The ADA4945-1 is a low-noise, low-distortion, fully differential amplifier with two selectable power modes. The device operates over a broad power supply range of 3 V to 10 V. The low DC offset, DC offset drift, and excellent dynamic performance of the ADA4945-1 make it well suited for a variety of data acquisition and signal processing applications. The device is an ideal choice for driving high-resolution, high-performance successive approximation register (SAR) and Σ-Δ analog-to-digital converters (ADCs) on 4 mA of quiescent current (full power mode). The device can also be selected to operate on 1.4 mA of quiescent current (low power mode) to scale the power consumption to the desired performance necessary for an ADC drive application. The adjustable common-mode voltage allows the ADA4945-1 to match the input common-mode voltage of multiple ADCs. The internal common-mode feedback loop provides exceptional output balance, as well as suppression of even order harmonic distortion products.With the ADA4945-1, differential gain configurations are achieved with a simple external feedback network of four resistors determining the closed-loop gain of the amplifier. The ADA4945-1 is fabricated using Analog Devices, Inc., proprietary, silicon germanium (SiGe), complementary bipolar process, enabling the device to achieve low levels of distortion with an input voltage noise of only 2.0 nV/√Hz (full power mode).The ADA4945-1 is available in a RoHS-compliant, 3 mm × 3 mm, 16-lead LFCSP package. It is specified to operate from −40°C to +125°C.ApplicationsLow power Σ-Δ, PulSAR®, and SAR ADC driversSingle-ended to differential convertersDifferential buffersMedical imagingProcess controlPortable electronics