AGERE LG1625AXF

Data Sheet
June 1999
LG1625AXF Laser Driver
Features
Description
■
High data-rate laser diode/LED driver
■
Adjustable output current
■
Operation up to 3 Gbits/s
■
Single –5.2 V power supply
■
90 ps rise and fall times
The LG1625AXF is a gallium-arsenide (GaAs) laser
diode driver to be used with direct modulated laser
diodes in high-speed nonreturn-to-zero (NRZ) transmission systems. The device is made in a high-performance 0.9 µm gate GaAs heterojunction FET
technology that utilizes high-density MIM capacitors,
airbridge interconnect, and NiCr film precision resistors.
The device contains three cascaded stages, operates with a single –5.2 V power supply and accepts
ECL level inputs. Voltages control the modulated output current and laser prebias current. The
LG1625AXF is available in a 24-lead hermetic, gullwing package.
Applications
■
SONET/SDH transmission systems
■
SONET/SDH test equipment
■
Optical transmitters
A test fixture (TF1006A) with SMA connectors is
available to allow quick evaluation of the LG1625AXF.
GND
MK
MK
VPRE
VIN
LG1625AXF
IOUT
VTH
VMOD
VSS3
VSS2
VSS1
5-7865(F)
Figure 1. Functional Diagram
Data Sheet
June 1999
LG1625AXF Laser Driver
Pin Information
GND
MK MK
VMOD
VPRE
+
–
+
+
–
–
IOUT
VIN
50 Ω
25 Ω
VTH
VSS1
VSS3
VSS2
5-7866(F)
VTH
VSS1
VSS1
VMOD
VSS3
VSS2
24
23
22
21
20
19
Figure 2. LG1625AXF Die Block Diagram
VSS1
1
18
VPRE
VIN
2
17
GND
GND
3
16
IOUT
LG1625AXF
12
VSS1
MK
13
11
6
MK
VSS1
10
GND
GND
14
9
5
GND
GND
8
GND
GND
15
7
4
VTH
(OPTIONAL)
GND
5-7867(F)r.1
Note: Figure 3 is not to scale.
Figure 3. LG1625AXF Package Pinout
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Lucent Technologies Inc.
Data Sheet
June 1999
LG1625AXF Laser Driver
Pin Information (continued)
Table 1. LG1625AXF Pin Description
Pin
Symbol
Type*
1, 6, 13, 22, 23
VSS1
P
VSS1 Supply. –5.2 V power supply pin.
2
VIN
I
Data Input.
3, 4, 5, 8, 9, 10,
14, 15, 17
GND
P
Ground.
7, 24
VTH†
I
Threshold Control. Input (eye crossing).
11
MK
O
Complementary Mark Density Output.
12
MK
O
Mark Density Output.
16
IOUT
O
Output. dc couple to laser cathode.
18
VPRE
I
Prebias Control Input.
19
VSS2
P
VSS2. –5.2 V supply for output prebias.
20
VSS3
P
VSS3. –5.2 V supply for output modulation.
21
VMOD
I
Modulation Current Control Input.
Name/Definition
* I = input, O = output, P = power.
† Connection to VTH for threshold adjustment should be made through pin 24. Pin 7 is made available for additional bypassing of V TH (See
Figure 5 on page 6, Typical Test Circuit).
Absolute Maximum Ratings
Stresses in excess of the absolute maximum ratings can cause permanent or latent damage to the device. These
are absolute stress ratings only. Functional operation of the device is not implied at these or any other conditions in
excess of those given in the operational sections of this device specification. Exposure to absolute maximum ratings for extended periods can adversely affect device reliability.
Table 2. Absolute Maximum Ratings (at TA = 25 °C unless otherwise specified)
Parameter
Symbol
Min
Max
Unit
Supply Voltage
VSS
—
–5.95
V
Storage Temperature
Tstg
–40
125
Operating Case Temperature Range
TC
0
75
°C
°C
Input Voltage
VI
GND
VSS
V
Power Dissipation
PD
—
1
W
Lucent Technologies Inc.
