ASM3P2107A

The ASM3P2107A is a versatile spread spectrum frequency modulator designed specifically for input clock frequencies from 12MHz to 22MHz. It can generate an EMI reduced clock from crystal, ceramic  resonator, or system clock. 

The ASM3P2107A reduces electromagnetic interference  (EMI) at the clock source, allowing system wide reduction  of EMI of  down stream clock and data dependent signals. The ASM3P2107A allows significant system cost savings by reducing the number of circuit board layers ferrite beads,  shielding and other passive components that are traditionally required to pass EMI regulations.

The ASM3P2107A uses the most efficient and optimized modulation profile approved by the FCC and is implemented in a proprietary all digital method. 

 The ASM3P2107A 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. ASM3P2107A 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'.