Preliminary Data Sheet January 1998 LG1628AXA SONET/SDH 2.488 Gbits/s Transimpedance Amplifier Features ■ High data rate: 2.5 Gbits/s ■ High gain: 5.8 kΩ transimpedance ■ Complementary 50 Ω outputs ■ Low noise ■ Ultrawide dynamic range ■ Single –5.2 V ECL power supply A complete receiver/regenerator can be constructed with an LG1628AXA followed by an LG1605 limiting amplifier and LG1600 clock and data regenerator. Figure 1 shows the block diagram of the LG1628AXA transimpedance amplifier. The amplifier consists of a 4.2 kΩ differential transimpedance stage followed by a limiting buffer that provides complementary 50 Ω outputs. RF GND Applications OUT+ IN– ■ SONET/SDH receivers ■ SONET/SDH test equipment ■ Digital video transmission ZEFF IN+ OUT– 50 Ω LIMITING BUFFER RF Functional Description The Lucent Technologies Microelectronics Group LG1628AXA is a hybrid integrated circuit that combines the Lucent LG1628A gallium arsenide (GaAs) transimpedance amplifier chip with an external Si dual operational amplifier and necessary filtering to achieve an ultrawide dynamic range amplifier. The LG1628AXA is capable of handling input currents from 3 µAavg to 4 mAavg (patent pending). Amplifier operation is from a single –5.2 V power supply. The targeted transmission system is SONET OC-48 and SDH STM-16. VSS OVERLOAD CONTROL 5-5329(F) Figure 1. LG1628AXA Functional Diagram LG1628AXA SONET/SDH 2.488 Gbits/s Transimpedance Amplifier Preliminary Data Sheet January 1998 Die Pad Configuration 22 GND1 23 20 GND2 21 GND1 DNC DNC DNC The die pad configuration is shown in Figure 2. 19 19 19 19 18 18 17 BG 16 GND2 15 24 OUT+ IN– 15 OUTSIDE DIE DIMENSIONS: 1.62 mm2 x 1.62 mm2 PAD SIZE: 100 µm2 x 100 µm2 (EXCEPT PAD #23, 100 µm2 x 150 µm2) PAD SEPARATION: 50 µm 24 14 OUT– 14 IN+ 1 13 GND1 2 12 3 12 GND2 VSS2 5 6 7 8 9 10 OP1– OP1+ OP2– OP2+A OP2+B 11 11 VSS1 4 OP1OUT 3 OP2OUT BYPASS 5-5336(F)r.2 Figure 2. Die Pad Configuration 2 Lucent Technologies Inc. Preliminary Data Sheet January 1998 LG1628AXA SONET/SDH 2.488 Gbits/s Transimpedance Amplifier Die Pad Configuration (continued) The pad descriptions for the LG1628AXA are given in Table 1. Table 1. Pad Descriptions Pad Symbol 1 2, 19, 23 3 4 5 6 7 8 9 10 IN+ GND1 BYPASS OP2OUT OP1OUT OP1– OP1+ OP2– OP2+A OP2+B Amplifier input; connect to detector anode, current should enter this node. Ground. Connections between these nodes and an external dual op amp form the overload control circuitry. See the test circuit in Figure 4 for wiring details. To operate the amplifier without overload control connect OP2OUT to VSS, OP1OUT to GND, and leave BYPASS and the remaining op amp connections open (Figure 5). 11 12 13, 16, 18 14 15 17 VSS1 VSS2 GND2 OUT– OUT+ BG 20, 21, 22 24 DNC IN– Supply voltage; –5.2 Vdc nominal. Supply voltage; –5.2 Vdc nominal. Ground. Inverted data output (produces low-level output for current entering IN+). Noninverted data output (produces high-level output for current entering IN+). Connection for external –2.5 Vdc voltage reference (typically use an Si bandgap). Do not connect; internal test point or reserved for future use. Inverting input; must provide ac bypass to ground when using overload control. Lucent Technologies Inc. Description 3 LG1628AXA SONET/SDH 2.488 Gbits/s Transimpedance Amplifier Preliminary Data Sheet January 1998 Typical Connections and Padout of the Hybrid Integrated Circuit OUT+* 50 Ω 9 10 4 125x60 60x30 5 60x30 60x30 7 OUT–* 50 Ω 17 18 IN+ 2 19 16 15 60X30 APD 13 60x30 8 60X30 6 60X30 12 14 APD+ 3 120X100 20 +VDET VSS GND THERMISTOR 5-5336(F).r3 * OUT– is delayed approximately 25 ps with respect to OUT+ due to the longer microstrip line associated with OUT–. An extra delay should be added to OUT+ before connecting to the next circuit. Figure 3. Typical Connections to the HIC (See Figure 4 for a Schematic of the Circuitry on the HIC.) Table 2. HIC Pad Functional Description Symbol IN+ APD+ +VDET VSS GND Thermistor OUT+ OUT– 4 