January 2008

P1708C

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 Power Notebook LCD Panel EMI Reduction IC

Features

•

FCC approved method of EMI attenuation.

•

Generates a low EMI spread spectrum clock of the

input frequency.

•

Optimized for frequency range from 50 to 110MHz.

•

Internal loop filter minimizes external components and

board space.

•

Four selectable spread ranges.

•

Low inherent cycle-to-cycle jitter.

•

3.3V operating voltage range.

•

TTL or CMOS compatible inputs and outputs.

•

Ultra-low power CMOS design.

•

8.46 mA @3.3V, 54MHz

•

9.79 mA @3.3V, 65MHz

•

12.06 mA @3.3V, 81MHz

•

16.51 mA @3.3V, 108MHz

•

Supports notebook VGA and other LCD timing

controller applications.

•

Pinout compatible to ICS MK1708 and Cypress

CY25560.

•

SSON/SBM pin for Spread Spectrum On/Off and

Standby Mode controls.

•

Available in 8-pin SOIC and TSSOP.

Product Description

The P1708C is a versatile spread spectrum frequency

modulator designed specifically for input clock frequencies.

The P1708C reduces electromagnetic interference (EMI) at

the clock source, allowing system wide reduction of EMI of

down stream clock and data dependent signals. The

P1708C 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 P1708C 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’.

The P1708C uses the most efficient and optimized

modulation profile approved by the FCC and is

implemented in a proprietary all digital method.

Applications

The P1708C is targeted towards notebook LCD displays,

and other displays using an LVDS interface, PC peripheral

devices, and embedded systems.

Block Diagram

VSS

CLKIN

Feedback

Divider

Modulation

Phase

Detector

Loop

Filter

VCO

Output

Divider

ModOUT

PLL

VDD

SSON

SR0 SR1

Frequency

Divider