DATA SHEET
PRELIMINARY
FEMTOCLOCKS™ CRYSTAL-TO-LVDS CLOCK
ICS844252-04
Integrated
ICS844252-04
Circuit
FEMTO
C
LOCKS™ C RYSTAL
-
TO-
Systems, Inc.
GENERATOR
LVDS CLOCK
GENERATOR
GENERAL DESCRIPTION
FEATURES
• Two differential LVDS outputs
The ICS844252-04 is a 10Gb/12Gb Ethernet
ICS
HiPerClockS™
Clock Generator and
a member of the
• Crystal oscillator interface designed for
18pF parallel resonant crystals
HiPerClocksTM family of high performance
devices from ICS. The ICS844252-04 can
synthesize 10 Gigabit Ethernet and 12 Gigabit
• Crystal input frequency range: 19.33MHz - 30MHz
• Output frequency range: 145MHz - 187.5MHz
• VCO frequency range: 580MHz - 750MHz
Ethernet with a 25MHz crystal. It can also generate SATA
and 10Gb Fibre Channel reference clock frequencies with
the appropriate choice of crystals. The ICS844252-04 has
excellent phase jitter performance and is packaged in a
small 16-pin TSSOP, making it ideal for use in systems with
limited board space.
• RMS phase jitter at 156.25MHz (1.875MHz - 20MHz):
0.36ps (typical)
• 3.3V operating supply
• 0°C to 70°C ambient operating temperature
• Industrial temperature information available upon request
• Available in both standard and lead-free compliant
packages
CONFIGURATION TABLE WITH 25MHZ CRYSTAL
Inputs
Output Frequency
Application
Crystal Frequency Feedback VCO Frequency
(MHz)
N Output Divide
(MHz)
Divide
(MHz)
25
30
750
4
4
187.5
12 Gigabit Ethernet
10 Gigabit Ethernet
25
25
625
156.25
CONFIGURATION TABLE WITH SELECTABLE CRYSTALS
Inputs
Output Frequency
(MHz)
Application
Crystal Frequency Feedback VCO Frequency
N Output Divide
(MHz)
Divide
(MHz)
20
30
600
4
4
4
4
4
150
159.375
150
SATA
21.25
24
30
637.5
600
10 Gigabit Fibre Channel
SATA
25
25.5
30
25
637.5
750
159.375
187.5
10 Gigabit Fibre Channel
12 Gigabit Ethernet
25
BLOCK DIAGRAM
PIN ASSIGNMENT
Pullup
OE
D
1
2
3
4
5
6
7
8
nQ1
Q1
16
15
14
13
12
11
10
9
XTAL_IN
XTAL_OUT
GND
Q
Pulldown
nPLL_SEL
LE
VDDO
OE
nPLL_SEL
VDDO
Q0
REF_CLK
CLK_SEL
VDD
VDDA
FREQ_SEL
Pulldown
REF_CLK
1
1
0
DIV. N
÷4
Q0
XTAL_IN
nQ0
VCO
nQ0
Phase
Detector
580MHz-750MHz
0
OSC
Q1
nQ1
ICS844252-04
16-Lead TSSOP
4.4mm x 5.0mm x 0.92mm
package body
XTAL_OUT
CLK_SEL
Pulldown
0 = ÷25 (default)
1 = ÷30
G Package
Top View
Pulldown
FREQ_SEL
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.
844252AG-04
www.icst.com/products/hiperclocks.html
REV.A JANUARY 26, 2006
IDT™ / ICS™ FEMTOCLOCKS™ CRYSTAL-TO-LVDS CLOCK GENERATOR
ICS844252-04
1
1