General Description

The MAX9945 operational amplifier features an excellent combination of low operating power and low input voltage noise. In addition, MOS inputs enable the MAX9945 to feature low input bias currents and low input current noise. The device accepts a wide supply voltage range from 4.75V to 38V and draws a low 400µA quiescent current. The MAX9945 is unity-gain stable and is capable of rail-to-rail output voltage swing.

The MAX9945 is ideal for portable medical and industrial applications that require low noise analog front-ends for performance applications such as photodiode transimpedance and chemical sensor interface circuits.

The MAX9945 is available in both an 8-pin µMAX® and a space-saving, 6-pin TDFN package, and is specified over the automotive operating temperature range (-40°C to +125°C).

Features

♦ +4.75V to +38V Single-Supply Voltage Range

♦ ±2.4V to ±19V Dual-Supply Voltage Range

♦ Rail-to-Rail Output Voltage Swing

♦ 400µA Low Quiescent Current

♦ 50fA Low Input Bias Current

♦ 1fA/√Hz Low Input Current Noise

♦ 15nV/√Hz Low Noise

♦ 3MHz Unity-Gain Bandwidth

♦ Wide Temperature Range from -40°C to +125°C

♦ Available in Space-Saving, 6-Pin TDFN Package (3mm x 3mm)

Applications

  Medical Pulse Oximetry

  Photodiode Sensor Interface

  Industrial Sensors and Instrumentation

  Chemical Sensor Interface

  High-Performance Audio Line Out

  Active Filters and Signal Processing