Low Power Peak EMI Reducing Solution
• Generates an EMI optimized clock signal at the
• Integrated loop filter components.
• Operates with a 3.3V /2.5V supply.
• Operating current less than 4mA.
• Low power CMOS design.
• Input frequency : 12MHz
• Generates a 1X low EMI spread spectrum clock
of the input frequency.
• Frequency deviation: ± 0.4%(Typ) @ 12MHz
• Available in 6-pin TSOT-23, 8-pin SOIC and 8-
pin TSSOP packages.
The ASM3P2863A is a versatile spread spectrum
frequency modulator designed specifically for a wide
range of clock frequencies. The ASM3P2863A reduces
electromagnetic interference (EMI) at the clock source,
allowing system wide reduction of EMI of all clock
dependent signals. The ASM3P2863A allows significant
system cost savings by reducing the number of circuit
board layers ferrite beads, shielding that are traditionally
required to pass EMI regulations.
The ASM3P2863A uses the most efficient and optimized
modulation profile approved by the FCC and is
implemented by using a proprietary all digital method.
The ASM3P2863A 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’.
The ASM3P2863A is targeted towards all portable
devices with very low power requirements like MP3
players, Notebooks and Digital still cameras.
Output Duty Cycle
Modulation Rate Equation
VDD = 2.5V / 3.3V
200 pS ( Max)
45/55% (worst case)
± 0.4 % (Typ) @ 12MHz
PulseCore Semiconductor Corporation
1715 S. Bascom Ave Suite 200, Campbell, CA 95008 • Tel: 408-879-9077 • Fax: 408-879-9018
Notice: The information in this document is subject to change without notice.