a
FEATURES
Low Offset Voltage: 250 V
Low Noise: 6 nV/√ Hz
Low Distortion: 0.0006%
High Slew Rate: 22 V/s
Wide Bandwidth: 9 MHz
Low Supply Current: 5 mA
Low Offset Current: 2 nA
Unity-Gain Stable
SO-8 Package
APPLICATIONS
High Performance Audio
Active Filters
Fast Amplifiers
Integrators
Dual 9 MHz Precision
Operational Amplifier
OP285
PIN CONNECTIONS
8-Lead Narrow-Body SO (S-Suffix)
8 V+
OUT A 1
–IN A 2
The OP285 is a precision high-speed amplifier featuring the
Butler Amplifier front-end. This new front-end design combines the accuracy and low noise performance of bipolar
transistors with the speed of JFETs. This yields an amplifier
with high slew rates, low offset and good noise performance
at low supply currents. Bias currents are also low compared
to bipolar designs.
The OP285 offers the slew rate and low power of a JFET
amplifier combined with the precision, low noise and low
drift of a bipolar amplifier. Input offset voltage is laser-trimmed
and guaranteed less than 250 µV. This makes the OP285 useful
in dc-coupled or summing applications without the need for
special selections or the added noise of additional offset
adjustment circuitry. Slew rates of 22 V/µs and a bandwidth
of 9 MHz make the OP285 one of the most accurate medium
speed amplifiers available.
6 –IN B
5 +IN B
V– 4
8-Lead Epoxy DIP (P-Suffix)
8
–IN A
2
3
V–
4
– +
+ –
OP285
V+
7
OUT A 1
+IN A
GENERAL DESCRIPTION
7 OUT B
OP285
TOP VIEW
(Not to Scale)
+IN A 3
OUT B
6
–IN B
5
+IN B
The combination of low noise, speed and accuracy can be used
to build high speed instrumentation systems. Circuits such as
instrumentation amplifiers, ramp generators, bi-quad filters and
dc-coupled audio systems are all practical with the OP285. For
applications that require long term stability, the OP285 has a
guaranteed maximum long term drift specification.
The OP285 is specified over the XIND—extended industrial—
(–40°C to +85°C) temperature range. OP285s are available in
8-pin plastic DIP and SOIC-8 surface mount packages.
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 that
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: 781/329-4700
www.analog.com
Fax: 781/326-8703
© Analog Devices, Inc., 2001
