Mini Led TV multi-output power supply circuit and display device

Abstract

The invention discloses a Mini Led TV multi-output power supply circuit and a display device. The Mini LED TV multi-output power supply circuit comprises a direct-current power supply end used for being connected with a direct-current power supply; the input end of the constant-voltage output circuit is connected with the direct-current power supply end, and the constant-voltage output circuit is used for converting the direct-current power supply and then outputting system voltage and backlight voltage; the input end of the negative feedback circuit is connected with the output end of the constant voltage output circuit, and the output end of the negative feedback circuit is connected with the feedback input end of the constant voltage output circuit. The negative feedback circuit is used for outputting a system voltage feedback signal and a backlight voltage feedback signal to the constant voltage output circuit according to the system voltage and the backlight voltage output by the constant voltage output circuit. According to the invention, through a simple power supply circuit structure, voltage output is carried out on the two power modules.

Description

Technical Field

[0001] This invention relates to the field of power supply circuits, and more particularly to a MiniLED TV multi-output power supply circuit and display device. Background Technology

[0002] In high-power Mini LED TV power supply circuit applications, the output power is generally above 200W, and the backlight module requires a current of over 10A; while the total power consumption of the system chip and power amplifier is about 70W, requiring a relatively large power supply module.

[0003] Therefore, traditional MiniLED TV power supplies require two topologies for circuit design to output voltage to two power modules: one module outputs voltage to the system chip and power amplifier, and the other module outputs voltage to the backlight module, which leads to a complex power supply circuit structure. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a MiniLED TV multi-output power supply circuit and display device, so as to output voltage to two power modules through a simple power supply circuit structure.

[0005] The technical solution of the present invention is as follows: A Mini-LED TV multi-output power supply circuit includes: DC power supply terminal, used to connect a DC power supply; A constant voltage output circuit, wherein the input terminal of the constant voltage output circuit is connected to the DC power supply terminal, and the constant voltage output circuit is used to convert the DC power supply and output the system voltage and backlight voltage; A negative feedback circuit is provided, wherein the input terminal of the negative feedback circuit is connected to the output terminal of the constant voltage output circuit, and the output terminal of the negative feedback circuit is connected to the feedback input terminal of the constant voltage output circuit. The negative feedback circuit is used to output system voltage feedback signals and backlight voltage feedback signals to the constant voltage output circuit based on the system voltage and backlight voltage output by the constant voltage output circuit.

[0006] Optionally, the constant voltage output circuit includes a voltage output control chip, a switching circuit, and a transformer. The control terminal of the voltage output control chip is connected to the controlled terminal of the switching circuit. The power supply terminal of the switching circuit is connected to the DC power supply terminal. The output terminal of the switching circuit is connected to the input terminal of the primary winding of the transformer. The input terminal of the switching circuit is connected to the output terminal of the primary winding of the transformer. The secondary winding of the transformer is connected to the input terminal of the negative feedback circuit.

[0007] Optionally, the switching circuit includes a first capacitor, a first resistor, a second resistor, a third resistor, a fourth resistor, a first MOSFET, and a second MOSFET. The drain of the first MOSFET is connected to the DC power supply terminal. The gate of the first MOSFET, the first end of the first resistor, and the first end of the second resistor are interconnected. The second end of the first resistor is connected to the first control terminal of the voltage output control chip. The second end of the second resistor, the source of the first MOSFET, and the drain of the second MOSFET are interconnected and connected to the input terminal of the primary winding of the transformer. The gate of the second MOSFET, the first end of the third resistor, and the first end of the fourth resistor are interconnected. The second end of the third resistor is connected to the second control terminal of the voltage output control chip. The second end of the fourth resistor, the source of the second MOSFET, and the second end of the first capacitor are grounded. The first end of the first capacitor is connected to the output terminal of the primary winding of the transformer.

[0008] Optionally, the constant voltage output circuit further includes: The first rectifier and filter circuit has its input terminal connected to the secondary winding of the transformer and its output terminal connected to the input terminal of the negative feedback circuit. The first rectifier and filter circuit is used to rectify and filter the AC power output from the secondary winding of the transformer into DC power and then output it to the negative feedback circuit.

