Micropower, Single- and Dual-Supply, Rail-to-Rail Instrumentation Amplifier Data Sheet AD627 FEATURES FUNCTIONAL BLOCK DIAGRAM Micropower, 85 A maximum supply current AD627 R 1 8 R G G Wide power supply range (+2.2 V to 18 V) IN 2 7 +V Easy to use S Gain set with one external resistor +IN 3 6 OUTPUT Gain range 5 (no resistor) to 1000 V 4 5 REF S Higher performance than discrete designs Rail-to-rail output swing Figure 1. 8-Lead PDIP (N) and SOIC N (R) High accuracy dc performance 100 0.03% typical gain accuracy (G = +5) (AD627A) 90 10 ppm/C typical gain drift (G = +5) 125 V maximum input offset voltage (AD627B dual supply) 80 AD627 200 V maximum input offset voltage (AD627A dual supply) 70 1 V/C maximum input offset voltage drift (AD627B) 60 3 V/C maximum input offset voltage drift (AD627A) 50 10 nA maximum input bias current TRADITIONAL 40 Noise: 38 nV/Hz RTI noise at 1 kHz (G = +100) LOW POWER DISCRETE DESIGN Excellent ac specifications 30 AD627A: 77 dB minimum CMRR (G = +5) 20 AD627B: 83 dB minimum CMRR (G = +5) 10 80 kHz bandwidth (G = +5) 0 135 s settling time to 0.01% (G = +5, 5 V step) 1 10 100 1k 10k FREQUENCY (Hz) Figure 2. CMRR vs. Frequency, 5 VS, Gain = +5 APPLICATIONS 4 mA to 20 mA loop-powered applications Low power medical instrumentationECG, EEG Transducer interfacing Thermocouple amplifiers Industrial process controls Low power data acquisition Portable battery-powered instruments ideal for battery-powered applications. Its rail-to-rail output GENERAL DESCRIPTION stage maximizes dynamic range when operating from low The AD627 is an integrated, micropower instrumentation supply voltages. Dual-supply operation (15 V) and low power amplifier that delivers rail-to-rail output swing on single and consumption make the AD627 ideal for industrial applications, dual (+2.2 V to 18 V) supplies. The AD627 provides excellent including 4 mA to 20 mA loop-powered systems. ac and dc specifications while operating at only 85 A maximum. The AD627 does not compromise performance, unlike other The AD627 offers superior flexibility by allowing the user to set micropower instrumentation amplifiers. Low voltage offset, the gain of the device with a single external resistor while con- offset drift, gain error, and gain drift minimize errors in the forming to the 8-lead industry-standard pinout configuration. system. The AD627 also minimizes errors over frequency by With no external resistor, the AD627 is configured for a gain of 5. providing excellent CMRR over frequency. Because the CMRR With an external resistor, it can be set to a gain of up to 1000. remains high up to 200 Hz, line noise and line harmonics are A wide supply voltage range (+2.2 V to 18 V) and micropower rejected. current consumption make the AD627 a perfect fit for a wide The AD627 provides superior performance, uses less circuit range of applications. Single-supply operation, low power board area, and costs less than micropower discrete designs. consumption, and rail-to-rail output swing make the AD627 Rev. E Document Feedback 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 20072013 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Technical Support www.analog.com Trademarks and registered trademarks are the property of their respective owners. CMRR (dB) 00782-001 00782-002AD627 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Reference Terminal .................................................................... 16 Applications ....................................................................................... 1 Input Range Limitations in Single-Supply Applications ....... 16 Functional Block Diagram .............................................................. 1 Output Buffering ........................................................................ 17 General Description ......................................................................... 1 Input and Output Offset Errors ................................................ 17 Revision History ............................................................................... 2 Make vs. Buy: A Typical Application Error Budget ............... 18 Specifications ..................................................................................... 3 Errors Due to AC CMRR .......................................................... 19 Single Supply ................................................................................. 3 Ground Returns for Input Bias Currents ................................ 19 Dual Supply ................................................................................... 5 Layout and Grounding .............................................................. 20 Dual and Single Supplies ............................................................. 6 Input Protection ......................................................................... 21 Absolute Maximum Ratings ............................................................ 7 RF Interference ........................................................................... 21 ESD Caution .................................................................................. 7 Applications Circuits ...................................................................... 22 Pin Configurations and Function Descriptions ........................... 8 Classic Bridge Circuit ................................................................ 22 Typical Performance Characteristics ............................................. 9 4 mA to 20 mA Single-Supply Receiver .................................. 22 Theory of Operation ...................................................................... 14 Thermocouple Amplifier .......................................................... 22 Using the AD627 ............................................................................ 15 Outline Dimensions ....................................................................... 24 Basic Connections ...................................................................... 15 Ordering Guide .......................................................................... 24 Setting the Gain .......................................................................... 15 REVISION HISTORY 12/13Rev. D to Rev. E 11/05Rev. B to Rev. C Updated Format .................................................................. Universal Change to Voltage Noise, 1 kHz Parameter, Table 3 .................... 6 Added Pin Configurations and Function Changes to Figure 35 ...................................................................... 14 Descriptions Section ......................................................................... 8 Change to Equation 3, Input Range Limitations in Single- Change to Figure 33 ....................................................................... 13 Supply Applications Section .......................................................... 16 Updated Outline Dimensions ....................................................... 24 Changes to Table 8 .......................................................................... 17 Changes to Ordering Guide .......................................................... 24 Changes to Figure 40 ...................................................................... 17 Change to Table 9 ........................................................................... 18 Rev. A to Rev. B Change to 4 mA to 20 mA Single-Supply Receiver Section ..... 22 Changes to Figure 4 and Table I, Resulting Gain column ......... 11 Change to Figure 9 ......................................................................... 13 11/07Rev. C to Rev. D Changes to Features .......................................................................... 1 Changes to Figure 29 to Figure 34 Captions ............................... 13 Changes to Setting the Gain Section ............................................ 15 Changes to Input Range Limitations in Single-Supply Applications Section ....................................................................... 16 Changes to Table 7 .......................................................................... 17 Changes to Figure 41 ...................................................................... 18 Rev. E Page 2 of 24