3.3 V, 50 Mbps to 4.25 Gbps,
Single-Loop, Laser Diode Driver
ADN2871
Data Sheet
FEATURES
GENERAL DESCRIPTION
SFP/SFF and SFF-8472 MSA-compliant
SFP reference design available
50 Mbps to 4.25 Gbps operation
Automatic average power control
Typical 60 ps rise/fall time
VCSEL, DFB, and FP laser support
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 supply
4 mm × 4 mm LFCSP
Voltage setpoint control
Resistor setpoint control
Pin-compatible with ADN2870
The ADN2871 laser diode driver (LDD) is designed for advanced
SFP and SFF modules, using SFF-8472 digital diagnostics. The
ADN2871 supports operation from 50 Mbps up to 4.25 Gbps.
Average power and extinction ratios 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 device
provides bias and modulation current monitoring, as well as
fail alarms and automatic laser shutdown (ALS). The device
interfaces easily with the Analog Devices, Inc., ADuC7019 and
ADuC7020 family of MicroConverter® devices and with the
ADN2890, ADN2891, and ADN2892 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 the same design to work with either device. For
dual-loop control 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.
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
Figure 1 shows an application diagram of the voltage setpoint
control with single-ended laser interface. Figure 36 shows a
differential-ended laser interface.
APPLICATIONS DIAGRAM
VCC
VCC
VCC
Tx_DISABLE
VCC
L
Tx_FAULT
VCC
FAIL
ALS
IMODN
LASER
R
MPD
IMODP
DATAP
PAVSET
ANALOG DEVICES
MICROCONTROLLER
PAVREF
DAC
×100
1kΩ
RZ
CCBIAS
IMOD
GND ERREF
ERSET
ADN2871
1kΩ
GND
IBMON
IMMON
VCC GND
PAVCAP
NC
GND
1kΩ
GND
470Ω
GND
05228-001
DAC
VCC
IBIAS
RPAV
ADC
DATAN
100Ω
CONTROL
Figure 1. Typical Application Setup
Rev. D
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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 ©2005–2020 Analog Devices, Inc. All rights reserved.
Technical Support
www.analog.com
ADN2871
Data Sheet
TABLE OF CONTENTS
Features .............................................................................................. 1
Theory of Operation ...................................................................... 13
Applications ...................................................................................... 1
Laser Control .............................................................................. 13
General Description ......................................................................... 1
Control Methods ........................................................................ 13
Applications Diagram ...................................................................... 1
Voltage Setpoint Calibration .................................................... 13
Revision History ............................................................................... 2
Resistor Setpoint Calibration ................................................... 15
Specifications .................................................................................... 3
IMPD Monitoring .......................................................................... 15
SFP Timing Specifications .............................................................. 5
Loop Bandwidth Selection ........................................................ 16
Absolute Maximum Ratings ........................................................... 6
Power Consumption .................................................................. 16
ESD Caution.................................................................................. 6
Automatic Laser Shutdown (Tx_Disable) .............................. 16
Pin Configuration and Function Descriptions ............................ 7
Bias and Modulation Monitor Currents ................................. 16
Typical Performance Characteristics ............................................. 8
Data Inputs.................................................................................. 17
Single-Ended Output ................................................................... 8
Laser Diode Interfacing ............................................................. 17
Differential Output ...................................................................... 9
Alarms.......................................................................................... 18
Performance Characteristics..................................................... 10
Outline Dimensions ....................................................................... 19
Optical Waveforms ........................................................................ 12
Ordering Guide .......................................................................... 19
REVISION HISTORY
