ASM3P2108A Datasheet | Alliance Semiconductor Corporation

Features - - - - - - - - FCC approved method of EMI attenuation. Generates a 1X low EMI spread spectrum clock of the input frequency. Input frequency range: 25MHz to 45MHz. Internal loop filter minimizes external ponents and board space. Frequency deviation: - 1.3%( Typ) @32MHz. Low cycle-to-cycle jitter. 5.0V ± 5% operating voltage range. TTL or CMOS patible outputs. Available in 8-pin SOIC and TSSOP Packages. savings by reducing the number of circuit board layers ferrite beads, shielding and other passive ponents that are traditionally required to pass EMI regulations. The ASM3P2108A uses the most efficient and optimized modulation profile approved by the FCC and is implemented in a proprietary all digital method. The ASM3P2108A 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 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’. - Product Description The ASM3P2108A is a versatile spread spectrum frequency modulator designed specifically for input clock frequencies from 25MHz to 45MHz. The ASM3P2108A can generate an EMI reduced clock from crystal, ceramic resonator, or system clock. The ASM3P2108A reduces electromagnetic interference (EMI) at the clock source, allowing system wide reduction of EMI of down stream clock and data dependent signals. The ASM3P2108A allows significant system cost Applications The ASM3P2108A is targeted towards EMI management for high speed digital applications such as PC peripheral devices, consumer electronics and embedded controller systems. Block Diagram Modulation XIN Crystal Oscillator XOUT Frequency Divider Feedback Divider Phase Detector Loop Filter Output Divider CLOCKOUT Alliance Semiconductor 2575...