Currently, red laser technology, in the form of the DVD disk, represents the limits of density available to developers. In future-generation optical storage systems using blue laser diodes, the amount of information stored on a given area of a disk's surface will be three or four times greater than that written by the red laser beams. The breakthrough in blue laser technology has far-reaching implications for both the size and storage capacity of applications in the PC, VCR, camcorder, PDA, set-top box and video game markets.
Currently, a DVD can hold about 4.7 gigabytes. Writing with a blue laser will increase that amount to approximately 20 gigabytes. That is sufficient storage to record one full two-hour HDTV movie or four regular DVD movies. The current format CD can store 650 megabytes of information. If the compact disk is double-sided, and dual level, the blue laser can pack into the same space the equivalent of nearly 100 CDs written with an infrared laser. This new high-density technology is expected to expand the consumer and PC applications for the small form factor disks in as well.
The main reason the blue laser has been such a sought after technology is due to the size of its wavelength. Compared with today's lasers, which typically use infrared light (780 to 850 nanometers) or red light (635 to 670 nanometers), blue lasers operate at a shorter wavelength (approximately 400 nanometers). Having a shorter wavelength creates a more concentrated beam of light that can focus to a smaller spot size, and therefore, is able to store and read much more information on the same size compact disk.
A key feature of the EL6250C blue laser driver is that it operates from two discrete supply voltages. The internal logic operates from +5V supply, while the blue laser diode threshold of +5V requires the output stage to run at greater than +6V. Having two supply voltages allows the EL6250C to minimize power consumption while driving the blue laser. In addition the EL6250C integrates the current channels needed for the read, erase, bias and write laser drive power levels, along with a high frequency modulator (HFM) oscillator with high-speed laser driver output. This high level of integration reduces component count, which reduces production costs, shortens signal routing to save design time, and saves board space to enable compact optical pick up unit (OPU) designs.
The EL6250C in a 24-pin QSOP package is priced at $3.60 in 10,000-piece quantities and samples are available now..." NULL