ICS308

ICS308 SERIAL PROGRAMMABLE QUAD PLL VERSACLOCK SYNTHESIZER Description The ICS308 is a versatile serially programmable, quad PLL clock source. The ICS308 can generate any frequency from 250 kHz to 200 MHz, and up to 6 different output frequencies simultaneously. The outputs can be reprogrammed on the fly, and will lock to a new frequency in 10 ms or less. Smooth transitions (in which the clock duty cycle remains roughly 50%) are guaranteed if the output divider is not changed. The device includes a PDTS pin which tri-states the output clocks and powers down the entire chip. The ICS308 default for non-programmed start-up are buffered reference clock outputs on all clock output pins. Features Packaged in 20-pin SSOP (QSOP) Operating voltage of 3.3 V Highly accurate frequency generation M/N Multiplier PLL: M = 1..2048, N = 1..1024 Serially programmable: user determines the output frequency via a 3-wire interface Eliminates need for custom quartz oscillators Input crystal frequency of 5 - 27 MHz Optional programmable on-chip crystal capacitors Output clock frequencies up to 200 MHz Reference clock output Power down tri-state mode Very low jitter Block Diagram V DD 3 CLK1 P LL1 CLK2 Divide Logic and Output Enable Control CLK3 CLK4 CLK5 CLK6 CLK7 CLK8 CLK9 STROBE SCLK DATA P LL3 C rystal or clock input X 1/IC LK C rystal O scillator X2 GND 2 P D TS P LL4 P LL2 E xternal capacitors are required w ith a crystal input. MDS 308 F I n t e gra te d C i r c...