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.
A first circuit that uses a phototransistor as a detector and is suitable for covering short...
We found this circuit in recent English documentation. The circuit uses CMOS technology and can be...
We found this circuit in an old Mullard (Philips) documentation on the 555 and 556 integrated circuit...