We found this circuit that converts a direct voltage into a proportional frequency signal. The circuit is from an Electronics Now from April 1993. The JFET can be of any type.
This circuit is from a publication by Newton C. Braga in the United States. The transistor can be...
The circuit is from the Texas Instruments optoelectronics manual. The capacitor depends on the...
This circuit was found in an application note of the LTC1164 from Linear Technology of the 1990s....