LED light source module with built-in constant current IC and independent driving circuit

Abstract

This invention discloses an LED light source module with a built-in constant current IC and independent driving circuit. The PCB of the light source module includes a constant current driver IC, a serial communication interface, a ground interface, a power supply interface, and at least two sets of tri-color LEDs. The constant current driver IC includes a control module, a voltage regulator module, a decoding module, a data latch module, a PWM brightness adjustment module, and multiple independent constant current driver modules. The PWM brightness adjustment module provides independent PWM adjustment for each independent constant current driver module. Each set of tri-color LEDs includes red, green, and blue LEDs. The cathodes of all LEDs are electrically connected to the ground interface, and the anodes of the LEDs are electrically connected to the control pins of the constant current driver IC. One control pin corresponds to one LED, and one control pin is electrically connected to the load terminal of one independent constant current driver module. This design allows for independent control of each LED and reduces the PCB layout area of ​​the light source module, thereby lowering hardware and manufacturing / assembly costs.

Description

Technical Field

[0001] This invention relates to the field of LED technology, and in particular to an LED light source module with a built-in constant current IC and an independent driving circuit. Background Technology

[0002] Currently, in the field of LED driver control, the driving solutions for multiple RGB LEDs are mainly divided into two categories: one is to use a single driver IC to drive one group of RGB LEDs, and multiple groups of LEDs require the same number of driver ICs; the other is to use an external constant current source multi-channel driving solution, which uses discrete components to build a constant current circuit to drive multiple groups of LEDs.

[0003] For the first type of solution, when using multiple sets of LEDs, a large number of driver ICs and supporting components are required, and the component layout requirements on the PCB board are higher, resulting in not only high hardware costs but also high production and assembly complexity.

[0004] For the second type of solution, the constant current accuracy of the constant current source is affected by the differences in the parameters of discrete components, and the brightness of the LED is easily affected by the difference in its own forward voltage drop Vf, resulting in uneven brightness of multiple groups of LEDs and affecting the display effect.

[0005] Both of the above solutions require more PCB layout area, making it difficult to meet the requirements of miniaturized application scenarios and high-density LED products, such as micro LED modules and portable lighting equipment.

[0006] Existing multi-LED driver solutions mostly use multi-line communication, which is cumbersome in terms of wiring; some single-line communication solutions cannot achieve independent control of multiple groups, and there are problems such as poor synchronization, weak anti-interference ability and unstable data transmission when cascaded; most solutions can only realize the synchronous on / off and color adjustment of multiple groups of LEDs, but cannot realize independent dimming and independent color adjustment of two or more groups of LEDs, which makes it difficult to meet diverse lighting control needs.

[0007] Therefore, there is an urgent need for an LED light source module with a built-in constant current IC and independent driving circuit that can solve one or more of the above problems. Summary of the Invention

[0008] To address one or more problems existing in the prior art, this invention provides an LED light source module with a built-in constant current IC and an independent driving circuit. The technical solution adopted by this invention to solve the above problems is: an LED light source module with a built-in constant current IC and an independent driving circuit, wherein the PCB of the light source module is provided with a constant current driving IC, a serial communication interface and a ground interface, a power supply interface and at least two sets of tri-color LED beads, and the power supply interface is electrically connected to the output terminal of an external power input module; The constant current driver IC is equipped with a control module, a voltage regulator module, a decoding module, a data latch module, a PWM brightness adjustment module, and multiple independent constant current driver modules. The PWM brightness adjustment module provides independent PWM adjustment for each of the independent constant current driver modules. The power supply terminal of the constant current driver IC is electrically connected to the power supply interface, the serial communication interface is electrically connected to the serial interface of the constant current driver IC, and the ground interface is electrically connected to the ground of the constant current driver IC. Each group of three-color LED beads is equipped with red, green and blue LED beads. The cathodes of all LED beads are electrically connected to the ground interface, and the anodes of the LED beads are electrically connected to the control pins of the constant current drive IC. Each control pin corresponds to one LED bead, and each control pin is electrically connected to the load terminal of one independent constant current drive module.

