Preliminary Specification
P1727/66
Low Power Notebook LCD Panel EMI Reduction IC
FEATURES
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Low inherent cycle-to-cycle jitter
3.3V operating voltage
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FCC approved method of EMI attenuation
Generates a low EMI spread spectrum of
the input clock frequency
CMOS/TTL compatible inputs and outputs
Ultra low power CMOS design
TBD mA @3.3V, 54 MHz
TBD mA @3.3V, 65 MHz
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Optimized for frequency range:
P1727X: 20MHz to 40MHz
P1766X: 40MHz to 80MHz
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Supports notebook VGA and other LCD
timing controller applications
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Internal loop filter minimizes external
components and board space
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Available in 8 pin SOIC and TSSOP
8 different frequency deviations ranging
Qualified for Industrial Temp Spec. (+85C)
from +/-0.625% to –3.50%
The P1727/66 uses the most efficient and
optimized modulation profile approved by the
FCC and is implemented by using a proprietary
all-digital method.
PRODUCT DESCRIPTION
The P1727/66 is a versatile spread spectrum
frequency modulator designed specifically for a
wide range of clock frequencies. The P1727/66
reduces electromagnetic interference (EMI) at
the clock source, allowing system wide
reduction of EMI of down stream (clock and
data dependent signals). The P1727/66 allows
significant system cost savings by reducing the
number of circuit board layers and shielding that
are traditionally required to pass EMI
regulations.
APPLICATIONS
The P1727/66 is targeted towards notebook
LCD displays, other displays using an LVDS
interface, PC peripheral devices, and embedded
systems.
Figure 1 – P1727/66 Pin Diagram
The P1727/66 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”.
CLKIN
VDD
1
2
3
8
7
6
5
PD#
NC
P1727X
P1766X
VSS
NC
ModOUT
4
REF
Oct., 2002
Revision B
3160 De La Cruz Blvd., Suite 200 • Santa Clara • CA • 95054
Tel (408) 748-6988 • Fax (408) 748-0009
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http://www.pulsecore.com