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 R
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
-12
10
BER, 10 dB extinction ratio, 0.85 A/W PD responsivity.
network on chip and
FCF
FUNCTIONAL BLOCK DIAGRAM
3.3V
VCC_FILT ER
200Ω
FI L TER
IN
20pF
0.85V
GND
Figure 1. ADN2821 Block Diagram.
Rev. PrL
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.
Bandwidth (BW)2 −3 dB 8 9.5 GHz
Total Input RMS Noise (I
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
Input Overload Current
Maximum Output Swing p-p diff, I
Linear Output Range p-p, < 1 dB gain compression 400 mV
Power Supply Noise Rejection <10MHz TBD dB
DC PERFORMANCE
Power Dissipation I
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 I
RSSI Offset I
1
Min/Max Vcc = +3.3V ± 0.3V, Ta = −40°C to +95°C; Typ Vcc = 3.3V, T
2
Photodiode capacitance CD = 0.22pF ± 0.04pF, Photodiode resistance = 15Ω, CB = 100pF Bond inductance LIN = L
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
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.
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.
Rev. PrL| Page 4 of 8
Preliminary Technical Data ADN2821
PAD DESCRIPTIONS
FILTER
RSSI
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.