nitride PFC chip U1, the other end of the inductor L2, the cathode of the diode D2, and one end of the resistor R3 are all electrically connected to the positive electrode of the capacitor EC1, the other end of the resistor R9 is electrically connected to one end of the resistor R29, the other end of the resistor R29 is electrically connected to one end of the resistor R30 The anode of the diode D2 is electrically connected to the DRAIN end of the gallium nitride PFC chip U1, the other end of the resistor R3 is electrically connected to one end of the resistor R8, the other end of the resistor R8 is electrically connected to one end of the resistor R5, the other end of the resistor R5, one end of the resistor R2, one end of the resistor R6, and one end of the capacitor C6 are all electrically connected to the INV end of the gallium nitride PFC chip U1, the other end of the resistor R2, the other end of the resistor R6, the other end of the capacitor C6, the GND end of the gallium nitride PFC chip U1, the other end of the resistor R4, the other end of the capacitor C3, and the other end of the capacitor CB1 are all electrically connected to the negative electrode of the capacitor EC1; The first anti-interference circuit is used to filter out common-mode interference generated by coupling between the primary side and the secondary side of the transformer T1.

3. The anti-interference LED controller based on a gallium nitride chip according to claim 1, characterized in that: The flyback unit includes a capacitor C11, a capacitor C14, a resistor R7, a resistor R16, a resistor R13, a resistor R14, a resistor R15, a resistor R21, an inductor L3, a gallium nitride flyback chip U2 and a second anti-interference circuit; the VDD end of the gallium nitride flyback chip U2 is used as the power supply end of the flyback unit, the HV end of the gallium nitride flyback chip U2 is used as the input end of the flyback unit, one end of the inductor L3 and the first end of the second anti-interference circuit are both used as the output end of the flyback unit, and one end of the resistor R13 is used as the ground end of the flyback unit; The HV end of the gallium nitride flyback chip U2 is electrically connected to the second end of the second anti-interference circuit, the DRAIN end of the gallium nitride flyback chip U2, the third end of the second anti-interference circuit, and the other end of the inductor L3 are all electrically connected to one end of the capacitor C14, the other end of the capacitor C14, one end of the resistor R21, one end of the resistor R15, one end of the resistor R14, and the other end of the resistor R13 are all electrically connected to the CS end of the gallium nitride flyback chip U2, the other end of the resistor R21, the other end of the resistor R15, and the other end of the resistor R14 are all electrically connected to one end of the resistor R13, the OVP end of the gallium nitride flyback chip U2, one end of the resistor R7, and one end of the resistor R16 are all electrically connected to one end of the capacitor C11, and the GND end of the gallium nitride flyback chip U2, the other end of the resistor R7, the other end of the resistor R16, and the other end of the capacitor C11 are all grounded; The second anti-interference circuit is used to absorb the instantaneous overvoltage on the primary side of the transformer T1.

4. The anti-interference LED controller based on a gallium nitride chip according to claim 1, characterized in that: The startup unit includes a capacitor C1, a capacitor C7, a capacitor C10 and a resistor R23; one end of the capacitor C7 is used as a first end of the startup unit, and one end of the capacitor C10 is used as a second end of the startup unit; One end of the resistor R23 is electrically connected to one end of the capacitor C10, the other end of the resistor R23 and one end of the capacitor C1 are electrically connected to one end of the capacitor C7, and the other end of the capacitor C1, the other end of the capacitor C7 and the other end of the capacitor C10 are grounded.

5. The anti-interference LED controller based on a gallium nitride chip according to claim 3, characterized in that: The second anti-interference circuit includes a capacitor C5, a resistor R10, a resistor R11, a resistor R12, a resistor R17 and a diode D3; one end of the capacitor C5 is used as a first end of the second anti-interference circuit, one end of the resistor R11 is used as a second end of the second anti-interference circuit, and an anode of the diode D3 is used as a third end of the second anti-interference circuit; One end of the resistor R11 and one end of the resistor R12 are electrically connected to one end of the capacitor C5, the other end of the resistor R11, the other end of the resistor R12, one end of the resistor R10, and one end of the resistor R17 are electrically connected to the other end of the capacitor C5, and the other end of the resistor R10 and the other end of the resistor R17 are electrically connected to the cathode of the diode D3.

6. The anti-interference LED controller based on a gallium nitride chip according to claim 2, characterized in that: The first anti-interference circuit includes a capacitor CY1; one end of the capacitor CY1 is used as a first end of the first anti-interference circuit, and the other end of the capacitor CY1 is used as a second end of the first anti-interference circuit.

7. The anti-interference LED controller based on a gallium nitride chip according to claim 1, characterized in that: The GaN flyback chip U2 has a MOS tube integrated therein.

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