[0009] In some embodiments, the input terminal of the decoding module is electrically connected to the receiving terminal of the serial communication interface, the decoding module performs serial-to-parallel conversion and decoding on the serial data, and the decoded data is stored in the data latch module; The PWM brightness adjustment module performs the PWM adjustment based on the data stored in the data latch module, and the PWM adjustment controls the start and stop time of each independent constant current drive module.

[0010] Furthermore, the constant current driver IC is equipped with a cascade forwarding module, which is electrically connected to the output of the decoding module and the transmitting end of the serial communication interface. The cascade forwarding module forwards data in the decoding module that exceeds the local processing range to the next level.

[0011] In some embodiments, the independent constant current driving module is a closed-loop negative feedback current detection circuit composed of an operational amplifier, a MOSFET, and a sampling resistor. The independent constant current driving module detects the sampling resistor to implement negative feedback on the conduction strength of the MOSFET.

[0012] In some embodiments, a decoupling capacitor is connected in parallel with the power supply terminal of the constant current driver IC and the ground of the constant current driver IC.

[0013] In some embodiments, a varistor is connected in parallel with the power supply terminal of the constant current drive IC and the ground of the constant current drive IC.

[0014] In some embodiments, the light source module is provided with a cascaded expansion mode. In the cascaded expansion mode, multiple light source modules form a group. The power supply interfaces of the light source modules in the same group are connected in parallel, and the ground interfaces of the light source modules in the same group share a common ground. The receiving end of the serial communication interface of the first light source module is electrically connected to an external main control unit, and the transmitting end of the serial communication interface of the preceding light source module is electrically connected to the receiving end of the serial communication interface of the following light source module.

[0015] The technical effects achieved by the present invention are as follows: the above-mentioned light source module achieves matching of at least two groups of six LED beads through the above-mentioned constant current driving IC, reduces the number of peripheral driving circuits and components, reduces the PCB layout area corresponding to the light source module, reduces hardware costs and production and assembly costs, and achieves the effect of independent dimming and color adjustment of each LED bead without interference, satisfying the lighting effects of monochrome constant light, gradient, jump, and zone image. Each LED bead is driven by an independent constant current drive module (high-end current detection constant current source) to ensure that the current of each LED bead is constant, avoid the influence of differences in forward voltage drop of LED beads and power supply fluctuations, and achieve a uniform brightness display effect. The light source module can integrate at least two sets of LEDs. Its PCB area is small, and only four pins are needed for control, power supply and interconnection. It can meet the needs of small-pitch dense arrangement to form a large-scale LED array. Compared with traditional dense LED display panels, the dense LED display panel composed of the light source module of this application has better cost and effect. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic block diagram of the present invention; Figure 2 This is a schematic diagram of the front side of the PCB of the present invention; Figure 3 This is a schematic diagram of the back side of the PCB of the present invention; Figure 4 This is a schematic diagram illustrating the principle of forming the array according to the present invention.

[0018] In the diagram, 1 is the light source module; 10 is DOUT; 100 is DOUT pad; 11 is VDD; 110 is VDD pad; 12 is GND; 120 is GND pad; 13 is DIN; 130 is DIN pad; 2 is the constant current driver IC; 3 is the LED bead; 4 is the VDD line; and 5 is the GND line. Detailed Implementation

[0019] To make the above-mentioned objects, features, and advantages of the present invention more readily understood, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0020] like Figure 1 As shown, this invention discloses an LED light source module with a built-in constant current IC and an independent driving circuit. The PCB of the light source module is provided with a constant current driving IC, a serial communication interface and a ground interface, a power supply interface and at least two sets of tri-color LED beads. The power supply interface is electrically connected to the output terminal of an external power input module. The constant current driver IC is equipped with a control module, a voltage regulator module, a decoding module, a data latch module, a PWM brightness adjustment module, and multiple independent constant current driver modules. The PWM brightness adjustment module provides independent PWM adjustment for each of the independent constant current driver modules. The control module is a conventional MCU used to control the operation of each module. The power supply terminal of the constant current driver IC is electrically connected to the power supply interface, the serial communication interface is electrically connected to the serial interface of the constant current driver IC, and the ground interface is electrically connected to the ground of the constant current driver IC. Each group of three-color LED beads is equipped with red, green and blue LED beads. The cathodes of all LED beads are electrically connected to the ground interface, and the anodes of the LED beads are electrically connected to the control pins of the constant current drive IC. Each control pin corresponds to one LED bead, and each control pin is electrically connected to the load terminal of one independent constant current drive module.