Description Amplifier input; connect to detector anode, current should enter this node. RF bypassed connection for the cathode of the APD. APD power supply connection. Supply voltage; –5.2 Vdc nominal. Ground (back of HIC is also ground). Negative temperature coefficient thermistor for APD gain control. Noninverted data output (produces high-level output for current entering IN+). Inverted data output (produces low-level output for current entering IN+). Lucent Technologies Inc. Preliminary Data Sheet January 1998 LG1628AXA SONET/SDH 2.488 Gbits/s Transimpedance Amplifier 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 the data sheet. Exposure to absolute maximum ratings for extended periods can adversely affect device reliability. Table 3. Absolute Maximum Ratings Parameter Min Max Unit Supply Voltage Range (VSS) –7 0.5 V Power Dissipation — 1 W Voltage (all pins) 0.5 VSS V Storage Temperature Range –40 125 °C 0 100 °C Operating Temperature Range Recommended Operating Conditions Table 4. Recommended Operating Conditions Parameter Symbol Min Max Unit Ambient Temperature TA 0 85 °C VSS –4.7 –5.7 V Power Supply 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 Technologies Microelectronics Group employs a human-body model (HBM) and a charged-device model (CDM) for ESD-susceptibility testing and protection design evaluation. 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 5. ESD Threshold HBM ESD Threshold Device Voltage LG1628AXA >500 V Lucent Technologies Inc. 5 LG1628AXA SONET/SDH 2.488 Gbits/s Transimpedance Amplifier Preliminary Data Sheet January 1998 Electrical Characteristics TA = 25 °C, VSS = –5.2 V, CDETECTOR = 0.5 pF, RLOAD = 50 Ω, unless otherwise indicated. Parameter Symbol Min Typ Max Unit Power Supply Voltage Power Supply Current Effective Small-signal Transimpedance (Single-ended input to either OUT+ or OUT– each driving a 50 Ω load, differential gain is twice this value.) Small-signal Bandwidth Transimpedance Peaking Output Return Loss Input Noise Current (100 kHz—2.5 GHz) Operating Temperature Range VSS ISS TZ –5.7 — — –5.2 140 5.8 –4.7 — — V mA kΩ BW TPK S22 INOISE 1.5 — 10 — 1.6 0 15 300 — 1 — 350 GHz dB dB nArms TOP 0 — 85 °C 6 Lucent Technologies Inc. Preliminary Data Sheet January 1998 LG1628AXA SONET/SDH 2.488 Gbits/s Transimpedance Amplifier Test Circuit with Overload Control BG 27 kΩ 0.02 µF 300 pF (SEE NOTE 3 FOR BIAS CONDITIONS) RIN APD 1 ~100 µA 17 VSS1 OUT+ 15 LOUT 50 Ω LIMITING BUFFER OUT– 14 LOUT 24 IN– APD+ 2.5 V BANDGAP2 GND2 RF 10 Ω 18 GND1 19 ZEFF IN+ LIN (SEE NOTE 4) 0.047 µF 50 Ω COUT 0.047 µF 50 Ω (LPF, SEE NOTE 5) RF 100 pF 100 V CAPS 3 4 5 6 7 8 9 10 VSS2 VSS1 OP2+B OP2+A OP2– OP1+ OP1– 1 kΩ OP1OUT 0.033 µF OP2OUT 50 Ω BYPASS OVERLOAD CONTROL 11 12 +VDET 0.047 µF 100 pF 300 pF 0.047 µF 0.1 µF 10 Ω – OP11 + 0.047 µF Vss 5.2 V + – OP21 + 0.047 µF 5-5335(F)r.1 1. Operational amplifiers OP1 and OP2 should have the following characteristics (suggested op amps are the LMC6082IM or OP291GS, both are available as dual op amps in an 8-pin SOIC package): a.Single 5 V supply operation. d.High-level output to within 2 V of the positive rail. b. Maximum input offset voltage of 1 mV. e.Gain bandwidth product ≥1.8 MHz. c. Low-level output includes negative rail. f. Large signal voltage gain ≥100 V/mV. 2. An on-chip 75 kΩ resistor to the negative supply is provided for biasing the voltage reference. Approximately 100 µA of current will be drawn. (Suggested bandgap reference is the LM4040BIM–2.5, available in an SOT-23 package.) 3. Node IN+ is nominally at –3.3 Vdc. APD supply voltage +Vdet should be adjusted appropriately. 4. RINLIN may be necessary to achieve stability depending on the physical arrangement of the APD and its associated electrical parasitics (series inductance and other resonances). The amplifier will be stable with a 0.5 pF detector capacitance in series with a 0.5 nH inductor, but packaged detectors usually do not behave so ideally at frequencies above a few gigahertz. A parallel RL network consisting of a 200 Ω resistor and a 6 nH inductor is provided on HIC and may be optionally used with a slight noise penalty. Good isolation from output to input is also essential for amplifier stability. 