[0009] Optionally, the secondary winding of the transformer includes a first output terminal, a second output terminal, a first input terminal, and a second input terminal. The first rectifier filter circuit includes a first Schottky diode, a second Schottky diode, a second capacitor, and a third capacitor. The input terminal of the first Schottky diode is connected to the first output terminal of the secondary winding of the transformer. The output terminal of the first Schottky diode is connected to the first terminal of the second capacitor and to the input terminal of the negative feedback circuit. The input terminal of the second Schottky diode is connected to the second output terminal of the secondary winding of the transformer. The output terminal of the second Schottky diode is connected to the first terminal of the third capacitor and to the input terminal of the negative feedback circuit. The second terminal of the second capacitor, the second terminal of the third capacitor, the first input terminal of the secondary winding of the transformer, and the second input terminal of the secondary winding of the transformer are interconnected and grounded.

[0010] Optionally, the output terminal of the constant voltage output circuit includes a system voltage output terminal and a backlight voltage output terminal, the feedback input terminal of the constant voltage output circuit includes a system voltage feedback input terminal and a backlight voltage feedback input terminal, and the negative feedback circuit includes: A system voltage feedback circuit is provided, wherein the input terminal of the system voltage feedback circuit is connected to the system voltage output terminal of the constant voltage output circuit, and the output terminal of the system voltage feedback circuit is connected to the system voltage feedback input terminal of the constant voltage output circuit. The system voltage feedback circuit is used to output a system voltage feedback signal to the constant voltage output circuit based on the system voltage output by the constant voltage output circuit. A backlight voltage feedback circuit is provided, wherein the input terminal of the backlight voltage feedback circuit is connected to the backlight voltage output terminal of the constant voltage output circuit, and the output terminal of the backlight voltage feedback circuit is connected to the backlight voltage feedback input terminal of the constant voltage output circuit. The backlight voltage feedback circuit is used to output a backlight voltage feedback signal to the constant voltage output circuit based on the backlight voltage output by the constant voltage output circuit.

[0011] Optionally, both the system voltage feedback circuit and the backlight voltage feedback circuit include a first optocoupler, a first Zener diode, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, and a fourth capacitor. The first terminal of the fifth resistor and the first terminal of the sixth resistor are interconnected and connected to the output terminal of the constant voltage output circuit. The second terminal of the fifth resistor is connected to the anode input terminal of the first optocoupler. The cathode input terminal of the first optocoupler, the first terminal of the seventh resistor, and the cathode of the first Zener diode are interconnected. The second terminal of the seventh resistor is connected to the first terminal of the fourth capacitor. The second terminal of the fourth capacitor, the second terminal of the sixth resistor, the first terminal of the eighth resistor, and the reference terminal of the first Zener diode are interconnected. The second terminal of the eighth resistor and the anode of the first Zener diode are grounded. The output terminal of the first optocoupler is connected to the feedback input terminal of the constant voltage output circuit.

[0012] Optionally, the MiniLed TV multi-output power supply circuit also includes: AC input terminal, used for connecting to AC power supply; The second rectifier and filter circuit has its input terminal connected to the AC input terminal and its output terminal connected to the DC power supply terminal. The second rectifier and filter circuit is used to rectify and filter the AC power supply and then output DC power to the DC power supply terminal.

[0013] Optionally, the MiniLed TV multi-output power supply circuit also includes: A power factor correction circuit is provided, wherein the input terminal of the power factor correction circuit is connected to the output terminal of the second rectifier and filter circuit, and the output terminal of the power factor correction circuit is connected to the DC power supply terminal. The power factor correction circuit is used to correct the power factor of the DC power supply output by the second rectifier and filter circuit and then output it to the DC power supply terminal.

[0014] The present invention also proposes a display device, including a system chip, a backlight module, and a MiniLed TV multi-output power supply circuit as described above. The constant voltage output circuit in the MiniLed TV multi-output power supply circuit is used to output system voltage to the system chip and output backlight voltage to the backlight module.

