P2027A Datasheet, PDF (1/9 Pages) Alliance Semiconductor Corporation – General Purpose EMI Reduction IC

October 2003
P2027A
rev E
General Purpose EMI Reduction IC
Features
ƒ FCC approved method of EMI attenuation
ƒ Provides up to 20 dB of EMI suppression
ƒ Generates a low EMI spread spectrum clock of
the input frequency
ƒ Optimized for 27 MHz operation
ƒ Internal loop filter minimizes external
components and board space
ƒ 3 selectable spread ranges and 2 modulation
rate options
ƒ SSON control pin for spread spectrum enable
and disable options
ƒ Low cycle-to-cycle jitter
ƒ 3.3V operating voltage
ƒ 16 mA output drives
ƒ TTL or CMOS compatible outputs
ƒ Low power CMOS design
ƒ Supports digital camera and other digital video
and imaging applications
ƒ Available in 8 pin SOIC and TSSOP
Product Description
The P2027 is a versatile spread spectrum frequency
modulator designed specifically for digital camera
and other digital video and imaging applications. The
P2027 reduces electromagnetic interference (EMI) at
the clock source, which provides system wide
reduction of EMI of all clock dependent signals. The
P2027 allows significant system cost savings by
reducing the number of circuit board layers and
shielding that are traditionally required to pass EMI
regulations.
The P2027 uses the most efficient and optimized
modulation profile approved by the FCC and is
implemented in a proprietary all-digital method.
The P2027 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 P2027 is targeted towards DSC market as well
as other imaging and digital video applications like
DVD and VCD players.
Block Diagram
Alliance Semiconductor
2575, Augustine Drive • Santa Clara, CA • Tel: [phone] • Fax: [phone] • www.alsc.com
Notice: The information in this document is subject to change without notice.