This filter was found in Texas Instruments documentation from the 1980s. The circuit uses a common operational amplifier and has its response curve in the figure.
This circuit was obtained in an 1975 English publication. It is a voltage regulator circuit for...
In the figure we have an infrared receiver circuit using an operational 741. The circuit is an...
This circuit is suggested by National Semiconductor and makes use of the negative regulator LM2990...