February 2007
rev 0.2
Peak EMI Reducing Solution
Features
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Generates an EMI optimized clock at the output.
Input frequency: 25MHz.
Frequency outputs:
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60MHz (unmodulated)
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2 x 48MHz (unmodulated)
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66.6MHz (modulated): -1.7% down spread
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Modulation rate: 30KHz.
Supply voltage range: 3.3V ± 0.3V.
Available in 8-pin SOIC Package.
Commercial and Industrial Temperature range.
RoHS Compliant
ASM3P2111B
allows significant system cost savings by reducing the
number of circuit board layers and shielding that are
required to pass EMI regulations. The ASM3P2111B
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 generation.
Applications
ASM3P2111B is targeted towards EMI management for
Product Description
The ASM3P2111B is a versatile spread spectrum
frequency
modulator
that
reduces
electromagnetic
interference (EMI) at the clock source. The ASM3P2111B
high speed digital applications such as PC peripheral
devices, consumer electronics and embedded controller
systems.
Block Diagram
V
DD
XIN /CLKIN
Crystal
Oscillator
XOUT
PLL1
60 MHz
48 MHz_1
48 MHz_2
48 MHz_1
PLL2
66.6 MHz
Modulated
V
SS
PulseCore Semiconductor Corporation
1715 S. Bascom Ave Suite 200, Campbell, CA 95008
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Tel: 408-879-9077
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Fax: 408-879-9018
www.pulsecoresemi.com
Notice: The information in this document is subject to change without notice.
PULSECORE [ PulseCore Semiconductor ]
