MPC992

The MPC992 features an onboard crystal oscillator to allow for seed clock generation as well as final distribution.

The onboard oscillator is completely self contained so that the only external component required is the crystal. As the oscillator is somewhat sensitive to loading on its inputs the user is advised to mount the crystal as close to the MPC992 as possible to avoid any board level parasitics. To facilitate colocation surface mount crystals are recommended, but not required.

The oscillator circuit is a series resonant circuit asopposed to the more common parallel resonant circuit, this eliminates the need for large onboard capacitors. Because the design is a series resonant design, for optimum frequency accuracy a series resonant crystal should be used (see specification table below). Unfortunately most off the shelf crystals are characterized in a parallel resonant mode.However a parallel resonant crystal is physically no different than a series resonant crystal, a parallel resonant crystal is simply a crystal which has been characterized in its parallel resonant mode. Therefore in the majority of cases a parallel specified crystal can be used with the MPC992 with just a minor frequency error due to the actual series resonant frequency of the parallel resonant specified crystal. Typically