SFP/SFF and SFF-8472 MSA-compliant
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 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
Pin-compatible with ADN2870
1×/2×/4× Fibre Channel SFP/SFF modules
Multirate OC3 to OC48-FEC SFP/SFF modules
DWDM/CWDM SFP modules
1GE SFP/SFF transceiver modules
VCSEL, DFB, and FP transmitters
3.3 V, 50 Mbps to 4.25 Gbps
Single-Loop Laser Diode Driver
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 ADuC70xx family of micro-
converters and with the ADN289x family of limiting amplifiers
to make a complete SFP/SFF transceiver solution. An SFP
reference design is available. The product is pin-compatible 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.
IMMON PAVCAP NC
Figure 1. Application Diagram of Voltage Setpoint Control with Single-Ended Laser Interface
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