10/2017—Rev. B to Rev. C
Changes to Figure 6.......................................................................... 7
Updated Outline Dimensions ....................................................... 19
Changes to Ordering Guide .......................................................... 19
Changes to Resistor Setpoint Calibration Section, Power-On
Sequence in Resistor Setpoint Mode Section, IMPD Monitoring
Section, Voltage Setpoint Section, and Method 2: Measuring
IMPD Across a Sense Resistor Section ................................................. 15
Changes to Loop Bandwidth Selection Section, Power
Consumption Section, and Bias and Modulation Monitor
Currents Section ..................................................................................... 16
Changes to Laser Diode Interfacing Section ................................... 17
Updated Outline Dimensions ...................................................... 19
Changes to Ordering Guide .......................................................... 19
1/2017—Rev. A to Rev. B
Changes to Features Section, General Description Section,
and Figure 1 Caption ................................................................................ 1
Added Applications Diagram Section ................................................... 1
Changes to Input Voltage Swing (Differential) Parameter,
Table 1 ......................................................................................................... 3
Change to ICC Parameter, Table 1 .......................................................... 4
Changes to Table 2 .................................................................................... 5
Deleted LFCSP Parameter, Table 3 ........................................................ 6
Changes to Figure 6 and Table 4 ............................................................ 7
Moved Optical Waveforms Section ............................................. 12
Changes to Voltage Setpoint Calibration Section and
Power-On Sequence in Voltage Setpoint Mode Section ............ 13
2/2007—Rev. 0 to Rev. A
Changes to Figure 1 ..........................................................................1
Changes to Table 3 ............................................................................6
Changes to Table 4 ............................................................................7
Changes to Figure 29 and Figure 30 ............................................ 14
Changes to Resistor Setpoint Calibration Section, Figure 32,
and Figure 33 .................................................................................. 15
Inserted Power-On Sequence in Resistor Setpoint
Mode Section .................................................................................. 15
Changes to Loop Bandwidth Selection Section ......................... 16
Changes to Laser Diode Interfacing Section, Figure 35, and
Figure 36 .......................................................................................... 17
Changes to Table 6 ......................................................................... 18
9/2020—Rev. C to Rev. D
Changed CP-24-2 to CP-24-14.................................... Throughout
Changes to Figure 6.......................................................................... 7
Updated Outline Dimensions ....................................................... 19
Changes to Ordering Guide .......................................................... 19
6/2005—Revision 0: Initial Version
Rev. D | Page 2 of 19
Data Sheet
ADN2871
SPECIFICATIONS
VCC = 3.0 V to 3.6 V. All specifications TMIN to TMAX1, unless otherwise noted. Typical values as specified at 25°C.
Table 1.
Parameter
LASER BIAS CURRENT (IBIAS)
Output Current (IBIAS)
Compliance Voltage
IBIAS when ALS is High
MODULATION CURRENT (IMODP, IMODN)2
Output Current (IMOD)
Compliance Voltage
IMOD when ALS is High
Rise Time, Single-Ended Output2, 3
Fall Time, Single-Ended Output2, 3
Random Jitter, Single-Ended Output2, 3
Deterministic Jitter, Single-Ended Output3, 4
Pulse-Width Distortion, Single-Ended Output2, 3
Rise Time, Differential Output3, 5
Fall Time, Differential Output3, 5
Random Jitter, Differential Output3, 5
Deterministic Jitter, Differential Output3, 6
Pulse-Width Distortion, Differential Output3, 5
Rise Time, Differential Output3, 5
Fall Time, Differential Output3, 5
Random Jitter, Differential Output3, 5
Deterministic Jitter, Differential Output3, 7
Pulse-Width Distortion, Differential Output3, 5
AVERAGE POWER SET (PAVSET)
Pin Capacitance
Voltage
Photodiode Monitor Current (Average Current)
EXTINCTION RATIO SET INPUT (ERSET)
Resistance Range
AVERAGE POWER REFERENCE VOLTAGE INPUT (PAVREF)
Voltage Range
Photodiode Monitor Current (Average Current)
