MAX4208 Datasheet, PDF (1/17 Pages) Maxim Integrated Products – Ultra-Low Offset/Drift, Precision Instrumentation Amplifiers with REF Buffer

19-0924; Rev 0; 9/07
EVAALVUAAILTAIOBNLEKIT
Ultra-Low Offset/Drift, Precision
Instrumentation Amplifiers with REF Buffer
General Description
The MAX4208/MAX4209 ultra-low offset and drift instru-
mentation amplifiers feature exceptional precision specifi-
cations, low power consumption, rail-to-rail output,
excellent gain-bandwidth product, and buffered
REFIN/MODE input in a very small µMAX^® package.
These devices use a patented^† spread-spectrum,
autozeroing technique that constantly measures and
corrects the input offset, eliminating drift over time and tem-
perature and the effect of 1/f noise. This technique
achieves less than 20µV offset voltage, allows ground-
sensing capability, provides ultra-low CMOS input bias cur-
rent and increased common-mode rejection performance.
The MAX4208/MAX4209 provide high-impedance inputs
optimized for small-signal differential voltages (±100mV).
All devices provide a gain-bandwidth product of 750kHz.
The MAX4208 provides an adjustable gain with two
external resistors or unity gain with FB connected to OUT.
The MAX4209 is available in fixed gains of 10V/V, 100V/V,
or 1000V/V (suffixed T, H, and K) with ±0.03% (typ) accu-
racy. Both devices include a reference input (REF) to
level-shift the output, allowing for bipolar signals in single-
supply applications. In both devices, REFIN/MODE is an
input to a precision unity-gain buffer, which sets the REF
voltage to level-shift the output. The internal REF buffer
allows the reference to be set by a simple resistive divider
or an ADC reference without any loading error.
The MAX4208/MAX4209 operate with a 2.85V to 5.5V
single-supply voltage and consume only 750µA
of quiescent current (when the internal buffer is off) and
only 1.4µA in shutdown mode. These amplifiers
also operate with ±2.5V dual supplies with REF
connected to ground and REFIN/MODE to V_SS.
The MAX4208/MAX4209 are available in space-saving
8-pin µMAX packages and are specified over the auto-
motive operating temperature range (-40°C to +125°C).
†_{US Patent #6,847,257.}
Applications
Automotive Transducer Applications
Strain-Gauge Amplifiers
Industrial Process Control
Battery-Powered Medical Equipment
Precision Low-Side Current Sense
Notebook Computers
Differential Voltage Amplification
µMAX is a registered trademark of Maxim Integrated Products, Inc.
Features
♦ Ultra-Low Input Offset Voltage
±20µV (max) at +25°C
♦ ±0.25% (max) Gain Error
♦ Low 0.2µV/°C Offset Voltage Drift
♦ 1pA CMOS Input Bias Current
♦ True Ground Sensing with Rail-to-Rail Output
♦ Buffered REF Input for High Accuracy and
Bipolar Operation
♦ 2.85V to 5.5V Single-Supply Operation
(or ±1.425V to ±2.75V Dual Supplies)
♦ 750µA Supply Current
♦ 1.4µA Shutdown Mode
♦ 750kHz Gain-Bandwidth Product
♦ Operate Over the -40°C to +125°C Automotive
Temperature Range
♦ Tiny 8-Pin µMAX Package
Ordering Information
PART
TEMP RANGE
PIN-
PACKAGE
GAIN
(V/V)
MAX4208AUA+T
-40°C to +125°C 8 µMAX-8
ADJ
MAX4209TAUA+T* -40°C to +125°C 8 µMAX-8
10
MAX4209HAUA+T -40°C to +125°C 8 µMAX-8
100
MAX4209KAUA+T* -40°C to +125°C 8 µMAX-8 1000
Note: All 8-pin µMAX packages have package code U8-1.
+Denotes a lead-free package.
*Future product—contact factory for availability.
Typical Application Circuit
5V
R4
V_DD/2
R3
MAX4208
G = 1 + ^R2
R1
IN-
IN+
V_DD
REFIN/MODE
REF
V_SS
FB
OUT
R2
C_FB
FB
R1
REF _{BUFFER OUT =}
V_DD/2
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