An all-in-one dimming LED driver based on a single-chip microcomputer and its application

Abstract

The present invention relates to the field of driver technology, and discloses an all-in-one dimming LED driver based on a single-chip microcomputer and its application. The driver includes a dimming signal sampling and shaping circuit for independently converting the signal of the pre-dimmer and the signal of the post-dimmer into two DC signals; an output rectification circuit for rectifying the output of the LED driver circuit; a dimming signal conversion circuit for driving an isolation component to transmit the signal of the post-dimmer to the single-chip microcomputer; a single-chip microcomputer controller for calculating the two DC signals to generate a comprehensive dimming signal; and a constant current control chip or a constant voltage constant current control loop or a chopping dimming circuit for controlling the brightness of the LED according to the comprehensive dimming signal. The present invention implements a simple and accurate dimming solution, which can greatly reduce the requirements for the computing power of the single-chip microcomputer, thereby effectively reducing costs and better meeting the needs of enterprises.

Description

Technical Field

[0001] The present invention relates to the field of driver technology, and in particular to an all-in-one dimming LED driver based on a single-chip microcomputer and applications thereof. Background Art

[0002] Currently, commonly used dimmers on the market can be categorized into two types: front-mounted and rear-mounted. Front-mounted dimmers are installed between the LED driver and the mains; rear-mounted dimmers are installed after the driver and isolated from both the mains and the driver. Front-mounted dimmers include leading and trailing phase dimmers; rear-mounted dimmers include 0-10V, PWM, and potentiometer dimmers.

[0003] However, compatibility with different dimmer types is difficult, and high-precision dimming control is impossible. For example, LED drivers designed for phase-cut dimmers are not directly compatible with other dimmer types, such as 0-10V, potentiometers, or PWM. LED drivers using constant current chips struggle to achieve high-precision dimming. LED drivers for different topologies also require different dimming solutions, making universal compatibility impossible. This limits the applicability and dimming performance of LED drivers.

[0004] Currently, no effective solutions have been proposed for the problems in related technologies. Summary of the Invention

[0005] In response to the problems in the related art, the present invention proposes an all-in-one dimming LED driver based on a single chip microcomputer and its application to overcome the above technical problems existing in the existing related art.

[0006] To this end, the specific technical solutions adopted in the present invention are as follows:

[0007] According to one aspect of the present invention, an all-in-one dimming LED driver based on a single-chip microcomputer is provided, comprising a dimming signal sampling and shaping circuit for independently converting a signal from a pre-dimmer and a signal from a post-dimmer into two DC signals;

[0008] Output rectifier circuit, used for rectifying the output of the LED driver circuit;

[0009] The dimming signal conversion circuit is used to drive the isolation component to transmit the signal from the rear dimmer to the microcontroller;

[0010] A single-chip microcomputer controller is used to calculate two DC signals to generate a comprehensive dimming signal;

[0011] The constant current control chip or constant voltage constant current control loop or chopping dimming circuit is used to control the brightness of the LED according to the comprehensive dimming signal.

[0012] Preferably, the dimming signal sampling and shaping circuit includes a phase-cut sampling circuit for sampling the phase-cut dimmer and a dimming signal shaping circuit for isolating, converting and standardizing the signals of the pre-dimmer and the post-dimmer.

[0013] Preferably, the chopping dimming circuit includes a MOSFET arranged in a loop between the LED and the driver and a chip or a totem pole for driving a gate pin of the MOSFET.

[0014] Preferably, the single chip controller and the dimming signal shaping circuit are arranged in the primary part or the secondary part.

[0015] Preferably, the single chip microcomputer controller is designed on the primary side for directly sampling and shaping the phase-cut dimmer, thereby saving the use of isolation components and improving accuracy.

[0016] Preferably, the single chip microcomputer is designed on the secondary side to directly dim the step-down constant current chip to achieve dimming control of the LED.

