ICS844252-04 Datasheet, PDF (1/12 Pages) Integrated Circuit Systems – FEMTOCLOCKS™ CRYSTAL-TO-LVDS CLOCK GENERATOR

Integrated
Circuit
Systems, Inc.
PRELIMINARY
ICS844252-04
FEMTOCLOCKS™ CRYSTAL-TO-
LVDS CLOCK GENERATOR
GENERAL DESCRIPTION
FEATURES
The ICS844252-04 is a 10Gb/12Gb Ethernet
ICS
Clock Generator and a member of the
HiPerClockS™ _HiPerClocksTM _{family of high perfor mance}
devices from ICS. The ICS844252-04 can
synthesize 10 Gigabit Ethernet and 12 Gigabit
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.
• Two differential LVDS outputs
• Crystal oscillator interface designed for
18pF parallel resonant crystals
• Crystal input frequency range: 19.33MHz - 30MHz
• Output frequency range: 145MHz - 187.5MHz
• VCO frequency range: 580MHz - 750MHz
• 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
CONFIGURATION TABLE WITH 25MHZ CRYSTAL
• Available in both standard and lead-free compliant
packages
Inputs
Crystal Frequency Feedback VCO Frequency
(MHz)
Divide
(MHz)
N Output Divide
Output Frequency
(MHz)
Application
25
30
750
4
187.5
12 Gigabit Ethernet
25
25
625
4
156.25
10 Gigabit Ethernet
CONFIGURATION TABLE WITH SELECTABLE CRYSTALS
Inputs
Crystal Frequency Feedback VCO Frequency
(MHz)
Divide
(MHz)
20
30
600
21.25
30
637.5
24
25
600
25.5
25
637.5
30
25
750
N Output Divide
4
4
4
4
4
Output Frequency
(MHz)
Application
150
159.375
150
159.375
187.5
SATA
10 Gigabit Fibre Channel
SATA
10 Gigabit Fibre Channel
12 Gigabit Ethernet
BLOCK DIAGRAM
OE
Pullup
nPLL_SEL
Pulldown
REF_CLK
Pulldown
1
XTAL_IN
OSC
0
XTAL_OUT
CLK_SEL
Pulldown
D
Q
LE
Phase
Detector
1
VCO
580MHz-750MHz
0
DIV. N
÷4
0 = ÷25 (default)
1 = ÷30
PIN ASSIGNMENT
nQ1 1
Q1 2
VDDO 3
OE 4
nPLL_SEL 5
VDDO 6
Q0
Q0 7
nQ0
nQ0 8
16 XTAL_IN
15 XTAL_OUT
14 GND
13 REF_CLK
12 CLK_SEL
11 VDD
10 VDDA
9 FREQ_SEL
Q1
nQ1
ICS844252-04
16-Lead TSSOP
4.4mm x 5.0mm x 0.92mm
package body
G Package
Top View
FREQ_SEL
Pulldown
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
1