EVAL-ADN2525-OP_15 [ADI]
Optical Evaluation Kit for the ADN2525;
| 型号： | EVAL-ADN2525-OP_15 |
| 厂家： | 
ADI |
| 描述： | Optical Evaluation Kit for the ADN2525 |
| 文件： | 总8页 (文件大小：553K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Optical Evaluation Kit for the ADN2525
EVAL-ADN2525-NT/ADN2525-OP
GENERAL DESCRIPTION
The power supply must be able to deliver 400 mA at 3.3 V. The
amplitude of the data signal from the pattern generator must be
This data sheet describes the optical evaluation kit for the
ADN2525, a 10 Gbps, active back-termination, differential
laser diode driver. The differential configuration of the output
stage combined with on-chip active back-termination ensures
high quality eye diagrams at lower power consumption compared
with traditional approaches on 10 Gbps laser diode drivers.
Complete specifications can be found in the ADN2525 data
sheet available from Analog Devices, Inc., and should be
consulted in conjunction with this data sheet when using the
evaluation board. The EVAL-ADN2525-OP evaluation kit
consists of an evaluation board that provides optical evaluation
of the ADN2525 with an Opnext 10 Gbps 1310 nm TOSA
(LD5033SMDL). The EVAL-ADN2525-NT evaluation kit
consists of the same evaluation board without a TOSA attached.
adjusted to within the ADN2525 data sheet specifications for
data inputs, typically 1 V peak-to-peak differential (500 mV
single-ended on DATAP and DATAN). The oscilloscope/digital
communications analyzer must have a 1310 nm optical channel
that can accept and display properly the optical signals generated by
the TOSA.
The coaxial cables used to connect the pattern generator to the
evaluation board DATAP/DATAN inputs must be suitable for
carrying 10 Gbps signals without significant reduction of
rise/fall time or introduction of pattern jitter. They should also
be a matched pair with a delay skew of ≤2 ps. An example of
suitable cables is the 60 cm Lab-Flex® 160 cables with 2.4 mm
connectors from Florida RF Labs.
To evaluate the performance of the ADN2525, the board must
be connected to the test setup as shown in Figure 1. A fiber
patch cord with an appropriate connector for the TOSA end is
required to connect the TOSA to the oscilloscope.
Z
= 50Ω
0
TRIGGER OUT
TRIGGER IN
OPTICAL
FIBER
Z
= 50Ω
= 50Ω
J6
J5
DATA
0
ADN2525
OPTICAL
EVALUATION
BOARD
PATTERN
GENERATOR
OSCILLOSCOPE/
DIGITAL
COMMUNICATIONS
Z
DATA
0
TOSA
ANALYZER
J2
J4
J1
POWER SUPPLY
0V TO 1.2V/2mA
POWER SUPPLY
3.3V/400mA
POWER SUPPLY
0V TO 1.2V/2mA
BSET
VCC
MSET
Figure 1. ADN2525 Optical Evaluation Board Test Setup
Rev. 0
Evaluation boards are only intended for device evaluation and not for production purposes.
Evaluation boards are supplied “as is” and without warranties of any kind, express, implied, or
statutory including, but not limited to, any implied warranty of merchantability or fitness for a
particular purpose. No license is granted by implication or otherwise under any patents or other
intellectual property by application or use of evaluation boards. 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. Analog Devices reserves the right to change devices or specifications at any time
without notice. Trademarks and registered trademarks are the property of their respective owners.
Evaluation boards are not authorized to be used in life support devices or systems.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
Fax: 781.461.3113
www.analog.com
©2007 Analog Devices, Inc. All rights reserved.
EVAL-ADN2525-NT/ADN2525-OP
TABLE OF CONTENTS
General Description......................................................................... 1
Using the Evaluation Board PCB Layout in an Optical
Transmitter design. .......................................................................5
Revision History ............................................................................... 2
Evaluation Board Hardware............................................................ 3
Connectors .................................................................................... 3
Terminals....................................................................................... 3
Jumpers .......................................................................................... 3
Quick Start for Optical Evaluation............................................. 4
Evaluation Board Schematics and Artwork...................................6
Ordering Information.......................................................................8
Bill of Materials..............................................................................8
Ordering Guide .............................................................................8
ESD Caution...................................................................................8
REVISION HISTORY
7/07—Revision 0: Initial Version
Rev. 0 | Page 2 of 8
EVAL-ADN2525-NT/ADN2525-OP
EVALUATION BOARD HARDWARE
CONNECTORS
TOP LAYER
6
5
4
3
2
1
The ADN2525 is capable of delivering an 80 mA differential
modulation current and 100 mA bias current. Applying dc
voltages to the ADN2525 BSET and MSET pins sets the bias
and modulation currents. The board is set up so that the
outputs of the ADN2525 are ac-coupled to the TOSA. The
board is fitted with connectors that allow the user to connect
the evaluation board to the test setup. Table 1 describes the
name and function of each connector on the board.