[0015] This invention provides a multi-output power supply circuit for Mini-LED TVs, comprising a DC power supply terminal, a constant voltage output circuit, and a negative feedback circuit. The DC power supply terminal connects to a DC power source. The input terminal of the constant voltage output circuit is connected to the DC power supply terminal, and it converts the DC power supply to output system voltage and backlight voltage. The input terminal of the negative feedback circuit is connected to the output terminal of the constant voltage output circuit, and its output terminal is connected to the feedback input terminal of the constant voltage output circuit. The negative feedback circuit outputs system voltage feedback signals and backlight voltage feedback signals to the constant voltage output circuit based on the system voltage and backlight voltage output by the constant voltage output circuit. Thus, this multi-output power supply circuit for Mini-LED TVs can output two different voltages to two power modules through a single constant voltage output circuit, eliminating the need for additional circuit topologies and simplifying the overall circuit structure. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 This is a functional module schematic diagram of an embodiment of the MiniLed TV multi-output power supply circuit of the present invention.

[0018] Figure 2 This is a functional block diagram of an embodiment of the MiniLed TV multi-output power supply circuit of the present invention.

[0019] Figure 3 This is a functional block diagram of another embodiment of the MiniLed TV multi-output power supply circuit of the present invention.

[0020] Explanation of reference numerals in the attached diagram: 10, constant voltage output circuit; 20, negative feedback circuit; 30, second rectifier and filter circuit; 40, power factor correction circuit; V, DC power supply terminal; AC, alternating current input terminal; R1, first resistor; R2, second resistor; R3, third resistor; R4, fourth resistor; R5, fifth resistor; R6, sixth resistor; R7, seventh resistor; R8, eighth resistor; C1, first capacitor; C2, second capacitor; C3, third capacitor; C4, fourth capacitor; Q1, first MOSFET; Q2, second MOSFET; DS1, first Schottky diode; DS2, second Schottky diode; T1, transformer; TL1, first Zener diode; PC1, first optocoupler. Detailed Implementation

[0021] To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0022] In the implementation methods and claims, unless otherwise specified in the text, the terms "a," "an," "the," and "the" may also include plural forms. If the embodiments of the present invention involve descriptions of "first," "second," etc., such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0023] It should be further understood that the term "comprising" as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when an element is referred to as "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements present. Furthermore, "connected" or "coupled" as used herein can include wireless connections or wireless coupling. The term "and / or" as used herein includes all or any unit and all combinations of one or more associated listed items.

[0024] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0025] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0026] In high-power Mini LED TV power supply circuit applications, the output power is generally above 200W, and the backlight module requires a current of over 10A; while the total power consumption of the system chip and power amplifier is about 70W, requiring a relatively large power supply module.

[0027] Therefore, traditional MiniLED TV power supplies require two topologies for circuit design to output voltage to two power modules: one module outputs voltage to the system chip and power amplifier, and the other module outputs voltage to the backlight module, which leads to a complex power supply circuit structure.

[0028] To address the aforementioned problems, this invention proposes a MiniLED TV multi-output power supply circuit.

[0029] Reference Figure 1 In one embodiment, the MiniLed TV multi-output power supply circuit includes: The DC power supply terminal V is used to connect a DC power source. A constant voltage output circuit 10, the input terminal of which is connected to the DC power supply terminal V, is used to convert the DC power supply and output the system voltage and backlight voltage. The negative feedback circuit 20 has its input terminal connected to the output terminal of the constant voltage output circuit 10, and its output terminal connected to the feedback input terminal of the constant voltage output circuit 10. The negative feedback circuit 20 is used to output system voltage feedback signals and backlight voltage feedback signals to the constant voltage output circuit 10 based on the system voltage and backlight voltage output by the constant voltage output circuit 10.

