November 2006
P2005A/S
rev 1.3
Notice: The information in this document is subject to change without notice.
PulseCore Semiconductor Corporation
1715 S. Bascom Ave Suite 200, Campbell, CA 95008
Tel: 408-879-9077 Fax: 408-879-9018
www.pulsecoresemi.com
Low Frequency EMI Reduction IC
Features
FCC approved method of EMI attenuation.
Provides up to 15dB of EMI suppression.
Generates a 1X or X low EMI spread spectrum
clock of the input frequency.
Input frequency range: 8MHz to 32MHz.
Internal
loop
filter
minimizes
external
components and board space.
Frequency deviation:
P2005A: ± 1% to ± 3%
P2005S: ± 0.6% to ± 1.8%
SSON# control pin for spread spectrum enable
and disable options.
Low cycle-to-cycle jitter.
3.3V or 5V operating voltage range.
Ultra-low power CMOS design.
Available in 8-pin SOIC and TSSOP.
Product Description
The P2005A/S is a versatile spread spectrum frequency
modulator
designed
specifically
for
input
clock
frequencies from 8MHz to 32MHz. Refer Output
Frequency Selection Table. The P2005A/S can generate
an EMI reduced clock from crystal, ceramic resonator, or
system clock. The P2005A/S offers various percentage
BlockDiagram
deviations ranging form ±0.6% to ±3.0%. Refer
Frequency Deviation Selections Table. The P2005A/S
reduces electromagnetic interference (EMI) at the clock
source, allowing system wide reduction of EMI of down
stream clock and data dependent signals. The P2005A/S
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 P2005A/S uses the most efficient and optimized
modulation profile approved by the FCC and is
implemented in a proprietary all digital method.
The P2005A/S 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’.
Applications
The P2005A/S is targeted towards EMI management for
high-speed digital applications such as PC peripheral
devices, consumer electronics and embedded controller
systems.
VSS
XIN
Frequency
Divider
Feedback
Divider
Modulation
Phase
Detector
Loop
Filter
VCO
Output
Divider
MODOUT
PLL
VDD
SSON#
DIV2
SR0
Crystal
Oscillator
XOUT