MAX4208_09 Datasheet, PDF (1/17 Pages) Maxim Integrated Products – Ultra-Low Offset/Drift, Precision Instrumentation Amplifiers with REF Buffer

19-0924; Rev 1; 4/09
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 with a fixed gain of 100V/V with
±0.03% (typ) accuracy. 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-
GAIN
PACKAGE (V/V)
MAX4208AUA+T -40°C to +125°C 8 µMAX
ADJ
MAX4209HAUA+T -40°C to +125°C 8 µMAX
100
Note: All 8-pin µMAX packages have package code U8-1.
+Denotes a lead(Pb)-free/RoHS-compliant package.
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
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.