The AD840 is a member of the Analog Devices' family of wide bandwidth operational amplifiers. This high speed/high precision family includes, among others, the AD841, which is unitygain stable, and the AD842, which is stable at a gain of two or greater and has 100 mA minimum output current drive. These devices are fabricated using Analog Devices' junction isolated complementary bipolar (CB) process. This process permits a combination of dc precision and wideband ac performance previously unobtainable in a monolithic op amp. In addition to its 400 MHz gain bandwidth product, the AD840 offers extremely fast settling characteristics, typically settling to within 0.01% of final value in 100 ns for a 10 volt step. The AD840 remains stable over its full operating temperature range at closed-loop gains of 10 or greater. It also offers a low quiescent current of 12 mA maximum, a minimum output current drive capability of 50 mA, a low input voltage noise of 4 nV/Hz and a low input offset voltage of 0.3 mV maximum (AD840K).