The AD684 is a monolithic quad sample-and-hold amplifier （SHA）。 It features four complete sampling channels， each controlled by an independent hold command. Each SHA is complete with an internal hold capacitor. The high accuracy SHA channels are self-contained and require no external components or adjustments. The AD684 is manufactured on a BiMOS process which provides a merger of high performance bipolar circuitry and low power CMOS logic. The AD684 is ideal for high performance， multichannel data acquisition systems. Each SHA channel can acquire a signal in less than 1 μs and retain the held value with a droop rate of less than 0.01 μV/μs. Excellent linearity and ac performance make the AD684 an ideal front end for high speed 12- and 14-bit ADCs. The AD684 has a self-correcting architecture that minimizes hold mode errors and insures accuracy over temperature. Each channel of the AD684 is capable of sourcing 5 mA and incorporates output short circuit protection. The AD684 is specified for three temperature ranges. The J grade device is specified for operation from 0 to +70°C， the A grade from –40°C to +85°C and the S grade from –55°C to +125°C.