CS3160

Part Number S3160 Revision A – August 12, 2004 S3160 2.5 Gbps Wide Bandwidth Transimpedance Amplifier FEATURES • • • • • • • Greater than 2 GHz Bandwidth 3 kΩ differential transimpedance Single 3.3 V supply 6.5 pA/√(Hz) typical noise current density 2.2 mA peak to peak max input current Voltage limited outputs Maximum Die size: 1.27 mm by 1.27 mm Data Sheet GENERAL DESCRIPTION The S3160 is a high-speed transimpedance amplifier (TIA) for 2.5 Gbps applications. Input currents as high as 2.2 mA can be amplified with low duty cycle distortion. The low input noise allows signals down to 4 µA (peak to peak) to be detected with a signal to noise ratio of 22 dB (allows for BER< 1E-10). The outputs are voltage limited to 1000 mV, differential, in order to allow a wide input dynamic range without exceeding the input voltage range of the post ( l i m i t i n g ) a m p l i f i e r. F i g u r e 1 s h o w s a t y p i c a l application. APPLICATIONS • • SONET OC-48 Fiber optic data links Figure 1. Typical Operating Circuit V CC C FILT FILT VCC Zo = 50 Ω (Limiting Amp and CDR) RBYPASS OUTP DINP SERDATOP S3160 OUTN IIN GND Zo = 50 Ω DINN S3078 SERDATON Alternate Connection AMCC Confidential and Proprietary 1 S3160 – 2.5 Gbps Wide Bandwidth Transimpedance Amplifier Revision A – August 12, 2004 Data Sheet DETAILED DESCRIPTION F igure 2 depicts the overall block diagram of the S3160 transimpedance amplifier. The amplifier cir cuitry consists of a transimpedance stage and an output driver stage with a 6 dB gain. The transimpedance amplifier converts the photodiode photocurrent to a voltage. The photodiode can be biased by connecting it to the RBYPASS pin or it can be connected directly to VCC. The amplifier gain is linear for an input of up to 300 µA. Above that the transimpedance of the input stage is reduced by the action of the schottky diode, to prevent overdrive of the output stage. The output of the output stage begins to fully limit when the input current reaches 700 µA. The output voltage is limited at 1000 mV, differential, peak to peak. Figure 2. S3160 Detailed Block Diagram V CC The output of the transimpedance stage is converted to a differential signal by the combination of the output stage and a bias block. This bias block averages the output of the transimpedance stage and establishes the DC input reference for the output stage. The bandwidth of this circuit is set by an on-chip capacitor, but can be reduced by adding an off-chip capacitor, CFILT. This bandwidth corresponds to the low frequency -3 dB cutoff of the TIA. Increasing the value of C FILT w ill reduce the low frequency -3 dB cutoff. With no CFILT capacitor added it will be at 45 kHz. CFILT (OPTIONAL) RBYPASS VCC 100 Ω OUTP IIN FILT X2 BIAS OUTN 1500 Ω GND 2 AMCC Confidential and Proprietary S3160 – 2.5 Gbps Wide Bandwidth Transimpedance Amplifier Revision A – August 12, 2004 Data Sheet Table 1. S3160 Pad Assignment and Description Pin Name VCC I/O S Pad # 8 9 10 11 12 1 2 3 4 13 15 14 7 Coordinates [X,Y] (1) [868.9, 1051.4] [669.6, 1051.4] [470.8, 1051.4] [271.8, 1051.4] [90.8, 892.5] [273, 91.4] [472, 91.4] [670.8, 91.4] [870.1, 91.4] [100.925, 702.425] [90.9, 293.3] [97.575, 473.975] [1052.3. 777] +3.3 V Power supply. Description GND S Ground. RBYPASS I Bypass connection for cathode of photodiode. IIN FILT I I PIN diode input. Filter capacitor input. A capacitor to ground can be added at this pad to reduce the low frequency -3 dB cutoff. (See Design Procedures). Negative transimpedance amplifier output. Positive transimpedance amplifier output. OUTN OUTP O O 6 5 [1049.275, 567.475] [1049.275, 375.225] 1. The coordinates represent the position of the center of the pad in µm, with respect to the lower left corner of the circuit die. 2. Note: I = Input pin, O = Output pin, S = Supply pin. AMCC Confidential and Proprietary 3 S3160 – 2.5 Gbps Wide Bandwidth Transimpedance Amplifier Revision A – August 12, 2004 Data Sheet Figure 3. S3160 Bonding Pad Location 1.27 mm (Total Die Size) Y-Axis 1.15 mm (Circuit Die Size) VCC VCC VCC VCC 11 10 9 8 VCC 12 1.15 mm (Circuit Die Size) 1.27 mm (Total Die Size) 7 RBYPASS 13 6 IIN 14 5 RBYPASS 15 FILT OUTN OUTP 1 2 1 3 4 X-Axis (0,0) Circuit Die Size GND Total Die Size 2 GND GND GND Note: Pad Size is 94 µm X 94 µm. The exposed area of the pad is 80 µm X 80 µm. Die thickness is 254 µm (10 mils). 