ASM3P2508SP
ASM3P2508SP is Clock Synthesizer and Frequency Generator manufactured by Alliance Semiconductor Corporation.
Features
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- - Dual PLL based Architecture Operates with a 3.3V ±0.3V supply. Generates an EMI optimized Spread Spectrum PCI Clock output Generates a high accuracy non Spread T1 clock of ±25ppm accuracy. Generates a non spread system reference clock Low power CMOS design. Input frequency: 25 MHz. Outputs: Sys_ REF_CLK: 20 MHz T1 Clock: 25 MHz (±25 ppm) PCI_CLK: 33.33MHz Spread Spectrum
- Frequency deviation: -0.5% (Typ). Available in 8L SOIC Package. The ASM3P2508SP uses the most efficient and optimized modulation profile approved by the FCC. ASM3P2508SP modulates the output of a PLL in order to “spread” the bandwidth of a synthesized clock, and more importantly, decreases the peak amplitudes of its harmonics. This results in a significantly lower system EMI pared 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’ (SSCG). In addition to the SSCG output, ASM3P2508SP generates two high accuracy clock signals T1 Clock @ 25.00MHz with +/- 25ppm stability, and a 20MHz Sys_ REF_CLK.
- Applications
The ASM3P2508SP is targeted towards Consumer, Industrial, Data and Telemunications applications.
Product Description
The ASM3P2508SP is a versatile Dual PLL based Clock Synthesizer and Frequency Generator optimised and designed specifically for three clock frequencies. The PCI_CLK output from ASM3P2508SP reduces
Key Specifications
Description Supply voltages Input Frequency Cycle-to-Cycle Jitter Output Duty Cycle Output Rise and Fall Time SSC Modulation Rate SSC Frequency Deviation Specification VDD = 3.3V ±0.3V 25 MHz 175 p S ( Max) 45/55% 1.1 n S (Max) 30KHz (Typ) -0.5% (Typ) electromagnetic interference (EMI) at the clock source, allowing system wide reduction of EMI of all clock dependent signals. ASM3P2508SP allows significant system cost savings by reducing the number of circuit board layers, ferrite beads & shielding that are...
