The NB2579A is a versatile spread spectrum frequency modulator designed specifically for a wide range of clock frequencies. The NB2579A reduces ElectroMagnetic Interference (EMI) at the clock source, allowing system wide reduction of EMI of all clock dependent signals. The NB2579A allows significant system cost savings by reducing the number of circuit board layers, ferrite beads and shielding that are traditionally required to pass EMI regulations. The NB2579A uses the most efficient and optimized modulation profile approved by the FCC and is implemented by using a proprietary all digital method. The NB2579A modulates the output of a single PLL in order to "spread" the bandwidth of a synthesized clock, and more importantly, decreases the peak amplitudes of its harmonics. This results in significantly lower system EMI compared to the typical narrow band signal produced by oscillators and most frequency generators. Lowering EMI by increasing a signal's bandwidth is called `spread spectrum clock generation'.