The MK2058-01 is a VCXO (Voltage Controlled Crystal Oscillator) based clock jitter attenuator designed for system clock distribution applications. This monolithic IC, combined with an external inexpensive quartz crystal, can be used to replace a more costly hybrid VCXO retiming module. The device accepts and outputs the same clock frequency in selectable ranges covering 4kHz to 27MHz. A dual input mux is also provided.