FUNCTIONAL BLOCK DIAGRAM

10k

Ω

5

6

7

8

4

3

2

1

AD8015

50

Ω

+1

NC

NC

–OUTPUT

+OUTPUT

G = 3

G = 30

NC = NO CONNECT

50

Ω

+1

– +

1.7V

25.0E+3

20.0E+3

000.E+0

10.0E+6

100.0E+6

1.0E+9

15.0E+3

10.0E+3

5.0E+3

FREQUENCY – Hz

DIFFERENTIAL

SINGLE-ENDED

Figure 1. Differential/Single-Ended Transimpedance vs.

Frequency

5.0

4.5

4.0

3.5

3.0

2.5

2.0

100.0E+6

20.0E+6

000.0E+0

80.0E+6

60.0E+6

40.0E+6

FREQUENCY – Hz

3.0pF

2.0pF

1.5pF

1.0pF

0.5pF

Figure 2. Noise vs. Frequency (SO-8 Package with

Added Capacitance)

REV. A

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

which may result from its use. No license is granted by implication or

otherwise under any patent or patent rights of Analog Devices.

a

Wideband/Differential Output

Transimpedance Amplifier

AD8015

FEATURES

Low Cost, Wide Bandwidth, Low Noise

Bandwidth: 240 MHz

Pulse Width Modulation: 500 ps

Rise Time/Fall Time: 1.5 ns

Input Current Noise: 3.0 pA/

√Hz @ 100 MHz

Total Input RMS Noise: 26.5 nA to 100 MHz

Wide Dynamic Range

Optical Sensitivity: –36 dBm @ 155.52 Mbps

Peak Input Current:

350

A

Differential Outputs

Low Power: 5 V @ 25 mA

Wide Operating Temperature Range: –40 C to +85 C

APPLICATIONS

Fiber Optic Receivers: SONET/SDH, FDDI, Fibre Channel

Stable Operation with High Capacitance Detectors

Low Noise Preamplifiers

Single-Ended to Differential Conversion

I-to-V Converters

PRODUCT DESCRIPTION

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. This high bandwidth

supports data rates beyond 300 Mbps. The differential outputs

drive ECL directly, or can drive a comparator/ fiber optic post

amplifier.

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. The 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.

The AD8015 is available in die form, or in an 8-pin SOIC

package.

© Analog Devices, Inc., 1996

One Technology Way, P.O. Box 9106, Norwood, 02062-9106, U.S.A.

Tel: 617/329-4700

Fax: 617/326-8703