PRELIMINARY
ICS840245I
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ 1:5, CRYSTAL-TO-
LVCMOS/LVTTL FREQUENCY SYNTHESIZER
GENERAL DESCRIPTION
FEATURES
• Five LVCMOS outputs, 15Ω typical output impedance
• Crystal oscillator interface
The ICS840245I is a low skew, 1-to-5 LVCMOS/
ICS
LVTTL SATA/SAS Clock Generator and is a
member of the HiPerClocksTM family of high
performance clock solutions from ICS. The
ICS840245I can synthesize 75MHz reference
HiPerClockS™
• Supports the following output frequency: 75MHz
• Output skew: 45ps (typical)
clock frequencies with a 25MHz crystal. Each of the 5 outputs
on the ICS840245I can drive two series terminated 50Ω
transmission lines, effectively making the ICS840245I a 1-to-10
clock generator. An output enable (OE) pin, which controls
only the Q4 output, allows the application to use Q4 as an
optional output (for example, test output pin).The ICS840245I
uses ICS’ 3rd generation low phase noise VCO technology
and can achieve 1ps or lower typical random rms phase
jitter.The ICS840245I is packaged in a 16-pin TSSOP package.
• RMS phase jitter @ 75MHz (900kHz - 7.5MHz):
0.454ps (typical)
• Output supply modes:
Core/Output
3.3V/3.3V
3.3V/2.5V
2.5V/2.5V
• -40°C to 85°C ambient operating temperature
• Available in both standard and lead-free RoHS compliant
packages
BLOCK DIAGRAM
PIN ASSIGNMENT
Q0
Pullup
1
2
3
4
5
6
7
8
XTAL_OUT
XTAL_IN
VDDA
OE
VDD
GND
PLL_SEL
GND
16
15
14
13
12
11
10
9
VDDO
Q0
Q1
GND
Q2
Q3
PLL_SEL
Q1
Q2
Q3
Q4
0
25MHz
XTAL_IN
Phase
Detector
VCO
600MHz
OSC
1
N = 8
VDDO
Q4
XTAL_OUT
M = 24
(fixed)
ICS840245I
16-LeadTSSOP
4.4mm x 5.0mm x 0.92mm
package body
Pullup
OE
G Package
Top View
The Preliminary Information presented herein represents a product in prototyping or pre-production. The noted characteristics are based on
initial product characterization. Integrated Circuit Systems, Incorporated (ICS) reserves the right to change any circuitry or specifications
without notice.
840245AGI
www.icst.com/products/hiperclocks.html
REV.A APRIL 28, 2006
1