ICS7151
Spread Spectrum Clock Generator
Description
The ICS7151-10, -20, -40, and -50 are clock
generators for EMI (Electro Magnetic Interference)
reduction (see below for frequency ranges and
multiplier ratios). Spectral peaks can be attenuated by
slightly modulating the oscillation frequency. Both down
and center spread profiles are selectable. Down spread
maintains an average frequency less than an unspread
clock, and will not exceed the maximum frequency of
an unspread clock.
Features
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Operating voltage of 3.3 V ±0.3 V
Packaged in 8-pin SOIC
Available in Pb (lead) free package
Input frequency range of 16.5 to 33.4 MHz
Output frequency ranges of 8.3 to 16.7 MHz, 16.5 to
33.4 MHz, 33.3 to 66.7 MHz, 66.6 to 133.4 MHz
±1.5% center spread; -1.0%, -3.0% down spread)
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Provides a spread spectrum clock output (±0.5%,
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Multiplication rates of x1/2, x1, x2, and x4
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Advanced, low-power CMOS process
Block Diagram
VDD
S1:0
2
ENS
PLL Clock
Synthesis
and Spread
Spectrum
Circuitry
Clock Buffer/
Crystal
Ocsillator
CKOUT
XIN
XOUT
External caps required with crystal for
accurate tuning of the clock
GND
Product Lineup
Product
Input Frequency Range
Multiplier Ratio
Output Frequency Range
ICS7151M-10, ICS7151MI-10
ICS7151M-20, ICS7151MI-20
ICS7151M-40, ICS7151MI-40
ICS7151M-50, ICS7151MI-50
16.5 MHz to 33.4 MHz
16.5 MHz to 33.4 MHz
16.5 MHz to 33.4 MHz
16.5 MHz to 33.4 MHz
X1
X2
X4
X1/2
16.5 MHz to 33.4 MHz
33.3 MHz to 66.7 MHz
66.6 MHz to 133.4 MHz
8.3 MHz to 16.7 MHz
MDS 7151 E
Integrated Circuit Systems, Inc.
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1
525 Race Street, San Jose, CA 95126
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Revision 012306
tel (408) 297-1201
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www.icst.com