CONNECTION DIAGRAMS

8-Pin Plastic Mini-DIP (N) Package

LOAD RESISTANCE –

30

0

10

10k

20

10

100

1k

Vs = ±15V

25

15

5

Ω

8-Pin SOIC (R) Package

1

2

3

4

8

7

6

5

AD795

NC

–IN

+IN

NC

OUTPUT

NC

NC = NO CONNECT

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

Low Power, Low Noise

Precision FET Op Amp

AD795

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

Tel: 617/329-4700

Fax: 617/326-8703

FEATURES

Low Power Replacement for Burr-Brown

OPA-111, OPA-121 Op Amps

Low Noise

2.5

V p-p max, 0.1 Hz to 10 Hz

11 nV/

√Hz max at 10 kHz

0.6 fA/

√Hz at 1 kHz

High DC Accuracy

250

V max Offset Voltage

3

V/ C max Drift

1 pA max Input Bias Current

Low Power: 1.5 mA max Supply Current

Available in Low Cost Plastic Mini-DIP and Surface

Mount (SOIC) Packages

APPLICATIONS

Low Noise Photodiode Preamps

CT Scanners

Precision l-to-V Converters

PRODUCT DESCRIPTION

The AD795 is a low noise, precision, FET input operational

amplifier. It offers both the low voltage noise and low offset drift

of a bipolar input op amp and the very low bias current of a

FET-input device. The 10

14

Ω common-mode impedance

insures that input bias current is essentially independent of

common-mode voltage and supply voltage variations.

The AD795 has both excellent dc performance and a guaran-

teed and tested maximum input voltage noise. It features 1 pA

maximum input bias current and 250

µV maximum offset volt-

age, along with low supply current of 1.5 mA max.

1k

10

1

10

100

10k

1k

100

FREQUENCY – Hz

AD795 Voltage Noise Spectral Density

Furthermore, the AD795 features a guaranteed low input noise

of 2.5

µV p-p (0.1 Hz to 10 Hz) and a 11 nV/√Hz max noise

level at 10 kHz. The AD795 has a fully specified and tested

input offset voltage drift of only 3

µV/°C max.

The AD795 is useful for many high input impedance, low noise

applications. The AD795J and AD795K are rated over the

commercial temperature range of 0

°C to +70°C.

The AD795 is available in 8-pin plastic mini-DIP and 8-pin

surface mount (SOIC) packages.

50

0

5

–4

10

–5

30

20

40

4

3

2

1

0

–1

–2

–3

INPUT OFFSET VOLTAGE DRIFT –

µV/°C

SAMPLE SIZE = 570

Typical Distribution of Average Input Offset Voltage Drift