ICS348
Quad PLL Field Programmable VersaClock Synthesizer
Description
Features
The ICS348 field programmable clock synthesizer
generates up to 9 high-quality, high-frequency clock
outputs including multiple reference clocks from a low
frequency crystal or clock input. The ICS348 has 4
independent on-chip PLLs and is designed to replace
crystals and crystal oscillators in most electronic
systems.
• Packaged as 20-pin SSOP (QSOP)
• Eight addressable registers
• Replaces multiple crystals and oscillators
• Output frequencies up to 200 MHz at 3.3V
• Input crystal frequency of 5 to 27 MHz
• Input clock frequency of 2 to 50 MHz
• Up to nine reference outputs
TM
Using ICS’ VersaClock software to configure PLLs
and outputs, the ICS348 contains a One-Time
Programmable (OTP) ROM to allow field
programmability. Programming features include eight
selectable configuration registers, up to two sets of four
low-skew outputs.
• Up to two sets of four low-skew outputs
• Operating voltages of 3.3 V
• Advanced, low power CMOS process
• For one output clock, use the ICS341 (8-pin). For two
output clocks, use the ICS342 (8-pin). For three
output clocks, use the ICS343 (8-pin). For more than
three outputs, use the ICS345 or ICS348.
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.
• Available in Pb (lead) free packaging
The ICS348 is also available in factory programmed
custom versions for high-volume applications.
Block Diagram
3
VDD
CLK1
CLK2
PLL1
OTP
ROM
with
PLL
S2:S0
3
CLK3
PLL2
PLL3
PLL4
Divide
Logic
and
Output
Enable
Control
Values
CLK4
CLK5
CLK6
CLK7
CLK8
CLK9
Crystal or
clock input
X1/ICLK
Crystal
Oscillator
X2
GND
2
External capacitors are
required with a crystal input.
PDTS
MDS 348 H
1
Revision 051705
Integrated Circuit Systems, Inc. ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com