Switched analog buffer (CB9315E)

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

Second-Order Low Pass Filter (CB25814E)
This 10 kHz filter is based on a 741 operational amplifier. The circuit is from Electronics Now...
Tunable Notch Filter CB14128E (CB14128E)
The circuit shown is from the 1994 Linear Applications Handbook from National Semiconductor. The...
Burglar Alarm CK722 (CB14745E)
We found this circuit in the 1957 Raytheon transistor application manual. The transistor can be a...