I2008A-08TT
| Model | I2008A-08TT |
| Description | Clock Generator, CMOS, PDSO8 |
| PDF file | Total 9 pages (File size: 173K) |
| Chip Manufacturer | ALSC |
July 2005
rev 1.3
General Purpose EMI Reduction IC
Features
FCC approved method of EMI attenuation.
Provides up to 15dB of EMI suppression.
Generates a 1X or �½ X low EMI spread spectrum
clock of the input frequency.
Input frequency range: 4MHz to 32MHz.
Internal loop filter minimizes external components
and board space.
Spreading ranges from ±0.8% to ±3.2%.
SSON# control pin for spread spectrum enable
and disable options.
Low Cycle-to-Cycle jitter.
3.3V Operating Voltage.
Ultra-low power CMOS design.
Available in 8-pin SOIC and TSSOP Packages.
P2008A
number of circuit board layers ferrite beads,
required to pass EMI regulations.
shielding
and other passive components that are traditionally
The P2008A uses the most efficient and optimized
modulation profile approved by the FCC and is
implemented in a proprietary all digital method.
The P2008A 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 P2008A is a versatile spread spectrum frequency
modulator designed specifically for digital camera and
other digital video and imaging applications. The P2008A
reduces electromagnetic interference (EMI) at the clock
source, allowing system wide reduction of EMI of down
stream clock and data dependent signals. The P2008A
allows significant system cost savings by reducing the
Applications
The P2008A is targeted towards cable, xDSL, fax
modem, set-top box, USB controller, DSC, and other
embedded systems.
Block Diagram
VDD
SR0 SSON#
DIV2
Modulation
XIN/CLKIN
XOUT
Feedback
Divider
Crystal
Oscillator
Frequency
Divider
PLL
Phase
Detector
Loop
Filter
VCO
Output
Divider
ModOUT
VSS
Alliance Semiconductor
2575 Augustine Drive
•
Santa Clara, CA
•
Tel: 408.855.4900
•
Fax: 408.855.4999
•
www.alsc.com
Notice: The information in this document is subject to change without notice.