[0030] In this embodiment, the DC power supply terminal V can be connected to a DC power supply for voltage conversion in subsequent circuits. The constant voltage output circuit 10 can adopt an asymmetric half-bridge (LLC) (AHB(LLC)) circuit structure. The constant voltage output circuit 10 with the AHB(LLC) structure can output energy through asymmetric positive and negative cycles, and the duty cycle of the positive and negative cycles can be adjusted separately to output the corresponding voltage. The asymmetric resonant half-bridge flyback converter has soft-switching characteristics, which can reduce switching losses and improve conversion efficiency. The half-bridge topology is usually composed of two switches (such as MOSFETs or IGBTs) and a transformer T1. The half-bridge structure allows the constant voltage output circuit 10 to better control the current and voltage during switching operations. For example, the voltage of the positive cycle can be used as the system voltage output, and the voltage of the negative cycle can be used as the backlight voltage output. The specific voltage value can be controlled by adjusting the duty cycle. The switching frequency and duty cycle of the two switches can be different. This asymmetry can optimize the output characteristics and improve the stability of the system. In this way, two different voltages can be output through a single circuit structure without the need for an additional topology.

[0031] The negative feedback circuit 20 can maintain the stability of the output voltage. For example, the negative feedback circuit 20 collects the system voltage and backlight voltage output by the constant voltage output circuit 10, and then outputs the collected voltage to the constant voltage output circuit 10. This allows the constant voltage output circuit 10 to adjust the actual output system voltage and backlight voltage according to the system voltage and backlight voltage at the output port, thereby achieving a constant voltage output effect. It is understandable that in the overall circuit, changes in component parameters (such as the β value of a transistor changing with temperature, power supply voltage fluctuations, etc.), environmental factors, and load changes can all cause fluctuations in the output voltage. After setting up the negative feedback circuit 20, when the output voltage changes due to the above reasons, the corresponding feedback signal will also change accordingly. By comparing it with the output voltage, the output voltage of the constant voltage output circuit 10 is automatically adjusted, making the output voltage tend to stabilize.

[0032] The technical solution of this invention constructs a Mini-LED TV multi-output power supply circuit using a DC power supply terminal V, a constant voltage output circuit 10, and a negative feedback circuit 20. The DC power supply terminal V is used to connect to a DC power source. The input terminal of the constant voltage output circuit 10 is connected to the DC power supply terminal V, and the constant voltage output circuit 10 converts the DC power supply to output system voltage and backlight voltage. The input terminal of the negative feedback circuit 20 is connected to the output terminal of the constant voltage output circuit 10, and the output terminal of the negative feedback circuit 20 is connected to the feedback input terminal of the constant voltage output circuit 10. The negative feedback circuit 20 outputs system voltage feedback signals and backlight voltage feedback signals to the constant voltage output circuit 10 based on the system voltage and backlight voltage output by the constant voltage output circuit 10. Thus, this Mini-LED TV multi-output power supply circuit can output two different voltages to two power modules through a single constant voltage output circuit 10, without requiring additional circuit topology, resulting in a simple overall circuit structure.

[0033] In one embodiment, the constant voltage output circuit 10 includes a voltage output control chip, a switching circuit, and a transformer T1. The control terminal of the voltage output control chip is connected to the controlled terminal of the switching circuit. The power supply terminal of the switching circuit is connected to the DC power supply terminal V. The output terminal of the switching circuit is connected to the input terminal of the primary winding of the transformer T1. The input terminal of the switching circuit is connected to the output terminal of the primary winding of the transformer T1. The secondary winding of the transformer T1 is connected to the input terminal of the negative feedback circuit 20.

[0034] In this embodiment, the constant voltage output circuit 10 can control the switching status of the switch switching circuit through the voltage output control chip, convert DC power into AC power, and then transmit it to the subsequent circuits, namely the system chip and backlight module, as well as the negative feedback circuit 20, through the transformer T1.

[0035] Furthermore, referring to Figure 2In one embodiment, the switching circuit includes a first capacitor C1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first MOSFET Q1, and a second MOSFET Q2. The drain of the first MOSFET Q1 is connected to the DC power supply terminal V. The gate of the first MOSFET Q1, the first end of the first resistor R1, and the first end of the second resistor R2 are interconnected. The second end of the first resistor R1 is connected to the first control terminal of the voltage output control chip. The second end of the second resistor R2, the source of the first MOSFET Q1, and the drain of the second MOSFET Q2 are interconnected and connected to the input terminal of the primary winding of the transformer T1. The gate of the second MOSFET Q2, the first end of the third resistor R3, and the first end of the fourth resistor R4 are interconnected. The second end of the third resistor R3 is connected to the second control terminal of the voltage output control chip. The second end of the fourth resistor R4, the source of the second MOSFET Q2, and the second end of the first capacitor C1 are grounded. The first end of the first capacitor C1 is connected to the output terminal of the primary winding of the transformer T1.

