Low Cost, Zero-Drift In-Amp with Filter and Fixed Gain AD8293G80/AD8293G160 FEATURES FUNCTIONAL BLOCK DIAGRAM Small package: 8-lead SOT-23 7 5 6 Reduced component count +V FILT OUT S Incorporates gain resistors and filter resistors R2 Low offset voltage: 20 V maximum +IN 8 Low offset drift: 0.3 V/C maximum R3 5k R1 Low gain drift: 25 ppm/C maximum 4 IN-AMP 4k ADC OUT OUTPUT TO ADC High CMR: 140 dB typical WITH ANTIALIASING IN 1 FILTER Low noise: 0.7 V p-p from 0.01 Hz to 10 Hz GND REF AD8293Gxx Single-supply operation: 1.8 V to 5.5 V 2 3 Rail-to-rail output Figure 1. Available in 2 fixed-gain models +5V APPLICATIONS C2 0.1F Current sensing 7 5 6 +V FILT OUT S Strain gauges LOAD R2 Laser diode control loops +IN 8 R3 Portable medical instruments 5k R1 I R 4 ADC IN-AMP SHUNT 4k ADC OUT Thermocouple amplifiers C3 IN REF 1 +3.3V 1.8V 0.1F 10F DC-DC GND REF AD8293Gxx 2 3 Figure 2. Measuring Current Using the AD8293G80/AD8293G160 Table 1. AD8293Gxx Models and Gains Model Gain AD8293G80 80 AD8293G160 160 GENERAL DESCRIPTION The AD8293G80/AD8293G160 are small, low cost, precision Precision instrumentation, position and pressure sensors, instrumentation amplifiers that have low noise and rail-to-rail medical instrumentation, and strain gauge amplifiers benefit outputs. They are available in two fixed-gain models: 80 and 160. from the low noise, low input bias current, and high common- They incorporate the gain setting resistors and filter resistors, mode rejection. The small footprint and low cost are ideal for reducing the number of ancillary components. For example, high volume applications. only two external capacitors are needed to implement a 2-pole The small package and low power consumption allow the maxi- filter. The AD8293G80/AD8293G160 also feature low offset mum channel density and the minimum board size required for voltage, offset drift, and gain drift coupled with high common- portable systems. Designed for ease of use, these instrumentation mode rejection. They are capable of operating on a supply of amplifiers, unlike more traditional ones, have a buffered reference, 1.8 V to 5.5 V. eliminating the need for an additional op amp to set the reference With a low offset voltage of 20 V (AD8293G160B), an offset voltage to midsupply. voltage drift of 0.3 V/C, and a voltage noise of only 0.7 V p-p The AD8293G80/AD8293G160 are specified over the industrial (0.01 Hz to 10 Hz), the AD8293G80/AD8293G160 are ideal temperature range from 40C to +85C. The AD8293G80/ for applications where error sources cannot be tolerated. AD8293G160 are available in a halogen-free, Pb-free, 8-lead SOT-23. Rev. 0 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 Tel: 781.329.4700 www.analog.com license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Fax: 781.461.3113 2008 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. 07451-001 07451-002AD8293G80/AD8293G160 TABLE OF CONTENTS Features .............................................................................................. 1 Theory of Operation ...................................................................... 10 Applications ....................................................................................... 1 High PSR and CMR ................................................................... 10 Functional Block Diagram .............................................................. 1 1/f Noise Correction .................................................................. 10 General Description ......................................................................... 1 Applications Information .............................................................. 11 Revision History ............................................................................... 2 Overview ..................................................................................... 11 Specif icat ions ..................................................................................... 3 Reference Connection ............................................................... 11 Electrical Characteristics ............................................................. 3 Output Filtering .......................................................................... 11 Absolute Maximum Ratings ............................................................ 5 Clock Feedthrough ..................................................................... 12 Thermal Resistance ...................................................................... 5 Power Supply Bypassing ............................................................ 12 ESD Caution .................................................................................. 5 Input Overvoltage Protection ................................................... 12 Pin Configuration and Function Descriptions ............................. 6 Outline Dimensions ....................................................................... 13 Typical Performance Characteristics ............................................. 7 Ordering Guide .......................................................................... 13 REVISION HISTORY 8/08Revision 0: Initial Version Rev. 0 Page 2 of 16