General Description

The MAX3766 is a complete, easy-to-program laser driver for fiber optic LAN transmitters, optimized for operation at 622Mbps. It includes a laser modulator, automatic power control (APC), and a failure indicator with latched shutdown.

Laser modulation current can be programmed up to 60mA at 622Mbps. A programmable modulation temperature coefficient can be used to keep the transmitted extinction ratio nearly constant over a wide temperature range. The modulator operates at data rates up to 1.25Gbps at reduced modulation current. APC circuitry uses feedback from the laser’s monitor photodiode to adjust the laser bias current, producing constant output power regardless of laser temperature or age. The MAX3766 supports laser bias currents up to 80mA.

The MAX3766 provides extensive laser safety features, including a failure indicator with latched shutdown and a smooth start-up bias generator. These features help ensure that the transmitter output does not reach hazardous levels. The MAX3766 is available in a compact 20-pin QSOP and dice.

Applications

622Mbps ATM Transmitters

1.25Gbps Fiber Optic LAN Transmitters

1.25Gbps Ethernet Transmitters

Features

♦ 60mA Modulation Current

♦ 80mA Bias Current

♦ 200ps Edge Speed

♦ Modulation-Current Temperature Compensation

♦ Automatic Power Control

♦ Laser-Fail Indicator with Latched Shutdown

♦ Smooth Laser Start-Up