HA-2420, HA-2425 pdf datasheet

The HA-2420 and HA-2425 is a monolithic circuit consisting
of a high performance operational amplifier with its output in
series with an ultra-low leakage analog switch and JFET
input unity gain amplifier.
With an external hold capacitor connected to the switch
output, a versatile, high performance sample-and-hold or
track-and-hold circuit is formed. When the switch is closed,
the device behaves as an operational amplifier, and any of
the standard op amp feedback networks may be connected
around the device to control gain, frequency response, etc.
When the switch is opened the output will remain at its last
level.
Performance as a sample-and-hold compares very favorably
with other monolithic, hybrid, modular, and discrete circuits.
Accuracy to better than 0.01% is achievable over the
temperature range. Fast acquisition is coupled with superior
droop characteristics, even at high temperatures. High slew
rate, wide bandwidth, and low acquisition time produce
excellent dynamic characteristics. The ability to operate at
gains greater than 1 frequently eliminates the need for
external scaling amplifiers.