本次研讨会介绍安森美半导体在中国荣获“最佳应用奖”的NCL30000单段式高功率因数LED驱动器的原理，以及基于NCL30000的TRIAC调光方案，旨在帮助设计人员更快开发出符合相关规范要求及市场需求的更低成本LED照明方案，加快LED通用照明的普及进程。安森美半导体作为全球应用于绿色电子产品的首要高性能、高能效硅方案供应商，针对不同功率等级的应用设计了不少LED照明驱动方案。

据国际能源署(IEA)估计，全球消耗的电能中有19%是用于照明。因此，近年来，世界各国纷纷致力于以更高能效的方案来替代低能效的白炽灯光源。而随着发光二极管(LED)在流明输出及光效方面持续快速进步，同时，平均每流明光输出的成本也在下降，再结合LED在高指向性、长寿命和低维护成本等方面的优势，LED照明(也称固态照明，或SSL)成为一种极为引人注目的替代解决方案。

据国际能源署(IEA)估计，全球消耗的电能中有19%是用于照明。因此，近年来，世界各国纷纷致力于以更高能效的方案来替代低能效的白炽灯光源。而随着发光二极管(LED)在流明输出及光效方面持续快速进步，同时，平均每流明光输出的成本也在下降，再结合LED在高指向性、长寿命和低维护成本等方面的优势，LED照明(也称固态照明，或SSL)成为一种极为引人注目的替代解决方案。

Single stage critical conduction mode (CrM) flyback converters require different design considerations compared to fixed frequency or quasi−resonant (QR) flyback converters. Information is presented in this application note on establishing design parameters for the power stage of an LED driver. This includes the design of the transformer, power component selections, and EMI filter design as well as the startup and biasing circuitry of the NCL30000 LED driver controller. To illustrate the design process, an example power supply will be used.

The NCL30000 is a switch mode power supply controller intended for low to medium power single stage power factor (PF) corrected LED Drivers. The device is designed to operate in critical conduction mode (CrM) and is suitable for flyback as well as buck topologies. Constant on time CrM operation is particularly suited for isolated flyback LED applications as the control scheme is straightforward and very high efficiency can be achieved even at low power levels. These are important in LED lighting to comply with regulatory requirements and meet overall system luminous efficacy requirements.

As LED lighting starts to enter the mainstream of general lighting it is important to be compatible with the existing line dimming infrastructure. This has been one of the limitations of wider acceptance of CFL bulbs as many applications require dimming and the user expectation of the dimming control range is that it is comparable to the incandescent lamps which are being replaced. There are two main types of phase cut dimmers − leading edge (triac based) or trailing edge (transistor based).

The NCL30000 is a power factor corrected LED driver controller. This evaluation board manual describes the setup and operation of the NCL30000LED2GEVB LED driver for 230 V input. The evaluation board implements an isolated single stage Critical conduction Mode (CrM) flyback converter providing a regulated constant current to an LED load. This board has been specifically configured to support leading and trailing edge line dimming and has been characterized across a range of commercially available dimmers.