11.1 Gbps 3.3 V Low Noise, High Gain TIA ADN2821 Preliminary Technical Data FEATURES GENERAL DESCRIPTION Bandwidth: 8 GHz min Input noise current density: 12 pA/Hz Optical sensitivity: -19 dBm1 Differential transimpedance/linear range: ADN2821_2: 2.0 k/0.20 mA p-p ADN2821_5: 5.0 k/0.08 mA p-p ADN2821_10: 10.0 k/0.04 mA p-p ADN2821_20: 20.0 k/0.02 mA p-p Power dissipation: 150 mW Input power monitor: 1 V/mA Differential output swing: 400 mV p-p min Input overload: 2.0 mA p-p min @ 4 dB ER 3.0 mA p-p min @ 10 dB ER Low-F cutoff: ADN2821_5: 25 kHz with CLF = 0.5 nF ADN2821_10: 25 kHz with CLF = 1 nF On-chip PD filter: RF = 200 , CF = 66 pF Die size: 0.90 mm x 1.10 mm The ADN2821 is a series of compact, high performance SiGe, 3.3 V transimpedance amplifiers (TIAs) optimized for small form factor 10 Gbps metro-access and Ethernet PD-TIA modules. The ADN2821 series features low input referred noise current and a range of transimpedance gains, suitable for driving a typical CDR or transceiver directly. Eight GHz minimum BW enables up to 11.1 Gbps operation; 1.2 A input referred noise current enables -19 dBm sensitivity; 2 mA p-p input overload current at 2.4 mA average input current enables better than 4 dBm overload operation at a 4 dB extinction ratio. For assembly in small form factor packages, the ADN2821 series integrates a photodiode low-pass filter network on-chip and features 25 kHz low frequency cutoff with a small 0.5 nF or 1.0 nF external capacitor. The POWMON output signal proportional to average input current is available for monitoring and alarm generation. The ADN2821 operates with a 3.3 V 0.3 V power supply and is available in die form. 3.3V 4 APPLICATIONS FILTER VCC FILTER 1 VCC ADN2821 RF 200 500 10.7 Gbps optical modules SONET/SDH OC-192/STM-64 and 10 GbE Receivers, transceivers, transponders 5 50 50 h IN 6, 8 OUT 9, 11 OUTB 2 AV = 20dB 10mA 13 3 GND 7, 10 12 GND CLF CLF 1nF POWMON 04369-0-001 0.85V CF 66pF Figure 1. AD2821_5 Functional Block Diagram/ Typical Operating Circuit (TOC) 1 10-12 BER, 10 dB extinction ratio, 0.85 A/W PD responsivity. Rev. PrJ Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.326.8703 (c) 2003 Analog Devices, Inc. All rights reserved. Preliminary Technical Data ADN2821 TABLE OF CONTENTS Electrical Specifications ................................................................... 3 Absolute Maximum Ratings............................................................ 5 Input Referred Linear Range vs. ADN2821 TransImpedance ....................................................................................................... 10 ESD Caution.................................................................................. 5 IN/FILTER -- OUT/OUTB Mutual Inductance Feedback vs. ADN2821 TransImpedance ...................................................... 10 Pad Configuration and Functional Descriptions ......................... 6 Low Frequency Cutoff ................................................................... 11 Assembly Recommendations.......................................................... 7 Typical Operating Performance ................................................... 11 5-Pin TO-CAN with Common Photodiode Supply and POWMON Output Pin................................................................ 7 On-Wafer Probe (LTEST, LOUT, LOUTB ~ 0.2 nH) ........................ 11 5-Pin TO-CAN with External Photodiode Supply VPD Connected through Filter Pin..................................................... 8 Butterfly Package with Common Photodiode Supply and POWMON Output Pin................................................................ 9 Frequency Response .................................................................. 