CY26049-22

CY26049-22 is a FailSafe frequency synthesizer with a reference clock input and 100-MHz output. The device provides an optimum solution for applications where continuous operation is required in the event of a primary clockfailure. The continuous, glitch-free operation is achieved by using a DCXO, which serves as a primary clock source. The FailSafe control circuit synchronizes the DCXO oscillator with the reference as long as the reference is within the pull range of the crystal.

In the event of a reference clock failure the DCXO maintains the last frequency of the reference clock. The unique feature of the CY26049-22 is that the DCXO is, in fact, the primary clocking source. When the reference clock is restored, the DCXO automatically resynchronizes to the reference. The status of the reference clock input, as detected by the CY26049-22, is reported by the SAFE pin.