FCC approved method of EMI attenuation Provides 15 dB EMI reduction Generates a low EMI spread spectrum clock and a non-spread reference clock of the input frequency Optimized for frequency range from 10 MHz to 160 MHz to 20 MHz to 40 MHz to 80 MHz to 40 MHz to 160 MHz Internal loop filter minimizes external components and board space Selectable spread options: Down Spread and Center Spread Low inherent cycle-to-cycle jitter Eight spread % selections: �3.5% 3.3V operating voltage CMOS/TTL compatible inputs and outputs Low power CMOS design Supports notebook VGA and other LCD timing controller applications Power down function for mobile application Products are available for industrial temperature range. Available in 8-pin SOIC and TSSOP

The is a versatile spread spectrum frequency modulator designed specifically for a wide range of input clock frequencies from to 160 MHz (see Input Frequency and Modulation Rate Selections). The P18xx can generate an EMI reduced clock from crystal, ceramic resonator, or system clock. The to P18xx-H offer various combinations of spread options and percentage deviations (see Spread Deviation Selections). These combinations include Down Spread, Center Spread and percentage deviation range from to -3.50%. The P18xx reduces electromagnetic interference (EMI) at the clock source, allowing a system wide EMI reduction for all the down stream clocks and data dependent signals. The P18xx allows significant system cost savings by reducing the number of circuit board layers, ferrite beads, shielding, and other passive components that are traditionally required to pass EMI regulations. The P18xx modulates the output of a single PLL in order to "spread" the bandwidth of a synthesized clock, thereby decreasing the peak amplitudes of its harmonics. This results in significantly lower system EMI compared to the typical narrow band signal produced by oscillators and most clock generators. Lowering EMI by increasing a signal's bandwidth is called "spread spectrum clock generation". The P18xx uses the most efficient and optimized modulation profile approved by the FCC and is implemented by using a proprietary all-digital method.

The P18xx is targeted toward EMI management for memory and LVDS interfaces in mobile graphic chipsets and high-speed digital applications such as PC peripheral devices, consumer electronics, and embedded controller systems.

Part number P1822 FRS=1 Input frequency range 10 MHz to 20 MHz 20 MHz to 40 MHz 40 MHz to 80 MHz 10 MHz to 20 MHz 20 MHz to 40 MHz 80 MHz to 160 MHz Output frequency range 10 MHz to 20 MHz 20 MHz to 40 MHz 40 MHz to 80 MHz 10 MHz to 20 MHz 20 MHz to 40 MHz 80 MHz to 160 MHz Modulation rate Input frequency / 256 Input frequency / 512 Input frequency / 2048 Input frequency / 256 Input frequency / 512 Input frequency / 3584

Part P1818/19/20G P18182/19/20H SRS N/A SR0 N/A D_C N/A Spread deviation -2.50% (Down) -3.50% (Down) -1.25% (Down) -1.75% (Down) +/-1.25% (Center) +/-1.75% (Center) +/-0.625% (Center) +/-0.875% (Center) -1.25% (Down) +/-0.625% (Center) -2.5% (Down) +/-1.25% (Center) -1.75% (Down) +/-0.875% (Center) -3.5% (Down) +/-1.75% (Center) -1.25% (Down) -2.50% (Down) -1.75% (Down) -3.50% (Down) +/-0.625% (Center) +/-1.25% (Center) +/-0.875% (Center) +/-1.75% (Center)

1. A through H represents various combinations of spread deviations, options, and modulation rates. 2. Refer to Frequency vs. Deviation (P1818A and P1818H).