ICS343
Field Programmable Triple Output SS VersaClock Synthesizer
Description
Features
The ICS343 is a low cost, triple-output, field program-
mable clock synthesizer. The ICS343 can generate
three output frequencies from 250 kHz to 200 MHz,
using up to three independently configurable PLLs.
The outputs may employ Spread Spectrum techniques
to reduce system electro-magnetic interference (EMI).
• 8-pin SOIC package
• Highly accurate frequency generation
•M/N Multiplier PLL: M = 1...2048, N = 1...1024
• Output clock frequencies up to 200 MHz
• Spread spectrum capability for lower system EMI
•Center or Down Spread up to 4% total
Using ICS’ VersaClock™software to configure the PLL
and output, the ICS343 contains a One-Time Program-
mable (OTP) ROM to allow field programmability. Using
Phase-Locked Loop (PLL) techniques, the device runs
from a standard fundamental mode, inexpensive crys-
tal, or clock. It can replace multiple crystals and oscilla-
tors, saving board space and cost.
•Selectable 32 kHz or 120 kHz modulation
• Input crystal frequency from 5 to 27 MHz
• Input clock frequency from 2 to 50 MHz
• Operating voltage of 3.3 V, using advanced, low
power CMOS process
The device also has a power down feature that
tri-states the clock outputs and turns off the PLLs when
the PDTS pin is taken low.
• For one output clock, use the ICS341. For two output
clocks, see the ICS342. For more than three outputs,
see the ICS345 or ICS348.
• Available in Pb (lead) free packaging
The ICS343 is also available in factory-programmed
custom versions for high-volume applications.
Block Diagram
VDD
OTP ROM
with PLL
Divider
CLK1
Values
PLL Clock Synthesis,
Spred Spectrum and
Control Circuitry
Crystal or
clock input
CLK2
CLK3
X1/ICLK
Crystal
Oscillator
X2
GND
External capacitors are
PDTS (both outputs and PLL)
required with a crystal input.
MDS 343 G
1
Revision 011205
Integrated Circuit Systems, Inc. ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com
IDT [ INTEGRATED DEVICE TECHNOLOGY ]
