Semiconductor vendors show LED focus with new driver ICs at APEC

Feb. 24, 2010
APEC LED-driver-IC announcements highlight PFC and efficiency, along with TRIAC dimming capabilities and single-stage power supplies.

The 2010 APEC (Applied Power Electronics Conference and Exposition) kicked off in Palm Springs Monday, and among the early highlights you will find several LED-centric developments. The power-electronics IC community has embraced LED lighting as a key application going forward, and the current trend appears to be more efficiency and power factor correction (PFC).

On Semiconductor, Fairchild Semiconductor, and Infineon have all made news in the LED space. Along with efficiency, other headlines include TRIAC dimming and varying power-supply topologies.

On Semiconductor launched the NCL30000 driver that is mainly used in critical-conduction-mode flyback supply architectures, although it can also support buck topologies. The IC can implement a single power stage working from the AC line, eliminating the need for a DC/DC stage.

On Semiconductor NCL30000

The design includes power factor correction (PFC). In a power supply, PFC circuits control input current to the load attempting to keep voltage and current in phase and to make the load appear purely resistive. A resistive load allows most efficient usage of AC mains power. PFC is expressed as a fraction of unity and the On Semiconductor component achieves a 0.95 rating.

Targeting residential and commercial applications, the NCL30000 also offers the efficiency needed for certifications such as Energy Star. In fact the IC can maintain efficiency even at very light loads and can implement TRIAC dimming to less than 2% of full light output.

Infineon also introduced a dimming capable IC at APEC. The company claims that the ICL8001G achieves 90% overall efficiency and a PFC rating of greater than 0.98. Moreover, the IC maintains efficiency of over 80% across the entire dimming range.

The Infineon IC targets residential applications including 40W to 100W incandescent bulb replacement. The AC-driven IC includes digital soft-start capability to limit in-rush current as well short-circuit, over-voltage, and over-temperature protection.

The Fairchild offerings include the FSEZ1307, FSEZ1317, and FAN103 PWM drivers. All of the products use primary-side regulation (PSR) techniques that don't require feedback from the secondary side of the supply. The constant-current drivers dissipate only 30 mW of standby power and achieve efficiency levels needed for Energy Star compliance.

Stay tuned for more APEC news later in the week.