Laser Diode Driver with Waveform Generator

The EL6900 is a highly integrated laser diode driver designed to support Blu-Ray writable optical drives. It accomplishes this by incorporating a waveform generator wherein the diode currents and timing details can be programmed before operation. The data input circuitry inspects the NRZ serial data waveform and generates programmed waveforms in recognition of 2, 3, 4, or 5 or more clock periods of space changing to 2, 3, 4, or 5 or more clock periods of mark, and vice versa. The part also has an IV amplifier with concurrent read and write sampling. The gains of the IV amplifier are programmable, eliminating the need for external potentiometers.

Features
• Complete programmable laser diode driver
• 350mA maximum total output
• 8-bit x 8-bit multiplying DAC output provides 8-bit full scale
   adjustment and 8-bit resolution at any full scale output
• 120ps timer resolution
• Blu-Ray Disc standard
• Two analog inputs support slope and read APC
• HFM oscillator programmable to 100mAP-P from 100MHz
   to 500MHz
• PLL allows reduced-frequency clock on flex cable
• Separate serial input works up to 25MHz
• Dual sampled IV amplifier with programmable sample
   select and gain select
• Programmable HFM offset when HFM is off

Applications
• Blu-Ray ultra-density optical (UDO) drives
• Blu-Ray consumer HDTV video recorders