output frequcency of SN74LS624

The capacitor will set your center frequency and then the charts will show you how much the voltage can chang the frequency. if you look at figure 4 they are using a 50pf capacitor and they can change the voltage control pin and adjust the output from 1 to 10Mhz

Thank you very much! But i have a next question that is how output frequency does depend on control pin. I have a example: i want to set output frequency at 20kHz, how to chose value resistor????Do you have a formula to calculate it??? Which is solution to calculate it,qualitative or quantitative????

Thank you because help me!!!!!

I do not know a formula. The chart figure 6 in the datasheet is the only chart that shows that low of a frequency.

The capacitor sets the frequency. From the chart you can pick the capacitor and then you can adjust it in by using the VCO pin.

Thank you so much