Sinrace Power Supply Technology (Shenzhen) Co., Ltd.

Viewing the power level, AC-DC power supply LED general lighting applications include low power, medium power and high power of different types. Power range of low-power applications is usually between 1 and 12 W, medium power range covers 8 ot 40 W, power of high-power applications often is higher than 40 W.

1. 1 W to 8 W LED general lighting application requirements and program

In the genera lighting of low power 1 W to 8 W LED lighting, typical applications are such as G13, GU10, PAR16, PAR20, and embedded lights. Their input voltage range is between AC 90 to 264 V, constant output current is included 350 mA and 700 mA, energy efficiency requirements is 80%, and ask for short-circuit and overvoltage protection and other protective features.

In such applications, you can use ON Semiconductor NCP1015 self-powered single-chip to switch IC. This device incorporates a fixed frequency (65/100/130 kHz) current-mode controller and a 700 V high voltage MOSFET, providing structuring all features required by strong low-cost power, such as soft start, frequency jittering, short-circuit protection, skip-cycle , the maximum peak current setpoint and dynamic self-powered functions (without auxiliary winding) and so on.

2. 8 W to 25 W LED general lighting application requirements and programs: with or without PFC

In the 8 W-25 W AC-DC LED lighting applications, we have to consider two cases. One is that the application does not require power factor correction (PFC). On the other hand, the U.S. Department of Energy (DOE) "Energy Star" Solid State Lighting (SSL) specification levels enforce that any power lever should force to provide power factor correction (PFC). This standard is applied to a range of specific products, such as embedded lights, cabinet lights and lamps, among which the power factor of LED drive for residential applications must be greater than 0.7, while that for commercial applications shall be greater than 0.9. But standards are voluntary standards, you can choose not to comply or complied with. Therefore, another situation to consider is to ask for the PFC.

8 W to 25 W AC-DC LED lighting without the PFC, typical applications are such as PAR30, PAR38, and embedded lights. In such applications, the input voltage is required to be 85 ~ 135 Vac or 185 ~ 264Vac (or universal input), energy efficiency requirements if greater than 80% of the, to provide short circuit protection and open circuit protection, protection features, constant output current is 350 mA, 700 mA and 1 A different current. Accordingly, you can use ON Semiconductor NCP1028 or NCP1351

The 8 W to 25 W AC-DC LED lighting required the PFC,thr typical application is also PAR30, PAR38, and embedded lights. Input voltage specifications of such applications is 90 to 264 Vac, energy efficiency requirements is 80%, to support 350 mA, 700 mA and 1 A constant current output, to provide short circuit and overvoltage protection, power factor requirements is higher than 0.9. Such applications are suitable for adopting Semiconductor NCL30000 single-stage PFC LED driver. Single-stage topological structure saves dedicated PFC boost, reduce component count and help reduce overall system cost. NCL30000 provide more than 0.9 power factor, harmonic content, meet the requirements of IEC C class. This device can directly drive the LED, with precise constant current output control, the power efficiency when 5 to 15 W lower output power is than 80%, typical efficiency is higher than 83%, and support theTRIAC existing dimmer program.

3. 50W to 200 W LED general lighting application requirements and programs

Above 50 W power AC-DC LED is widely used for street lighting and high-power area lighting, you can adopt different LED program ,to used for the 50 W-150 W or 100W -200 W power range. Assume that the input voltage specification is 90 - 264 Vac, power factor is higher than 0.9, efficiency is greater than 85%, provide short-circuit and overvoltage protection, and 350 mA, 700 mA and 1 A constant current output. Such applications can use the following different options. to suit different needs:
NCL30001: single-stage PFC LED driver;
NCP1607 NCP1377: CrM PFC QR PWM;
NCP1607 NCP1397 or NCP1392 / 3: CrM PFC LLC PWM.

For example as NCL30001, this is a continuous current mode (CCM) control , used for 40 W to 150 W single-stage PFC LED driver. This device supports 20 to 250 kHz adjustable switching frequency, support frequency jitter and voltage feed-forward, include input under-voltage and overload timer, providing high efficiency and high power factor and robust protection features.

It is worth mentioning that in recent years, the industry has growing interests for the high efficiency LED lighting topology, expect a relatively low power levels (<50 W) to provide more than 90% of the energy efficiency, this energy efficiency goal is even more higher than this "Energy Star" version 2.0 external power supply efficiency requirements (no more than 49 W power efficiency higher than 87% of the time). To achieve such a high energy efficiency, we need a new topology, such as from the flyback topology to be  , resonant half-bridge topology, to maximize to allow full play the advantages of the zero-voltage switching (ZVS). Advantage is that ON Semiconductor has already started to develop the power energy-efficient half-bridge solution that can be used to LED driver, such as NCP1397 and upgraded version NCP1396 high-performance resonant mode controller. NCP1397 built-in high and low drivers, support an adjustable and accurate minimum frequencies ,to provide high energy efficiency, and have a variety of fault protection features.