Infinite Resolution Frequency Multiplier/Divider

Normally, frequency multiplier or divider has only discrete ratio operation since it uses digital divider as the main process for division or multiplication. By first converting the incoming frequency into a proportional DC voltage, we can perform frequency scaling easily with no restriction of discrete ratio operation. Here is the block diagram the scheme:

We can accomplished it by using the TC9400 in the F/V mode. It is easy to scale this voltage up or down by use of a single potentiometer once the frequency is in a voltage format. Then, we can apply the resultant voltage to a TC9400 V/F converter, which generates a proportional output frequency. The division/multiplication factor can be any number, including fractions (K1 is simply Vout/Fin, while K2 is Fout/Vin) since the potentiometer is infinitely variable. [System’s block diagram source: Microchip Application Note]