11 10 Gbps Eye Diagrams................................................................... 12 Outline Dimensions ....................................................................... 13 Ordering Guide............................................................................... 13 Transimpedance Selection Guidelines......................................... 10 Optical Sensitivity vs. ADN2821 Transimpedance and LA/CDR Input Sensitivity ......................................................... 10 REVISION HISTORY Revision PrJ Rev. PrJ | Page 2 of 13 Preliminary Technical Data ADN2821 ELECTRICAL SPECIFICATIONS Table 1. Parameter DYNAMIC PERFORMANCE Bandwidth (BW)3 Total Input RMS Noise (Irms)2 Small Signal Transimpedance (TZ) Transimpedance Ripple2 Group Delay Variation2 Low Frequency Cutoff Output Return Loss2 Total p-p Jitter2 Input Overload Current2 Maximum Output Swing Linear Output Range Power Supply Rejection Ratio DC PERFORMANCE Power Dissipation Input Voltage Output Impedance POWMON Sensitivity POWMON Offset PD FILTER Resistance PD FILTER Capacitance 1 2 Conditions1 Min Typ -3dB DC to 10 GHz ADN2821_2, 100 MHz ADN2821_5, 100 MHz ADN2821_10, 100 MHz ADN2821_20, 100 MHz 50 MHz to 5 GHz 50 MHz to 8 GHz ADN2821_2, CLF = 200 pF ADN2821_5, CLF = 500 pF ADN2821_10, CLF = 1000 pF ADN2821_20, CLF = 1000 pF DC to 8 Hz, differential IIN, p-p = 2.0 mA, 4 dB ER p-p, 10-12 BER, 4 dB ER p-p, 10-12 BER, 10 dB ER p-p diff, IIN, p-p =2.5 mA p-p, <1 dB gain compression TBD 8 9.5 1.2 2000 5000 10000 20000 1 10 25 25 25 25 -12 5 1500 3500 6000 12000 2.0 3.0 400 IIN, AVE = 0.1 mA, VCC = 3.3 V 5% Single-ended IIN, AVE = 0 A to 1 mA IIN, AVE = 0 A RF CF 0.75 45 0.75 5 180 Max TBD 2500 6500 15000 30000 50 50 50 50 -10 Unit GHz A dB ps kHz kHz kHz kHz dB ps mA mA mV mV dB 520 400 TBD 650 150 200 mW 0.85 50 1 10 200 66 1.00 55 1.25 15 220 V V/mA mV pF Min/Max VCC = 3.3 V 0.3 V, TAMBIENT = -20C to +85C; Typ VCC = 3.3 V, TAMBIENT = 25C. Photodiode capacitance CD = 0.22 pF 0.04 pF. Photodiode resistance = 15 , CB = 100 pF. Bond inductance LIN = LFILTER = 0.3 nH 0.1 nH. LOUT = LOUTB = 0.5 nH 0.1 nH. Load impedance = 50 (each output, ac-coupled). Rev. PrJ | Page 3 of 13 Preliminary Technical Data ADN2821 Rev. PrJ | Page 4 of 13 Preliminary Technical Data ADN2821 ABSOLUTE MAXIMUM RATINGS Table 2. Parameter Supply Voltage (VCC to GND) Output Short Circuit Duration Maximum Input Current Storage Temperature Range Operating Ambient Temperature Range Maximum Junction Temperature Die Attach Temperature (<30 seconds) Rating 5.2 V Indefinite 5 mA -65C to +125C -20C to +85C 150C 420C Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other condition s above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ESD CAUTION ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although this product features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality. Rev. PrJ | Page 5 of 13 Preliminary Technical Data ADN2821 P1 P2 1 2 3 GND TEST FILTER IN GND 13 POWMON 12 CLF 11 OUTB VCCFILTER 4 VCC 5 OUT 6 0,0 GND OUTB OUT GND 10 9 8 7 04369-0-002 PAD CONFIGURATION AND FUNCTIONAL DESCRIPTIONS Figure 2. Pad Layout Table 3. Pad Descriptions No. P1 P2 1 2 3 4 5 6, 8 7, 10 9, 11 12 13 Pad GND TEST FILTER IN GND VCCFILTER VCC OUT GND OUTB CLF POWMON Function GND Probe Pad. Leave floating. Test Probe Pad. Leave floating. Filter Output. Bond directly to PD cathode. Current Input. Bond directly to PD anode. Ground (input return). Filter Supply. Connect to VCC to enable on-chip 200 x 66 pF filter. 