AD8237 Datasheet, PDF (1/28 Pages) Analog Devices – Micropower, Zero Drift, True Rail-to-Rail Instrumentation Amplifier

Data Sheet
Micropower, Zero Drift, True Rail-to-Rail
Instrumentation Amplifier
AD8237
FEATURES
Gain set with 2 external resistors
Can achieve low gain drift at all gains
Ideal for battery powered instruments
Supply current: 115 µA
Rail-to-rail input and output
Zero input crossover distortion
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
8-lead MSOP package
APPLICATIONS
Bridge amplification
Pressure measurement
Medical instrumentation
Thermocouple interface
Portable systems
Current measurement
GENERAL DESCRIPTION
The AD8237 is a micropower, zero drift, rail-to-rail input and
output instrumentation amplifier. The relative match of two
resistors sets any gain from 1 to 1000. The AD8237 has excellent
gain accuracy performance that can be preserved at any gain
with two ratio-matched resistors.
The AD8237 employs the indirect current feedback architecture to
achieve a true rail-to-rail capability. Unlike conventional in-amps,
the AD8237 can fully amplify signals with common-mode voltage
at or even slightly beyond its supplies. This enables applications
with high common-mode voltages to use smaller supplies and
save power.
The AD8237 is an excellent choice for portable systems. With a
minimum supply voltage of 1.8 V, a 115 µA typical supply current,
and wide input range, the AD8237 makes full use of a limited
power budget, yet offers bandwidth and drift performance suitable
for bench-top systems.
Rev. 0
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PIN CONFIGURATION
AD8237
BW 1
+IN 2
–IN 3
–V_S 4
+
–
–
+
TOP VIEW
(Not to Scale)
8 V_OUT
7 FB
6 REF
5 +V_S
Figure 1.
Table 1. Instrumentation Amplifiers by Category¹
General
Purpose
Zero
Drift
Military
Grade Micropower
AD8421
AD8237 AD620 AD8237
AD8221/AD8222 AD8231 AD621 AD8420
AD8220/AD8224 AD8293 AD524 AD8235/AD8236
AD8228
AD8553 AD526 AD627
AD8295
AD8556 AD624
AD8226
AD8557
Digital
Gain
AD8250
AD8251
AD8253
AD8231
1 _{See www.analog.com for the latest instrumentation amplifiers.}
The AD8237 is available in an 8-lead MSOP package. Performance
is specified over the full temperature range of −40°C to +125°C.
6
AD8237
5
4
TRADITIONAL IN-AMP
(RAIL-TO-RAIL OUT)
G = 100
V_S = 5V
V_REF = 2.5V
3
2
1
0
–1
0
1
2
3
4
5
OUTPUT VOLTAGE (V)
Figure 2. Input Common-Mode Voltage vs. Output Voltage, +V_S = 5 V, G = 100
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