ASM3P2190A Datasheet | Alliance Semiconductor Corporation

Features - Generates an EMI optimized clocking - - - - - - signal at the output. Selectable output frequency range. Single 1.25% or 2.4% down spread output. Integrated loop filter ponents. Operates with a 3.3V supply. Low-power CMOS design. Available in 8-pin SOIC and 8-pin TSSOP packages. Key Specifications Description Supply voltages Frequency range Cycle-to-cycle jitter Selectable spread percentage Output duty cycle Output rise and fall time Specification VDD = 3.3V ± 5% 6 MHz ≤ 30 MHz 325 ps (typical) -1.25% or - 2.4% 40/60% (worst case) 5ns (maximum) Product Description The ASM3P2190A is a versatile spread spectrum frequency modulator designed specifically for a wide range of clock frequencies. The ASM3P2190A reduces electromagnetic interference (EMI) at the clock source, allowing system wide reduction of EMI of down stream clock and data dependent signals. The ASM3P2190A allows significant system cost savings by reducing the number of circuit board layers and shielding that are traditionally required to pass EMI regulations. The ASM3P2190A modulates the output of a single 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. The ASM3P2190A uses the most efficient and optimized modulation profile approved by the FCC and is implemented by using a proprietary all-digital method. Simplified Block Diagram 3.3V X1 X2 Spread spectrum output (EMI suppressed) Pin Diagram CLKIN / X1 NC / X2 GND SS% 1 2 8 7 NC FS1 VDD CLKOUT Applications The ASM3P2190A is targeted towards notebook LCD displays, other displays using an LVDS interface, PC peripheral devices and embedded systems. 3 4 6 5 Alliance Semiconductor 2595, Augustine Drive - Santa Clara - CA 95054 -...