DS1181L:20MHz to 134MHz Spread-Spectrum Clock Modulator for LCD Panels

Low-Jitter, Spread-Spectrum Clock Modulators Reduce EMI in Large-Format LCD Panels

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 modulated 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 dithering 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 associated 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.

Key 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: Block Diagram
DS1181L: Block Diagram
Applications/Uses
  • LCD Panels for TVs, Desktop Monitors, and Notebook and Tablet PCs
  • Printers
DataSheet
titleDownload file
DS1181L Data SheetDS1181L.pdf
Parametrics
Part NumberApplicationsfIN
(MHz)
fIN
(MHz)
fOUT
(MHz)
fOUT
(MHz)
Fixed or Continuous FrequencyOutput LevelsOut-
puts
PLLsProgram-
mability
Spread SpectrumOutput Jitter
(ps)
VSUPPLY
(V)
Package/PinsBudgetary
Price
minmaxminmaxRMSSee Notes
DS1181LGeneral Purpose2013420134ContinuousLVCMOS11PinYes753.3TSSOP/8$1.27 @1k
Quality and Environmental Data
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
DS1181LE+ActiveTSSOP,;8 pin;20.3 mm²-40°C to +125°CLead Free
DS1181LE+TActiveTSSOP,;8 pin;20.3 mm²-40°C to +125°CLead Free
DS1181L.pdf DS1181L
DS1181L_cn.pdf DS1181L
DS1181L.pdf DS1181L
DS1181L.pdf DS1181L
DS1181L.pdf DS1181L