a
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
30
Low Power, Low Noise
Precision FET Op Amp
AD795
CONNECTION DIAGRAMS
8-Pin Plastic Mini-DIP (N) Package
OUTPUT VOLTAGE SWING – Volts p-p
V
s
= ±15V
25
20
15
10
5
0
10
100
1k
LOAD RESISTANCE –
Ω
10k
8-Pin SOIC (R) Package
NC 1
–IN 2
+IN 3
–V
S
4
8 NC
7 +V
S
6 OUTPUT
5 NC
AD795
NC = NO CONNECT
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.
VOLTAGE NOISE SPECTRAL DENSITY – nV/√Hz
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.
1k
50
SAMPLE SIZE = 570
40
PERCENTAGE OF UNITS
100
30
20
10
10
1
10
100
1k
FREQUENCY – Hz
10k
0
–5
–4
–3
–2
–1
0
1
2
3
4
5
INPUT OFFSET VOLTAGE DRIFT –
µV/°C
AD795 Voltage Noise Spectral Density
Typical Distribution of Average Input Offset Voltage Drift
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.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700
Fax: 617/326-8703
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