September 2005
rev 1.4
LCD Panel EMI Reduction IC
Features
FCC approved method of EMI attenuation.
Provides up to 15dB of EMI suppression
Generates a low EMI spread spectrum clock of the
input frequency
50MHz to 170MHz input frequency range
Optimized for 54MHz, 65MHz, 81MHz, 140MHz,
and 162MHz pixel clock frequencies
Internal loop filter minimizes external components
and board space
8 selectable spread ranges, up to 卤 2.2%
SSON# control pin for spread spectrum enable and
disable options
2 selectable modulation rates
Low Cycle-to-cycle jitter
3.3V Operating Voltage
Ultra low power CMOS design
Supports most mobile graphic accelerator and LCD
timing controller specifications
Available in 8 pin SOIC and TSSOP Packages
P2040C
system wide reduction of EMI of all clock dependent
signals. The P2040C allows significant system cost
savings by reducing the number of circuit board layers and
shielding that are traditionally required to pass EMI
regulations.
The P2040C uses the most efficient and optimized
modulation
profile
approved
by
the
FCC
and
is
implemented in a proprietary all-digital method. The
P2040C modulates the output of a single PLL in order to
鈥渟pread鈥?the bandwidth of a synthesized clock and, more
importantly, decreases the
peak amplitudes of its
harmonics. This result in a significantly lower system EMI
compared to the typical narrow band signal produced by
oscillators and most frequency generators. Lowering EMI
by increasing a signal鈥檚 bandwidth is called 鈥榮pread
spectrum clock generation鈥?
Applications
The P2040C is targeted towards digital flat panel
applications for Notebook PCs, Palm-size PCs, Office
Automation Equipments and LCD Monitors.
Product Description
The P2040C is a selectable spread spectrum frequency
modulator designed specifically for digital flat panel
applications.
The
P2040C
reduces
electromagnetic
interference (EMI) at the clock source which provides
Block Diagram
SR0 SR1 MRA SSON#
VDD
Modulation
CLKIN
Frequency
Divider
Feedback
Divider
PLL
Phase
Detector
Loop
Filter
VCO
Output
Divider
ModOUT
VSS
Alliance Semiconductor
2575 Augustine Drive
鈥?/div>
Santa Clara, CA
鈥?/div>
Tel: 408.855.4900
鈥?/div>
Fax: 408.855.4999
鈥?/div>
www.alsc.com
Notice: The information in this document is subject to change without notice.
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