ICS281 Datasheet, PDF (1/8 Pages) Integrated Circuit Systems – Triple PLL Field Prog. Spread Spectrum Clock Synthesizer

PRELIMINARY INFORMATION
ICS281
Triple PLL Field Prog. Spread Spectrum Clock Synthesizer
Description
The ICS281 field programmable spread spectrum
clock synthesizer generates up to three high-quality,
high-frequency clock outputs including multiple
reference clocks from a low-frequency crystal input. It
is designed to replace crystals, crystal oscillators and
stand alone spread spectrum devices in most
electronic systems.
Using ICS’ VersaClock^TM software to configure PLLs
and outputs, the ICS281 contains a One-Time
Programmable (OTP) ROM for field programmability.
Programming features include input/output
frequencies, spread spectrum amount and eight
selectable configuration registers.
Using Phase-Locked Loop (PLL) techniques, the
device runs from a standard fundamental mode,
inexpensive crystal, or clock. It can replace multiple
crystals and oscillators, saving board space and cost.
The ICS281 is also available in factory programmed
custom versions for high-volume applications.
Features
• Packaged as 16-pin TSSOP
• Eight addressable registers
• Replaces multiple crystals and oscillators
• Output frequencies up to 200 MHz at 3.3 V
• Configurable Spread Spectrum Modulation
• Input crystal frequency of 5 to 27 MHz
• Input clock frequency of 3 to 166 MHz
• Up to three reference outputs
• Operating voltages of 3.3 V
• VDDO output control from 1.8 V to 3.3 V
• Controllable output drive levels
• Advanced, low-power CMOS process
• Available in Pb (lead) free packaging
Block Diagram
3
S2:S0
OTP
ROM
with PLL
Values
Crystal or
clock input
X1/ICLK
X2
Crystal
Oscillator
External capacitors
are required with a crystal input.
VDD ³
PLL1 with
Spread
Spectrum
PLL2
PLL3
VDDO
Divide
Logic
and
Output
Enable
Control
GND ³
PDTS
CLK1
CLK2
CLK3
MDS 281 C
1
Revision 062205
Integrated Circuit Systems, Inc. ● 525 Race Street, San Jose, CA 95126 ● tel [phone] ● www.icst.com