DATASHEET
LOW EMI CLOCK GENERATOR
ICS181-52
Description
The ICS181-52 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 ICS181-52 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 W181-52
• Packaged in 8-pin SOIC
• Provides a spread spectrum output clock
• Accepts a clock input and provides same frequency
dithered output
• Input frequency of 28 to 48 MHz for Clock input
• 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
VDD
FS1
SSON#
SS%
X1/CLKIN
X2
Clock Buffer/
Crystal
Oscillator
PLL Clock
Synthesis
and Spread
Spectrum
Circuitry
CLK
GND
IDT™ / ICS™ LOW EMI CLOCK GENERATOR
1
ICS181-52 REV C 051310
