DatasheetsPDF.com

ASM3P2579A Dataheets PDF



Part Number ASM3P2579A
Manufacturers Alliance Semiconductor Corporation
Logo Alliance Semiconductor Corporation
Description Low Power Peak EMI Reducing Solution
Datasheet ASM3P2579A DatasheetASM3P2579A Datasheet (PDF)

August 2005 www.DataSheet4U.com rev 1.0 ASM3P2579A Low Power Peak EMI Reducing Solution Features ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ Generates an EMI optimized clock signal at the output. Integrated loop filter components. Operates with a 3.3 / 2.5V Supply. Operating current less than 4mA. Low power CMOS design. Input frequency range: 12MHz to 30MHz for 2.5V : 12MHz to 30MHz for 3.3V Generates a 1X low EMI spread spectrum clock of the input frequency. Spread Spectrum Enable Control. Frequency deviation: ±1% @ 2.

  ASM3P2579A   ASM3P2579A



Document
August 2005 www.DataSheet4U.com rev 1.0 ASM3P2579A Low Power Peak EMI Reducing Solution Features ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ Generates an EMI optimized clock signal at the output. Integrated loop filter components. Operates with a 3.3 / 2.5V Supply. Operating current less than 4mA. Low power CMOS design. Input frequency range: 12MHz to 30MHz for 2.5V : 12MHz to 30MHz for 3.3V Generates a 1X low EMI spread spectrum clock of the input frequency. Spread Spectrum Enable Control. Frequency deviation: ±1% @ 24MHz Available in 6 pin TSOT-23, 8 pin SOIC and 8 pin TSSOP Packages. The ASM3P2579A uses the most efficient and optimized modulation profile approved by the FCC and is implemented by using a proprietary all digital method. The ASM3P2579A modulates the output of a single PLL in order to “spread” the bandwidth of a synthesized clock, and more importantly, decreases 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 frequency generators. Lowering EMI by increasing a signal’s bandwidth is called ‘spread spectrum clock generation’. ƒ Applications The ASM3P2579A is targeted towards all portable devices with very low power requirements like MP3 players and digital still cameras. Product Description The ASM3P2579A is a versatile spread spectrum frequency modulator designed specifically for a wide range of clock frequencies. The ASM3P2579A reduces electromagnetic interference (EMI) at the clock source, allowing system wide reduction of EMI of all clock dependent signals. The ASM3P2579A allows significant system cost savings by reducing the number of circuit board layers ferrite beads, shielding that are traditionally required to pass EMI regulations. Key Specifications Description Supply voltages Cycle-to-Cycle Jitter Output Duty Cycle Modulation Rate Equation Frequency Deviation Specification VDD = 3.3V/2.5V 200pS (Max) 45/55% (worst case) FIN/640 ±1% @ 24MHz Block Diagram VDD SSON XIN Crystal Oscillator Frequency Divider Feedback Divider Modulation PLL XOUT Phase Detector Loop Filter VCO Output Divider ModOUT VSS 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. August 2005 www.DataSheet4U.com rev 1.0 ASM3P2579A Pin Configuration (6-pin TSOT-23 Package) SSON XOUT XIN/CLKIN 1 2 3 6 VSS ModOUT VDD ASM3P2579A 5 4 Pin Description Pin# 1 2 3 4 5 6 Pin Name SSON XOUT XIN/CLKIN VDD ModOUT VSS Type I O I P O P Description When SSON is HIGH, the spread spectrum is enabled and when LOW, it turns off the spread spectrum. Connect the pin to ground When Spread Spectrum feature is not required. Crystal connection. If using an external reference, this pin must be left unconnected. Crystal connection or external reference frequency input. This pin has dual functions. It can be connected either to .


ASM3P2531A ASM3P2579A ASM3P2669A


@ 2014 :: Datasheetspdf.com :: Semiconductors datasheet search & download site.
(Privacy Policy & Contact)