Laser Diode Driver with Serial Control and Write Current DAC

The ISL58781 is a highly integrated laser diode driver designed to support multi-standard writable optical drives in CD, DVD, and Blu-Ray at various speeds. It is a ‘hybrid’ part having an interface compatible with a conventional LDD, but an internal architecture similar to a write strategy LDD. This combination adds versatility to the conventional interface. The rise and fall times and overshoot of the blue output are adjustable to compensate for high and low resistance lasers. There are two banks of write currents with a bank select line, BSEL. This eliminates the need to synchronize the serial port to the media. The oscillator can be controlled by external LVDS lines, or internally activated through program assignment to any WEN state. The WEN lines have internal 100Ω terminators. There is a skew detector on the WEN receiver outputs. The ISL58781 requires a single 5V supply.