GENERAL DESCRIPTION

The ADA4940-1/ADA4940-2 are low noise, low distortion fully differential amplifiers with very low power consumption. They are an ideal choice for driving low power, high resolution, high performance SAR and sigma-delta (Σ-Δ) analog-to-digital converters (ADCs) with resolutions up to 16 bits from dc to 1 MHz on only 1.25 mA of quiescent current. The adjustable level of the output common-mode voltage allows the ADA4940-1/ADA4940-2 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.

FEATURES

Small signal bandwidth: 260 MHz

Ultralow power 1.25mA

Extremely low harmonic distortion

   −122 dB THD at 50 kHz

   −96 dB THD at 1 MHz

Low input voltage noise: 3.9 nV/√Hz

0.35 mV maximum offset voltage

Balanced outputs

Settling time to 0.1%: 34 ns

Rail-to-rail output: −VS + 0.1 V to +VS − 0.1 V

Adjustable output common-mode voltage

Flexible power supplies: 3 V to 7 V (LFCSP)

Disable pin to reduce power consumption

ADA4940-1 is available in LFCSP and SOIC packages