The AD745 is an ultralow noise, high speed, FET input operational amplifier. It offers both the ultralow voltage noise and high speed generally associated with bipolar input op amps and the very low input currents of FET input devices. Its 20 MHz bandwidth and 12.5 V/µs slew rate makes the AD745 an ideal amplifier for high speed applications demanding low noise and high dc precision. Furthermore, the AD745 does not exhibit an output phase reversal. The AD745's guaranteed, tested maximum input voltage noise of 4 nV/(root)Hz at 10 kHz is unsurpassed for a FET-input monolithic op amp, as is its maximum 1.0 µV p-p noise in a 0.1 Hz to 10 Hz bandwidth. The AD745 also has excellent dc performance with 250 pA maximum input bias current and 0.5 mV maximum offset voltage.The internal compensation of the AD745 is optimized for higher gains, providing a much higher bandwidth and a faster slew rate. This makes the AD745 especially useful as a preamplifier where low level signals require an amplifier that provides both high amplification and wide bandwidth at these higher gains. The AD745 is available in five performance grades. The AD745J and AD745K are rated over the commercial temperature range of 0°C to +70°C. The AD745A and AD745B are rated over the industrial temperature range of -40°C to +85°C. The AD745S is rated over the military temperature range of -55°C to +125°C and is available processed to MIL-STD-883B, Rev. C.The AD745 is available in 8-pin plastic mini-DIP, 8-pin cerdip, 16-pin SOIC, or in chip form.