Precision, Dual-Channel, JFET Input, Rail-to-Rail Instrumentation Amplifier Data Sheet AD8224 FEATURES FUNCTIONAL BLOCK DIAGRAM Two channels in a small 4 mm 4 mm LFCSP Custom LFCSP package with hidden paddle 16 15 14 13 Permits routing and vias underneath package Allows full bias current performance AD8224 IN1 1 12 IN2 Low input currents 2 11 R R G1 G2 10 pA maximum input bias current (B grade) R 3 10 R G1 G2 0.6 pA maximum input offset current (B grade) +IN1 4 9 +IN2 High CMRR 100 dB CMRR (minimum), G = 10 (B grade) 5 6 7 8 90 dB CMRR (minimum) to 10 kHz, G = 10 (B grade) Excellent ac specifications and low power 1.5 MHz bandwidth (G = 1) Figure 1. 14 nV/Hz input noise (1 kHz) Slew rate: 2 V/s Table 1. In Amps and Difference Amplifiers by Category 750 A quiescent current per amplifier High Low High Mil Low Digital Versatility Perform Cost Voltage Grade Power Gain Rail-to-rail output 1 1 1 1 AD8220 AD8553 AD628 AD620 AD627 AD8231 Input voltage range to below negative supply rail 1 AD8221 AD623 AD629 AD621 AD8250 4 kV ESD protection AD8222 AD524 AD8251 4.5 V to 36 V single supply 1 AD526 AD8555 2.25 V to 18 V dual supply 1 AD624 AD8556 Gain set with single resistor (G = 1 to 1000) 1 AD8557 1 Rail-to-rail output. APPLICATIONS Medical instrumentation Precision data acquisition Transducer interfaces Differential drives for high resolution input ADCs Remote sensors GENERAL DESCRIPTION The AD8224 is the first single-supply, JFET input instrumentation to alleviate this problem, the AD8224 can operate on a 18 V amplifier available in the space-saving 16-lead, 4 mm 4 mm dual supply, as well as on a single +5 V supply. The devices rail- LFCSP. It requires the same board area as a typical single to-rail output stage maximizes dynamic range on the low voltage instrumentation amplifier yet doubles the channel density supplies common in portable applications. Its ability to run on a and offers a lower cost per channel without compromising single 5 V supply eliminates the need for higher voltage, dual performance. supplies. The AD8224 draws 750 A of quiescent current per amplifier, making it ideal for battery powered devices. Designed to meet the needs of high performance, portable In addition, the AD8224 can be configured as a single-channel, instrumentation, the AD8224 has a minimum common-mode differential output, instrumentation amplifier. Differential rejection ratio (CMRR) of 86 dB at dc and a minimum CMRR outputs provide high noise immunity, which can be useful when of 80 dB at 10 kHz for G = 1. Maximum input bias current is 10 pA the output signal must travel through a noisy environment, such and typically remains below 300 pA over the entire industrial as with remote sensors. The configuration can also be used to temperature range. Despite the JFET inputs, the AD8224 drive differential input ADCs. For a single-channel version, use typically has a noise corner of only 10 Hz. the AD8220. With the proliferation of mixed-signal processing, the number of power supplies required in each system has grown. Designed Rev. D 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 20072016 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. Technical Support www.analog.com +V +V S S REF1 OUT1 REF2 OUT2 V V S S 06286-001AD8224 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Layout .......................................................................................... 22 Applications ....................................................................................... 1 Solder Wash................................................................................. 23 Functional Block Diagram .............................................................. 1 Input Bias Current Return Path ............................................... 23 General Description ......................................................................... 1 Input Protection ......................................................................... 23 Revision History ............................................................................... 2 RF Interference ........................................................................... 24 Specifications ..................................................................................... 3 Common-Mode Input Voltage Range ..................................... 24 Absolute Maximum Ratings ............................................................ 9 Applications Information .............................................................. 25 Thermal Resistance ...................................................................... 9 Driving an ADC ......................................................................... 25 ESD Caution .................................................................................. 9 Differential Output .................................................................... 25 Pin Configurations and Function Descriptions ......................... 10 Driving a Differential Input ADC ............................................ 26 Typical Performance Characteristics ........................................... 12 Driving Cabling .......................................................................... 26 Theory of Operation ...................................................................... 21 Outline Dimensions ....................................................................... 27 Gain Selection ............................................................................. 21 Ordering Guide .......................................................................... 28 Reference Terminal .................................................................... 22 REVISION HISTORY Added Hidden Paddle Package Section and Exposed Paddle 4/16Rev. C to Rev. D Package Section and Figure 58 ..................................................... 21 Changed CP-16-13 to CP-16-26 .................................. Throughout Updated Outline Dimensions ....................................................... 26 Changes to Figure 3 ........................................................................ 10 Changes to Ordering Guide .......................................................... 27 Added Figure 4 and Table 12 Renumbered Sequentially ......... 11 Updated Outline Dimensions ....................................................... 27 4/07Rev. 0 to Rev. A Changes to Ordering Guide .......................................................... 28 Changes to Features, General Description, and Figure 1 ............. 1 Changes to Table 2 ............................................................................. 3 12/13Rev. B to Rev. C Changes to Table 3 and Table 4........................................................ 5 Changes to Input Current Parameter and Power Supply Changes to Table 5 ............................................................................. 6 Parameter, Table 2 ............................................................................. 3 Changes to Table 6 and Table 7........................................................ 8 Changes to Table 3 and Table 4 ....................................................... 5 Changes to Figure 2 ........................................................................... 9 Changes to Input Current Parameter and Power Supply Changes to Figure 3 ........................................................................ 10 Parameter, Table 5 ............................................................................. 6 Inserted Figure 4, Figure 5, and Figure 6 Renumbered Changes to Table 9 ............................................................................ 9 Sequentially ..................................................................................... 11 Changes to Figure 53 ...................................................................... 19 Changes to Figure 7 ........................................................................ 11 Change to Theory of Operation Section ..................................... 20 Changes to Figure 20 and Figure 21 ............................................ 13 Change to Exposed Paddle Package Section ............................... 21 Changes to Figure 28 ...................................................................... 15 Change to Input Protection Section ............................................. 22 Changes to Theory of Operation and Figure 55 ........................ 20 Updated Outline Dimensions (Dimensions Not Changed, Changes to Ordering Guide .......................................................... 26 Minimums and Maximums Added) ............................................ 26 1/07Revision 0: Initial Version 5/10Rev. A to Rev. B Changes to Features Section............................................................ 1 Added Table 10 ................................................................................. 9 Changes to Figure 3 and Table 11 ................................................. 10 Rev. D Page 2 of 28