Peak EMI Reducing Solution
Generates an EMI optimized clock signal at
Input frequency: 25 MHz.
o USB Clock (48 MHz unmodulated)
o 50 MHz (modulated), ±1% centre spread
Modulation rate: 39 KHz.
Spread Spectrum ON/OFF control
Supply voltage range 2.5V ± 5%.
Available in 8-pin SOIC package.
Commercial Temperature range.
The ASM3P2853A is a versatile spread spectrum
frequency modulator. The ASM3P2853A reduces
electromagnetic interference (EMI) at the clock source.
The ASM3P2853A allows significant system cost savings
by reducing the number of circuit board layers and
shielding that are required to pass EMI regulations. The
ASM3P2853A modulates the output of PLL in order to
spread the bandwidth of a synthesized clock, thereby
decreasing 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 clock generators. Lowering EMI by increasing a
signal’s bandwidth is called spread spectrum clock
ASM3P2853A is targeted towards EMI management for
high speed digital applications such as PC peripheral
devices, consumer electronics and embedded controller
2575 Augustine Drive • Santa Clara CA • Tel: 408-855-4900 • Fax: 408-855-4999 • www.alsc.com