Data Sheet May 2001 LG1627BXC Clocked Laser Driver Features Functional Description ■ High data-rate clocked laser diode driver ■ Clock disable mode for data feedthrough ■ Adjustable high output current ■ Operation up to 3 Gbits/s The LG1627BXC is a gallium arsenide (GaAs) laser diode driver to be used with direct modulated laser diodes in high-speed non-return-to-zero (NRZ) transmission systems. The device is made in a highperformance 0.9 µm gate GaAs hetero-junction FET technology that utilizes high-density MIM capacitors, airbridge interconnect, and NiCr film precision resistors. The driver includes differential data and clock inputs. The high-output, low overshoot drive current and prebias can be set separately. Data retiming is accomplished by the internal flip-flop, minimizing jitter on the data. Clocking can be disabled for data feedthrough. A pulse-width control enables the user to compensate for laser turn-on delay. A 2.5 V bandgap reference is required for stable operation over temperature and varying power supply voltage. Applications ■ SONET/SDH transmission systems ■ SONET/SDH test equipment ■ Optical transmitters Functional Diagram GND BG2P5 MK MK VTH VPRE IOUT-PRE VIN VIN CLK IOUT LG1627BXC CLK VMOD CLK_E VSS3 MOD_E VSS2 VSS1 PWN PWP 5-6549(F).b Figure 1. Functional Diagram Data Sheet May 2001 LG1627BXC Clocked Laser Driver Block Diagram CLK_E PWP PWN GND MK MK VMOD VPRE IOUT-PRE VTH VIN 50 Ω 50 Ω IOUT D Q VIN CLK CLK 22 Ω GND 50 Ω 50 Ω BG2P5 VSS1 MOD_E VSS3 VSS2 5-7675(F)r.1 Figure 2. Block Diagram 2 Agere Systems Inc. Data Sheet May 2001 LG1627BXC Clocked Laser Driver VSS2 VSS3 VMOD VSS1 VSS1 CLK_E Pin Information 24 23 22 21 20 19 17 IOUT-PRE 3 16 IOUT GND 4 15 IOUT CLK 5 14 GND CLK 6 13 9 10 11 12 GND 7 8 MK 2 VIN MK VIN PWN VPRE PWP 18 MOD_E 1 BG2P5 VTH 5-6551(F).br.3 Figure 3. Pin Diagram Table 1. Pin Descriptions Pin Symbol 1 2 3 4, 13, 14, package bottom 5 6 7 8 9 10 11 12 15, 16 17 18 19 20 21 22, 23 24 VTH VIN V IN GND CLK CLK BG2P5 MOD_E PWP PWN MK MK IOUT IOUT-PRE VPRE VSS2 VSS3 VMOD VSS1 CLK_E Description Capacitor to ground (data input reference). Data input. Complementary data input. Ground. For optimum performance, the package bottom must be soldered to the ground plane. Clock input. Complementary clock input. −2.5 V band-gap reference (National Semiconductor * p/n LM4040). Modulation enable (connect to VSS1 to enable, float to disable). Pulse width adjust positive. Pulse width adjust negative. Complementary mark density output. Mark density output. Output modulation current (dc coupled to laser cathode). Output prebias current. Prebias control input. VSS2 supply −5.2 V for output prebias. VSS3 supply −5.2 V for output modulation. Modulation current control input. VSS1 supply −5.2 V. Clock enable (connect to VSS1 to enable, float to disable). * National Semiconductor is a registered trademark of National Semiconductor Corporation. Agere Systems Inc. 3 Data Sheet May 2001 LG1627BXC Clocked Laser Driver Absolute Maximum Ratings Stresses in excess of the absolute maximum ratings can cause permanent 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 the data sheet. Exposure to absolute maximum ratings for extended periods can adversely affect device reliability. Table 2. Absolute Maximum Ratings Parameter Symbol Min