August 2007
rev 1.5
LCD Panel EMI Reduction IC
Features
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FCC approved method of EMI attenuation.
Provides up to 15dB EMI reduction.
Generates a 1X low EMI spread spectrum clock of
the input frequency.
Input frequency range: 25MHz to 210MHz.
Internal loop filter minimizes external components
and board space.
Center spread.
4 spread frequency deviation selections: ± 0.13% to
± 1.24%.
Low inherent Cycle-to-cycle jitter.
3.3V Operating Voltage.
TTL or CMOS compatible inputs and outputs.
Low power CMOS design.
Supports notebook VGA and other LCD timing
controller applications.
Products are available for Industrial temperature
range.
Available in 8-pin SOIC and TSSOP Packages.
ASM3P2182A
The ASM3P2182A reduces electromagnetic interference
(EMI) at the clock source, allowing system wide
reduction of EMI of
down stream clock and data
dependent signals. The ASM3P2182A 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 ASM3P2182A uses the most efficient and optimized
modulation profile approved by the FCC and is
implemented in a proprietary all digital method.
The ASM3P2182A 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’.
Product Description
The ASM3P2182A is a versatile spread spectrum
frequency modulator designed specifically for a wide
range of input clock frequencies from 25MHz to 210MHz.
(Refer Input Frequency and Modulation Rate Table).
The
ASM3P2182A can generate an EMI reduced clock from
an
OSC
or
a
system
generated
clock.
The
ASM3P2182A offers a Center Spread clock and with a
percentage deviation from ± 0.13% or ± 1.24%.
FS0
FS1
S0
Applications
The ASM3P2182A 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.
V
DD
Modulation
CLKIN
Crystal
Oscillator
Frequency
Divider
Feedback
Divider
PLL
Phase
Detector
Loop
Filter
VCO
Output
Divider
ModOUT
VSS
LCD Panel EMI Reduction IC
Notice: The information in this document is subject to change without notice.
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PULSECORE [ PulseCore Semiconductor ]
