On Semi's new chip uses CrM flyback to eliminate the need for DC-DC converters, and allows for TRIAC dimmable LEDs. Dimmable to <2% led brightness.
neat.

http://www.eetasia.com/ART_8800598793_480700_NP_41807e5f.HTM

 

Hello,

Unfortunately you need to register.
I do not know what happens when you leave your email addres there.

Bertus

 

Humph? I didn't register, or see a place where I needed to.
Here is the page:

ON Semiconductor has launched a new power factor corrected dimmable LED driver for residential and commercial lighting applications.



Housed in a compact 8-pin surface mount package, the NCL30000 achieves high power factor (>0.95) in a single-stage topology by using a critical conduction mode (CrM) flyback architecture, eliminating the need for a DC/DC conversion stage. Constant on-time CrM operation is particularly suited to isolated flyback LED applications, as the control scheme is straightforward and very high efficiency can be achieved—even at low power levels. This is important in LED lighting in order to support compliance with regulatory requirements and meet overall system efficacy requirements.

Typical applications include LED driver power supplies, LED-based down lights, TRIAC dimmable LED-based lamps and power factor corrected constant voltage supplies. This device is compatible with both leading edge TRIAC-based and trailing edge transistor-based dimmers. Depending on the dimmer used, the LED output can be controlled down to <2 percent.

Three up to 15W reference designs are provided and are intended to drive from 4-15 LEDs at 350mA. They can however, be easily modified to support power levels ranging from 5W to 30W:

• NCL30000LED1GEVB: 115Vac version, 90- to 135Vac input line (Dimmable)
• NCL30000LED2GEVB: 230Vac version, 180- to 265Vac (TRIAC Dimmable)
• NCL30000LED3GEVB: Extended universal version, 90- to 305Vac

An operating temperature range of -40°C to +125°C ensures the NCL30000 can be used across environmental operating ranges specified in the majority of solid state lighting applications. The NCL30000 has a low startup current of 24µA (typical) and a low operating current of 2mA (typical) that helps support high efficiency designs.

Other key features of the NCL30000 include a programmable on time limiter, zero current detect sense block, gate driver, plus all other pulse width modulation circuitry and protection functions needed to implement a CrM switch mode power supply. The NCL30000 is the key device in a fully tested, GreenPoint reference design for offline high power factor TRIAC dimmable LED drivers intended for ENERGY STAR commercial and residential luminaires.

"Our customers have a need for dimmable LED driver solutions that are compatible with existing wiring and controls," said Christophe Warin, AC/DC business unit manager at ON Semiconductor. "The NCL30000 offers excellent dimming performance down to greater than 2 percent. This device is ideally suited for isolated flyback but can also be used with non-isolated buck topologies."

The Pb-, halogen- and BFR-free NCL30000 is RoHS-compliant and is available in an eight-pin SOIC package. It is priced at $0.45 per unit in 10,000-unit quantities. Samples are available now. Projected lead-time for production quantities is currently eight to 12 weeks ARO.

 

Hello,

This is part of what I see:

For Registered Users Home / For Registered Users

LED driver achieves >0.95 power factor


ON Semiconductor has launched a new power factor corrected dimmable LED driver for residential and commercial lighting applications.​

Please login or register with us to view this article>>

Bertus

 

Here's a link to a PDF datasheet for the NCL30000 from OnSemi's website.

Jeff