This is the basic configuration of an operational amplifier sample & hold circuit. The FET and transistor are commonly used. The circuit is from an 80's documentation.
This circuit is from a Popular Electronics from the 90s. Its gain is 22 dB and can be used as a...
This circuit was found in an article in Radio Electronics magazine from October 1962. At that...
This circuit can be implemented with other operational amplifiers. The formulas for calculating the...