ADN2870(RevA) Просмотр технического описания (PDF) - Analog Devices

Номер в каталоге

Компоненты Описание

производитель

ADN2870
(Rev.:RevA)

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

Analog Devices 

3.3 V Dual-Loop, 50 Mbps to 3.3 Gbps

Laser Diode Driver

ADN2870

FEATURES

SFP/SFF MSA and SFF-8472 compliant

SFP reference design available

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

RoHS compliant

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

GENERAL DESCRIPTION

The ADN28701 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

to be calibrated at 25°C, eliminating the expensive and time

consuming temperature calibration. The ADN2870 supports

single-rate operation from 50 Mbps to 3.3 Gbps or multirate

operation from 155 Mbps to 3.3 Gbps.

Average power and extinction ratios can be set with reference

voltages provided by a microcontroller DAC or by adjustable

resistors. The ADN2870 provides bias and modulation current

monitoring as well as fail alarms and automatic laser shutdown.

The device interfaces easily with the ADuC702x family of

MicroConverters® 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 available in a

space-saving 4 mm × 4 mm LFCSP specified over the −40°C to

+85°C temperature range.

1 Protected by U.S. Patent 6,414,974.

APPLICATIONS DIAGRAM

VCC

Tx_FAULT

Tx_FAIL

VCC

MPD

FAIL

ALS

VCC

IMODN

VCC

L

R

IMODP

VCC

LASER

DATAP

ANALOG DEVICES

MICROCONTROLLER

PAVSET

DAC

PAVREF

ADC

RPAV

1kΩ

DAC

GND ERREF

1kΩ ERSET

GND

IMOD

CONTROL

IBIAS

100Ω

IBIAS

DATAN

VCC

RZ

CCBIAS

ADN2870

VCC GND

IBMON

IMMON PAVCAP ERCAP

GND

GND

1kΩ

470Ω

GND

GND

Figure 1. Application Diagram Showing Microcontroller Interface

Rev. A

Information furnished by Analog Devices is believed to be accurate and reliable. However, no

responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other

rights of third parties that may result from its use. Specifications subject to change without notice. No

license is granted by implication or otherwise under any patent or patent rights of Analog Devices.

Trademarks and registered trademarks are the property of their respective owners.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 781.329.4700

www.analog.com

Fax: 781.461.3113 ©2004–2008 Analog Devices, Inc. All rights reserved.

Share Link: