Top

Ultra-Low Offset/Drift, Precision Instrumentation Amplifiers with REF Buffer

Instrumentation Amplifiers Use Autozero to Achieve 20µV (max) Offset

Product Details

Key Features

Parametric specs for Instrumentation/Difference Amplifiers
Architecture Indirect Current-Feedback
# Amplifiers 1
VCMVR (to Neg. Rail) Yes
Rail to Rail Output Only
AV (V/V) 10
100
1000
ICC per Amp. (mA) (typ) 0.75
VOS (µV) (max) 20
CMRR @DC (dB) (typ) 135
PSRR @DC (dB) (typ) 125
Input IBIAS (nA) (max) 0.01
Unity Gain BW (MHz) (typ) 0.75
Oper. Temp. (°C) -40 to +125
Package/Pins UMAX/8
Budgetary
Price (See Notes)
1.8
View Less

Simplified Block Diagram

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .

Parameters

Parametric specs for Instrumentation/Difference Amplifiers
Architecture Indirect Current-Feedback
# Amplifiers 1
VCMVR (to Neg. Rail) Yes
Rail to Rail Output Only
AV (V/V) 10
100
1000
ICC per Amp. (mA) (typ) 0.75
VOS (µV) (max) 20
CMRR @DC (dB) (typ) 135
PSRR @DC (dB) (typ) 125
Input IBIAS (nA) (max) 0.01
Unity Gain BW (MHz) (typ) 0.75
Oper. Temp. (°C) -40 to +125
Package/Pins UMAX/8
Budgetary
Price (See Notes)
1.8

Key Features

  • Spread-Spectrum, Auto-Zero Instrumentation Amplifiers Improve DC Characteristics to Maximize Sensor Performance
    • 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
    • 750kHz Gain-Bandwidth Product
  • Buffered REF Input for High Accuracy and Bipolar Operation
  • Low Power Operation Supports Remote Sensing and Battery-Powered Applications
    • 2.85V to 5.5V Single-Supply Operation (or ±1.425V to ±2.75V Dual Supplies)
    • 750µA Supply Current
    • 1.4µA Shutdown Mode
  • Adjustable (MAX4208) and Fixed Gain of 100 (MAX4209) Provide Design Flexibility

Applications/Uses

  • Battery-Powered Medical Equipment
  • Differential Voltage Amplification
  • Industrial Process Control
  • Notebook Computers
  • Precision Low-Side Current Sense
  • Strain-Gauge Amplifiers

Description

The MAX4208/MAX4209 ultra-low offset and drift instrumentation amplifiers feature exceptional precision specifications, 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 spread-spectrum, autozeroing technique that constantly measures and corrects the input offset, eliminating drift over time and temperature 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 current 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 VSS. The MAX4208/MAX4209 are available in space-saving 8-pin µMAX packages and are specified over the automotive operating temperature range (-40°C to +125°C).

Simplified Block Diagram

MAX4208, MAX4209: Typical Application Circuit MAX4208, MAX4209: Application Circuit Zoom icon

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .