Description The P2010A is a selectable spread spectrum frequency modulator designed specifically for PC peripheral and embedded controller markets. The P2010A reduces electromagnetic interference (EMI) at the clock source which provides system wide reduction of EMI of all clock dependent signals. The P2010A allows significant system cost savings by reducing the number of circuit board layers and shielding that are traditionally required to pass EMI regulations. The P2010A uses the most efficient and optimized modulation profile approved by the FCC and is implemented in a proprietary all−digital method. The P2010A 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.