Electronic Design

Blue Laser Driver Handles High-Capacity Blu-Ray Disc DVD Standard

The EL6900C is the world's first laser driver designed specifically for the new Blu-Ray Disc industry-standard disc-recording format.

The complete laser diode driver includes a two-channel sample and hold that can be programmed for four separate gains under register control. Each channel's 8- by 8-bit multiplying digital-to-analog (DAC) output provides 8-bit full-scale adjustment and 8-bit resolution at any full-scale output. The parts eliminate the need for an external driver by integrating the high-current output that directly drives current into the blue-violet laser.

The EL6900C enables up to 3× Blu-Ray Disc write performance through each channel's 210-MHz clock speed. Closed-loop automatic power control is supported with the EL6900's additional Islope and IAPC inputs. A digital serial bus makes it easy to program the internal command and data registers.

The programmable driver has the Blu-Ray Disc standard write-strategy waveforms integrated into its high-speed waveform generator. This eliminates the need to drive high-speed timing signals and the critical accuracy write-current power levels over the flex cable. A phase-locked loop permits a reduced clock frequency on flex cable. The various driving signals are programmed digitally and converted internally to the analog output to drive the laser. Multilevel programmability increases the write operation's fidelity.

The driver can handle programmable amplitude and frequency modulation. It has 120-ps timer resolution and a high-frequency modulator oscillator programmable to 100 mA p-p from 100 to 500 MHz. The serial data input works up to 25 MHz. Output driver functions include a programmable laser slope compensation DAC and programmable laser threshold current DAC to match the drive to the laser diode requirements. The EL6900 also has a low-noise read amplifier and dual sampled I/V amplifier with programmable sample select and gain select.

The Blu-Ray Disc standard is the next-generation recording technology beyond DVD. It dramatically increases recording density by using a 405-nm blue-violet laser, compared to the conventional 650-nm red laser used in today's DVD technology. The shorter wavelength allows a smaller spot size and track pitch to be recorded on the disc, increasing storage density from 4.7 to 27 Gbytes on a one-side disc.

The Blu-Ray Disc format is targeting a variety of applications, including PC archival data storage Ultra Density Optical (UDO) drives and consumer digital video recorders (DVRs) to record up to two hours of high-definition television (HDTV) on one 120-mm DVD/CD-size disc. The EL6900C is available now in a 38-pin leadless plastic package. Each IC costs $5.00 in 10,000-unit quantities.

Intersil Inc., (888) 468-3774; www.intersil.com.

TAGS: Intersil
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