The THS4521, THS4522, and THS4524 family of devices are very low-power, fully differential op amps with rail-to-rail output and an input common-mode range that includes the negative rail. These amplifiers are designed for low-power data acquisition systems and high-density applications where power dissipation is a critical parameter, and provide exceptional performance in audio applications. The family includes single (THS4521), dual (THS4522), and quad (THS4524) versions. These fully differential op amps feature 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, these devices are ideally suited for driving both successive-approximation register (SAR) and delta-sigma (ΔΣ) ADCs using only a single +2.5V to +5V and ground power supply. The THS4521, THS4522, and THS4524 family of fully differential op amps is characterized for operation over the full industrial temperature range from –40°C to +85°C.