16 V Rail-to-Rail, Zero-Drift, Precision Instrumentation Amplifier AD8230 FEATURES CONNECTION DIAGRAM 1 Resistor programmable gain range: 10 to 1000 1 8 V V S OUT Supply voltage range: 4 V to 8 V 2 7 R +V S G Rail-to-rail input and output 3 6 V 1 V 2 REF REF Maintains performance over 40C to +125C +IN 4 5 IN Excellent ac and dc performance AD8230 TOP VIEW 110 dB minimum CMR 60 Hz, G = 10 to 1000 (Not to Scale) 10 V maximum offset voltage (RTI, 5 V operation) Figure 1. 8-Lead SOIC (R-8) 50 nV/C maximum offset drift 2.0 20 ppm maximum gain nonlinearity 1.5 APPLICATIONS 1.0 Pressure measurements 0.5 Temperature measurements 0 Strain measurements Automotive diagnostics 0.5 1.0 GENERAL DESCRIPTION 1.5 The AD8230 is a low drift, differential sampling, precision 2.0 instrumentation amplifier. Auto-zeroing reduces offset voltage 50 30 10 10 30 50 70 90 110 130 150 drift to less than 50 nV/C. The AD8230 is well-suited for TEMPERATURE (C) thermocouple and bridge transducer applications. The Figure 2. Relative Offset Voltage vs. Temperature AD8230s high CMR of 110 dB (minimum) rejects line noise in +5V measurements where the sensor is far from the instrumentation. 5V The 16 V rail-to-rail, common-mode input range is useful for 0.1F noisy environments where ground potentials vary by several 0.1F volts. Low frequency noise is kept to a minimal 3 V p-p, 2 4 1 making the AD8230 perfect for applications requiring the V TYPE K THERMOCOUPLE AD8230 8 OUT utmost dc precision. Moreover, the AD8230 maintains its high 7 5 performance over the extended industrial temperature range of 6 34.8k 3 40C to +125C. 284 Two external resistors are used to program the gain. By using matched external resistors, the gain stability of the AD8230 is much higher than instrumentation amplifiers that use a single Figure 3. Thermocouple Measurement resistor to set the gain. In addition to allowing users to program 1 the gain between 10 and 1000, users can adjust the output The AD8230 is versatile yet simple to use. Its auto-zeroing offset voltage. topology significantly minimizes the input and output transients typical of commutating or chopper instrumentation amplifiers. The AD8230 operates on 4 V to 8 V (+8 V to +16 V) supplies and is available in an 8-lead SOIC. 1 The AD8230 can be programmed for a gain as low as 2, but the maximum input voltage is limited to approximately 750 mV. Rev. B 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 20042007 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. OFFSET VOLTAGE (V RTI) 05063-041 05063-002 05063-001AD8230 TABLE OF CONTENTS Features .............................................................................................. 1 Level-Shifting the Output ......................................................... 12 Applications....................................................................................... 1 Source Impedance and Input Settling Time ........................... 12 General Description ......................................................................... 1 Input Voltage Range................................................................... 13 Connection Diagram ....................................................................... 1 Input Protection ......................................................................... 13 Revision History ............................................................................... 2 Power Supply Bypassing............................................................ 13 Specifications..................................................................................... 3 Power Supply Bypassing for Multiple Channel Systems ....... 13 Absolute Maximum Ratings............................................................ 5 Layout .......................................................................................... 14 Thermal Characteristics .............................................................. 5 Applications ................................................................................ 14 ESD Caution.................................................................................. 5 Outline Dimensions ....................................................................... 15 Typical Performance Characteristics ............................................. 6 Ordering Guide .......................................................................... 15 Theory of Operation ...................................................................... 11 Setting the Gain .......................................................................... 11 REVISION HISTORY 9/07Rev. A to Rev. B 7/05Rev. 0 to Rev. A Changes to Features and Layout..................................................... 1 Changes to Excellent AC and DC Performance............................1 Changes to Table 1............................................................................ 3 Changes to Table 1.............................................................................3 Changes to Table 2............................................................................ 4 Changes to Table 2.............................................................................4 Changes to Layout ............................................................................ 5 Changes to Figure 7 and Figure 8....................................................6 Inserted Figure 13, Figure 14, and Figure 15 Renumbered Changes to Figure 10 and Figure 11................................................7 Sequentially ....................................................................................... 7 Changes to Level-Shifting the Output Section........................... 11 Changes to Figure 16 and Figure 19............................................... 8 Changes to Figure 31...................................................................... 11 Updated Outline Dimensions ....................................................... 15 Inserted Figure 32 and Figure 33 Renumbered Sequentially .. 11 Changes to Source Impedance and Input Settling Time Section, Input Protection Section and Power Supply Bypassing for Multiple Channel Systems Section............................................... 12 Changes to Figure 36...................................................................... 13 Changes to Applications Section.................................................. 13 10/04Revision 0: Initial Version Rev. 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