3.3 V Positive Supply. Recommended bypass to GND is 1000 pF RF capacitor. Positive Output. Drives 50 termination (ac or dc termination). Ground (Output Return). Negative Output. Drives 50 termination (ac or dc termination). Low Frequency Setpoint. Connect with 1 nF capacitance to GND for <50 kHz. Input Power Monitor Output. Rev. PrJ | Page 6 of 13 Preliminary Technical Data ADN2821 ASSEMBLY RECOMMENDATIONS 5-PIN TO-CAN WITH COMMON PHOTODIODE SUPPLY AND POWMON OUTPUT PIN 4.2mm 4mm OUT 3mm Cb TIA VCC 2mm PD OUTB Clf POWMON 0mm 04369-0-003 1mm Figure 3. 5-Pin TO-CAN with Common Photodiode Supply and POWMON Output Pin Assembly Drawing Table 4. Bill of Materials PD TIA Cb Clf Qty. 1 1 1 1 Description Vendor Specific (0.5 mm x 0.5 mm) AD2821_X (0.87 mm x 1.06 mm) D20BV201J5PX (0.5 mm x 0.5 mm) GM250X7R10216 (0.5 mm x 0.5 mm) Source 10 Gbps Photodiode Analog Devices SiGe 10 Gbps Transimpedance Amplifier DiLabs 100 pF RF Single-Layer Capacitor muRata 1000 pF Ceramic Single-Layer Capacitor Minimize all GND bond wire lengths. Double bond to wide GND pads and OUT, OUTB pads where possible. Minimize IN, FILTER, OUT, and OUTB bond wire lengths. Maintain symmetry in length and orientation between IN and FILTER bond wires. Maintain symmetry in length and orientation between OUT and OUTB bond wires. Double bond OUT, OUTB wires perpendicular to IN, FILTER. Maintain symmetry between IN/FILTER and OUT/OUTB bond wires. Rev. PrJ | Page 7 of 13 Preliminary Technical Data ADN2821 5-PIN TO-CAN WITH EXTERNAL PHOTODIODE SUPPLY VPD CONNECTED THROUGH FILTER PIN 4.2mm 4mm OUT 3mm Cb TIA VCC 2mm PD OUTB Clf 1mm RFILTER FILTER 0mm 04369-0-004 VPD Figure 4. 5-Pin TO-CAN with External Photodiode Supply VPD Connected through FILTER Pin Assembly Drawing Table 5. Bill of Materials PD TIA Cb Clf Qty. 1 1 1 1 Description Vendor Specific (0.5 mm x 0.5 mm) ADN2821_X (0.9 mm x 1.1 mm) D20BV201J5PX (0.5 mm x 0.5 mm) GM250X7R10216 (0.5 mm x 0.5 mm) Source 10 Gbps Photodiode Analog Devices SiGe 10 Gbps Transimpedance Amplifier DiLabs 100 pF RF Single-Layer Capacitor muRata 1000 pF Ceramic Capacitor Minimize all GND bond wire lengths. Double bond to wide GND pads and OUT, OUTB pads where possible. Minimize IN, FILTER, OUT, and OUTB bond wire lengths. Maintain symmetry in length and orientation between IN and FILTER bond wires. Maintain symmetry in length and orientation between OUT and OUTB bond wires. Double bond OUT, OUTB wires perpendicular to IN, FILTER. Maintain symmetry between IN/FILTER and OUT/OUTB bond wires. Rev. PrJ | Page 8 of 13 Preliminary Technical Data ADN2821 BUTTERFLY PACKAGE WITH COMMON PHOTODIODE SUPPLY AND POWMON OUTPUT PIN VCC 7.5mm OUT Cb 5.0mm OUTB PD Clf 2.5mm POWMON 04369-0-005 0mm Figure 5. Butterfly Package with Common Photodiode Supply and POWMON Output Pin Assembly Drawing Table 6. Bill of Materials PD TIA Cb Clf Qty. 1 1 1 1 Description Vendor Specific (0.5 mm x 0.5 mm) ADN2821_X (0.9 mm x 1.1 mm) D20BV201J5PX (0.5 mm x 0.5 mm) GM250X7R10216 (0.5 mm x 0.5 mm) Source 10 Gbps Photodiode Analog Devices SiGe 10 Gbps Transimpedance Amplifier DiLabs 100 pF RF Single-Layer Capacitor muRata 1000 pF Ceramic Capacitor Minimize all GND bond wire lengths. Double bond to wide GND pads where possible. Minimize IN, FILTER, OUT, and OUTB bond wire lengths. Maintain symmetry in length and orientation between IN and FILTER bond wires. Maintain symmetry in length and orientation between OUT and OUTB bond wire. Maintain symmetry between IN/FILTER and OUT/OUTB bond wires. Rev. PrJ | Page 9 of 13 Preliminary Technical Data ADN2821 TRANSIMPEDANCE SELECTION GUIDELINES OPTICAL SENSITIVITY VS. ADN2821 TRANSIMPEDANCE AND LA/CDR INPUT SENSITIVITY (I x + VS ZT ) x (ER + 1) x 1000 Sensitivity (dBm ) = 10 log10 RMS 2 (ER - 1) Table 7. IRMS ER VS ZT Description Photodiode responsivity (A/W) TIA input referred noise (A) BER Scaling Factor Extinction ratio PA/CDR input