General Description
The DS1181L is a spread-spectrum clock modulator IC
that reduces EMI in high clock-frequency-based, digital
electronic equipment.
Using an integrated phase-locked loop (PLL), the
DS1181L accepts an input clock signal in the range of
20MHz to 134MHz and delivers a spread-spectrum mod-
ulated output clock signal. The PLL modulates, or dithers,
the output clock about the center input frequency at a
pin-selectable magnitude, allowing direct EMI control and
optimization. In addition, through an enable pin the dither-
ing can be enabled or disabled for easy comparison of
system performance during EMI testing. This same input
pin also allows the DS1181L output to be three-stated.
By dithering the system clock, all the address, data,
and timing signals generated from this signal are also
dithered so that the measured EMI at the fundamental
and harmonic frequencies is greatly reduced. This is
accomplished without changing clock rise/fall times or
adding the space, weight, design time, and cost asso-
ciated with mechanical shielding.
The DS1181L is provided in an 8-pin TSSOP package
and operates over a full automotive temperature range
of -40°C to +125°C.
Applications
LCD Panels for TVs, Desktop Monitors, and
Notebook and Tablet PCs
Automotive Telematics and Infotainment
Printers
Features
♦ Modulates a 20MHz to 134MHz Clock with Center
Spread-Spectrum Dithering
♦ Selectable Spread-Spectrum Modulation
Magnitudes of:
±0.5%
±1.0%
±1.5%
±2.0%
♦ Low 75ps Cycle-to-Cycle Jitter
♦ Spread-Spectrum Disable Mode
♦ Pin Compatible with Alliance/PulseCore
Semiconductor P2040 Series Devices
♦ Clock Output Disable
♦ Low Cost
♦ Low Power Consumption
♦ 3.3V Single Voltage Supply
♦ -40°C to +125°C Temperature Range
♦ Small 8-Pin TSSOP Package
DS1181L
20MHz to 134MHz Spread-Spectrum
Clock Modulator for LCD Panels
________________________________________________________________
Maxim Integrated Products
1
Rev 1; 8/08
+
Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
Ordering Information