[0036] In this embodiment, the first MOSFET Q1 and the second MOSFET Q2 can be NMOS transistors. The first resistor R1 can be used as the driving resistor for the first MOSFET Q1, the second resistor R2 as the bias resistor for the first MOSFET Q1, the third resistor R3 as the driving resistor for the second MOSFET Q2, and the fourth resistor R4 as the bias resistor for the second MOSFET Q2. The voltage output control chip can control the conduction and turn-off of the first MOSFET Q1 and the second MOSFET Q2 by outputting different voltages to the gates of the first MOSFET Q1 and the second MOSFET Q2. When the first MOSFET Q1 is on and the second MOSFET Q2 is off, the current at the DC power supply terminal V flows from the drain of the first MOSFET Q1, passes through the input terminal of the primary winding of the transformer T1 and the first capacitor C1 in sequence, and then flows to the ground terminal. The ground terminal is connected to the DC power supply terminal V (not shown in the figure), thus forming a current loop, which is equivalent to charging the first capacitor C1. When the first MOSFET Q1 is off and the second MOSFET Q2 is on, it is equivalent to the first capacitor C1 discharging. The first terminal of the first capacitor C1 forms a current loop through the primary winding output terminal of transformer T1, the DC power supply terminal V, and the second MOSFET Q2. In these two cases, transformer T1 outputs energy in positive and negative cycles respectively. Thus, the voltage output control chip can control the secondary winding output of transformer T1 to produce two different voltages by controlling the on and off times of the first MOSFET Q1 and the second MOSFET Q2, thereby meeting the needs of different power modules.

[0037] In one embodiment, the constant voltage output circuit 10 further includes: The first rectifier and filter circuit has its input terminal connected to the secondary winding of the transformer T1 and its output terminal connected to the input terminal of the negative feedback circuit 20. The first rectifier and filter circuit is used to rectify and filter the AC power output from the secondary winding of the transformer T1 into DC power and then output it to the negative feedback circuit 20.

[0038] In this embodiment, the secondary winding of transformer T1 outputs AC power. By setting a first rectifier and filter circuit, the AC power output by transformer T1 can be rectified and filtered. Rectification can convert AC power into DC power for the subsequent load to work normally, and filtering can smooth the pulsating DC power after rectification, reduce the AC component (ripple) in it, and make the output DC voltage more stable and closer to the ideal DC power. In addition, the negative feedback circuit 20 will also collect the DC power output by the first rectifier and filter circuit.

[0039] Furthermore, referring to Figure 2 In one embodiment, the secondary winding of the transformer T1 includes a first output terminal, a second output terminal, a first input terminal, and a second input terminal. The first rectifier filter circuit includes a first Schottky diode DS1, a second Schottky diode DS2, a second capacitor C2, and a third capacitor C3. The input terminal of the first Schottky diode DS1 is connected to the first output terminal of the secondary winding of the transformer T1. The output terminal of the first Schottky diode DS1 is connected to the first terminal of the second capacitor C2 and to the input terminal of the negative feedback circuit 20. The input terminal of the second Schottky diode DS2 is connected to the second output terminal of the secondary winding of the transformer T1. The output terminal of the second Schottky diode DS2 is connected to the first terminal of the third capacitor C3 and to the input terminal of the negative feedback circuit 20. The second terminal of the second capacitor C2, the second terminal of the third capacitor C3, the first input terminal of the secondary winding of the transformer T1, and the second input terminal of the secondary winding of the transformer T1 are interconnected and grounded.

[0040] In this embodiment, the two AC outputs from the secondary winding of transformer T1 are rectified by the first Schottky diode DS1 and the second Schottky diode DS2, while the two rectified DC outputs are filtered by the second capacitor C2 and the third capacitor C3. This results in two DC outputs: the system voltage and the backlight voltage.

