3.3 V Dual-Loop, 50 Mbps to 3.3 Gbps Laser Diode Driver

Like the ADN2870, the ADN2872 laser diode driver is designed for advanced SFP and SFF modules, using SFF-8472 digital diagnostics. The device features dual-loop control of the average power and extinction ratio (ER), which automatically compensates for variations in laser characteristics over temperature and aging. The laser needs only be calibrated at 25°C, eliminating the need for expensive and time consuming temperature calibration. The ADN2872 supports single-rate operation from 50 Mbps to 3.3 Gbps, or multirate operation from 155 Mbps to 3.3 Gbps. With a new alarm scheme, this device avoids the shutdown issue caused by the system transient generated from various lasers.

The average power and ER can be set with a voltage provided by a microcontroller digital-to-analog converter (DAC) or by a trimmable resistor. The device provides both bias and modulation current monitoring, as well as fail alarms and automatic laser shutdown. The ADN2872, a SFF-/SFP-compliant laser diode driver, can work with the Analog Devices, Inc., ADuC7019, ADuC7020, and ADuC7023 MicroConverter® family and the ADN2890, ADN2891, and ADN2892 limiting amplifier family, to form a complete SFP/SFF transceiver solution. The ADN2872 is available in a space-saving 4 mm × 4 mm LFCSP specified over the −40°C to +85°C temperature range.

APPLICATIONS

* Multirate OC3 to OC48-FEC SFP/SFF modules

* 1×/2×/4× Fibre Channel SFP/SFF modules

* LX-4 modules

* DWDM/CWDM SFP modules

* 1GE SFP/SFF transceiver modules

* SFP/SFF and SFF-8472 MSA compliant

* SFP reference design available

* Any rate from 50 Mbps to 3.3 Gbps operation

* Dual-loop control of average power and extinction ratio

* Typical rise/fall time: 60 ps

* Bias current range: 2 mA to 100 mA

* Modulation current range: 5 mA to 90 mA