January 2007

PCS3P2191A

rev 0.1

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

Spread Spectrum Clock Generator

Features

•

Generates four 4X low EMI spread spectrum clocks

•

Input frequency: 15MHz

•

Output frequency: 60MHz

•

Internal loop filter minimizes external components

and board space

•

Selectable Centre Spread frequency deviation:

±0.5%, ±0.75%, ± 1.0%,

± 1.25%, ± 1.5%, ± 1.75% ± 2.0%

•

3.3V ± 0.3V Operating Voltage

•

Commercial Temperature range

•

Available in 16-pin TSSOP

•

Advanced low power CMOS process

Product Description

PCS3P2191A is a versatile spread spectrum frequency

modulator that generates four low EMI 4x clocks at the

output. PCS3P2191A

offers seven selectable centre spread options of ±0.5% to

±2.0%, and a no spread option. (Refer Spread Deviation

Selection Table). PCS3P2191A reduces electromagnetic

interference (EMI) at the clock source, allowing system

wide reduction of EMI of all clock dependent signals.

The PCS3P2191A allows significant system cost savings

by reducing the number of circuit board layers, ferrite

beads, and shielding that are traditionally required to

pass EMI regulations. The PCS3P2191A uses the most

efficient and optimized modulation profile approved by

the FCC and is implemented in a proprietary all digital

method.

Application

PCS3P2191A is targetted for LCD panel application

Block Diagram

ModOUT

CLKIN / XIN

GND

Frequency

Divider

Feedback

Divider

Modulation

Phase

Detector

Loop

Filter

VCO

Output

Divider

PLL

VDD

XOUT

Crystal

Oscillator

S2

S0

S1

4

2

5