[0041] In one embodiment, the output terminal of the constant voltage output circuit 10 includes a system voltage output terminal and a backlight voltage output terminal, the feedback input terminal of the constant voltage output circuit 10 includes a system voltage feedback input terminal and a backlight voltage feedback input terminal, and the negative feedback circuit 20 includes: A system voltage feedback circuit is provided, wherein the input terminal of the system voltage feedback circuit is connected to the system voltage output terminal of the constant voltage output circuit 10, and the output terminal of the system voltage feedback circuit is connected to the system voltage feedback input terminal of the constant voltage output circuit 10. The system voltage feedback circuit is used to output a system voltage feedback signal to the constant voltage output circuit 10 based on the system voltage output by the constant voltage output circuit 10. A backlight voltage feedback circuit is provided, wherein the input terminal of the backlight voltage feedback circuit is connected to the backlight voltage output terminal of the constant voltage output circuit 10, and the output terminal of the backlight voltage feedback circuit is connected to the backlight voltage feedback input terminal of the constant voltage output circuit 10. The backlight voltage feedback circuit is used to output a backlight voltage feedback signal to the constant voltage output circuit 10 according to the backlight voltage output by the constant voltage output circuit 10.

[0042] In this embodiment, for the system voltage and backlight voltage output by the constant voltage output circuit 10, the negative feedback circuit 20 is correspondingly equipped with a system voltage feedback circuit and a backlight voltage feedback circuit. Through the two feedback circuits, the system voltage and backlight voltage can be collected, and the corresponding system voltage feedback signal and backlight voltage feedback signal can be output to the constant voltage output circuit 10. The voltage output control chip in the constant voltage output circuit 10 can adjust the output voltage of the constant voltage output circuit 10 according to the system voltage feedback signal and the backlight voltage feedback signal to maintain the stability of the output voltage.

[0043] Furthermore, referring to Figure 2 In one embodiment, both the system voltage feedback circuit and the backlight voltage feedback circuit include a first optocoupler PC1, a first Zener diode TL1, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, and a fourth capacitor C4. The first end of the fifth resistor R5 and the first end of the sixth resistor R6 are interconnected and connected to the output terminal of the constant voltage output circuit 10. The second end of the fifth resistor R5 is connected to the anode input terminal of the first optocoupler PC1. The cathode input terminal of the first optocoupler PC1, the first end of the seventh resistor R7, and the cathode of the first Zener diode TL1 are interconnected. The second end of the seventh resistor R7 is connected to the first end of the fourth capacitor C4. The second end of the fourth capacitor C4, the second end of the sixth resistor R6, the first end of the eighth resistor R8, and the reference terminal of the first Zener diode TL1 are interconnected. The second end of the eighth resistor R8 and the anode of the first Zener diode TL1 are grounded. The output terminal of the first optocoupler PC1 is connected to the feedback input terminal of the constant voltage output circuit 10.

[0044] In this embodiment, the fifth resistor R5 is the current-limiting resistor for the first optocoupler PC1, and the sixth resistor R6 and the eighth resistor R8 are voltage-dividing resistors. The sixth resistor R6 and the eighth resistor R8 divide the acquired voltage before outputting it, preventing damage to the first optocoupler PC1 due to excessive voltage. The seventh resistor R7 and the fourth capacitor C4 form an RC circuit. The first Zener diode TL1 can be a TL431 three-terminal adjustable precision parallel voltage regulator for voltage regulation; other devices with similar functions can also be used. Furthermore, in this embodiment, signal isolation transmission via the first optocoupler PC1 protects the voltage output control chip in the constant voltage output circuit 10. It should be noted that the system voltage feedback circuit and the backlight voltage feedback circuit have the same circuit structure in this embodiment, and each outputs two signals to the two feedback input terminals of the constant voltage output circuit 10.

[0045] Reference Figure 3 In one embodiment, the MiniLed TV multi-output power supply circuit further includes: AC input terminal, used for connecting to AC power supply; The second rectifier and filter circuit 30 has its input terminal connected to the AC input terminal and its output terminal connected to the DC power supply terminal V. The second rectifier and filter circuit 30 is used to rectify and filter the AC power supply and output DC power to the DC power supply terminal V.

