This 4-transistor amplifier can work from 4.5 or 6 V power supplies. We found it in a Mullard transistors manual from 1960. The transistors are from the time.
We found this circuit with an operational transconductance amplifier in the Motorola Linear...
We found this circuit in the 1994 Linear Applications Handbook by National Semiconductor. The...
In the figure we have a differentiator with the LM3900 transconductance amplifier. The circuit is...