3.2 Gbps, 3.3 V, Low Noise,
Transimpedance Amplifier
ADN2880
FEATURES
Bandwidth: 2.5 GHz
Optical sensitivity: 鈭?4.2 dBm
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Differential transimpedance: 4400 V/A
Power dissipation: 70 mW
Differential output swing: 260 mV p-p
Input overload current: 4.3 mA p-p
On-chip RSSI function
Low frequency cutoff: 20 kHz
On-chip PD filter: R
F
= 200 惟, C
F
= 20 pF
Die size: 0.7 mm 脳 1.2 mm
GENERAL DESCRIPTION
The ADN2880 is a 3.3 V, high gain SiGe transimpedance
amplifier (TIA). The TIA converts the small signal current of a
photo detector into differential voltage output. The ADN2880
features a 315 nA typical input-referred noise, enabling an
optical sensitivity of 鈭?4.2 dBm (0.85 A/W PIN). With a
bandwidth of 2.5 GHz, the ADN2880 allows a data rate
operation up to 3.2 Gbps. Typical power dissipation is
approximately 70 mW.
To facilitate the assembly in small form factor packages, such
as TO-46 headers, the ADN2880 provides an on-chip RC filter
(200 惟, 20 pF) and features a 20 kHz low frequency cutoff
without using an external capacitor. An on-chip RSSI circuit,
which generates a voltage proportional to the average photo-
diode current, is also available for power monitoring and
assembly alignment.
The ADN2880 is available in die form. With a chip area of
1.2 mm 脳 0.7 mm, the TIA layout is specifically optimized for
TO-Can-based packages.
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APPLICATIONS
3.2 Gbps or below optical receivers
SONET/GbE/FC optical receivers
SFF-8472-compliant receivers
PIN/APD-TIA receive optical subassemblies (ROSA)
Based on 1550 nm PIN, responsivity = 0.85 A/W, ER = 9 dB, BER < 10
鈭?0
.
FUNCTIONAL BLOCK DIAGRAM
3.3V
VCCFILTER
VCC
200惟
FILTER
50惟
1400惟
50惟
OUT
OUTB
IN
20pF
0.85V
5mA
RSSI
Figure 1.
Rev. 0
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漏 2005 Analog Devices, Inc. All rights reserved.
04945-001
GND
GND
CAP
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