[0046] In this embodiment, the AC input terminal AC can be connected to the AC power output from the power grid or the AC power output from an external power supply device; after the AC power is rectified and filtered by the second rectifier and filter circuit 30, the DC power is output to the DC power supply terminal V for subsequent power conversion.

[0047] Reference Figure 3 In one embodiment, the MiniLed TV multi-output power supply circuit further includes: A power factor correction circuit 40 is provided, the input terminal of which is connected to the output terminal of the second rectifier and filter circuit 30, and the output terminal of which is connected to the DC power supply terminal V. The power factor correction circuit 40 is used to correct the power factor of the DC power supply output by the second rectifier and filter circuit 30 and then output it to the DC power supply terminal V.

[0048] In this embodiment, the power factor correction circuit 40 can be used to improve the power factor of the DC power supply, as well as reduce harmonic current, stabilize output voltage, and reduce the burden on the power grid.

[0049] The present invention also proposes a display device.

[0050] In one embodiment, the display device includes a system chip, a backlight module, and a MiniLED TV multi-output power supply circuit as described above. The constant voltage output circuit 10 in the MiniLED TV multi-output power supply circuit is used to output system voltage to the system chip and output backlight voltage to the backlight module. In this embodiment, the display device can be a television or similar device. It is understood that since the MiniLED TV multi-output power supply circuit described above is used in the display device of this invention, the embodiments of the display device of this invention include all the technical solutions of all embodiments of the MiniLED TV multi-output power supply circuit described above, and the achieved technical effects are completely the same, and will not be repeated here.

[0051] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A MiniLED TV multi-output power supply circuit, characterized in that, include: DC power supply terminal, used to connect to a DC power supply; A constant voltage output circuit, wherein the input terminal of the constant voltage output circuit is connected to the DC power supply terminal, and the constant voltage output circuit is used to convert the DC power supply and output the system voltage and backlight voltage; A negative feedback circuit is provided, wherein the input terminal of the negative feedback circuit is connected to the output terminal of the constant voltage output circuit, and the output terminal of the negative feedback circuit is connected to the feedback input terminal of the constant voltage output circuit. The negative feedback circuit is used to output system voltage feedback signals and backlight voltage feedback signals to the constant voltage output circuit based on the system voltage and backlight voltage output by the constant voltage output circuit.

2. The Mini-LED TV multi-output power supply circuit as described in claim 1, characterized in that, The constant voltage output circuit includes a voltage output control chip, a switching circuit, and a transformer. The control terminal of the voltage output control chip is connected to the controlled terminal of the switching circuit. The power supply terminal of the switching circuit is connected to the DC power supply terminal. The output terminal of the switching circuit is connected to the input terminal of the primary winding of the transformer. The input terminal of the switching circuit is connected to the output terminal of the primary winding of the transformer. The secondary winding of the transformer is connected to the input terminal of the negative feedback circuit.

3. The MiniLED TV multi-output power supply circuit as described in claim 2, characterized in that, The switching circuit includes a first capacitor, a first resistor, a second resistor, a third resistor, a fourth resistor, a first MOSFET, and a second MOSFET. The drain of the first MOSFET is connected to the DC power supply terminal. The gate of the first MOSFET, the first end of the first resistor, and the first end of the second resistor are interconnected. The second end of the first resistor is connected to the first control terminal of the voltage output control chip. The second end of the second resistor, the source of the first MOSFET, and the drain of the second MOSFET are interconnected and connected to the input terminal of the primary winding of the transformer. The gate of the second MOSFET, the first end of the third resistor, and the first end of the fourth resistor are interconnected. The second end of the third resistor is connected to the second control terminal of the voltage output control chip. The second end of the fourth resistor, the source of the second MOSFET, and the second end of the first capacitor are grounded. The first end of the first capacitor is connected to the output terminal of the primary winding of the transformer.

4. The Mini-LED TV multi-output power supply circuit as described in claim 2, characterized in that, The constant voltage output circuit also includes: The first rectifier and filter circuit has its input terminal connected to the secondary winding of the transformer and its output terminal connected to the input terminal of the negative feedback circuit. The first rectifier and filter circuit is used to rectify and filter the AC power output from the secondary winding of the transformer into DC power and then output it to the negative feedback circuit.