[0017] Preferably, the single chip controller is used to change the output voltage loop or the output current loop to adjust the output voltage or the output current, thereby achieving dimming control of the LED.

[0018] Preferably, the front dimmer includes a front phase dimmer and a rear phase dimmer, and the rear dimmer includes three types: 0-10V, PWM and potentiometer.

[0019] According to another aspect of the present invention, an all-in-one dimming LED driver based on a single-chip microcomputer is provided for application in a variety of LED driver topologies, including single-stage and two-stage types.

[0020] Wherein, the single-stage type includes a primary-side or secondary-side high power factor flyback constant current control circuit and a primary-side or secondary-side high power factor flyback constant voltage and constant current control circuit;

[0021] The two-stage type includes a primary side or secondary side high power factor flyback constant voltage connected to an output step-down constant current control circuit, and a boost power factor correction circuit connected to a primary side or secondary side isolated DC / DC constant voltage constant current control circuit.

[0022] Compared with the prior art, the present invention provides an all-in-one dimming LED driver based on a single-chip microcomputer and its application, which has the following beneficial effects:

[0023] (1) The present invention utilizes two independent dimming signal sampling and shaping circuits to independently convert the signals of the front dimmer and the rear dimmer into two DC signals, which are then sent to the single-chip microcomputer for sampling. After the single-chip microcomputer calculates, a PWM dimming signal is identified and sent to the constant current control chip or the constant voltage constant current control loop or the chopping dimming circuit for output brightness control, thereby being able to control the brightness of the LED based on the integrated dimming signal. This method realizes a simple and accurate dimming solution, which can greatly reduce the requirements for the computing power of the single-chip microcomputer, thereby effectively saving costs and better meeting the use needs of enterprises.

[0024] (2) The present invention is compatible with phase-cut dimmers and various post-dimmers such as 0-10V and PWM through dimming signal sampling and shaping circuits and a single-chip microcomputer controller, and achieves high-precision dimming control, which is applicable to various LED driver topologies. The present invention adopts a software method to achieve compatibility and signal conversion for different dimmers, simplifies the hardware circuit, reduces costs, and achieves higher compatibility, lower costs, and higher dimming performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0026] Figure 1 This is a schematic diagram of an application of an all-in-one dimming LED driver based on a single-chip microcomputer in a primary-side high power factor flyback constant current control LED driver circuit according to an embodiment of the present invention;

[0027] Figure 2 1. This is a schematic diagram of an application of an all-in-one dimming LED driver based on a single-chip microcomputer in a single-stage flyback constant voltage control LED driver circuit according to an embodiment of the present invention;

[0028] Figure 3 This is a schematic diagram of an application of an all-in-one dimming LED driver based on a single-chip microcomputer in a single-stage secondary-side flyback constant current and constant voltage control LED driver circuit according to an embodiment of the present invention;

[0029] Figure 4 2 is a schematic diagram of an application of an all-in-one dimming LED driver based on a single-chip microcomputer in a zero-ripple dimming architecture according to an embodiment of the present invention;

[0030] Figure 5 1 is a schematic diagram of an application of an all-in-one dimming LED driver based on a single-chip microcomputer in a flicker-free LED constant current drive architecture according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] According to an embodiment of the present invention, an all-in-one dimming LED driver based on a single-chip microcomputer and its application are provided. Two independent dimming signal sampling and shaping circuits are combined with a single-chip microcomputer to perform calculations and generate a comprehensive dimming signal to control the brightness of the LED.

[0033] The present invention is now further described with reference to the accompanying drawings and specific embodiments. According to one embodiment of the present invention, an all-in-one dimming LED driver based on a single-chip microcomputer is provided, comprising:

[0034] The dimming signal sampling and shaping circuit is used to independently convert the signal of the front dimmer and the signal of the rear dimmer into two DC signals;

[0035] The dimming signal sampling and shaping circuit includes a phase-cut sampling circuit for sampling the phase-cut dimmer and a dimming signal shaping circuit for isolating, converting and standardizing the signals of the pre-dimmer and the post-dimmer.