5. A low-pass filter is provided on the LG1628AXA HIC to reduce higher-frequency noise contributions (Butterworth N = 2, Zo = 50 and fc = 4.25 GHz, LOUT = 2.65 nH, COUT = 0.5 pF). Figure 4. Optical Receiver with Overload Control Lucent Technologies Inc. 7 LG1628AXA SONET/SDH 2.488 Gbits/s Transimpedance Amplifier Preliminary Data Sheet January 1998 Test Circuit with Overload Control Disabled 0.02 µF BG 27 kΩ 300 pF ZEFF RIN 1 ~100 µA 17 VSS1 OUT+ 15 LOUT 50 Ω LIMITING BUFFER OUT– 14 LOUT 24 IN– APD 2.5 V BANDGAP GND2 RF 10 Ω 18 GND1 19 IN+ 0.047 µF 50 Ω COUT 0.047 µF 50 Ω LIN APD+ 3 NC 4 5 7 8 9 OP2+B OP2+A OP2– OP1+ OP1– 6 10 VSS2 100 V CAPS VSS1 1 kΩ OP2OUT 0.033 µF BYPASS 50 Ω OP1OUT RF OVERLOAD CONTROL 100 pF 11 12 VSS NC NC NC NC NC 100 pF 0.1 µF + 5.2 V 10 Ω 5-5334(F)r.3 Note: Notes 2, 3, 4, and 5 from the previous page (Figure 4) apply to this drawing. Figure 5. Optical Receiver with Overload Control Disabled 8 Lucent Technologies Inc. Preliminary Data Sheet January 1998 LG1628AXA SONET/SDH 2.488 Gbits/s Transimpedance Amplifier Characteristic Curves (at TA = 25 °C, VSS = –5.2 V, CDETECTOR = 0.0 pF, 0.5 pF, 1.0 pF, RLOAD = 50 Ω) 600 80 OUTPUT VOLTAGE (mVp-p) TRANSIMPEDANCE (dBΩ) 77 74 71 1.0 pF 68 0.5 pF 65 0.0 pF 62 59 56 500 400 300 200 100 53 50 0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 0.001 0.1 10 1 FREQUENCY (GHz) APD CURRENT (mAavg) A. Small-Signal Transimpedance B. Overload Characteristics1 30 400 1.0 pF 25 350 1.0 pF 0.5 pF 300 0.0 pF 20 ITOT (nArms) SITOT (pA/ Hz) 0.01 15 10 0.5 pF 0.0 pF 250 200 150 100 5 0 50 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 FREQUENCY (GHz) FREQUENCY (GHz) C. Input Spectral Noise Density D. Total Input Noise Current 3.5 4.0 5-5330(F)r.1, 5-5331(F).ar2, 5-5332(F)r.2, 5-5333(F)r.2 1. >25 dB dynamic range requires an external Si dual operational amplifier. The detector polarity is such that current enters the LG1628A (i.e., the detector anode is connected to the LG1628A). Figure 6. Characteristic Curves as Measured on the LG1628AXA Hybrid Integrated Circuit Lucent Technologies Inc. 9 LG1628AXA SONET/SDH 2.488 Gbits/s Transimpedance Amplifier Preliminary Data Sheet January 1998 Dimensional Drawing of the Hybrid Integrated Circuit (HIC) Dimensions are in inches. Ceramic thickness is 0.025 inches. 0.327 0.224 0.005 60x30 9 10 4 125x60 0.005 5 60x30 60x30 7 17 18 2 19 16 15 60X30 0.550 13 60x30 8 0.358 60X30 6 60X30 12 14 0.141 3 120X100 20 0.018 0.019 0.238 0.035 0.318 0.380 0.525 5-5336(F).ar3 Figure 7. HIC Dimensions and Location of Bonding Pads Ordering Information Device Code Package Temperature LG1628AXA Hybrid Integrated Circuit Differential Output Hybrid Integrated Circuit Single-ended Output 0 °C to 85 °C Comcode (Ordering Number) 107791469 0 °C to 85 °C 108052085 LG1628BXA* * Second output on BXA is terminated through to ground 50 Ω on hybrid. 10 Lucent Technologies Inc. Preliminary Data Sheet January 1998 LG1628AXA SONET/SDH 2.488 Gbits/s Transimpedance Amplifier Notes Lucent Technologies Inc. 11 LG1628AXA SONET/SDH 2.488 Gbits/s Interactive Terminal Transmission Convergence Preliminary Data Sheet January 1998 For additional information, contact your Microelectronics Group Account Manager or the following: INTERNET: http://www.lucent.com/micro E-MAIL: [email protected] U.S.A.: 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 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 (Bracknell), FRANCE: (33) 1 41 45 77 00 (Paris), SWEDEN: (46) 8 600 7070 (Stockholm), FINLAND: (358) 9 4354 2800 (Helsinki), ITALY: (39) 2 6601 1800 (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 © 1998 Lucent Technologies Inc. All Rights Reserved Printed in U.S.A. January 1998 DS97-156FCE