ASM3X2105A

The ASM3X2105A is a versatile spread spectrum frequency modulator designed specifically for input clock frequencies from 6MHz to 12MHz. The ASM3X2105A can generate an EMI reduced clock from crystal, ceramic resonator, or system clock. The ASM3X2105A offers frequency deviation of ± 1%.

The ASM3X2105A reduces electromagnetic interference (EMI) at the clock source, allowing system wide reduction of EMI of down stream clock and data dependent signals. The ASM3X2105A 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 ASM3X2105A uses the most efficient and optimized modulation profile approved by the FCC and is implemented in a proprietary all digital method.

The ASM3X2105A 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'.