Superlinear FM (Frequency Modulator)

Designing various electronic circuit system (synthesizer, modem, decoder, data converter, etc) of ten need a frequency modulator subsystem. An FM modulator is very easy to build with TC9400 since the it has very good linearity as V/F converter. Here is the system’s block diagram:

While Vin determines the amount of modulation (FM deviation) around the center frequency, the potentiometer determines the center frequency. Vin can be negative as well as positive. [Block diagram’s source: Microchip Application Note]