This filter was found in Exar documentation from the 1980s. The circuit has an attenuation of 60 dB at the selected frequency. The power supply must be symmetrical.
The circuit shown in figure 5 generates square signals based on a transconductance operational amplifier...
By adding a transistor to the output and some polarization features we can obtain a higher output...
Found in the 1990 special issue of Radio Electronics Experimenter magazine, this circuit uses an...