ADN2871 Datasheet | Analog Devices

FEATURES SFP/SFF and SFF-8472 MSA-pliant SFP reference design available 50 Mbps to 4.25 Gbps operation Automatic average power control Typical rise/fall time 60ps Supports VCSEL, DFB, and FP lasers Bias current range 2 m A to 100 m A Modulation current range 5 m A to 90 m A 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 Pin-patible with ADN2870 GENERAL DESCRIPTION The ADN2871 laser diode driver is designed for advanced SFP and SFF modules, using SFF-8472 digital diagnostics. The ADN2871 supports operation from 50 Mbps to 4.25 Gbps. Average power and extinction ratio can be set with a voltage provided by a microcontroller DAC or by a trimmable resistor or digital potentiometer. The average power control loop is implemented using feedback from a monitor photodiode. The part provides bias and modulation current monitoring as well as fail alarms and automatic laser shutdown. The device interfaces easily with the ADI ADu C70xx family of microconverters and with the ADN289x family of limiting amplifiers to make a plete SFP/SFF transceiver solution. An SFP reference design is available. The product is pin-patible with the ADN2870 dual-loop LDD, allowing one PC board layout to work with either device. For dual-loop applications, refer to the ADN2870 data sheet. The product is available in a space-saving 4 mm × 4 mm LFCSP specified over the - 40°C to +85°C temperature range. Figure 1 shows an application diagram of the voltage setpoint control with single-ended laser interface. Figure 36 shows a differential laser interface. APPLICATIONS 1×/2×/4× Fibre Channel SFP/SFF modules Multirate OC3 to OC48-FEC SFP/SFF modules LX-4 modules DWDM/CWDM SFP modules 1GE SFP/SFF transceiver modules VCSEL, DFB, and FP transmitters VCC VCC VCC VCC L VCC MPD FAIL ALS IMODN R IMODP DATAP ADI MICROCONTROLLER DAC ADC 1kΩ DAC GND ERREF ERSET 1kΩ GND IBMON VCC GND 1kΩ GND...