This circuit uses an HA2400 consisting of 4 digitally controlled operational amplifiers. The circuit is from a Radio Electronics magazine from March 1980. The power supply must be symmetrical.
This filter is suggested by the Texas Instruments Linear Circuits Applications, 1986 edition. The...
This CMOS circuit was obtained in a 1980s documentation. The circuit has a 10-second time delay...
This circuit consists of a switched mixer with digital touch control. The circuit was found in old...