Data Sheet February 1999 LG1626DXC Modulator Driver Features Functional Description ■ High data-rate optical modulator driver ■ Adjustable output voltage up to 3 Vp-p (RL = 50 Ω) ■ Adjustable modulator dc offset ■ Operation up to 3 Gbits/s ■ Single ended or differential inputs ■ Single –5.2 V power supply ■ 90 ps rise and fall times ■ Enable control The LG1626DXC is a gallium-arsenide (GaAs) intergrated circuit used to provide voltages to drive optical modulators 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 device contains four cascaded stages, operates with a single –5.2 V power supply, and accepts ECL 100K level inputs. The output is an open drain designed to drive 50 Ω loads. Voltages control the output modulation amplitude and modulator dc offset. A –2.5 V band-gap reference is required for stable operation over temperature and varying power supply voltage. The LG1626DXC is available in a 24-lead hermetic, gull-wing package. Applications ■ SONET/SDM transmission systems ■ SONET/SDM test equipment ■ Optical transmitters GND BG2P5 MK VTH MK VDC-ADJ VIN VOUT VIN VOUT-DC VTH VMOD MOD_E VSS3 VSS2 VSS1 5-6549(F) Figure 1. Functional Diagram Data Sheet February 1999 LG1626DXC Modulator Driver Pin Information GND MK MK VMOD VDC-ADJ VTH + – 50 Ω VIN + VIN – 50 Ω VOUT 50 Ω VTH VSS1 MOD_E VSS3 VSS2 5-6550(F) Figure 2. LG1626DXC Die Block Diagram 2 Lucent Technologies Inc. Data Sheet February 1999 LG1626DXC Modulator Driver VTH VSS1 VSS1 VMOD VSS3 VSS2 24 23 22 21 20 19 Pin Information (continued) GND 1 18 VDC-ADJ 17 VOUT-DC 16 VOUT 15 GND VIN 2 GND 3 GND 4 VIN 5 14 GND VTH 6 13 GND 7 8 9 10 11 12 BG2P5 MOD_E GND GND MK MK LG1626DXC MODULATOR DRIVER 5-6551(F) Note: Figure is not to scale. Figure 3. LG1626DXC Package Pinout Table 1. LG1626DXC Pin Description Symbol Pin GND 1, 3, 4, 9, 10, 13, 14, 15, Package Bottom 2 5 6 7 8 11 12 16 17 18 19 20 21 22, 23 24 VIN ---------V IN ----------V TH BG2P5 MOD_E MK MK VOUT VOUT-DC VDC-ADJ VSS2 VSS3 VMOD VSS1 VTH Description Ground. For optimum performance, the package bottom must be soldered to the ground plane. Data input. Complementary data input. Complementary threshold control (eye crossing) input. –2.5 V band-gap reference ( National Semiconductor * LM4040). Modulation enable (connect to V SS1 to enable, float to disable). Complementary mark density output. Mark density output. Output, ac couple to 50 Ω modulator. Output, modulator dc offset. Modulator dc offset control input. VSS2 supply –5.2 V for output prebias. VSS3 supply –5.2 V for output modulation. Output modulation control input. VSS1 supply –5.2 V. Threshold control (eye crossing) input. * National Semiconductor is a registered trademark of National Semiconductor Corporation. Lucent Technologies Inc. 3 Data Sheet February 1999 LG1626DXC Modulator Driver Absolute Maximum Ratings (at TA = 25 °C unless otherwise specified) Table 2. Absolute Maximum Ratings Parameter Symbol Min Max Unit Supply Voltage Input Voltage Power Dissipation Storage Temperature Range Operating Temperature Range VSS VI PD Tstg TC — GND — –40 0 5.75 VSS 1 125 100 V V W °C °C 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 threshold 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 comparision. The HBM ESD threshold presented here was obtained by using these circuit parameters. Table 3. ESD Threshold Voltage Human-Body Model ESD Threshold Device LG1626DXC Voltage >200 V Mounting and Connections Cetain 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 the ground. 4 Lucent Technologies Inc. Data Sheet February 1999 LG1626DXC Modulator Driver Electrical Characteristics TA = 25 °C, VSS1 = VSS2 = VSS3 = –5.2 V, VTH = – 1.3 V, VMOD = – 3.8 V, 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 4. LG1626DXC Minimum and Maximum Values Parameter Symbol Data Input Voltage (peak to peak) Single Ended VIN Voltage Control for Output Modulation Current VMOD Maximum Modulated Output Voltage1 VOUT 2 Minimum Modulated Output Voltage VOUT Output Rise and Fall Times (20%—80%) tR, tF Power Supply Voltage VSS1, VSS2, VSS3 Power Supply Current3 ISS1 MK Mark Density4 4 Complementary Mark Density MK Voltage Control for Modulator dc Offset VDC-ADJ VOUT-DC Maximum Output, Modulator dc Offset5 6 Minimum Output, Modulator dc Offset VOUT-DC Min Typ Max Unit 300 –5.5 2.70 0 — –5.5 100 — — –5.5 1.2 0 600 — — — 90 –5.2 140 –0.5 –0.5 — — — 1000 –4 3.00 0.2 — –4.9 180 — — –3 1.5 0.1 mV V V V ps V mA V V V V V 1. Maximum output modulation at maximum VMOD (RL = 50 Ω). 