11.1 Gbps 3.3V
Transimpedance Amplifier
Preliminary Technical Data
ADN2821
Rev. PrL
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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
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FEATURES
Bandwidth: 8 GHz min
Input Noise Current Density: 12pA√Hz
Optical sensitivity: −19 dBm1
Differential Transimpedance /Linear Range:
ADN2821_2: 2.0 kΩ/0.20 mA p-p
ADN2821_5: 5.0 kΩ/0.08 mA p -p
ADN2821_10: 10.0 kΩ/0.04 mA p-p
Power Dissipation: 150 mW
Differential Output Swing: 400 mV p-p min
Input Overload: 3.25 dBm @ 10 dB ER
Low-F cutoff:
ADN2821_10: 25 kHz w/CLF = 0.5 nF
On-Chip PD filter: RF = 200 Ω, CF = 20 pF
RSSI voltage and current ratio: 0.8V/mA
Die Size: 0.65 mm × 1.20 mm
APPLICATIONS
10.7 Gbps Optical Modules
SONET/SDH OC-192/STM-64 and 10 GbE
Receivers, Transceivers, Transponders
PRODUCT DESCRIPTION
The ADN2821_2/5/10 are a series of compact, high
performance SiGe 3.3V power supply Trans-impedance
Amplifiers (TIAs) optimized for small form factor 10Gbps
Metro-Access and Ethernet PD-TIA modules. The ADN2821
series features low input referred noise current and a range of
trans-impedance gains, suitable for driving a typical CDR or
transceiver directly. 8GHz minimum BW enables up to
11.1Gbps operation; 1.1µA input referred noise current enables
−19dBm sensitivity; 3.25dBm input overload current at a 10dB
extinction ratio. RSSI output signal proportional to average
input current is available for monitoring and alarm generation.
For assembly in small form factor packages, the ADN2821
series integrates a photodiode filter RFCF network on chip and
features 25kHz low frequency cutoff with small 0.5nF external
capacitor The ADN2821 operates with a 3.3V ±0.3V power
supply and is available in die form.
1 10-12 BER, 10 dB extinction ratio, 0.85 A/W PD responsivity.
FUNCTIONAL BLOCK DIAGRAM
Figure 1. ADN2821 Block Diagram.
500Ω50Ω50Ω
0.85V 10mA
200Ω
20pF
OUT
OUTB
GND GND CLF
FILTER
IN
VCC
VCC_FILTER
3.3V
RSSI
ADN2821 Preliminary Technical Data
Rev. PrL| Page 2 of 8
TABLE OF CONTENTS
Electrical Specifications................................................................... 3
Absolute Maximum Ratings............................................................ 4
ESD Caution.................................................................................. 4
Pad Descriptions............................................................................... 5
Pad Layout......................................................................................... 6
Pad Coordinates ............................................................................6
Die Information.............................................................................6
Assembly Recommendations...........................................................7
Ordering Guide..................................................................................8
REVISION HISTORY
Revision PrL: Preliminary Version
11/04 Revision Pr-A: Add RSSI function Spec.
Preliminary Technical Data ADN2821
Rev. PrL | Page 3 of 8
ELECTRICAL SPECIFICATIONS
Table 1.
Parameter Conditions1 Min Typ Max Units
DYNAMIC PERFORMANCE
Bandwidth (BW)2 −3 dB 8 9.5 GHz
Total Input RMS Noise (IRMS)2 DC to 10GHz 1.1 1.3 µA
Small Signal Trans-impedance (TZ) ADN2821_2, 100 MHz 1500 2000 2500 V/A
ADN2821_5, 100 MHz 3500 5000 6500 V/A
ADN2821_10, 100 MHz 6000 10000 15000 V/A
Trans-impedance Ripple2 50 MHz to 5 GHz ±1 dB
Group Delay Variation2 50 MHz to 8 GHz ±10 ps
Low Frequency Cut-Off CLF = 1000 pF 15 kHz
Output Return Loss2 DC to 8 GHz, differential −12 −10 dB
Total pk-pk Jitter2 I
IN,PK- PK = 2.0 mA, 4 dB ER 5 TBD ps
Input Overload Current3, 2 Pav, 10-12 BER, 10 dB ER TBD 3.25 dBm
Maximum Output Swing p-p diff, IIN,PK- PK = 2.5mA 400 520 650 mV
Linear Output Range p-p, < 1 dB gain compression 400 mV
Power Supply Noise Rejection <10MHz TBD dB
DC PERFORMANCE
Power Dissipation IIN,AVE = 0.1 mA, Vcc = 3.3 V ± 5% 150 200 mW
Input Voltage 0.85 V
Output Impedance single-ended 50 Ω
PD FILTER Resistance RF 200 Ω
PD FILTER Capacitance CF 20 pF
RSSI Sensitivity IIN, AVE = 0 uA to 1 mA 0.8 V/mA
RSSI Offset IIN, AVE = 0 uA TBD mV
1 Min/Max Vcc = +3.3V ± 0.3V, Ta = −40°C to +95°C; Typ Vcc = 3.3V, Tambient = +25C
2 Photodiode capacitance CD = 0.22pF ± 0.04pF, Photodiode resistance = 15Ω, CB = 100pF Bond inductance LIN = LFILTER = 0.3nH ± 0.1nH; LOUT = LOUTB = 0.5nH ± 0.1nH
Load impedance = 50Ω (each output, AC coupled)
3 10-12 BER, 10dB extinction ratio, 0.85 A/W PD responsivity
ADN2821 Preliminary Technical Data
Rev. PrL| Page 4 of 8
ABSOLUTE MAXIMUM RATINGS
Table 2.
