What criteria are used to select a varactor diode?
A1 Use a varactor diode whose capacitance changes in the range of approximately 2 to 10 pF when the voltage varies by 1 to 4 V. Also, since the capacitance of the capacitor connected to pin 12 is the value when 1SV163 is used, be sure to re-evaluate the capacitance of the capacitor when the varactor diode is changed.