This circuit is from Motorola's 1990 Linear Databook. We can implement it with other operational amplifier. The power supply must be symmetrical.
We found this circuit at Popular Electronics. The components are still current. Changes can be...
This circuit was found in ancient American documentation. Diodes are general-purpose types. |...
We found this CMOS circuit based on the PLL4046 in the December 1989 issue of Radio Electronics magazine....