P R E L I M I N A RY I N F O R M AT I O N
ICS650-44
Spread Spectrum Clock Synthesizer
Description
The ICS650-44 is a spread spectrum clock synthesizer
intended for video projector and digital TV applications.
It generates three copies of an EMI optimized 50 MHz
clock signal (EMI peak reduction of 7 to 14 dB on 3rd
through 19th harmonics) through the use of Spread
Spectrum techniques from a 25 MHz crystal or clock
input. The modulation rate is 50 kHz.
Features
• Packaged in 16-pin TSSOP (173 mil)
• Supply voltages: VDD = 3.3 V, VDDO = 2.5 V
• Peak-to-peak jitter: ±125 ps typ
• Output duty cycle 45/55% (worst case)
• 25 MHz crystal or reference clock input
• Zero (0) ppm frequency error on all output clocks
• Advanced, low-power CMOS process
• Industrial temperature range (-40 to +85°C)
• Available in Pb (lead) free package
Block Diagram
25 MHz crystal
or clock input
X1/CLKIN
X2
External capacitors are
required with a crystal
input.
FS3:0
Crystal
OSC
Control
Logic
VDD
3
VDDO
PLL with
Spread
Spectrum
50M
50M
50M
GND 2
PDTS
MDS 650-44 C
1
Revision 080305
Integrated Circuit Systems, Inc. ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com