1. The circuit die size is the smallest possible size of the die. The lower left-hand corner of the circuit die is the origin of the xy-coordinate system. Pad coordinates indicated in Table 1 are measured from this origin to the pad's center. 2. The total die size is the largest possible size of the die. It includes a splicing area around the circuit die. The actual size of any given die may vary in size from the minimum (circuit die) size to the maximum (total die) size. 4 AMCC Confidential and Proprietary S3160 – 2.5 Gbps Wide Bandwidth Transimpedance Amplifier Revision A – August 12, 2004 Data Sheet Table 2. Recommended Operating Conditions Parameter Ambient Temperature, TA Junction Operating Temperature, TJ Voltage on VCC with respect to GND Min -40 -20 3.135 3.3 Typ Max +85 +105 3.465 Units °C °C V Table 3. Absolute Maximum Ratings The following are the absolute maximum stress ratings for the S3160. Stresses beyond those listed may cause permanent damage to the device. Absolute maximum ratings are stress ratings only and operation of the device at the maximums stated or any other conditions beyond those indicated in the "Recommended Operating Conditions" of this document are not inferred. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Parameter Voltage on VCC with respect to GND Voltage on all Other Pads Storage Temperature Range Min -0.5 -0.5 -55 Typ Max 4 VCC +0.3 150 Units V V °C Electrostatic Discharge (ESD) Sensitivity Rating - Human Body Model (HBM): The S3160 is rated to the following ESD voltages based upon JEDEC standard: JESD22-A114-B CLASS 0 - All pins are rated at or above 1000 volts except pins IIN, OUTP and OUTN. OUTP and OUTN are rated at 500 V and IIN is rated to 100 volts. Adherence to standards for ESD protection should be taken during the handling of the devices to ensure that the devices are not damaged. The standards to be used are defined in ANSI standard ANSI/ESD S20.20-1999, "Protection of Electrical and Electronic Parts, Assemblies and Equipment." Contact your local FAE or sales representative for applicable ESD application notes. AMCC Confidential and Proprietary 5 S3160 – 2.5 Gbps Wide Bandwidth Transimpedance Amplifier Revision A – August 12, 2004 Data Sheet Table 4. AC Electrical Characteristics (Vcc = 3.3 V ± 5%, TA = -40°C to +85°C) Parameter RT Description AC Transimpedance Min 2.56 Typ 2.95 Max 3.34 Units kV/A Conditions 50 Ohm load 0.5 pF photodiode capacitance, 1.5 nH input bond wire inductance. No CFILT connected Peak-to-peak Peak-to-peak, differential BW -3 dB Bandwidth 2.7 3.2 3.6 GHz BWLF IPK VOD IIN, CL IND IN Low Frequency -3 dB Cutoff Maximum Input Current Maximum Differential output voltage Input Current before clipping Input Noise Current Density Input Noise Current Total Jitter (Pk to Pk) (At 1E-12 BER) Output Ripple Group Delay Variation Output Reflection Coefficient Output Impedance 45 -0.5 -25 250 2.2 45 57 kHz mA 1000 1200 mV µA 300 6.5 325 9.3 465 1 dB compression point 0 - 2.5 GHz (Output rms noise)/RT, 2.5 GHz bandwidth Input is 2.488 Gbps, 223-1 PRBS. IIN = 2.2 mA 1 - 2000 MHz 100 - 2500 MHz 1 - 3500 MHz pA/√(Hz) nA JT RIPPLE Group Delay S22 ROUT 0.12 +0.5 +25 -18 50 58 UI dB pS dB Ω Table 5. DC Electrical Characteristics (Vcc = 3.3 V ± 5%, TA = -40°C to +85°C) Parameter ICC VBIAS Description Supply Current Input Bias Voltage 0.79 VCC -0.9 Min Typ 40 0.92 VCC -0.65 Max 57 1.0 VCC -0.25 Units mA V 50 Ω line termination to GND (AC Coupled) or 100 Ω line-to-line termination. Conditions VCM Common Mode Output Voltage V Note: AC Electrical Characteristics are guaranteed by characterization. 