[0036] Specifically, the aforementioned all-in-one dimming LED driver is compatible with both phase-cut and post-stage dimmers. Phase-cut dimmers include leading and trailing types, while post-stage dimmers include 0-10V, PWM, and potentiometer types. Currently, popular topologies include single-stage or two-stage LED drivers with primary-side or secondary-side constant current output, or constant voltage and constant current output.

[0037] Output rectifier circuit, used for rectifying the output of the LED driver circuit;

[0038] The dimming signal conversion circuit is used to drive the isolation component to transmit the signal from the rear dimmer to the microcontroller;

[0039] A single-chip microcomputer controller is used to calculate two DC signals to generate a comprehensive dimming signal;

[0040] The single chip controller and the dimming signal shaping circuit are arranged in the primary part or the secondary part.

[0041] The single chip controller is designed on the primary side for directly sampling and shaping the phase-cut dimmer, thereby reducing the use of isolation components and improving accuracy.

[0042] The single chip microcomputer is designed on the secondary side and is used to directly dim the step-down constant current chip to achieve dimming control of the LED.

[0043] The single chip controller is used to change the output voltage loop or the output current loop to adjust the output voltage or output current, thereby achieving dimming control of the LED.

[0044] The constant current control chip or constant voltage constant current control loop or chopping dimming circuit is used to control the brightness of the LED according to the comprehensive dimming signal.

[0045] The chopping dimming circuit includes a MOSFET arranged in a loop between the LED and the driver and a chip or a totem pole for driving the gate pin of the MOSFET.

[0046] According to another embodiment of the present invention, an all-in-one dimming LED driver based on a single-chip microcomputer is provided for application to various popular LED driver topologies, which can achieve a simple and accurate dimming solution. The various LED driver topologies include single-stage and two-stage types.

[0047] Wherein, the single-stage type includes a primary-side or secondary-side high power factor flyback constant current control circuit and a primary-side or secondary-side high power factor flyback constant voltage and constant current control circuit;

[0048] The two-stage type includes a primary side or secondary side high power factor flyback constant voltage connected to an output step-down constant current control circuit, and a boost power factor correction circuit connected to a primary side or secondary side isolated DC / DC constant voltage constant current control circuit.

[0049] In order to better understand the application of the present invention, the following specific Figures 1 to 5 For detailed explanation:

[0050] Figure 1 This is a primary-side high-power-factor flyback constant-current controlled LED driver circuit. The main control chip is a popular dedicated dimming chip that supports PWM dimming signals. Therefore, the present invention places a single-chip microcontroller on the primary side, enabling direct sampling and shaping of the phase-cut dimmer, eliminating the need for isolation components and improving accuracy. The post-dimmer requires a dimming signal conversion circuit to drive an isolation component, typically an optocoupler, to transmit the signal to the primary side. After shaping and sampling, and then processing by the single-chip microcontroller, a comprehensive dimming signal is generated, which can be used to dim the PWM dimming pin of the main control chip. When a single-stage approach cannot support higher-power LEDs, a two-stage approach is adopted. Typically, a boost-type power factor correction circuit is connected to a primary-side flyback constant-current control chip. This chip also features a PWM dimming pin.

[0051] Figure 2This is a single-stage flyback constant voltage controlled LED driver circuit. The main control chip is a popular primary-side control chip equipped with power factor correction, which simplifies the previous secondary-side control circuit. For the above architecture, a control circuit specifically designed for fast switching is required, called a chopper dimming circuit. This circuit mainly consists of a MOSFET and a chip or totem pole that drives the gate pin, connected in the loop between the LED and the driver. Different from Figure 1 In this architecture, the MCU and dimming signal shaping circuit need to be connected with the chopping dimming circuit and designed in the secondary part. Therefore, after sampling the phase-cut dimmer, an optocoupler needs to be driven to transmit the dimming signal to the secondary. The post-dimming part is connected with the Figure 1 Similarly, a dimming signal conversion circuit is required to drive the optocoupler and transmit the signal to the secondary stage. After shaping and sampling, and then processing by the microcontroller, a comprehensive dimming signal is generated, which is used to dim the chopper dimming circuit. Similarly, when a single-stage approach cannot support higher-power LEDs, a two-stage solution is used. This typically involves a boost-type power factor correction circuit connected to a primary-side flyback constant-voltage controller or a constant-current constant-voltage controller. Again, dimming is achieved through the chopper dimming circuit.

