LED area lighting power supply architecture and typical LED drive scheme
1) Distributed/modular solutions suitable for linear and slot lamps
In the application of high-power LED regional lighting, a common power supply architecture is the three-stage architecture of "PFC + CV + CC". In this architecture, the AC input power supply, after power factor correction and isolated DC-DC (DC-DC) conversion, outputs a fixed voltage of 24 to 80 Vdc, which is provided to the constant-current LED module with built-in DC-DC step-down conversion circuit (see Figure 2). This architecture is designed to provide a modular approach to on-site upgrades that can flexibly change the number of LED light bars to increase or decrease the light output to meet the lighting application requirements of specific areas. Under this architecture, the AC-DC (AC-DC) conversion is not integrated with the LED drive circuit, but adopts a distributed configuration, which simplifies security considerations and enhances system flexibility. Also known as a distributed solution, typical applications include linear lights and slot lights.
In this modular approach, a design can be extended for multiple optical output levels. And as the LED light output performance is enhanced, the LED module to provide the same light output level, the required light bar is better. Each strip is equipped with a dedicated DC-DC LED driver, such as ansemel's CAT4201 high efficiency step-down LED driver. CAT4201 is specifically optimized for driving high-current leds using proprietary switching control algorithms to provide high energy efficiency and accurate LED current stabilization up to 350 mA. CAT4201 can be supplied at up to 36 V and is compatible with 12 V and 24 V standard lighting systems. 

Not all regional lighting applications require a distributed/modular approach. With the rapid improvement of the performance of white LED, new LED has been able to cooperate with new LED driver design methods. Leading LED manufacturers have introduced new LED models that support higher current and higher luminous performance, such as Cree's XP-G series (forward pressure drop of 3.3V), which can provide output of 330 lumen light at 1A current, and Seoul Semiconductor's P7 series (forward pressure drop of 3.3V), which can provide output of 400 lumen light at 1.4a. Under these conditions, novel LED drivers can be configured to drive large currents directly from 1 A to 3 A. For example, ansemel's NCL30001 POWER factor correction TRIAC dimmable LED driver can be used.
NCL30001 is an integral/single-stage LED drive solution that integrates PFC and isolated DC-DC conversion circuits and provides a constant current to drive the LED directly. This solution is equivalent to integrating ac-DC conversion and LED drive circuits, both of which are located in lighting fixtures, eliminating linear or DC-DC converters integrated in LED strips. This integrated solution has fewer power conversion segments, reduces the number of components used (such as optical components, leds, electronic components, and printed circuit boards), reduces system costs, and supports higher overall LED power efficiency. Of course, this scheme has a higher power density and may not be suitable for all regional lighting applications. Its optical pattern may be more suitable for lower power leds, and typical applications include LED street lights, external wall lights, wall washing lights and refrigerator box lighting.

This 90 W constant pressure constant current demo board accept from 90 to 265 Vac extend universal input voltage (under the condition of replacement components can support 305 Vac) and provide 0.7 A and 1.5 A constant current output range (can choose by slightly adjusting resistance) and 30 V to 55 V constant output voltage range (can choose) through the resistor voltage divider, maximum output power 90 W, support 50-1000 Hz dimming control, and contain can be connected to the transferring light card 6 pins interface, used to simulate/double brightness levels to adjust current intelligent dimming applications such as digital dimming. In addition, the demo board also provides short circuit protection, open circuit protection, over-temperature protection, over-current protection and over-voltage protection and other protection features. Tests show that the panel's energy efficiency is higher than 87% under conditions of 50 W output power, 1,000 mA output voltage /48 V forward voltage drop, and its power factor is higher than 0.9 under conditions of 50% to 100% load. It also meets the iEC61000-3-2 class C equipment harmonic content standard.
3) High-efficiency LLC topological drive power supply for high-power area lighting applications
In recent years, the industry has been increasingly interested in ultra-energy-efficient LED lighting topologies, which are expected to provide high energy efficiency (e.g., more than 90%) in higher power 50 to 250 W LED area lighting applications. To provide such high energy efficiency, it is necessary to adopt high energy efficiency power supply topology, such as resonant half-bridge dual inductance plus single capacitance (LLC) topology, so as to give full play to the advantages of zero voltage switch (ZVS).
In this type of high-power LED area lighting application that requires ultra-high energy efficiency, ansemel semiconductor's NCP1607 PFC controller and NCP1397 dual inductance plus single capacitor (LLC) can be used in combination.

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