BOTTOM LAYER
Figure 2. Pinout of TOSA Footprint on PCB
(Looking Toward the Edge of the Board Cross Section)
For additional optical eye diagram performance data and for
information on optimizing the performance of the evaluation
board for different TOSAs, contact a local Analog Devices
representative.
Table 1. Connector Description
Connector Description
J1
J2
J3
Allows the user to apply an external dc voltage
source to control the differential modulation
current provided by the ADN2525.
Allows the user to apply an external dc voltage
source to control the bias current provided by the
ADN2525.
Automatic Laser Shutdown. Allows the user to
enable/disable the bias and modulation current by
applying a low/high logic level (not greater than
VCC).
JUMPERS
Automatic laser shutdown is configurable, driven either by
voltages generated on the board or by external voltages as
described in Table 3.
Table 3. Jumper Configurations
Jumper
Jumper Setting
Configuration Description
J4
J5
J6
J9
Power Supply Connector. The board supply
voltage is 3.3 V with respect to GND.
Negative data input. A PECL/CML data signal
should be applied.
Positive Data Input. A PECL/CML data signal
should be applied.
25 Ω Test Transmission Line.
P4
A
Enables the bias and differential
modulation currents.
B
Disables the bias and differential
modulation currents.
Removed
Allows the user to enable/disable the
bias and differential modulation
currents by applying a low/high logic
level to J3 from an external source.
TERMINALS
The evaluation board accommodates the terminal assignment
of the multisource agreement for the 10 Gbps XMD miniature
device (EVAL-ADN2525-OP).
Table 2. XMD MSA TOSA Terminal Function Definition
Terminal Number
Option 1
Option 2
1
2
3
4
5
6
PD Cathode
Signal Ground
LD Cathode
LD Anode
Signal Ground
Thermistor
PD Cathode
Signal Ground
LD Cathode
LD Anode
Signal Ground
NC
Rev. 0 | Page 3 of 8
EVAL-ADN2525-NT/ADN2525-OP
should be investigated. Less significant differences can
sometimes be attributed to one or more of the following:
a. Dirt in the fiber connectors, optical attenuators,
or oscilloscope optical input can cause errors in
average power.
b. Optical coupling can be quite variable at the TOSA
because there is no latching mechanism for the fiber
connector. By ensuring that the connector is fully
inserted and rotating, the connector can eliminate
small discrepancies in real average power.
QUICK START FOR OPTICAL EVALUATION
1. If using evaluation kit EVAL-ADN2525-NT, solder a TOSA
to the evaluation board, following soldering guidelines in
the TOSA data sheet.
2. If required, change the ALS jumper settings to obtain the
desired configuration, using Table 3.
3. Connect the evaluation board to an oscilloscope, pattern
generator, and power supplies as shown in Figure 1. A
suitable pattern generator is the Anritsu MP1763B and a
suitable oscilloscope is the Agilent 86100B with 86105C
optical plug-in. Use coaxial cables for DATAP and DATAN
of the type recommended in the General Description
section.
4. Run any applicable user calibrations on the oscilloscope
optical input.
5. Turn on the power supply (3.3 V) connected to J4. Check
that the current drawn from the 3.3 V power supply is
within the limits of the ISUPPLY specifications in the
ADN2525 data sheet.
6. Increase the voltage applied to J2 starting from 0 V until
the desired optical average power is obtained.
7. Increase the voltage applied to J1 starting from 0 V until
the desired extinction ratio is obtained.
8. To prevent damage to the TOSA, it is advisable to gradually
adjust the BSET and MSET voltages back to 0 V before
turning off the power supplies.
c. Calibration differences between the oscilloscope in the
test setup and the oscilloscope used to measure the
sample optical eye diagram can cause small
discrepancies in measured average power.
