P2040C Datasheet, PDF (1/9 Pages) Alliance Semiconductor Corporation – LCD Panel EMI Reduction IC

November 2006
P2040C
rev 1.6
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 173MHz 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 ± 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
Product Description
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
“spread” 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’s bandwidth is called ‘spread
spectrum clock generation’.
Applications
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
The P2040C is targeted towards digital flat panel
applications for Notebook PCs, Palm-size PCs, Office
Automation Equipments and LCD Monitors.
Block Diagram
SR0 SR1 MRA SSON#
VDD
CLKIN
Frequency
Divider
Feedback
Divider
Modulation
Phase
Detector
Loop
Filter
PLL
VCO
Output
Divider
ModOUT
VSS
PulseCore Semiconductor Corporation
1715 S. Bascom Ave Suite 200, Campbell, CA 95008 • Tel: [phone] • Fax: [phone]
www.pulsecoresemi.com
Notice: The information in this document is subject to change without notice.