Max Unit VSS — –5.7 V Input Voltage VI GND VSS V Power Dissipation PD — 1 W Storage Temperature Tstg −40 125 °C Operating Case Temperature Range TC 0 100 °C Supply Voltage Recommended Operating Conditions Table 3. Recommended Operating Conditions Parameter Case Temperature Power Supply Symbol Min Max Unit tCASE 0 70 °C VSS –4.7 –5.7 V 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 a charged-device model (CDM) for ESD-susceptibility testing and protection design evaluation. ESD voltage thresholds are dependent on the circuit parameters used to define the 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. The HBM ESD threshold presented here was obtained by using these circuit parameters. Table 4. ESD Threshold Voltage Human-Body Model ESD Threshold Device Voltage LG1627BXC >200 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. This device is supplied with solder on the back of the package. For optimum performance, it is recommended to solder the back of the package to ground. 4 Agere Systems Inc. Data Sheet May 2001 LG1627BXC Clocked Laser Driver Electrical Characteristics (TA = 25 °C, VSS1 = VSS2 = VSS3 = –5.2 V, data input = 600 mV (single ended), and RL = 50 Ω) 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 5. Electrical Characteristics Parameter Data Input Voltage, Single Ended Symbol Min Typ Max Unit VIN 300 600 1000 mV VSS1, VSS2, VSS3 –4.9 –5.2 –5.5 V 1 ISS1 100 140 160 mA Voltage Control for Output Modulation Current VMOD –4.0 — –5.5 V IOUT LOW — 0 2 mA mA Power Supply Voltage Power Supply Current Output Minimum Modulation Current 2 Output Maximum Modulation Current Voltage Control for Prebias Current Output Minimum Prebias Current 3 IOUT HIGH 75 85 — VPRE –3.0 — –5.5 V IPRE LOW — 0 0.5 mA mA IPRE HIGH 50 60 — Mark Density, 50% Duty Cycle (1 kΩ to GND) MK — –0.5 — V Mark Density Complement, 50% Duty Cycle (1 kΩ to GND) MK — –0.5 — V Pulse Width Adjust Plus PWP –3.0 –4.2 –5.5 V Pulse Width Adjust Negative PWN –3.0 –4.2 –5.5 V tR, tF — 90 — ps Jitter (rms) — — 4 — ps Phase Margin — — 270 — deg tR, tF — 90 — ps — — 6 — ps tR, tF — 100 — ps Jitter (rms) — — 4 — ps Phase Margin — — 270 — deg tR, tF — 100 — ps — — 6 — ps Output Maximum Prebias Current Output Modulation IOUT = 40 mA, Clock Enabled Output Rise and Fall Times (20%—80%) Output Modulation IOUT = 40 mA, Clock Disabled Output Rise and Fall Times (20%—80%) Jitter (rms) Output Modulation IOUT = 80 mA, Clock Enabled Output Rise and Fall Times (20%—80%) Output Modulation IOUT = 80 mA, Clock Disabled Output Rise and Fall Times (20%—80%) Jitter (rms) 1. Excludes IPRE and average IMOD. Power supply current ISS2 (relating to prebias) is dependent on VPRE. Power supply current ISS3 (relating to modulation) is dependent on VMOD. 2. Maximum modulation at maximum VMOD. 3. Maximum prebias at maximum VPRE. Agere Systems Inc. 5 Data Sheet May 2001 LG1627BXC Clocked Laser Driver Typical Optical Evaluations and Performance Characteristics 24 23 22 21 20 19 VTH Zo = 50 Ω 2 VIN (OPTIONAL) 3 Zo = 50 Ω CLOCKED LASER 4 0.1 µF LASER RF INPUT IOUT 9 6 10 5 D2500 LASER 2000 4 LASER dc BIAS 12 3 Zo = 25 Ω 15 DRIVER 7 11 IOUT-PRE 16 8 14 13 2 CLK (OPTIONAL) 6 13 9 10 11 12 14 1 5 kΩ 1 kΩ LM4040 VSS MOD_E BG2P5 VOLTAGE DIVIDER 8 PWP 7 MK CLK 5 MK 0.047 µF 17 LG1627BXC 1 kΩ CLOCK IN 18 PWN 0.047 