ANALOG DEVICES AD743 Data Sheet

Ultralow Noise Bi FET Op Amp AD743

FEATURES CONNECTION DIAGRAMS Ultralow Noise Performance

8-Lead PDIP (N) 16-Lead SOIC (R)

2.9 n V/√Hz at 10 k Hz 0.38
V p-p, 0.1 Hz to 10 Hz

NULL NC NC NC

6.9 f A/√Hz Current Noise at 1 k Hz AD743

OFFSET AD743 –IN +VS NC NULL

Excellent DC Performance

0.5 m V Max Offset Voltage +IN –IN NC

250 p A Max Input Bias Current

–VS NC +VS

1000 V/m V Min Open-Loop Gain TOP VIEW

+IN OUTPUT

NC = NO CONNECT

AC Performance

OFFSET

2.8 V/
s Slew Rate NULL

4.5 MHz Unity-Gain Bandwidth NC NC

THD = 0.0003% @ 1 k Hz TOP VIEW

NC NC

Available in Tape and Reel in Accordance with

NC = NO CONNECT

EIA-481A Standard

APPLICATIONS Sonar Preamplifiers High Dynamic Range Filters (>140 d B)

2. The combination of low voltage and low current noise make

Photodiode and IR Detector Amplifiers

IN IS z)

the AD743 ideal for charge sensitive applications such as

Accelerometers

accelerometers and hydrophones. 3. The low input offset voltage and low noise level of the AD743

GENERAL DESCRIPTION

provide >140 d B dynamic range.

The AD743 is an ultralow noise, precision, FET input, monolithic

ww .BDTIC.com/ADI 4. The typical 10 k Hz noise level of 2.9 n V/√Hz permits a three

operational amplifier. It offers a combination of the ultralow volt-

op amp instrumentation amplifier, using three AD743s, to be

age noise generally associated with bipolar input op amps and

built which exhibits less than 4.2 n V/√Hz noise at 10 k Hz

the very low input current of a FET input device. Furthermore,

and which has low input bias currents.

the AD743 does not exhibit an output phase reversal when the negative common-mode voltage limit is exceeded.

RSOURCE OP27 AND

The AD743’s guaranteed, maximum input voltage noise of

RESISTOR

4.0 n V/√Hz at 10 k Hz is unsurpassed for a FET input mono- ( — )

lithic op amp, as is the maximum 1.0 µV p-p, 0.1 Hz to 10 Hz noise. The AD743 also has excellent dc performance with 250 p A RSOURCE maximum input bias current and 0.5 m V maximum offset voltage.

The AD743 is specifically designed for use as a preamp in capaci- AD743 AND RESISTOR

AD743 AND

tive sensors, such as ceramic hydrophones. The AD743J is rated RESISTOR

OP27 AND RESISTOR

over the commercial temperature range of 0°C to 70°C. The AD743 is available in a 16-lead SOIC and 8-lead PDIP.

PRODUCT HIGHLIGHTS RESISTOR NOISE ONLY

1. The low offset voltage and low input offset voltage drift of the AD743 coupled with its ultralow noise performance mean

that the AD743 can be used for upgrading many applications

SOURCE RESISTANCE ()

now using bipolar amplifiers.

Figure 1. Input Voltage Noise vs. Source Resistance

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

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

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

under any patent or patent rights of Analog Devices. Trademarks and Tel: 781/329-4700 www.analog.com registered trademarks are the property of their respective companies. Fax: 781/326-8703 © 2003 Analog Devices, Inc. All rights reserved.