Datasheet OP297 (Analog Devices)

Dual Low Bias Current Precision Operational Amplifier OP297 FEATURES PIN CONFIGURATION Low offset voltage: 50 μV maximum OUTA 1 8 V+ Low offset voltage drift: 0.6 μV/°C maximum –INA 2 7 OUTB A B Very low bias current: 100 pA maximum +INA 3 6 –INB Very high open-loop gain: 2000 V/mV minimum
01
V–
0
4 5 +INB
0-
Low supply current (per amplifier): 625 μA maximum
30 00
Operates from ±2 V to ±20 V supplies
Figure 1.
High common-mode rejection: 120 dB minimum APPLICATIONS 60 VS = ±15V Strain gage and bridge amplifiers VCM = 0V 40 High stability thermocouple amplifiers Instrumentation amplifiers A) p 20 Photocurrent monitors ( NT I High gain linearity amplifiers E B– 0 Long-term integrators/filters I CURR B+ Sample-and-hold amplifiers UT P –20 Peak detectors IN IOS Logarithmic amplifiers –40 Battery-powered systems GENERAL DESCRIPTION –60–75 –50 –25 0 25 50 75 100 125
02 0 0- The OP297 is the first dual op amp to pack precision perform-
TEMPERATURE (°C)
030 0 ance into the space saving, industry-standard 8-lead SOIC Figure 2. Low Bias Current over Temperature package. The combination of precision with low power and extremely low input bias current makes the dual OP297 useful
400
in a wide variety of applications.
1200 UNITS TA = 25°C VS = ±15V
Precision performance of the OP297 includes very low offset
VCM = 0V
(less than 50 μV) and low drift (less than 0.6 μV/°C). Open-
300
loop gain exceeds 2000 V/mV, ensuring high linearity in every
S T NI
application.
U F 200
Errors due to common-mode signals are eliminated by the
R O BE
common-mode rejection of over 120 dB, which minimizes
NUM
offset voltage changes experienced in battery-powered systems.
100
The supply current of the OP297 is under 625 μA. The OP297 uses a super-beta input stage with bias current cancellation to maintain picoamp bias currents at all tempera-
0
3
–100 –80 –60 –40 –20 0 20 40 60 80 100
00 tures. This is in contrast to FET input op amps whose bias
INPUT OFFSET VOLTAGE (µV)
0300- 0 currents start in the picoamp range at 25°C, but double for Figure 3. Very Low Offset every 10°C rise in temperature, to reach the nanoamp range above 85°C. Input bias current of the OP297 is under 100 pA at Combining precision, low power, and low bias current, the 25°C and is under 450 pA over the military temperature range OP297 is ideal for a number of applications, including instru- per amplifier. This part can operate with supply voltages as low mentation amplifiers, log amplifiers, photodiode preamplifiers, as ±2 V. and long term integrators. For a single device, see the OP97; for a quad device, see the OP497.
Rev. G 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 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Tel: 781.329.4700 www.analog.com Trademarks and registered trademarks are the property of their respective owners. Fax: 781.461.3113 ©2008 Analog Devices, Inc. All rights reserved.
Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION PIN CONFIGURATION TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS ELECTRICAL CHARACTERISTICS ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE ESD CAUTION TYPICAL PERFORMANCE CHARACTERISTICS APPLICATIONS INFORMATION AC PERFORMANCE GUARDING AND SHIELDING OPEN-LOOP GAIN LINEARITY APPLICATION CIRCUITS PRECISION ABSOLUTE VALUE AMPLIFIER PRECISION CURRENT PUMP PRECISION POSITIVE PEAK DETECTOR SIMPLE BRIDGE CONDITIONING AMPLIFIER NONLINEAR CIRCUITS OUTLINE DIMENSIONS ORDERING GUIDE