
DATASHEET
LOW EMI CLOCK GENERATOR
ICS180-51
IDT / ICS LOW EMI CLOCK GENERATOR
1
ICS180-51
REV C 051310
Description
The ICS180-51 generates a low EMI output clock from
a clock or crystal input. The device uses IDT’s
proprietary mix of analog and digital Phase-Locked
Loop (PLL) technology to spread the frequency
spectrum of the output, thereby reducing the frequency
amplitude peaks by several dB.
The ICS180-51 offers center spread selection of
+/-0.625% and +/-1.875%. Refer to the MK1714-01/02
for the widest selection of input frequencies and
multipliers.
IDT offers a complete line of EMI reducing clock
generators. Consult us when you need to remove
crystals and oscillators from your board.
Features
Pin and function compatible to Cypress W180-51
Packaged in 8-pin SOIC
Provides a spread spectrum output clock
Accepts a clock input and provides same frequency
dithered output
Input frequency of 8 to 28 MHz
Peak reduction by 7dB - 14dB typical on 3rd - 19th
odd harmonics
Spread percentage selection for +/-0.625% and
+/-1.875%
Operating voltage of 3.3 V and 5 V
Advanced, low-power CMOS process
Block Diagram
PLL Clock
Synthesis
and Spread
Spectrum
Circuitry
SS%
CLK
GND
VDD
FS2:1
X1/CLKIN
X2
Clock Buffer/
Crystal
Oscillator