GENERAL DESCRIPTION

Like the ADN2870, the ADN28721 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, 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.

FEATURES

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

Laser FAIL alarm and automatic laser shutdown (ALS)

Bias and modulation current monitoring

3.3 V operation

4 mm × 4 mm LFCSP

Voltage setpoint control

Resistor setpoint control

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