Milpitas, Calif. - Elantec Semiconductor Inc. has developed its EL6250C laser driver specifically for the new breed of violet/blue laser diodes, which are expected to dramatically increase data storage capability in compact-disk and CD-ROM devices, and in rewritable technologies such as HDTV-capable DVD. The part is now sampling.

Red-laser technology, used in DVD disks, currently limits the storage capacity available to developers. A DVD can hold about 4.7 Gbytes, but next-generation optical storage systems using blue-laser diodes will be able to store approximately 20 Gbytes, which is enough for a two-hour HDTV movie or four regular DVD movies. Similarly, where a CD can store 650 Mbytes, blue-laser technology can stuff the content of nearly 100 CDs into the space of a single disk.

The greater density results from a blue laser's shorter wavelength-approximately 440 nanometers, compared with 780 to 850 nm for infrared and 635 to 670 nm for red lasers. The shorter wavelength creates a more concentrated beam of light that can focus to a smaller spot, said Steve Sacarisen, director of strategic marketing for Elantec's Optical Products Group. Therefore, it can store and read more information.

Elantec's blue-laser driver operates from two discrete supply voltages. The internal logic runs from a 5-V supply, while the blue-laser diode's 5-V threshold requires the output stage to run at greater than 6 V.

"Having two supply voltages allows the EL6250C to minimize power consumption while driving the blue laser," said Sacarisen. "Also, our driver integrates the write channels needed for the read, erase, bias and write laser-drive power levels, along with a high-frequency modulator oscillator with high-speed laser-driver output. This reduces the component count, which reduces production costs, shortens signal routing to save design time and saves board space to enable compact optical-pickup-unit designs."

Packaged in a 24-pin QSOP, the EL6250C is priced at $3.60 in quantities of 10,000.

Call (888) ELANTEC (352-6832)
www.elantec.com
EETInfo No. 613