Parameter Rating
Supply Voltage (Vcc to Gnd) 5V
Internal Power Dissipation
Output Short Circuit Duration Indefinite
Maximum Input Current 10 mA
Storage Temperature Range −65°C to +125°C
Operating Ambient Temperature Range −40°C to +95°C
Maximum Junction Temperature +165°C
Die Attach Temperature (<60 seconds) +450°C
Stresses above those listed under ‘Absolute Maximum Rating’
may cause permanent damage to the device. This is a stress
rating only and functional operation of the device at these or
any other conditions 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.
Preliminary Technical Data ADN2821
Rev. PrL | Page 5 of 8
PAD DESCRIPTIONS
Table 3.
Pad No. Pad Function
1 GND Ground (input return)
2 IN Current input. Bond directly to PD anode.
3 TEST Test probe Pad. Leave Floating.
4 FILTER Filter Output.
5 FILTER Filter Output.
6 GND Ground
7 RSSI Voltage Output (provides average input current reading)
8 CAP Low Frequency set point. Connect with .5nF capacitance to GND for <30kHz
9 GND Ground
10 GND Ground (output return)
11 OUTB Negative Output. Drives 50 ohm termination (AC or DC termination)
12 OUT Positive Output. Drives 50 ohm termination (AC or DC termination)
13 GND Ground (output return)
14 GND Ground
15 VCCFILTER Filter Supply. Connect to Vcc to enable on-chip 200 ohm*20pf Filter.
16 VCC 3.3 V positive Supply. Recommended bypass to GND is 100 pF RF capacitor.
17 VCC 3.3 V positive Supply. Recommended bypass to GND is 100 pF RF capacitor.
B
FILTER
RSSI
ADN2821 Preliminary Technical Data
Rev. PrL| Page 6 of 8
PAD LAYOUT
Figure 2.. Pad Layout
PAD COORDINATES
Table 4.
PAD # PAD X (um) Y (um)
1 GND −500 260
2 IN −500 130
3 TEST −500 10
4 FILTER −500 −120
5 FILTER −500 −260
6 GND −350 −260
7 RSSI −200 −260
8 CAP −50 −260
9 GND 130 −260
10 GND 500 −260
11 OUTB 350 −60
12 OUT 350 60
13 GND 500 260
14 GND 130 260
15 VCCFILTER −50 260
16 VCC −200 260
17 VCC −350 260
DIE INFORMATION
Die Size
0.7mm × 1.2mm
(edge-edge including 1mil scribe)
Die Thickness
10mils = 0.25mm
Passivation Openings
0.075 mm × 0.075 mm
(pads 1-8, 9, 10, 13, 15, 16, 17)
0.144mm × 0.075mm
(pads 9, 11, 12, 14)
Passivation Composition
5000Å Si3N4 (top)
+5000 Å SiO2 (bot)
Pad Composition
Al/1%Cu
Backside Contact
B
FILTER
RSSI
Preliminary Technical Data ADN2821
Rev. PrL | Page 7 of 8
ASSEMBLY RECOMMENDATIONS
560pF
200pF
1000pF
VPD VCC
OUTB OUT
Figure 3. 5-Pin TO-46 w/External Photodiode Supply VPD
• 1× VENDOR SPECIFIC (0.3mm × 0.3mm) 10.0Gbps Photo Diode
• 1× ADN2821 (0.7mm × 1.2mm) Analog Devices SiGe 10.0Gbps Trans-Impedance Amplifier
• 200pF RF Single Layer Capacitor
• 560pF RF Single Layer Capacitor
• 1000pF Ceramic Cap
Notes:
1. Minimize all GND bond wire lengths.
2. Minimize IN, FILTER, OUT and OUTB bond wire lengths.
3. Maintain symmetry in length and orientation between IN and FILTER bond wires.
4. Maintain symmetry in length and orientation between OUT and OUTB bond wires.
5. Maintain symmetry between IN/FILTER and OUT/OUTB bond wires.
ADN2821 Preliminary Technical Data
Rev. PrL| Page 8 of 8
ORDERING GUIDE
Model Temperature Package Description Package Option
ADN2821XCHIP-02KWP -40oC to 95oC NA Tested Die
ADN2821XCHIP-05KWP -40oC to 95oC NA Tested Die
ADN2821XCHIP-10KWP -40oC to 95oC NA Tested Die
© 2004 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective companies.
Printed in the U.S.A. PR04369–0–11/04(PrL)
