Switched analog buffer (CB9315E)

This circuit was obtained from an application note from Analog Devices from the 90s. The components are from that time.

VCO with a Frequency Range of 100: 1 (CB1545E )
We find this circuit in a documentation for engineers from 1971. The circuit generates rectangular and...
High Q Filter (CB25362E)
This 1/2 hertz high selectivity filter was found in the December 1990 issue of Radio Electronics...
High Resistance Adapter (CB24718E)
Connected to the low current input of a standard multimeter, this circuit enables the reading of...