3
Data Sheet
June 1999
LG1625AXF Laser Driver
Handling Precautions
Although protection circuitry has been designed into this device, proper precautions should be taken to avoid exposure to electrostatic discharge (ESD) during handling and mounting. Lucent employs a human-body model (HBM)
and charged-device model (CDM) for ESD-susceptibility testing and protection design evaluation. ESD voltage
thresholds are dependent on the circuit parameters used in the defined model. No industry-wide standard has
been adopted for the CDM. However, a standard HBM (resistance = 1500 Ω, capacitance = 100 pF) is widely used
and, therefore, can be used for comparison purposes. The HBM ESD threshold presented here was obtained by
using these circuit parameters.
Table 3. ESD Threshold Voltage
Human-Body Model ESD Threshold
Device
Voltage
LG1625AXF
≥200 V
Mounting and Connections
Certain precautions must be taken when using solder. For installation using a constant temperature solder, temperatures of under 300 °C may be employed for periods of time up to 5 seconds, maximum. For installation with a soldering iron (battery operated or nonswitching only), the soldering tip temperature should not be greater than 300 °C
and the soldering time for each lead must not exceed 5 seconds.
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Lucent Technologies Inc.
Data Sheet
June 1999
LG1625AXF Laser Driver
Electrical Characteristics
TA = 25 °C, VSS1 = VSS2 = VSS3 = –5.2 V, VTH = –1.3 V, VMOD = –3.4 V, RL = 25 Ω, data input = 600 mVp-p.
Minimum and Maximum values are testing requirements. Typical values are characteristics of the device and are
the result of engineering evaluations. Typical values are for information purposes only and are not part of the testing requirements. Stresses in excess of the absolute maximum ratings can cause permanent damage to the
device.
Table 4. Electrical Characteristics
Parameter
Symbol
Min
Typ
Max
Unit
Data Input Voltage
VINp-p
300
600
2000
mV
Voltage Control for Output Modulation
Current
VMOD
–5.5
—
–3.0
V
IMOD LOW
IMOD HIGH
—
55
0
65
2
—
mA
mA
VPRE
–5.5
—
–3.0
V
IPRE LOW
IPRE HIGH
—
30
0
40
0.5
—
mA
mA
TRISE
TFALL
—
—
90
90
—
—
ps
ps
VSS1, VSS2, VSS3
–4.9
–5.2
–5.5
V
ISS1
50
100
120
mA
Output Modulation Current
Minimum
Maximum*
Voltage Control for Prebias Current
Output Prebias Current
Minimum
Maximum†
Output Rise & Fall Times (20%—80%)
Rise
Fall
Power Supply Voltage
Power Supply
Current‡
* Maximum modulation at maximum VMOD
† Maximum prebias at maximum VPRE
‡ Excludes IPRE and average IMOD. Power supply current ISS2 (relating to prebias) is dependant on VPRE. Power supply current ISS3
(relating to modulation) is dependant on VMOD
HORZ.: 100 pS/DIV., VERT.: 15 mA/DIV.
5-7869(F)
Figure 4. Typical Eye Diagram of IMOD
Lucent Technologies Inc.
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Data Sheet
June 1999
LG1625AXF Laser Driver
Test Circuit
0.1 µF
500 Ω
0.1 µF
500 Ω
1000 Ω
1000 Ω
VSS –5.2 V
1000 Ω
VSS –5.2 V
MK
1000 Ω
MK
12
11
MK
18
MK
21
VPRE
0.1 µF 2
50 Ω
VIN
+
LG1625AXF
IOUT
VSS3
VSS2
0.1 µF
7
0.1 µF
0.1 µF
20 Ω
19
VSS1
VTH
0.1 µF
5000 Ω
VTH
16
IMOD
20
50 Ω
0.1 µF
24
DATA
GENERATOR
IPRE IF VPRE > –5.0 V
VMOD
1Ω
x
x
50 Ω
SCOPE
IMOD
MONITOR
20 Ω
1Ω
IPRE
MONITOR
VSS –5.2 V
Notes:
GND pins 3, 4, 5, 8, 9, 10, 14, 15, 17.
VSS1 pins 1, 6, 13, 22, 23.