EXTINCTION RATIO REFERENCE VOLTAGE INPUT (ERREF)
Voltage Range
ERREF Voltage to IMOD Gain
DATA INPUTS (DATAP, DATAN)8
Input Voltage Swing (Differential)
Input Impedance (Single-Ended)
LOGIC INPUTS (ALS)
VIH
VIL
Min
Typ
Max
Unit
2
1.2
100
VCC
0.1
mA
V
mA
5
1.5
90
VCC
0.1
104
96
1.1
35
30
mA
V
mA
ps
ps
ps (rms)
ps
ps
ps
ps
ps (rms)
ps
ps
ps
ps
ps (rms)
ps
ps
5 mA < IMOD < 90 mA
5 mA < IMOD < 90 mA
5 mA < IMOD < 90 mA
5 mA < IMOD < 90 mA
20 mA < IMOD < 90 mA
20 mA < IMOD < 90 mA
5 mA < IMOD < 30 mA
5 mA < IMOD < 30 mA
5 mA < IMOD < 30 mA
5 mA < IMOD < 30 mA
5 mA < IMOD < 30 mA
5 mA < IMOD < 90 mA
5 mA < IMOD < 90 mA
5 mA < IMOD < 90 mA
5 mA < IMOD < 90 mA
5 mA < IMOD < 90 mA
80
1.3
1200
pF
V
μA
Resistor setpoint mode
25
1.01
kΩ
kΩ
Resistor setpoint mode
Voltage setpoint mode
0.07
1
V
70
1000
μA
Voltage setpoint mode
(RPAV fixed at 1 kΩ)
Voltage setpoint mode
(RPAV fixed at 1 kΩ)
0.05
0.9
V
60
60
0.8
19
21
47.1
46
0.64
12
2.1
56
55
0.61
17
1.6
1.1
50
1.5
0.99
1.2
1
100
0.4
Voltage setpoint mode
(RERSET fixed at 1 kΩ)
mA/V
2.4
50
2
0.8
Rev. D | Page 3 of 19
Test Conditions/Comments
V p-p
Ω
V
V
AC-coupled
ADN2871
Data Sheet
Parameter
ALARM OUTPUT (FAIL)9
VOFF
Min
Typ
VON
IBMON/IMMON DIVISION RATIO
IBIAS/IBMON3
IBIAS/IBMON3
IBIAS/IBMON3
IBIAS/IBMON Stability3, 10
IMOD/IMMON
IBMON Compliance Voltage
SUPPLY
ICC11
VCC (with Respect to GND)12
76
85
92
Unit
Test Conditions/Comments
>1.8
V
1.2 V typical (±10% tolerance)
Alarm if > threshold (typical threshold: 1.5 V to 2.1 V)
Alarm if shorted to VCC (the alarm is valid for
voltage setting mode only)
Undervoltage or Short to GND Condition
Ignore
Alarm, if < threshold (typical threshold: 0.6 V to 1.1 V)
Ignore
Ignore
Alarm, if shorted to GND
Table 6. ADN2871 Response to Various Single-Point Faults in AC-Coupled Configuration (as shown in Figure 35)
Pin
CCBIAS
PAVSET
PAVREF
Short to VCC
Fault state occurs
Fault state occurs
Voltage mode: Fault state occurs
Resistor mode: Tied to VCC
Short to GND
Fault state occurs
Fault state occurs
Fault state occurs
RPAV
Voltage mode: Fault state occurs
Resistor mode: Tied to VCC
Fault state occurs
PAVCAP
DATAP
DATAN
ALS
ERSET
IMMON
ERREF
Fault state occurs
Does not increase laser average power
Does not increase laser average power
Output currents shut off
Does not increase laser average power
Does not affect laser power
Voltage mode: Fault state occurs
IBMON
FAIL
IMODP
IMODN
IBIAS
Resistor mode: Tied to VCC
Fault state occurs
Fault state occurs
Does not increase laser average power
Does not increase laser average power
Fault state occurs
Fault state occurs
Does not increase laser average power
Does not increase laser average power
Normal currents
Does not increase laser average power
Does not increase laser average power
Voltage mode: Does not increase
average power
Resistor mode: Fault state occurs
Does not increase laser average power
Does not increase laser average power
Does not increase laser average power
Does not increase laser average power
Fault state occurs
Rev. D | Page 18 of 19
Open
Does not increase laser average power
Fault state occurs
Fault state occurs
Circuit designed to tie to VCC in resistor
setting mode, so no open case
Voltage mode: Fault state occurs
Resistor mode: Does not increase
average power
Fault state occurs
Does not increase laser average power
Does not increase laser average power
Output currents shut off
Does not increase laser average power
Does not increase laser average power
Does not increase laser average power
Does not increase laser average power
Does not increase laser average power
Does not increase laser average power
Does not increase laser power
Fault state occurs
Data Sheet
ADN2871
OUTLINE DIMENSIONS
DETAIL A
(JEDEC 95)
4.10
4.00 SQ
3.90
1
0.50
BSC
2.44
2.30 SQ
2.16
EXPOSED
PAD
13
TOP VIEW
0.80
0.75
0.70
SIDE VIEW
PKG-003994/5111
SEATING
PLANE
0.50
0.40
0.30
P IN 1
IN D IC ATO R AR E A OP T IO N S
(SEE DETAIL A)
24
19
18
6
12
7
BOTTOM VIEW
0.05 MAX
0.02 NOM
COPLANARITY
0.08
0.203 REF
0.20 MIN
FOR PROPER CONNECTION OF
THE EXPOSED PAD, REFER TO
THE PIN CONFIGURATION AND
FUNCTION DESCRIPTIONS
SECTION OF THIS DATA SHEET.
COMPLIANT TO JEDEC STANDARDS MO-220-WGGD-8
09-07-2018-B
PIN 1
INDICATOR
AREA
0.30
0.25
0.20
Figure 38. 24-Lead Lead Frame Chip Scale Package [LFCSP]
4 mm × 4 mm Body and 0.75 mm Package Height
(CP-24-14)
Dimensions shown in millimeters
ORDERING GUIDE
Model1
ADN2871ACPZ
ADN2871ACPZ-RL7
1
Temperature Range
−40°C to +85°C
−40°C to +85°C
Package Description
24-Lead Lead Frame Chip Scale Package [LFCSP]
24-Lead Lead Frame Chip Scale Package [LFCSP]
Z = RoHS Compliant Part.
©2005–2020 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D05228-9/20(D)
Rev. D | Page 19 of 19
Package Option
CP-24-14
CP-24-14