Wideband/Differential Output
Transimpedance Amplifier
a
AD8015
FUNCTIO NAL BLO CK D IAGRAM
FEATURES
Low Cost, Wide Bandw idth, Low Noise
Bandw idth: 240 MHz
Pulse Width Modulation: 500 ps
Rise Tim e/ Fall Tim e: 1.5 ns
Input Current Noise: 3.0 pA/ √Hz @ 100 MHz
Total Input RMS Noise: 26.5 nA to 100 MHz
Wide Dynam ic Range
AD8015
+VS
8
7
6
5
1
2
3
NC
IIN
10kΩ
50Ω
+OUTPUT
–OUTPUT
+1
+1
G = 30
G = 3
NC
50Ω
Optical Sensitivity: –36 dBm @ 155.52 Mbps
Peak Input Current: ؎350 A
Differential Outputs
–VS
VBYP
– +
+V
S
4
1.7V
NC = NO CONNECT
Low Pow er: 5 V @ 25 m A
Wide Operating Tem perature Range: –40؇C to +85؇C
APPLICATIONS
25.0E+3
20.0E+3
15.0E+3
10.0E+3
5.0E+3
Fiber Optic Receivers: SONET/ SDH, FDDI, Fibre Channel
Stable Operation w ith High Capacitance Detectors
Low Noise Pream plifiers
Single-Ended to Differential Conversion
I-to-V Converters
DIFFERENTIAL
SINGLE-ENDED
P RO D UCT D ESCRIP TIO N
The AD8015 is a wide bandwidth, single supply transimpedance
amplifier optimized for use in a fiber optic receiver circuit. It is a
complete, single chip solution for converting photodiode current
into a differential voltage output. The 240 MHz bandwidth enables
AD8015 application in FDDI receivers and SONET /SDH
receivers with data rates up to 155 Mbps. T his high bandwidth
supports data rates beyond 300 Mbps. T he differential outputs
drive ECL directly, or can drive a comparator/ fiber optic post
amplifier.
000.E+0
10.0E+6
100.0E+6
FREQUENCY – Hz
1.0E+9
Figure 1. Differential/Single-Ended Transim pedance vs.
Frequency
5.0
In addition to fiber optic applications, this low cost, silicon al-
ternative to GaAs-based transimpedance amplifiers is ideal for
systems requiring a wide dynamic range preamplifier or single-
ended to differential conversion. T he IC can be used with a
standard ECL power supply (–5.2 V) or a PECL (+5 V) power
supply; the common mode at the output is ECL compatible.
T he AD8015 is available in die form, or in an 8-pin SOIC
package.
3.0pF
4.5
4.0
2.0pF
1.5pF
3.5
3.0
2.5
1.0pF
0.5pF
2.0
000.0E+0
20.0E+6
40.0E+6
60.0E+6
80.0E+6
100.0E+6
FREQUENCY – Hz
Figure 2. Noise vs. Frequency (SO-8 Package with
Added Capacitance)
REV. A
Inform ation furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assum ed by Analog Devices for its
use, nor for any infringem ents of patents or other rights of third parties
which m ay result from its use. No license is granted by im plication or
otherwise under any patent or patent rights of Analog Devices.
© Analog Devices, Inc., 1996
One Technology Way, P.O. Box 9106, Norw ood, 02062-9106, U.S.A.
Tel: 617/ 329-4700 Fax: 617/ 326-8703