Found in Motorola documentation from the 90's, this circuit has a high input impedance. The power supply must be symmetrical. The circuit can be implemented with modern operational amplifiers.
This circuit, which can act as a shield, was found in a 1990 PE Hobbyst Handbook. The circuit...
The LM109 was manufactured by many semiconductor companies that presented different configurations in their...
This two-stage circuit has a voltage gain of 100 times, with a high input impedance. The circuit is...