[0021] It should be noted that the control module, voltage regulator module, decoding module, data latch module, PWM brightness adjustment module, and multi-channel independent constant current drive module in the constant current drive IC can be existing conventional circuits.

[0022] It should be noted that the independent constant current drive module is a closed-loop negative feedback current detection circuit composed of an operational amplifier, a MOSFET, and a sampling resistor. The independent constant current drive module detects the sampling resistor to provide negative feedback on the conduction strength of the MOSFET. For example, the independent constant current drive module is a high-side current sensing constant current source, which is a conventional existing circuit. By using multiple independent constant current drive modules, it is convenient to integrate at least two sets of LED beads on the PCB and implement independent constant current control, thereby reducing the number of external components and the PCB area.

[0023] Specifically, in combination Figure 1 As shown, the input terminal of the decoding module is electrically connected to the receiving terminal of the serial communication interface. The decoding module performs serial-to-parallel conversion and decoding on the serial data. The decoded data is stored in the data latch module, which provides stable brightness and color control. The serial data consists of color and brightness information of multiple LED beads (typical data format is R2 / G2 / B2 / R1 / G1 / B1, with each color information occupying 8 bits, for a total of 48 bits of data). The PWM brightness adjustment module executes the PWM adjustment according to the data stored in the data latch module. The PWM adjustment uses the duty cycle signal to control the on and off time of each independent constant current drive module to implement brightness control. Furthermore, the constant current driver IC is equipped with a cascade forwarding module, which is electrically connected to the output of the decoding module and the transmitting end of the serial communication interface. The cascade forwarding module forwards data in the decoding module that exceeds the local processing range to the next level, thereby realizing cascade forwarding and achieving the purpose of forming a large-scale LED array.

[0024] To filter out high-frequency noise at the power supply terminal and improve power supply stability, a decoupling capacitor is connected in parallel between the power supply terminal and the ground of the constant current driver IC. To implement overvoltage and surge protection, a varistor is connected in parallel between the power supply terminal and the ground of the constant current driver IC.

[0025] like Figure 2 , Figure 3 As shown, the constant current drive IC2 of the light source module 1 is located on the front side of the PCB. The constant current drive IC2 has its DOUT10, VDD11, GND12 and DIN13 pins connected out, and DOUT pad 100, VDD pad 110, GND pad 120 and DIN pad 130 are formed on the back side of the PCB so that multiple light source modules 1 can be set on the same PCB to form an array LED panel. Two groups of six LED beads 3 are set on the front side of the PCB and electrically connected to the constant current drive IC2. The simplicity and small size of the PCB of the light source module 1 can be seen.

[0026] Combination Figure 4 As shown, multiple light source modules 1 are arranged on the same PCB to form an array LED panel. The VDD of each light source module 1 is electrically connected to the VDD line 4, and the GND is electrically connected to the GND line 5. The light source modules 1 in the same row form a display module. Multiple display modules are arranged sequentially. In the same display module, the DIN of the first light source module 1 is brought out and electrically connected to an external control terminal, while the DOUT of the last light source module 1 is brought out or not brought out. The transmitting end of the serial communication interface of the first light source module 1 is electrically connected to the receiving end of the serial communication interface of the last light source module 1, forming a row of display modules where each light source module 1 is independently controllable.

