DATASHEET
FIELD PROGRAMMABLE SS VERSACLOCK SYNTHESIZER
ICS251
Description
Features
The ICS251 is a low cost, single-output, field programmable
clock synthesizer. The ICS251 can generate an output
frequency from 314 kHz to 200 MHz and may employ
Spread Spectrum techniques to reduce system
electro-magnetic interference (EMI).
• 8-pin SOIC package
• Four addressable registers
• Input crystal frequency of 5 to 27 MHz
• Clock input frequency of 3 to 150 MHz
™
• Output clock frequencies up to 200 MHz
• Configurable Spread Spectrum Modulation
Using ICS’ VersaClock software to configure the PLL and
output, the ICS251 contains a One-Time Programmable
(OTP) ROM to allow field programmability. Programming
features include 4 selectable configuration registers.
• Operating voltage of 3.3 V
• Replaces multiple crystals and oscillators
The device employs Phase-Locked Loop (PLL) techniques
to run from a standard fundamental mode, inexpensive
crystal, or clock. It can replace multiple crystals and
oscillators, saving board space and cost.
• Controllable output drive levels
• Advanced, low-power CMOS process
• Available in RoHS compliant packaging
The device also has a power-down feature that tri-states the
clock outputs and turns off the PLLs when the PDTS pin is
taken low.
The ICS251 is also available in factory programmed custom
versions for high-volume applications.
Block Diagram
VDD
OTP ROM
with PLL
Divider
2
S1:0
Values
PLL Clock Synthesis,
Spred Spectrum and
Control Circuitry
CLK
Crystal or
clock input
X1/ICLK
Crystal
Oscillator
X2
GND
External capacitors are
required with a crystal input.
PDTS (output and PLL)
IDT™ / ICS™ FIELD PROGRAMMABLE SS VERSACLOCK SYNTHESIZER
1
ICS251
REV B 061306