6 AMCC Confidential and Proprietary S3160 – 2.5 Gbps Wide Bandwidth Transimpedance Amplifier Revision A – August 12, 2004 Data Sheet DESIGN PROCEDURES Determining Capacitor Values CFILT can be selected using the formula: Low frequency –3 dB cutoff = 1 / [2π*400kΩ*(10pF + CFILT)] APPLICATION INFORMATION Filtering Through RBYPASS To reduce the effect of supply voltage noise at the cathode of the photodiode, the cathode connection to VCC should be made through the RBYPASS resistor. The RBYPASS resistor and an external capacitor to ground at the cathode of the photodiode will act as a filter to reduce this noise and dampen any resonance at the cathode of the photodiode. Wire Bonding and Layout Information For best performance all GND pads should be connected and the bond wire inductance between the photodiode and the IIN pin should be kept to below 1.5 nH – 2 nH. The back of the die is not metallized and should be connected to ground or left electrically unconnected. The outputs OUTP and OUTN should be terminated equally to prevent instabilities. Figures 4 and 5 show the differential and single-ended terminations. AMCC Confidential and Proprietary 7 S3160 – 2.5 Gbps Wide Bandwidth Transimpedance Amplifier Revision A – August 12, 2004 Data Sheet Figure 4. Output Differential Termination Vcc CFILT S3160 FILT VDD RBYPASS OUTP Zo = 50 Ω Zo = 50 Ω 100 Ω Limiting Amplifier OUTN I IN GND Alternate Connection Figure 5. Output Single-Ended Termination Vcc C FILT S3160 FILT VDD RBYPASS OUTP Zo = 50 Ω 50 Ω Zo = 50 Ω 50 Ω OUTN I IN GND Alternate Connection 8 AMCC Confidential and Proprietary S3160 – 2.5 Gbps Wide Bandwidth Transimpedance Amplifier Revision A – August 12, 2004 Data Sheet Typical Operating Characteristics Figure 6. Frequency Response (Gain vs. Frequency) Figure 8. Output Voltage vs. Input Current Figure 9. Supply Current vs. Temperature Figure 7. Eye Diagram (at 2.5 Gbps) (IIN = 2.2 mA) AMCC Confidential and Proprietary 9 S3160 – 2.5 Gbps Wide Bandwidth Transimpedance Amplifier Revision A – August 12, 2004 Data Sheet DOCUMENT REVISION HISTORY Revision A NC Date 08/12/04 2/28/01 Description • Pg. 6, Table 4, changed S22 Max from -22 dB to -18 dB; changed Rout Max from 55 Ω to 58 Ω. • Production release version. 10 AMCC Confidential and Proprietary S3160 – 2.5 Gbps Wide Bandwidth Transimpedance Amplifier Revision A – August 12, 2004 Data Sheet Ordering Information Prefix S–Integrated Circuit Device 3160 Package DI–Industrial Grade Die X Prefix XXXX Device X Package Applied Micro Circuits Corporation 6290 Sequence Dr., San Diego, CA 92121 Phone: (858) 450-9333 — (800) 755-2622 — Fax: (858) 450-9885 http://www.amcc.com AMCC reserves the right to make changes to its products, its datasheets, or related documentation, without notice and warrants its products solely pursuant to its terms and conditions of sale, only to substantially comply with the latest available datasheet. Please consult AMCC’s Term and Conditions of Sale for its warranties and other terms, conditions and limitations. AMCC may discontinue any semiconductor product or service without notice, and advises its customers to obtain the latest version of relevant information to verify, before placing orders, that the information is current. AMCC does not assume any liability arising out of the application or use of any product or circuit described herein, neither does it convey any license under its patent rights nor the rights of others. AMCC reserves the right to ship devices of higher grade in place of those of lower grade. AMCC SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, INTENDED, AUTHORIZED, OR WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT APPLICATIONS, DEVICES OR SYSTEMS OR OTHER CRITICAL APPLICATIONS. AMCC is a registered Trademark of Applied Micro Circuits Corporation. Copyright © 2005 Applied Micro Circuits Corporation. AMCC Confidential and Proprietary 11