November 2006
rev 1.1
P2180 / 81 / 82 / 83 / 84
Peak Reducing EMI Solution
Features
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•
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FCC approved method of EMI attenuation.
•
Eight spread % selections:
± 0.625% to -3.5%.
Provides up to 15dB EMI reduction.
Generates a 1X low EMI spread spectrum clock
from the input frequency.
•
•
•
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3.3V operating voltage.
CMOS/TTL compatible inputs and outputs.
Low-power CMOS design.
Supports notebook VGA and other LCD timing
controller applications.
Drop-in replacement to Cypress W180/1.
Products are available for industrial temperature
range.
•
Optimized for frequency range:
•
P2180 / 84: 20MHz to 40MHz
P2181: 60MHz to 160MHz
P2182 / 83: 10MHz to 20MHz
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•
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Internal
loop
filter
minimizes
external
components and board space.
Selectable spread options: Down Spread and
Center Spread.
•
Available in 8-pin SOIC and TSSOP packages.
Low inherent cycle-to-cycle jitter.
Product Description
The P2180/81X modulates the output of a single
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.
The P2180/81X is a versatile spread spectrum
frequency modulator designed specifically for a
wide range of clock frequencies from 20MHz to
40MHz and 60MHz to 160MHz (Refer Input
Frequency and Modulation Rate Table.) The
P2180/81X can generate an EMI reduced clock
form an OSC or a system generated clock. The
P2180/81A
to
P2180/81D
offer
various
combinations of spread options and percentage
deviations. (Refer Spread Deviation Selections
Table.) These combinations include Down and
Center Spread and percentage deviation range
from ± 0.625% to –3.50%.
The P2180/81X uses the most efficient and
optimized modulation profile approved by the FCC
and is implemented by using a proprietary all-digital
method.
Applications
The
P2180/81X
reduces
electromagnetic
interference (EMI) at the clock source, allowing
system wide reduction of EMI of down stream clock
and data dependent signals. The P2180/81X allows
significant system cost savings by reducing the
number of circuit board layers and shielding that
are traditionally required to pass EMI regulations.
The P2180/81X is targeted towards EMI
management for memory and LVDS interfaces in
mobile graphic chipsets and high-speed digital
applications such as PC peripheral devices,
consumer electronics, and embedded controller
systems.
PulseCore Semiconductor Corporation
1715 S. Bascom Ave Suite 200, Campbell, CA 95008 • Tel: 408-879-9077 • Fax: 408-879-9018
www.pulsecoresemi.com
Notice: The information in this document is subject to change without notice.
PULSECORE [ PulseCore Semiconductor ]
