ASM3P2853A Datasheet | Alliance Semiconductor Corporation

Features Generates an EMI optimized clock signal at output. Input frequency: 25 MHz. Frequency outputs: o o USB Clock (48 MHz unmodulated) 50 MHz (modulated), ±1% centre spread shielding that are required to pass EMI regulations. The ASM3P2853A modulates the output of 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 pared 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. Modulation rate: 39 KHz. Spread Spectrum ON/OFF control Supply voltage range 2.5V ± 5%. Available in 8-pin SOIC package. mercial Temperature range. Applications ASM3P2853A is targeted towards EMI management for high speed digital applications such as PC peripheral devices, consumer electronics and embedded controller systems. Product Description The ASM3P2853A is a versatile spread spectrum frequency modulator. The ASM3P2853A reduces electromagnetic interference (EMI) at the clock source. The ASM3P2853A allows significant system cost savings by reducing the number of circuit board layers and Block Diagram VDD PWDNB XIN XOUT Crystal Oscillator PLL1 USB Clock (48 MHz Unmodulated) 50 MHz Modulated SSONB PLL2 Alliance Semiconductor 2575 Augustine Drive - Santa Clara CA - Tel: 408-855-4900 - Fax: 408-855-4999 - .alsc. December 2004 .. ASM3P2853A rev 0.7 Pin Configuration XIN XOUT VDD VSS 1 2 3 4 50 MHz USB Clock SSONB PWDNB 6 5 Pin Description Pin Name Type Description Connection to crystal or external reference frequency input. This pin has dual functions. It can be connected either to an external crystal or an external reference clock. Connection to crystal. If using an external reference clock, this pin must be left unconnected. Power supply for the analog and digital blocks Ground to entire chip. Power-down...