[0052] Figure 3 This is a single-stage secondary-side flyback constant current and constant voltage controlled LED driver circuit. The main control chip is a traditional flyback control chip equipped with power factor correction function. Figure 2 Similarly, for the above architecture, the dimming circuit part needs to be coordinated with the chopping dimming circuit. Figure 2 Similarly, the microcontroller and dimming signal shaping circuit are connected to the chopping dimming circuit and designed in the secondary part. Therefore, after sampling the phase-cut dimmer, it is necessary to drive an optocoupler to transmit the dimming signal to the secondary. Figure 2 The rear dimming part is the same as Figure 1 Similarly, a dimming signal conversion circuit is required to drive the optocoupler and transmit the signal to the secondary. After shaping and sampling, and then processing by the microcontroller, a comprehensive dimming signal is generated, which is used to dim the chopper dimming circuit. When a single-stage solution cannot support higher-power LED applications, a two-stage solution is used. Typically, a boost-type power factor correction circuit is connected to a secondary-side flyback control chip. For higher power applications, the flyback type is generally replaced with a resonant control chip. Similarly, dimming is achieved through the chopper dimming circuit.

[0053] Figure 4 Overall with Figure 3This is similar to the CMOS, but it uses a zero-ripple dimming architecture. Its principle is to abandon the chopper dimming circuit and use the integrated dimming signal to change the output voltage loop, thereby changing the output voltage to achieve the dimming effect. The same method can also be applied to constant current outputs. Simply connect the integrated dimming signal to the output current loop to adjust the output current to achieve the dimming effect.

[0054] Figure 5 This is a popular flicker-free LED constant-current driver architecture. The primary stage consists of a high-power-factor flyback constant-voltage control circuit on either the primary or secondary side, and a dimmable step-down constant-current drive circuit on the secondary side. This architecture integrates a microcontroller on the secondary side, allowing the step-down constant-current chip to be dimmed directly via a comprehensive dimming signal. This solution is specifically designed for LED dimming, easily achieving precise 1% dimming. With specialized processing, it can even achieve deep dimming down to 0.01%.

[0055] In summary, with the help of the above technical solution of the present invention, the present invention utilizes two independent dimming signal sampling and shaping circuits to independently convert the signal of the front dimmer and the signal of the rear dimmer into two DC signals, which are then sent to the single-chip microcomputer for sampling. After calculation by the single-chip microcomputer, a PWM dimming signal is identified and sent to the constant current control chip or constant voltage constant current control loop or chopper dimming circuit for output brightness control, so that the brightness of the LED can be controlled based on the integrated dimming signal. This method realizes a simple and accurate dimming solution, which can greatly reduce the requirements for the computing power of the single-chip microcomputer, thereby effectively reducing costs and better meeting the usage needs of enterprises.

[0056] In addition, the present invention is compatible with phase-cut dimmers and various post-dimmers such as 0-10V and PWM through dimming signal sampling and shaping circuits and a single-chip microcomputer controller, and can achieve high-precision dimming control, suitable for various LED driver topologies. The present invention uses software methods to achieve compatibility and signal conversion for different dimmers, simplifying the hardware circuit, reducing costs, and achieving higher compatibility, lower costs, and higher dimming performance.

