ICS309

MDS 309 G

1

Revision 122704

Description

The ICS309 is a versatile serially-programmable, triple

PLL with spread spectrum clock source. The ICS309

can generate any frequency from 250kHz 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.

To reduce system EMI emissions, spread spectrum is

available that supports modulation frequencies of

31 kHz and 120 kHz, as well as modulation amplitudes

of +/-0.25% to +/-2.0%. Both center and down-spread

options are available.

The device includes a PDTS pin which tri-states the

output clocks and powers down the entire chip.

The ICS309 default for non-programmed start-up are

buffered reference clock outputs on all clock output

pins.

user to configure up to 9 outputs with target

frequencies, spread spectrum capabilities or buffered

automatically configures the PLLs for optimal overall

performance.

Features

frequency via a 3-wire interface

system EMI

Block Diagram

C rystal

O sc illator

PLL1 with

Spread

Spectrum

GND

2

3

VDD

PD T S

PLL2

PLL3

Divide

Logic

and

Output

Enable

Control

CLK1

CLK9

CLK8

CLK7

CLK6

CLK5

CLK4

CLK3

CLK2

X2

C rystal or

clock input

E xternal capacitors are

required w ith a crystal input.

X 1/IC LK

SCLK

DATA

STROBE