5-7876(F)r.1
Figure 5. LG1625AXF Typical Test Circuit
LG1625AXF Application Notes
■
■
VSS bypass capacitors should be mounted close to the package.
5000 Ω potentiometer is typically set for 2500 Ω. This establishes an approximate –1.3 V VTH which will track
with VSS.
■
Mark density (MK and MK) outputs are terminated with 1 kΩ pull-up resistors.
■
IMOD and IPRE can be measured and used to control VMOD and VPRE.
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Lucent Technologies Inc.
Data Sheet
June 1999
LG1625AXF Laser Driver
Typical Performance Characteristics
0 °C
25 °C
50 °C
75 °C
VSS = –5.95 V
100
VSS = –5.20 V
VSS =
–5.95 V
VSS =
–5.20 V
VSS = –4.45 V
80
–––IMOD (mA) or ---IPRE (mA)
VSS =
–4.45 V
60
VSS = –5.95 V
40
VSS = –5.20 V
VSS = –4.45 V
20
0
–5.0
–4.5
–4.0
–3.5
–3.0
–2.5
VMOD (V) OR VPRE (V)
5-7870(F)r.1
Figure 6. Output Modulation Current IMOD vs. the External Control Voltage VMOD
or Output Prebias Current IPRE vs. the External Control Voltage VPRE
Lucent Technologies Inc.
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Data Sheet
June 1999
LG1625AXF Laser Driver
Typical Performance Characteristics (continued)
TRISE OR TFALL (ps)
100
80
75 °C
50 °C
25 °C
0 °C
60
40
–6.0
–5.5
–5.0
–4.5
–4.0
VSS (V)
5-7871(F)
Figure 7. Typical TRISE or TFALL vs. VSS for IMOD = 40 mA
–550
75 °C
50 °C
25 °C
0 °C
MK or MK (mV)
–600
–650
–700
–750
–6.0
–5.5
–5.0
–4.5
VSS (V)
5-7872(F)
Figure 8. Typical MK or MK vs. VSS for IMOD = 40 mA
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Lucent Technologies Inc.
Data Sheet
June 1999
LG1625AXF Laser Driver
Outline Diagram
24-Pin, Gull-Wing, Surface-Mount Package
Dimensions are in inches. Tolerance is ±0.005 inches unless otherwise noted.
0.364 SQ.
0.260
0.050
0.010
BEFORE
SOLDER
DIP
1
0.012
LUCENT
1625AXF
XXXXXX
0.604
±0.015 TYP.
R0.010
0.065
0.074
0.008
BEFORE
SOLDER
DIP
5-7875(F)r.2
Ordering Information
Device
Type
Comcode (Ordering Number)
LG1625AXF
24-Lead Gull Wing
107529067
TF1006A
Test Fixture
106733371
Lucent Technologies Inc.
9
Data Sheet
June 1999
LG1625AXF Laser Driver
Appendix
The test fixture mentioned in the data sheet is sold separately and is described in detail below.
5-7868(F)
Figure 9. TF1006A Test Fixture
TF1006A Test Fixture Features
■
SMA connectors
■
Easy package placement
■
Good RF performance
Test Fixture Functional Description
The TF1006A test fixture is used to characterize 24-lead gullwing packages for high-speed fiber-optic communications. The fixture is a metallized substrate (PTFE filled material) fastened to a brass base. The package leads make
contact to the microstrip lines on the fixture through use of a pressure ring and two thumb screws.
Three RF connectors are provided for connections to the input and outputs. BNC connectors are provided on soldered leads for dc bias lines.
The TF1006A is preassembled and fully tested prior to shipment.
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Lucent Technologies Inc.
Data Sheet
June 1999
LG1625AXF Laser Driver
Appendix (continued)
Test Fixture Functional Description (continued)
FIXTURE BOUNDARY
PACKAGE OUTLINE
VSS1
VIN
0.01 µF
0.01 µF
6
5
4
3
2
1
0.01 µF
VSS1
24
0.01 µF
VTH
0.01 µF
VSS1
21
0.01 µF
VMOD
20
0.01 µF
VSS3
8
9
23
22
10
MK
11
MK
12
13
14
15
16
17
18
19
VSS2
0.01 µF
VSS1
GND
100 Ω
100 Ω
100 Ω
100 Ω
0.01 µF
IOUT
VPRE
5-7873(F)
Figure 10. TF1006A Electrical Diagram
Before Use of Test Fixture
■
Due to possible stress during shipment, SMA connectors may be misaligned.
