ICS307

Serially Programmable Clock Source

MDS 307 D

1

Revision 042501

Integrated Circuit Systems, Inc. • 525 Race Street • San Jose •CA•95126•(408) 295-9800tel •www.icst.com

• Packaged as 16 pin narrow SOIC

• Highly accurate frequency generation

• Serially programmable: user determines

the output frequency via a 3 wire interface.

• Eliminates need for custom quartz

• Input crystal frequency of 5 - 27 MHz

• Output clock frequencies up to 200 MHz

• Power Down Tri-State mode

• Very low jitter

• Operating voltages of 3.0 to 5.5 V

• 25 mA drive capability at TTL levels

• Industrial temperature available

The ICS307-01 and ICS307-02 are versatile

serially programmable clock sources which take

up very little board space.

They can generate any frequency from 6 to

200 MHz, and have a second configurable

output. 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 devices include a PDTS pin which tri-states

the output clocks and powers down the entire

chip.

The ICS307-02 features a default clock output

at start-up and is recommended for all new

designs.

Block Diagram

Description

Features

Crystal or

clock input

X1/ICLK

X2

Reference

Divider

Phase Comparator,

Charge Pump,

and Loop Filter

Crystal

Oscillator

VCO

Divider

VCO

Output

Buffer

VDD GND

CLK1

Output

Buffer

CLK2

R6:R0

V8:V0

S2:S0

3

9

7

Output

Divider

Function

Select

F1:F0

2

2

3

2

C1:C0

S2:S0

F1:F0

TTL

TTL

C1:C0

SCLK

Shift

Register

DATA

STROBE

PDTS