5. The MiniLED TV multi-output power supply circuit as described in claim 4, characterized in that, The secondary winding of the transformer includes a first output terminal, a second output terminal, a first input terminal, and a second input terminal. The first rectifier filter circuit includes a first Schottky diode, a second Schottky diode, a second capacitor, and a third capacitor. The input terminal of the first Schottky diode is connected to the first output terminal of the secondary winding of the transformer. The output terminal of the first Schottky diode is connected to the first terminal of the second capacitor and to the input terminal of the negative feedback circuit. The input terminal of the second Schottky diode is connected to the second output terminal of the secondary winding of the transformer. The output terminal of the second Schottky diode is connected to the first terminal of the third capacitor and to the input terminal of the negative feedback circuit. The second terminal of the second capacitor, the second terminal of the third capacitor, the first input terminal of the secondary winding of the transformer, and the second input terminal of the secondary winding of the transformer are interconnected and grounded.

6. The Mini-LED TV multi-output power supply circuit as described in claim 1, characterized in that, The constant voltage output circuit includes a system voltage output terminal and a backlight voltage output terminal. The feedback input terminal of the constant voltage output circuit includes a system voltage feedback input terminal and a backlight voltage feedback input terminal. The negative feedback circuit includes: A system voltage feedback circuit is provided, wherein the input terminal of the system voltage feedback circuit is connected to the system voltage output terminal of the constant voltage output circuit, and the output terminal of the system voltage feedback circuit is connected to the system voltage feedback input terminal of the constant voltage output circuit. The system voltage feedback circuit is used to output a system voltage feedback signal to the constant voltage output circuit based on the system voltage output by the constant voltage output circuit. A backlight voltage feedback circuit is provided, wherein the input terminal of the backlight voltage feedback circuit is connected to the backlight voltage output terminal of the constant voltage output circuit, and the output terminal of the backlight voltage feedback circuit is connected to the backlight voltage feedback input terminal of the constant voltage output circuit. The backlight voltage feedback circuit is used to output a backlight voltage feedback signal to the constant voltage output circuit based on the backlight voltage output by the constant voltage output circuit.

7. The Mini-LED TV multi-output power supply circuit as described in claim 6, characterized in that, Both the system voltage feedback circuit and the backlight voltage feedback circuit include a first optocoupler, a first Zener diode, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, and a fourth capacitor. The first end of the fifth resistor and the first end of the sixth resistor are interconnected and connected to the output terminal of the constant voltage output circuit. The second end of the fifth resistor is connected to the anode input terminal of the first optocoupler. The cathode input terminal of the first optocoupler, the first end of the seventh resistor, and the cathode of the first Zener diode are interconnected. The second end of the seventh resistor is connected to the first end of the fourth capacitor. The second end of the fourth capacitor, the second end of the sixth resistor, the first end of the eighth resistor, and the reference terminal of the first Zener diode are interconnected. The second end of the eighth resistor and the anode of the first Zener diode are grounded. The output terminal of the first optocoupler is connected to the feedback input terminal of the constant voltage output circuit.

8. The Mini-LED TV multi-output power supply circuit as described in claim 1, characterized in that, Also includes: AC input terminal, used for connecting to AC power supply; The second rectifier and filter circuit has its input terminal connected to the AC input terminal and its output terminal connected to the DC power supply terminal. The second rectifier and filter circuit is used to rectify and filter the AC power supply and then output DC power to the DC power supply terminal.

9. The Mini-LED TV multi-output power supply circuit as described in claim 8, characterized in that, Also includes: A power factor correction circuit is provided, wherein the input terminal of the power factor correction circuit is connected to the output terminal of the second rectifier and filter circuit, and the output terminal of the power factor correction circuit is connected to the DC power supply terminal. The power factor correction circuit is used to correct the power factor of the DC power supply output by the second rectifier and filter circuit and then output it to the DC power supply terminal.

10. A display device, characterized in that, The system includes a system chip, a backlight module, and a MiniLed TV multi-output power supply circuit as described in any one of claims 1-9, wherein the constant voltage output circuit in the MiniLed TV multi-output power supply circuit is used to output system voltage to the system chip and output backlight voltage to the backlight module.

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