Clock modulators reduce EMI in large-format LCD panels

Sunnyvale, Calif. — Maxim Integrated Products has introduced the DS1081L and DS1083L center spread-spectrum clock modulators. The low-cost 16 MHz to 134 MHz modulators are suitable for dithering the row/column-driver clock signal in large-format LCD panels used in televisions and PC monitors.

These DS1081L and DS1083L modulators use an integrated phase-locked loop (PLL) to dither the clock output around its center frequency at a user-selectable magnitude from 0 (disabled) to ±2.0%, thus reducing peak electromagnetic interference (EMI) at fundamental and harmonic frequencies. This EMI reduction is accomplished without changing clock rise/fall times or adding the space, weight, design time, and costs associated with mechanical shielding, said Maxim.

The DS1081L and DS1083L clock modulators provide 3.0-V to 3.6-V operation over the wide temperature range of -40°C to +125°C. Packaged in an 8-pin TSSOP, the DS1081L provides logic inputs that allow the user to set the dither rate and magnitude, disable/enable spread-spectrum modulation, and shutdown the output to conserve power.

The DS1083L is packaged in a smaller, thin 6-lead SOT23. Because it has fewer pins than the DS1081L, the DS1083L does not offer the ability to disable spread-spectrum modulation or shutdown the output. Both products use the same PLL design to ensure low 75 ps cycle-to-cycle jitter performance.

Pricing: Starts at $0.87 (10,000-up, FOB USA).
Datasheet: DS1081L

Maxim Integrated Products , 1-800-998-8800,

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