■
Check each SMA for continuity.
■
If necessary, realign and retighten with a 5/64 in. hex key wrench.
Instructions for Use of Test Fixture
A pair of flat-tip tweezers can be used to insert or remove a package from the test fixture. Always wear a grounding
strap to prevent ESD.
1. To insert a package, remove the two thumb screws and gently lift the pressure ring off of the test fixture.
2. Place the pressure ring, cavity side up, on a flat ESD safe surface.
3. Connect the metal tube to a suitable vacuum source with flexible tubing.
4. Place the package, lid down, on a flat ESD safe surface. Locate pin 1 on the package.
Lucent Technologies Inc.
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Data Sheet
June 1999
LG1625AXF Laser Driver
Appendix (continued)
Instructions for Use of Test Fixture (continued)
5. Insert the package into the pressure ring (lid down) with pin 1 located next to the orientation mark and turn on
the vacuum. The vacuum will retain the package in the pressure ring during the following steps.
6. Align the vertically conductive material on the circuit board.
7. Place the pressure ring down over the alignment pins and gently tighten the thumb screws.
8. Remove vacuum, if desired.
DATA IN
LW5
VSS1 (OPTIONAL)
GND
VTH
(OPTIONAL) VSS1
NC
GND
MK
MK
GND
(OPTIONAL) VSS1
VSS1
VMOD
VSS3
VSS2
VPRE
GND
OUTPUT
Note: Pressure ring not shown.
5-7874(F)
Figure 11. TF1006A Connector Assignment
For additional information, contact your Microelectronics Group Account Manager or the following:
http://www.lucent.com/micro
INTERNET:
docmaster@micro.lucent.com
E-MAIL:
N. AMERICA: Microelectronics Group, Lucent Technologies Inc., 555 Union Boulevard, Room 30L-15P-BA, Allentown, PA 18103
1-800-372-2447, FAX 610-712-4106 (In CANADA: 1-800-553-2448, FAX 610-712-4106)
ASIA PACIFIC: Microelectronics Group, Lucent Technologies Singapore Pte. Ltd., 77 Science Park Drive, #03-18 Cintech III, Singapore 118256
Tel. (65) 778 8833, FAX (65) 777 7495
CHINA:
Microelectronics Group, Lucent Technologies (China) Co., Ltd., A-F2, 23/F, Zao Fong Universe Building, 1800 Zhong Shan Xi Road, Shanghai
200233 P. R. China Tel. (86) 21 6440 0468, ext. 316, FAX (86) 21 6440 0652
JAPAN:
Microelectronics Group, Lucent Technologies Japan Ltd., 7-18, Higashi-Gotanda 2-chome, Shinagawa-ku, Tokyo 141, Japan
Tel. (81) 3 5421 1600, FAX (81) 3 5421 1700
EUROPE:
Data Requests: MICROELECTRONICS GROUP DATALINE: Tel. (44) 1189 324 299, FAX (44) 1189 328 148
Technical Inquiries: GERMANY: (49) 89 95086 0 (Munich), UNITED KINGDOM: (44) 1344 865 900 (Ascot),
FRANCE: (33) 1 40 83 68 00 (Paris), SWEDEN: (46) 8 594 607 00 (Stockholm), FINLAND: (358) 9 4354 2800 (Helsinki),
ITALY: (39) 02 6608131 (Milan), SPAIN: (34) 1 807 1441 (Madrid)
Lucent Technologies Inc. reserves the right to make changes to the product(s) or information contained herein without notice. No liability is assumed as a result of their use or application. No
rights under any patent accompany the sale of any such product(s) or information.
Copyright © 1999 Lucent Technologies Inc.
All Rights Reserved
June 1999
DS99-187HSPL