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 2 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. 4 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. 5 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. 6 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. 7 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 8 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. 10 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. 11 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: [email protected] 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