sensitivity (V) TIA transimpedance (V/A) Value 0.85 A/W typical 1.2 A typical for ADN2821 family 14.1 for 10-12 BER 10 dB typical 5 mV to 100 mV 2 k to 20 k for ADN2821 family Table 8. Optical Input Sensitivity (dBm) PA/CDR Input Sensitivity (VS) 100 mV 50 mV 25 mV 10 mV 5 mV ADN2821 Transimpedance (ZT) 5 k 10 k -15.8 -17.1 -17.1 -18.0 -18.0 -18.6 -18.7 -18.9 -18.9 -19.0 2 k -13.2 -15.2 -16.8 -18.0 -18.6 20 k -18.0 -18.6 -18.8 -19.0 -19.1 INPUT REFERRED LINEAR RANGE VS. ADN2821 TRANSIMPEDANCE LinearRange (dBm) = 10 log10 (VLR Z T x 1000) Table 9. VLR ZT Description Photodiode responsivity (A/W) TIA output linear range (V) TIA transimpedance (V/A) Value 0.85 A/W typical 400 mV typical for ADN2821 family 2 k to 20 k for ADN2821 family Table 10. Optical Input Referred Linear Range (dBm) ADN2821 Transimpedance (ZT) 2 k 5 k -6.3 -10.3 10 k -13.3 IN/FILTER -- OUT/OUTB MUTUAL INDUCTANCE FEEDBACK VS. ADN2821 TRANSIMPEDANCE Mutual inductance feedback from OUT/OUTB bond wires to IN/FILTER bond wires is proportional to ADN2821 TZ. Selecting the lowest ADN2821 TZ required to achieve the desired sensitivity will reduce this feedback gain and the possibility of associated positive feedback frequency peaking 20 k -16.3 and time domain ringing. This mutual inductance feedback path will be suppressed by ensuring short and symmetric IN/FILTER/OUT/OUTB bond wires to reduce their absolute and differential mutual inductances (See assembly recommendations, Figures 3-5). Rev. PrJ | Page 10 of 13 Preliminary Technical Data ADN2821 LOW FREQUENCY CUTOFF TYPICAL OPERATING PERFORMANCE Digital encoding methods may generate long strings of 1s or 0s, requiring the transimpedance amplifier pass band to extend to 1 MHz or below. The ADN2821 includes on-chip low frequency filter circuitry to provide nominal low frequency cutoff in the 100 kHz to 500 kHz range with no external set capacitance, depending on the TZ option. This low frequency cutoff can be tuned lower by adding an external capacitance to the CLF bond pad. ON-WAFER PROBE (LTEST, LOUT, LOUTB ~ 0.2 nH) 1MHz FREQUENCY RESPONSE Test setup: HP8722ES Network Analyzer AC-coupled outputs terminated 50 to GND Network analyzer port power = -42 dBm (ITEST = 10 A p-p, IAVE = 5 A) 500kHz 250kHz ADN2821_10k, 20k 100kHz 50kHz 2 1 25kHz 10kHz ADN2821_02k 5kHz 50pF 100pF 0.5nF 1nF 2.5nF 10nF 5nF Figure 6. Typical Low Frequency Cutoff vs. CLF Capacitance 04369-0-007 5pF 2.5pF 10pF Figure 7. Single-Ended s21 Plot of ADN2821_05k Measured at OUT 2 1 04369-0-008 1kHz 0pF 04369-0-006 ADN2821_05k 2.5kHz Figure 8. Single-Ended s21 Plot of ADN2821_10k Measured at OUT Rev. PrJ | Page 11 of 13 Preliminary Technical Data ADN2821 10 Gbps EYE DIAGRAMS 04369-0-009 Test setup: Agilent Infiniium DCA 86100B oscilloscope Advantest D3186 PRBS generator AC-coupled outputs terminated 50 to GND 04369-0-010 Figure 9. ADN2821_5k Differential Output (OUT-OUTB) with 231 10 Gbps PRBS Input at TEST (ITEST = 100 A p-p, IAVE = 50 A) Figure 10. ADN2821_10k Differential Output (OUT-OUTB) with 231 10 Gbps PRBS Input at TEST (ITEST = 100 A p-p, IAVE = 50 A) Rev. PrJ | Page 12 of 13 Preliminary Technical Data ADN2821 OUTLINE DIMENSIONS P1 P2 GND TEST 1 2 3 13 4 ADN2821 12 11 0.90 mm 5 SINGLE PAD SIZE: 0.076 mm x 0.076mm (pads 2, 4, 5, 8, 9, 12, 13) DOUBLE PAD SIZE: 0.144 mm x 0.076mm (pads 1, 3, 6, 7, 10, 11) 10 9 8 6 7 1.10 mm 0.30 mm Figure 11. Die Form ORDERING GUIDE Model ADN2821ACHIPS-02K ADN2821ACHIPS-05K ADN2821ACHIPS-10K ADN2821ACHIPS-20K Temperature Range -25C to +85C -25C to +85C -25C to +85C -25C to +85C Package Description Die Form Die Form Die Form Die Form (c) 2003 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. C04369-0-11/03(PrJ) Rev. PrJ | Page 13 of 13