6. Confirm that the extinction ratio is close to the value
reported in the sample optical eye diagram. If the value is
significantly different, this indicates that there is a problem
with the test setup, evaluation board, or TOSA and this
should be investigated. Because the extinction ratio is a
sensitive measurement, small discrepancies can be
attributed to using different oscilloscope or optical plug-in
models or even different optical plug-ins of the same model.
7. Select the same eye mask and mask Y-alignment method as
used in the sample optical eye diagram.
8. Select the same number of waveforms for the eye diagram
capture as used in the sample optical eye diagram.
9. Confirm that the average mask margin is close to the value
reported in the sample optical eye diagram. If the value is
significantly different, this indicates that there is a problem
with the test setup, evaluation board, or TOSA and this
should be investigated. Differences can be attributed to one
or more of the following:
Using the EVAL-ADN2525-OP Evaluation Kit
When using the EVAL-ADN2525-OP evaluation kit, it is
recommended that the kit be initially set up to reproduce the
sample optical eye diagram that is included with the kit. This
confirms that the test setup is configured correctly to produce a
high quality optical eye diagram. The following steps should be
followed to reproduce the sample optical eye diagram:
a. A poor quality differential electrical eye diagram at
the output of the coaxial cables from the pattern
generator results in a poor optical eye diagram.
Measuring the electrical eye diagram on these signals
confirms or eliminates this possibility. Delay skew
>2 ps between the DATAP and DATAN signals is one
example of a degraded input signal that leads to a
degraded optical eye diagram.
b. Small discrepancies can be attributed to using
different oscilloscope or optical plug-in models or
even different optical plug-ins of the same model.
Different optical plug-in models have different
bandwidths, noise, and time-base jitter and this can
affect eye mask margin. Different optical plug-ins of
the same model can have different frequency
responses in the optical filter that is within the
allowed tolerance and this can affect eye mask margin.
c. If an optical attenuator is required to keep the eye
diagram within the oscilloscope range, an attenuation
value should be chosen that keeps the optical signal in
the upper end of the oscilloscope range. Otherwise,
the effect of oscilloscope noise on the eye mask
margin is increased.
1. Set up the board following the recommendations in the
Quick Start for Optical Evaluation section.
2. Adjust the data rate and pattern to the settings used in the
sample optical eye diagram and select the appropriate
optical filter and wavelength on the oscilloscope.
3. Adjust the BSET and MSET voltages to the settings used in
the sample optical eye diagram.
4. Confirm that the VCC supply current (ICC) and the
IBMON voltage at TP1 are close to the values reported in
the sample optical eye diagram. If either of the values is
significantly different, this indicates that there is a problem
with the test setup, evaluation board, or TOSA, and this
should be investigated.
5. Confirm that the real average power is close to the value
reported in the sample optical eye diagram. The real
average power is the average power as measured by the test
equipment plus the measured attenuation of any optical
attenuators in the optical signal path. If the value is
significantly different, this indicates that there is a problem
with the test setup, evaluation board, or TOSA, and this
Rev. 0 | Page 4 of 8
EVAL-ADN2525-NT/ADN2525-OP
affect the high frequency performance in ways that are difficult
to predict; therefore, changing them increases the risk of losing
some mask margin performance. Following this recommenda-
tion gives the highest likelihood that eye diagram performance
measured on the evaluation board is reproduced in the optical
transmitter (ignoring any performance loss contributed by
retiming or other circuitry that precedes the ADN2525). It is
possible that changing the PCB dielectric material or making
small changes to the PCB layout causes negligible degradation
in the performance or even improves the performance. How-
ever, this is difficult to predict.