[0027] In summary, the above-mentioned light source module uses the constant current driving IC to match at least two groups of six LED beads, reducing the number of peripheral driving circuits and components, reducing the PCB layout area of ​​the light source module, reducing hardware costs and production and assembly costs, and achieving the effect of independent dimming and color adjustment of each LED bead without interference, satisfying the lighting effects of single color constant light, gradient, jump, and zone image. Each LED bead is driven by an independent constant current drive module (high-end current detection constant current source) to ensure that the current of each LED bead is constant, avoid the influence of differences in forward voltage drop of LED beads and power supply fluctuations, and achieve a uniform brightness display effect. The light source module can integrate at least two sets of LEDs. Its PCB area is small, and only four pins are needed for control, power supply and interconnection. It can meet the needs of small-pitch dense arrangement to form a large-scale LED array. Compared with traditional dense LED display panels, the dense LED display panel composed of the light source module of this application has better cost and effect.

[0028] The embodiments described above are merely illustrative of one or more implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. An LED light source module with a built-in constant current IC and an independent driving circuit, characterized in that, The PCB of the light source module is provided with a constant current driver IC, a serial communication interface and a ground interface, a power supply interface and at least two sets of tri-color LEDs. The power supply interface is electrically connected to the output terminal of the external power input module. The constant current driver IC is equipped with a control module, a voltage regulator module, a decoding module, a data latch module, a PWM brightness adjustment module, and multiple independent constant current driver modules. The PWM brightness adjustment module provides independent PWM adjustment for each of the independent constant current driver modules. The power supply terminal of the constant current driver IC is electrically connected to the power supply interface, the serial communication interface is electrically connected to the serial interface of the constant current driver IC, and the ground interface is electrically connected to the ground of the constant current driver IC. Each group of three-color LED beads is equipped with red, green and blue LED beads. The cathodes of all LED beads are electrically connected to the ground interface, and the anodes of the LED beads are electrically connected to the control pins of the constant current drive IC. Each control pin corresponds to one LED bead, and each control pin is electrically connected to the load terminal of one independent constant current drive module.

2. The LED light source module with built-in constant current IC and independent driving circuit according to claim 1, characterized in that, The input terminal of the decoding module is electrically connected to the receiving terminal of the serial communication interface. The decoding module performs serial-to-parallel conversion and decoding on the serial data, and the decoded data is stored in the data latch module. The PWM brightness adjustment module performs the PWM adjustment based on the data stored in the data latch module, and the PWM adjustment controls the start and stop time of each independent constant current drive module.

3. The LED light source module with built-in constant current IC and independent driving circuit according to claim 2, characterized in that, The constant current driver IC is equipped with a cascaded forwarding module, which is electrically connected to the output of the decoding module and the transmitting end of the serial communication interface. The cascaded forwarding module forwards data in the decoding module that exceeds the local processing range to the next level.

4. The LED light source module with built-in constant current IC and independent driving circuit according to claim 1, characterized in that, The independent constant current drive module is a closed-loop negative feedback current detection circuit composed of an operational amplifier, a MOSFET, and a sampling resistor. The independent constant current drive module detects the sampling resistor to implement negative feedback on the conduction strength of the MOSFET.

5. The LED light source module with built-in constant current IC and independent driving circuit according to claim 1, characterized in that, A decoupling capacitor is connected in parallel between the power supply terminal of the constant current driver IC and the ground of the constant current driver IC.

6. The LED light source module with built-in constant current IC and independent driving circuit according to claim 1 or 5, characterized in that, A varistor is connected in parallel with the power supply terminal of the constant current drive IC and the ground of the constant current drive IC.

7. The LED light source module with built-in constant current IC and independent driving circuit according to claim 1, characterized in that, The light source module is configured with a cascaded expansion mode. In the cascaded expansion mode, multiple light source modules form a group. The power supply interfaces of the light source modules in the same group are connected in parallel, and the ground interfaces of the light source modules in the same group share a common ground. The receiving end of the serial communication interface of the first light source module is electrically connected to an external main control unit, and the transmitting end of the serial communication interface of the preceding light source module is electrically connected to the receiving end of the serial communication interface of the following light source module.

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