[0057] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. An all-in-one dimming LED driver based on a single-chip microcomputer, characterized in that: include: The dimming signal sampling and shaping circuit is used to independently convert the signal of the front dimmer and the signal of the rear dimmer into two DC signals; Output rectifier circuit, used for rectifying the output of the LED driver circuit; A dimming signal conversion circuit is used to drive an isolation component to transmit the signal from the rear dimmer to the microcontroller. The isolation component is an optocoupler. A single-chip microcomputer controller is used to calculate two DC signals to generate a comprehensive dimming signal; A constant current control chip or a constant voltage and constant current control loop or a chopping dimming circuit for controlling the brightness of the LED according to the integrated dimming signal; The dimming signal sampling and shaping circuit includes a phase-cut sampling circuit for sampling the phase-cut dimmer and a dimming signal shaping circuit for isolating, converting and standardizing the signals of the pre-dimmer and the post-dimmer; The front dimmer includes a front phase dimmer and a rear phase dimmer, and the rear dimmer includes three types: 0-10V, PWM and potentiometer; The phase-cut sampling circuit input end is respectively connected to the circuit between the phase-cut dimmer and the rectifier bridge and the circuit after the rectifier bridge; After the single chip microcomputer performs calculations, it identifies a PWM dimming signal and transmits it to the constant current control chip or the constant voltage constant current control loop or the chopping dimming circuit; When applied to the primary-side high power factor flyback constant current control LED driver circuit, the MCU is set on the primary side to directly sample and shape the phase-cut dimmer, omitting isolation components and improving accuracy. When applied to a single-stage flyback constant voltage control LED driver circuit or a single-stage secondary-side flyback constant current and constant voltage control LED driver circuit, a chopper dimming circuit is set on the secondary side, and a comprehensive dimming signal is generated by the microcontroller calculation to dim the chopper dimming circuit; When a two-stage control chip is used or the flyback type is changed to a resonant type, dimming is performed through a chopping dimming circuit; When used in a single-stage secondary-side flyback constant-current and constant-voltage controlled LED driver circuit, the secondary side does not have a chopper dimming circuit. The microcontroller generates a comprehensive dimming signal to change the output voltage loop, thereby changing the output voltage to achieve a dimming effect. When applied to a flicker-free LED constant current drive architecture, with the primary side or secondary side high power factor flyback constant voltage control circuit and the secondary side being a dimmable buck constant current drive circuit, the MCU is set on the secondary side and directly dims the buck constant current chip through the integrated dimming signal; The single chip controller and the dimming signal shaping circuit are arranged in the primary part or the secondary part.

2. The all-in-one dimming LED driver based on a single chip microcomputer according to claim 1, characterized in that: The chopping dimming circuit includes a MOSFET arranged in a loop between the LED and the driver and a chip or a totem pole for driving the gate pin of the MOSFET.

3. The all-in-one dimming LED driver based on a single chip microcomputer according to claim 1, characterized in that: The single chip controller is designed on the primary side for directly sampling and shaping the phase-cut dimmer, thereby reducing the use of isolation components and improving accuracy.

4. The all-in-one dimming LED driver based on a single chip microcomputer according to claim 1, characterized in that: The single chip microcomputer is designed on the secondary side and is used to directly dim the step-down constant current chip to achieve dimming control of the LED.

5. The all-in-one dimming LED driver based on a single chip microcomputer according to claim 1, characterized in that: The single chip controller is used to change the output voltage loop or the output current loop to adjust the output voltage or output current, thereby achieving dimming control of the LED.

6. The application of the all-in-one dimming LED driver based on a single chip microcomputer in various LED driver topologies according to any one of claims 1 to 5, characterized in that: The various LED driver topologies include single-stage and two-stage types; Wherein, the single-stage type includes a primary-side or secondary-side high power factor flyback constant current control circuit and a primary-side or secondary-side high power factor flyback constant voltage and constant current control circuit; The two-stage type includes a primary side or secondary side high power factor flyback constant voltage connected to an output step-down constant current control circuit, and a boost power factor correction circuit connected to a primary side or secondary side isolated DC / DC constant voltage constant current control circuit.

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