The AD820 is a precision, low power FET input op amp that can operate from a single supply of 5 V to 36 V, or dual supplies of ±2.5 V to ±18 V. It has true single-supply capability, with an input voltage range extending below the negative rail, allowing the AD820 to accommodate input signals below ground in the single-supply mode. Output voltage swing extends to within 10 mV of each rail, providing the maximum output dynamic range. Offset voltage of 800 μV maximum, offset voltage drift of 2 μV/°C, typical input bias currents below 25 pA, and low input voltage noise provide dc precision with source impedances up to 1 GΩ. 1.8 MHz unity gain bandwidth, ?93 dB THD at 10 kHz, and 3 V/μs slew rate are provided for a low supply current of 800 μA. The AD820 drives up to 350 pF of direct capacitive load and provides a minimum output current of 15 mA. This allows the amplifier to handle a wide range of load conditions. This combination of ac and dc performance, plus the outstanding load drive capability, results in an exceptionally versatile amplifier for the single-supply user.