本次研討會介紹安森美半導(dǎo)體在中國榮獲“最佳應(yīng)用獎”的NCL30000單段式高功率因數(shù)LED驅(qū)動器的原理，以及基于NCL30000的TRIAC調(diào)光方案，旨在幫助設(shè)計人員更快開發(fā)出符合相關(guān)規(guī)范要求及市場需求的更低成本LED照明方案，加快LED通用照明的普及進(jìn)程。安森美半導(dǎo)體作為全球應(yīng)用于綠色電子產(chǎn)品的首要高性能、高能效硅方案供應(yīng)商，針對不同功率等級的應(yīng)用設(shè)計了不少LED照明驅(qū)動方案。

據(jù)國際能源署(IEA)估計，全球消耗的電能中有19%是用于照明。因此，近年來，世界各國紛紛致力于以更高能效的方案來替代低能效的白熾燈光源。而隨著發(fā)光二極管(LED)在流明輸出及光效方面持續(xù)快速進(jìn)步，同時，平均每流明光輸出的成本也在下降，再結(jié)合LED在高指向性、長壽命和低維護(hù)成本等方面的優(yōu)勢，LED照明(也稱固態(tài)照明，或SSL)成為一種極為引人注目的替代解決方案。

據(jù)國際能源署(IEA)估計，全球消耗的電能中有19%是用于照明。因此，近年來，世界各國紛紛致力于以更高能效的方案來替代低能效的白熾燈光源。而隨著發(fā)光二極管(LED)在流明輸出及光效方面持續(xù)快速進(jìn)步，同時，平均每流明光輸出的成本也在下降，再結(jié)合LED在高指向性、長壽命和低維護(hù)成本等方面的優(yōu)勢，LED照明(也稱固態(tài)照明，或SSL)成為一種極為引人注目的替代解決方案。

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.