2. Minimum output modulation when MOD_E is floating and VMOD = VSS3. 3. Excludes IPRE and average IMOD: Power suppy current ISS2 (relating to prebias) is dependent on VPRE. Power suppy current ISS3 (relating to modulation) is dependent on VMOD. 4. Both MK and MK are open drains, the typical value is obtained by driving a 1kΩ load. 5. Maximum modulator dc offset voltage (RL = 50 Ω) at maximum VDC-ADJ. 6. Minimum modulator dc offset voltage (RL = 50 Ω) at VDC-ADJ = VSS2. Note: All parameters measured at 25 °C ambient. Lucent Technologies Inc. 5 Data Sheet February 1999 LG1626DXC Modulator Driver Electrical Characteristics (continued) 1 VIN Zo = 50 Ω 50 Ω 3 0.1 µF VOUT-DC VOUT Zo = 50 Ω 7 8 13 9 10 11 12 BG2P5 MOD_5 1 kΩ LM4040 VSS VOLTAGE DIVIDER VSS VSS = –5.2 V CURRENT SENSE 0.1 µF SCOPE 10 Ω GENERATOR 1Ω 50 Ω 14 6 0.1 µF 2.5 kΩ 15 DRIVER 5 50 Ω DATA 16 MODULATOR 4 0.047 µF 17 LG1626DXC 1 kΩ + 18 2 10 Ω VDC-ADJ 24 23 22 21 20 19 DATA IN 0.047 µF VOLTAGE DIVIDER CURRENT SENSE CURRENT SENSE VSS2 VTH VSS1 2.5 kΩ* VMOD 0.1 µF VSS3 10 Ω VOLTAGE DIVIDER VSS1 BYPASS VSS = –5.2 V TO USER-SUPPLIED VOLTAGE MONITOR (DVM). TO NODE VSS2 AND VSS3 ONE EACH. MK MK BYPASS FOR VSS1 2 kΩ VSS 3 kΩ 0.1 µF 0.1 µF VSS1 REQUIRED TO SET VMOD AND VDC-ADJ TO ACHIEVE DESIRED MODULATION, ONE EACH. 5-6553(F).b *A 2.5 kΩ resistor will set the eye crossing at 50%. A 5 kΩ potentiometer will allow the eye crossing to be varied. Notes: All bypass caps should be mounted close to the package. ISS3 can be measured and used to control VMOD. ISS2 can be measured and used to control VOUT-DC. For optimal performance, the proximity of the two components should be minimized and the package bottom must be soldered to the circuit board (GND). For proper impedance matching, high-speed transmission lines should be 50 Ω controlled impedance lines. Figure 4. LG1626DXC Typical Electrical Evaluation (ac Coupled to Scope) 6 Lucent Technologies Inc. Data Sheet February 1999 LG1626DXC Modulator Driver Electrical Characteristics (continued) VOLTAGE DIVIDER 8 VSS2 CURRENT SENSE CURRENT SENSE VSS3 VTH VMOD VSS1 BYPASS 0.1 µF VSS1 10 Ω 2.5 kΩ* VOLTAGE DIVIDER VSS = –5.2 V 7 dc SUPPLY 10 Ω 9 DATA IN + 1 VIN Zo = 50 Ω 3 MODULATOR 4 0.047 µF 50 Ω EM-ILM 17 14 6 13 7 8 9 11 Zo = 50 Ω 2.5 kΩ +2 V MAX 12 3 13 2 14 1 Zo = 50 Ω DMM 10 11 12 10 µH 10 Ω BG2P5 1 kΩ LM4040 50 Ω 1 kΩ DATA GENERATOR 4 INPUT 16 5 0.1 µF 0.047 µF VOUT 15 DRIVER 5 E2500 10 µH VOUT-DC LG1626DXC 10 100 µH 18 2 50 Ω 0.1 µF VDC-ADJ 24 23 22 21 20 19 0.047 µF 6 MOD_E VSS = –5.2 V MK MK 5-6554(F).b *A 2.5 kΩ resistor will set the eye crossing at 50%. A 5 kΩ potentiometer will allow the eye crossing to be varied. Notes: All bypass caps should be mounted close to the package. ISS3 can be measured and used to control VMOD. ISS2 can be measured and used to control VOUT-DC. For optimal performance, the proximity of the two components should be minimized and the package bottom must be soldered to the circuit board (GND). For proper impedance matching, high-speed transmission lines should be 50 Ω controlled impedance lines. Figure 5. Typical Optical Evaluation of the LG1626DXC and EM2500 EM-ILM Lucent Technologies Inc. 7 Data Sheet February 1999 LG1626DXC Modulator Driver 750 mV/div Electrical Characteristics (continued) 80 ps/div 5-7341(F) 500 mW/div Figure 6. Typical Electrical Eye Diagram (ac Coupled to Scope) 60 ps/div 5-7342(F) Figure 7. Typical Optical Eye Diagram Table 5. Pin Description of Lucent’s E2500 EM-ILM Modulator 8 Pin Description 1, 2 3 4 5 6 7 8, 9 10, 14 11, 13 12 Thermistor Laser Anode Monitor Anode Monitor Cathode Thermoelectric Cooler (+) Thermoelectric Cooler (–) Case Ground No Connect Laser/Modulator Ground Modulator Anode (–) 50 Ω RF Input Lucent Technologies Inc. Data Sheet February 1999 LG1626DXC Modulator Driver Outline Diagram 0.465 0.280 1 0.012 1 LUCENT LG1626DXC XXXXXXX 0.030 0.082 0.005 0 — 0.004 0.092 0.035 0.045 12-3224(F).a Assembly Notes: Standoff specifications applies 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 in. Board solder pattern for the package base should not exceed 50% of the package base area. Insertion pressure should not exceed 125 grams. LG1626DXC Ordering Information Device Type Comcode Number LG1626DXC 24-Pin Package 108192865 Lucent Technologies Inc. 9 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 February 1999 DS99-145HSPL