ASM3P2109A October 2003 rev 0.3 PRELIMINARY INFORMATION Low Power EMI Reduction IC Features FCC approved method of EMI attenuation. Provides up to 15dB EMI reduction. Generates a 4X REF EMI spread output Spectrum clock of the input frequency. Optimized for input frequency range from 10 to 20MHz. External Loop Filter for configurability and flexibility in application and design (spread percentage adjust) Reference Output Power Down Mode Very Low Cycle-to-Cycle Jitter. 3.3V operating Range CMOS / TTL compatible inputs and outputs Available in 8-pin SOIC and 8-pin TSSOP packages. Product Description The ASM3P2109A device is a versatile spread spectrum Frequency Synthesizer / Modulator designed specifically for a wide Range of input clock frequencies from 10MHz to 20MHz with a 4X multiplier for output clock frequencies from 40MHz to 80 MHz. The ASM3P2109A generates an EMI reduced clock signal from a crystal, ceramic resonator, or system clock. The ASM3P2109A generates a range of modulation rates and deviations (spread) from Center Frequency based upon the input frequency, and is set / determined via an external filter network ( see Loop Filter Selection table ) The ASM3P2109A reduces Electro Magnetic Interference (EMI), at the Clock Source, allowing system wide reduction of EMI on downstream clock and data dependant signals. The resulting EMI reduction provides for significant cost savings by reducing the number of circuit board layers and shielding that are traditionally associated with designs in order to achieve EMI regulatory compliance. The ASM3P2109A modulates the output of a single PLL in order to “spread” the bandwidth of a synthesized clock, thereby decreasing the Peak amplitudes of its associated harmonics. This results in significantly lower radiated EMI compared to the narrow band signal produced by standard oscillators and most clock synthesizers & generators. This technique of lowering EMI by increasing the signals bandwidth is called Spread Spectrum Clocking (SSC). The ASM3P2109A utilizes the most efficient and optimized modulation profile approved by the FCC, and is implemented using a proprietary, AllDigital method. Applications The ASM3P2109A is targeted towards the Consumer and PC/Data Processing, or Computation markets. Entertainment devices, LCD displays, Notebook computers, PC peripheral devices, embedded systems, PDA’s, and hand held devices provide a platform to take full advantage of the feature set of the ASM3P2109A. Alliance Semiconductor 2575, Augustine Drive Santa Clara, CA Tel: 408.855.4900 Fax: 408.855.4999 www.alsc.com Notice: The information in this document is subject to change without notice. October 2003 ASM3P2109A rev 0.3 PRELIMINARY INFORMATION ASM3P2109A Notice: The information in this document is subject to change without notice. 2 of 7 October 2003 ASM3P2109A rev 0.3 PRELIMINARY INFORMATION ASM3P2109A Notice: The information in this document is subject to change without notice. 3 of 7 October 2003 ASM3P2109A rev 0.3 PRELIMINARY INFORMATION Loop Filter Selection Table VDD = 3.3V, Temp =25 degrees C For frequency deviations other than noted above, contact the factory applications group for information and details… ASM3P2109A Notice: The information in this document is subject to change without notice. 4 of 7 October 2003 ASM3P2109A rev 0.3 PRELIMINARY INFORMATION Package Dimensions ASM3P2109A Notice: The information in this document is subject to change without notice. 5 of 7 October 2003 ASM3P2109A rev 0.3 PRELIMINARY INFORMATION Package Dimensions ASM3P2109A Notice: The information in this document is subject to change without notice. 6 of 7 October 2003 ASM3P2109A rev 0.3 PRELIMINARY INFORMATION ASM3P2109A Notice: The information in this document is subject to change without notice. 7 of 7