USING THE EVALUATION BOARD PCB LAYOUT IN
AN OPTICAL TRANSMITTER DESIGN
The evaluation kit PCB is fabricated using FR4 (Polyclad PCL-
FR-370HR) with 4.5 mil dielectric thickness between the top-
side signal and ground layers. When using the evaluation board
PCB layout as a guide for designing an optical transmitter, it is
recommended that the same dielectric material and thickness
be used and the PCB layout associated with the ADN2525, the
ac-coupling components, and the TOSA be copied exactly. This
includes features such as component pad positions and sizes,
track widths and lengths, via sizes, and positions. These features
1.059
0.27
0.6
0.098
2.974
2.82
2.606
2.276
2.106
1.496
1.776
THERMISTOR
CASE GND
3.128
LD ANODE
LD CATHODE
CASE GND
MPD CATHODE
0.506
0.176
0.886
0
0.155
0.27
0.6
0.87
0.964
0
NOTES
1. DIMENSIONS SHOWN IN INCHES.
0.095
Figure 3. Evaluation Board Outline
Rev. 0 | Page 5 of 8
EVAL-ADN2525-NT/ADN2525-OP
EVALUATION BOARD SCHEMATICS AND ARTWORK
GND
R3
TP1
R12
GND
TP2
J2
GND
VCC
C12
VCC
TP5
VCC
GND
GND
C10
R1
L2
L1
L5
R10
R8
BSET IBMON IBIAS GND
1
PD_CATHODE
GND
VCC
C5
VCC
VCC
2
3
L6
Z
= 50Ω
T6
Z
= 50Ω
T9
Z
= 25Ω
Z = 25Ω
0
GND
0
0
0
T1
T3
C15
C14
U3
LD_CATHODE
DATAP
IMODP
IMODN
ROS
J6
GND
ADN2525
R2
GND
GND
GND
GND
3 × 3 LFCSP
C6
C3
4
5
6
EXPOSED PAD
TO GND
LD_ANODE
GND
ROS
DATAN
VCC
J5
GND
Z
= 50Ω
T7
Z = 50Ω
0
T8
Z
= 25Ω
T2
Z = 25Ω
0
0
0
GND
T4
VCC
VCC
GND
L8
L4
L7
L3
VCC
THERMISTOR
TOSA
C11
GND
MSET NC
ALS
A B
R11
R9
TP4
1
P4
C13
VCC
GND VCC
GND
VCC
C2
SMA
J4
GND
Z
= 25Ω
T5
0
C1
SMA
J9
GND GND
J3
GND
J1
R30
GND
GND
NC = NO CONNECT
Figure 4. Schematic of Generation F Evaluation Board
Figure 5. Layer 1 (Signal)
Figure 6. Layer 2 (GND)
Rev. 0 | Page 6 of 8
EVAL-ADN2525-NT/ADN2525-OP
Figure 7. Layer 3 (VCC)
Figure 9. Silkscreen Top
Figure 8. Layer 4 (Signal)
Figure 10. Silkscreen Bottom (Bottom View)
Rev. 0 | Page 7 of 8
EVAL-ADN2525-NT/ADN2525-OP
ORDERING INFORMATION
BILL OF MATERIALS
Table 4.
Qty Reference Designator
Description
Supplier/Number
2
2
2
2
4
3
2
2
4
1
1
1
1
1
1
2
4
1
1
R1, R3
R10, R11
R8, R9
C14, C15
C10, C11, C12, C13
C1, C5, C6
L6, L8
L5, L7
L1, L2, L3, L4
R2
C3
C2
P4
R12
R30
J5, J6
0 Ω, 0402 size resistor
10 Ω, 0603 size resistor
100 Ω, 0603 size resistor
1000 nF, 0402 size capacitor;
100 nF, 0402 size ceramic capacitor;
10 nF, 0402 size ceramic capacitor;
18 nH, 0402 size inductor;
0402 size ferrite
10 μH, 0805 size inductor
33 Ω, 0201 size resistor; mounted upside-down
0.1 pF, 0201 size capacitor
10 μF, Case-C tantalum capacitor
Jumper and 3-pin header
1 kΩ, 0603 size, 0.1% resistor
25 Ω, not populated
Panasonic ECJ-0EB0J105K
BC Components VJ0402V104ZXJCW1BC
BC Components VJ0402Y103KXJCW1BC
Murata LQW15AN20NJ0
Murata BLM15HG102SN1
Murata LQM21FN100M70L
Panasonic ERJ-1GEF330C
AVX 02013J0R1PBWTR
2.92 mm connector
Rosenberger
J1, J2, J3, J4
U3
TOSA (EVAL-ADN2525-OP only)
Side-launch SMA connector
10.7 Gbps differential laser diode driver
10 Gbps XMD TOSA
Analog Devices ADN2525
OpNext LD5033SMDL
ORDERING GUIDE
Model
Description
EVAL-ADN2525-OPZ1
EVAL-ADN2525-NTZ1
Optical Evaluation Board with an XMD TOSA Populated
Optical Evaluation Board Without an XMD TOSA Populated
1 Z = RoHS Compliant Part.
ESD CAUTION
©2007 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
EB06368-0-7/07(0)
Rev. 0 | Page 8 of 8
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