Zero-Drift, Single-Supply, Rail-to-Rail Input/Output Operational Amplifiers Data Sheet AD8571/AD8572/AD8574 FEATURES PIN CONFIGURATIONS Low offset voltage: 1 V 1 8 NC NC AD8571 Input offset drift: 0.005 V/C IN A 2 7 V+ TOP VIEW +IN A 3 6 OUT A Rail-to-rail input and output swing (Not to Scale) V 4 5 NC 5 V/2.7 V single-supply operation High gain: 145 dB typical NC = NO CONNECT CMRR: 140 dB typical Figure 1. 8-Lead MSOP (RM Suffix) PSRR: 130 dB typical NC 1 8 NC Ultralow input bias current: 10 pA typical IN A 2 7 V+ AD8571 Low supply current: 750 A per op amp +IN A 3 6 OUT A TOP VIEW (Not to Scale) Overload recovery time: 50 s V 4 5 NC No external capacitors required NC = NO CONNECT Figure 2. 8-Lead SOIC (R Suffix) APPLICATIONS OUT A 1 8 V+ Temperature sensors AD8572 IN A 2 7 OUT B TOP VIEW Pressure sensors +IN A 3 6 IN B (Not to Scale) Precision current sensing V 4 5 +IN B Strain gage amplifiers Figure 3. 8-Lead TSSOP (RU Suffix) Medical instrumentation OUT A 1 8 V+ Thermocouple amplifiers AD8572 2 7 IN A OUT B TOP VIEW +IN A 3 6 IN B (Not to Scale) V 4 5 +IN B GENERAL DESCRIPTION Figure 4. 8-Lead SOIC (R Suffix) This family of amplifiers has ultralow offset, drift, and bias 1 OUT A 1 14 OUT D current. The AD8571/AD8572/AD8574 are single, dual, and IN A 2 13 IN D quad amplifiers, respectively, featuring rail-to-rail input and +IN A 3 12 +IN D AD8574 output swings. All are guaranteed to operate from 2.7 V to 5 V V+ 4 11 V TOP VIEW single supply. (Not to Scale) +IN B 5 10 +IN C IN B 6 9 IN C The AD8571/AD8572/AD8574 provide benefits previously OUT B 7 8 OUT C found only in expensive auto-zeroing or chopper-stabilized Figure 5. 14-Lead TSSOP (RU Suffix) amplifiers. Using Analog Devices, Inc., topology, these zero- drift amplifiers combine low cost with high accuracy. (No OUT A 1 14 OUT D external capacitors are required.) Using a spread-spectrum, IN A 2 13 IN D auto-zero technique, the AD8571/AD8572/AD8574 eliminate +IN A 3 12 +IN D AD8574 V+ 4 11 V the intermodulation effects from interaction of the chopping TOP VIEW (Not to Scale) +IN B 5 10 +IN C function with the signal frequency in ac applications. IN B 6 9 IN C OUT B 7 8 OUT C With an offset voltage of only 1 V and drift of 0.005 V/C, the AD8571/AD8572/AD8574 are perfectly suited for applications Figure 6. 14-Lead SOIC (R Suffix) where error sources cannot be tolerated. Position and pressure The AD8571/AD8572/AD8574 are specified for the extended sensors, medical equipment, and strain gage amplifiers benefit industrial/ automotive temperature range (40C to +125C). greatly from nearly zero drift over their operating temperature The AD8571 single amplifier is available in 8-lead MSOP and range. Many more systems require the rail-to-rail input and narrow SOIC packages. The AD8572 dual amplifier is available in output swings provided by the AD8571/AD8572/AD8574. 8-lead narrow SOIC and surface-mount TSSOP packages. The AD8574 quad amplifier is available in 14-lead narrow SOIC and TSSOP packages. 1 Protected by U.S. Patent 6,130,578. Rev. F 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 19992015 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. 01104-004 01104-001 01104-006 01104-003 01104-002 01104-005AD8571/AD8572/AD8574 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Maximizing Performance Through Proper Layout ............... 17 Applications ....................................................................................... 1 1/f Noise Characteristics ........................................................... 18 General Description ......................................................................... 1 Random Auto-Zero Correction Eliminates Intermodulation Distortion .................................................................................... 18 Pin Configurations ........................................................................... 1 Broadband and External Resistor Noise Considerations .......... 19 Revision History ............................................................................... 3 Output Overdrive Recovery ...................................................... 19 Specifications ..................................................................................... 4 Input Overvoltage Protection ................................................... 19 5 V Electrical Characteristics ...................................................... 4 Output Phase Reversal ............................................................... 19 2.7 V Electrical Characteristics ................................................... 5 Capacitive Load Drive ............................................................... 20 Absolute Maximum Ratings ............................................................ 6 Power-Up Behavior .................................................................... 20 Thermal Characteristics .............................................................. 6 Applications Information .............................................................. 21 ESD Caution .................................................................................. 6 5 V Precision Strain Gage Circuit ............................................ 21 Typical Performance Characteristics ............................................. 7 3 V Instrumentation Amplifier ................................................ 21 Functional Description .................................................................. 15 High Accuracy Thermocouple Amplifier ............................... 22 Amplifier Architecture .............................................................. 15 Precision Current Meter ............................................................ 22 Basic Auto-Zero Amplifier Theory .......................................... 15 Precision Voltage Comparator .................................................. 22 Auto-Zero Phase ......................................................................... 16 Outline Dimensions ....................................................................... 23 Amplification Phase ................................................................... 16 Ordering Guide .......................................................................... 25 High Gain, CMRR, and PSRR .................................................. 17 Rev. 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