Datasheet AD8237 (Analog Devices)

Micropower, Zero Drift, True Rail-to-Rail Instrumentation Amplifier Data Sheet AD8237 FEATURES PIN CONFIGURATION Gain set with 2 external resistors AD8237 Can achieve low gain drift at all gains BW 1 8 VOUT Ideal for battery powered instruments +IN 2 + – 7 FB Supply current: 115 µA –IN 3 – + 6 REF Rail-to-rail input and output
001
–V TOP VIEW S 4 5 +VS (Not to Scale) Zero input crossover distortion
10289- Figure 1.
Designed for excellent dc performance Minimum CMRR: 106 dB Maximum offset voltage drift: 0.3 µV/°C Maximum gain error: 0.005% (all gains) Maximum gain drift: 0.5 ppm/°C (all gains) Input bias current: 1 nA guaranteed to 125°C Bandwidth mode pin (BW) to adjust compensation 8 kV HBM ESD rating RFI filter on-chip Single-supply operation: 1.8 V to 5.5 V Table 1. Instrumentation Amplifiers by Category1 8-lead MSOP package General Zero Military Digital Purpose Drift Grade Micropower Gain APPLICATIONS
AD8421 AD8237 AD620 AD8237 AD8250 AD8221/AD8222 AD8231 AD621 AD8420 AD8251
Bridge amplification
AD8220/AD8224 AD8293 AD524 AD8235/AD8236 AD8253
Pressure measurement
AD8228 AD8553 AD526 AD627 AD8231
Medical instrumentation
AD8295 AD8556 AD624
Thermocouple interface
AD8226 AD8557
Portable systems Current measurement
1 See www.analog.com for the latest instrumentation amplifiers.
GENERAL DESCRIPTION
The AD8237 is a micropower, zero drift, rail-to-rail input and The AD8237 is available in an 8-lead MSOP package. Performance output instrumentation amplifier. The relative match of two is specified over the ful temperature range of −40°C to +125°C. resistors sets any gain from 1 to 1000. The AD8237 has excellent
6
gain accuracy performance that can be preserved at any gain
AD8237
with two ratio-matched resistors.
5 G = 100 V E (V) S = 5V V
The AD8237 employs the indirect current feedback architecture to
G REF = 2.5V A TRADITIONAL IN-AMP 4 T (RAIL-TO-RAIL OUT)
achieve a true rail-to-rail capability. Unlike conventional in-amps,
L
the AD8237 can ful y amplify signals with common-mode voltage
E VO 3 D
at or even slightly beyond its supplies. This enables applications
-MO N
with high common-mode voltages to use smaller supplies and
2
save power.
MMO O 1 C T
The AD8237 is an excellent choice for portable systems. With a
PU
minimum supply voltage of 1.8 V, a 115 µA typical supply current,
0 IN
and wide input range, the AD8237 makes full use of a limited
–1
power budget, yet offers bandwidth and drift performance suitable
0 1 2 3 4 5
002 for bench-top systems.
OUTPUT VOLTAGE (V)
10289- Figure 2. Input Common-Mode Voltage vs. Output Voltage, +VS = 5 V, G = 100
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 rights of third parties that may result from its use. Specifications subject to change without notice. No One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Tel: 781.329.4700 www.analog.com Trademarks and registered trademarks are the property of their respective owners. Fax: 781.461.3113 ©2012 Analog Devices, Inc. All rights reserved.
Document Outline Features Applications General Description Pin Configuration Table of Contents Revision History Specifications Absolute Maximum Ratings Thermal Resistance ESD Caution Pin Configuration and Function Descriptions Typical Performance Characteristics Theory of Operation Architecture Setting the Gain Gain Accuracy Clock Feedthrough Input Voltage Range Input Protection Filtering Radio Frequency Interference Using the Reference Pin Layout Common-Mode Rejection Ratio over Frequency Power Supplies Reference Input Bias Current Return Path Applications Information Battery Current Monitor Programmable Gain In-Amp AD8237 in an ECG Front End Outline Dimensions Ordering Guide