PRELIMINARY INFORMATION
ICS525-07/08
LVCMOS User Configurable Clock
Description
Features
• Packaged as 28-pin SSOP (150 mil body)
• Available in Pb (lead) free package
The ICS525-07/08 are the most flexible way to
generate a high-quality clock output from an
inexpensive crystal or clock input at low supply
voltages. The user can configure the device to produce
nearly any output frequency from any input frequency
by grounding or floating the select pins or by driving or
hard wiring the select pins high or low. Neither
microcontroller, software, nor device programmer are
needed to set the frequency. Using Phase-Locked
Loop (PLL) techniques, the device accepts a standard
fundamental mode, inexpensive crystal to produce
output clocks up to 250 MHz. It can also produce a
highly accurate output clock from a given input clock,
keeping them frequency locked.
• User determines the output frequency by setting all
internal dividers
• Eliminates need for custom oscillators
• Low voltage operation
• Pull-ups on all select inputs
• Input crystal frequency of 5 - 27 MHz
• Input clock frequency of 2 - 50 MHz
• Compensated loop bandwidth
• Enhanced low frequency operation (-08 version)
• Low jitter
For similar capability with a serial interface, use the
ICS307.
• Duty cycle of 45/55 up to 200 MHz
• Operating voltage of 1.8 V to 2.5 V
• Ideal for oscillator replacement
This product is intended for clock generation. It has low
output jitter (variation in the output period), but input to
output skew is not defined nor guaranteed.
• Available in commercial and industrial temperature
ranges
Block Diagram
VDD
VDD
2
2
PD
PD
REF
REF
X1/ICLK
Phhaassee CCoommppaarraattoor,
Reference
Reference
Divider
Divider
Crystal
Crystal
Oscillator
Oscillator
Charge Pump, and
VCO
VCO
Charge Pump, and
Crystal or clock
Crystal or clock
Loop Filter
Loop Filter
Output
Output
Divider
X2
X2
input
input
CLK
CLK
Divider
VCO
Divider
Divider
VCO
Optional crystal capacitors
Optional crystal capacitors
2
2
GND
GND
R Configuration Pins
R Configuration Pins
V Configuration Pins
V Configuration Pins
S Configuration Pins
S Configuration Pins
MDS 525-07/08 A
1
Revision 101105
Integrated Circuit Systems, Inc. ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com