20MHz to 134MHz Spread-Spectrum

Clock Modulator for LCD Panels

Spread-Spectrum Enable

On power-up, the output clock (SSO) remains three-stat-

ed until the internal PLL reaches a stable frequency. The

SSEN input can be used to disable the spread-spec-

trum modulation and to three-state the SSO output. If the

SSEN pin is pulled high, the spread-spectrum modula-

tion is turned off, but the device still uses the internal

PLL to generate the clock signal at SSO. If the SSEN pin

is floated, the output is three-stated.

Application Information

Power-Supply Decoupling

To achieve best results, it is highly recommended that a

decoupling capacitor is used on the IC power-supply

pins. Typical values of decoupling capacitors are 0.01µF

and 0.1µF. Use a high-quality, ceramic, surface-mount

and GND pins of the IC to minimize lead inductance.

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are

implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 5

© 2007 Maxim Integrated Products

is a registered trademark of Maxim Integrated Products, Inc.

TIME

1

DITHER CYCLE

RATE

DITHER AMOUNT

(

±0.5%, ±1.0%, ±1.5%, OR ±2.0%)

CLKIN RANGE (MHz)

DITHER RATE

20 TO 134

IF SSEN = 1

Figure 1. DS1181L Spread-Spectrum Frequency Modulation

CLKIN

SMSEL1

SMSEL2

GND

CRSEL

DECOUPLING

CAPACITOR

SSO

134MHz

NOTE: IN THE ABOVE CONFIGURATION WITH SMSEL1, SMSEL2, AND SSEN CONNECTED TO GND AS WELL AS

±2.0%,

AND ALLOWS A CLKIN BETWEEN 20MHz and 38MHz.

DITHERED

SSEN

DS1181L

Typical Operating Circuit

Package Information

(For the latest package outline information, go to

PACKAGE TYPE

DOCUMENT NO.

8 TSSOP

56-G2021-000