The THS4521 is a very low-power, fully differential op amp with rail-to-rail output and an input common-mode range that includes the negative rail. This amplifier is designed for low-power data acquisition systems and high-density applications where power dissipation is a critical parameter, and provides exceptional performance in audio applications. The THS4521 features accurate output common-mode control that allows for dc-coupling when driving analog-to-digital converters (ADCs). This control, coupled with an input common-mode range below the negative rail as well as rail-to-rail output, allows for easy interfacing between single-ended, ground-referenced signal sources. Additionally, this device is ideally suited for driving both successive-approximation register (SAR) and delta-sigma (ΔΣ) ADCs using only a single 2.5-V to 3.3-V and ground power supply. The THS4521 is characterized for operation from –55°C to 210°C.