A VCXO allows the user to vary the output by varying a control voltage to pin 1. Control voltage is usually specified by a maximum and minimum voltage applied to pin 1 of VCXO oscillators. Typical control voltage ranges are 0.5 to 4.5 Vdc for a 5.0 Vdc supply voltage and 0.3 to 3.0 Vdc for a 3.3 Vdc supply voltage. The center frequency of a VCXO is the output at the center control voltage @ 25°C. It is specified as a target with an allowable deviation. The target frequency is specified in MHz or kHz and tolerance is in ± ppm. For more information on Frequency Management Inc.’s VCXO, contact us at (800) 800-9825.