µF 1 VIN VPRE VSS2 0.1 µF DATA IN VOLTAGE DIVIDER CURRENT SENSE CURRENT SENSE VOLTAGE DIVIDER VSS3 VSS1 CLK_E VMOD VSS1 BYPASS VSS = –5.2 V 2 kΩ VSS = –5.2 V VSS 3 kΩ 0.1 µF CURRENT SENSE REQUIRED TO SET VMOD AND VPRE TO ACHIEVE DESIRED MODULATION AND PREBIAS 0.1 µF BYPASS FOR VSS1 1Ω TO USER VOLTAGE MONITOR (DVM) TO NODE VSS2 AND VSS3 ONE EACH VSS 0.1 µF TO VSS1 5-7693(F)r.4 Notes: All bypass capacitors should be mounted close to the package. For optimum performance, the package must be soldered to ground. Mark density (MK and MK) outputs are terminated with 1 kΩ pull-up resistors. For single-ended operation, unused data and clock inputs should be ac coupled to a 50 Ω termination. Pin 13 and pin 14 should be tied together with a separate path to the ground plane. Figure 4. Typical Optical Evaluation of the LG1627BXC and D2500 Laser 6 Agere Systems Inc. Data Sheet May 2001 LG1627BXC Clocked Laser Driver Typical Optical Evaluations and Performance Characteristics (continued) HORIZONTAL: 60 ps/div, VERTICAL: 1.5 mW/div Figure 5. Typical Optical Eye-Diagram IOUT = 85 mA; IOUT-PRE = 5 mA 100 90 80 IOUT (mA) 70 60 50 40 30 20 10 0 –5.5 –5.0 –4.5 –4.0 VMOD (V) 5-7676(F) Figure 6. Typical IOUT vs. VMOD 80 70 IOUT-PRE (mA) 60 50 40 30 20 10 0 –5.5 –5.0 –4.5 –4.0 –3.5 VPRE (V) 5-7677(F)r.1 Figure 7. Typical IOUT-PRE vs. VPRE Agere Systems Inc. 7 Data Sheet May 2001 LG1627BXC Clocked Laser Driver Outline Diagram 0.465 0.280 1 0.012 1 0.030 0.082 0.005 0.092 0 — 0.004 0.045 0.035 5-6555(F).a Assembly Notes: Standoff specifications apply to package prior to solder dipping of leads and package base. During board assembly, use back lighting to silhouette the package. This will eliminate reflection problems with the solder on the bottom of the package. Lead space tolerance should be set to ±0.012”. Board solder pattern for the package base should not exceed 50% of the package base area. Insertion pressure should not exceed 125 grams. Ordering Information 8 Device Code Package Temperature Comcode (Ordering Number) LG1627BXC 24-pin hermetic small outline 0 °C to 70 °C 108325754 Agere Systems Inc. Data Sheet May 2001 LG1627BXC Clocked Laser Driver Notes Agere Systems Inc. 9 LG1627BXC Clocked Laser Driver Data Sheet May 2001 For additional information, contact your Agere Systems Account Manager or the following: http://www.agere.com INTERNET: [email protected] E-MAIL: N. AMERICA: Agere Systems Inc., 555 Union Boulevard, Room 30L-15P-BA, Allentown, PA 18109-3286 1-800-372-2447, FAX 610-712-4106 (In CANADA: 1-800-553-2448, FAX 610-712-4106) ASIA PACIFIC: Agere Systems Singapore Pte. Ltd., 77 Science Park Drive, #03-18 Cintech III, Singapore 118256 Tel. (65) 778 8833, FAX (65) 777 7495 CHINA: Agere Systems (Shanghai) Co., Ltd., 33/F Jin Mao Tower, 88 Century Boulevard Pudong, Shanghai 200121 PRC Tel. (86) 21 50471212, FAX (86) 21 50472266 JAPAN: Agere Systems 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: DATALINE: Tel. (44) 7000 582 368, 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 3507670 (Helsinki), ITALY: (39) 02 6608131 (Milan), SPAIN: (34) 1 807 1441 (Madrid) Agere Systems 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. Copyright © 2001 Agere Systems Inc. All Rights Reserved Printed in U.S.A. May 2001 DS01-219HSPL (Replaces DS99-143HSPL)