ICS844008I Datasheet, PDF (1/18 Pages) Integrated Device Technology – FEMTOCLOCKS™ CRYSTAL-TO-LVDS FREQUENCY SYNTHESIZER

FEMTOCLOCKS™ CRYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER
ICS844008I-01
GENERAL DESCRIPTION
The ICS844008I-01 is an 8 output LVDS Synthesizer
ICS
optimized to generate GbE/10GbE reference clock
HiPerClockS™ _{frequencies and is a member of the HiPerClocks}TM
family of high performance clock solutions from IDT.
Using a 25MHz parallel resonant crystal, the following
frequencies can be generated based on the F_SEL pin: 125MHz
or 156.25MHz. The ICS844008I-01 uses IDT’s 3^rd generation low
phase noise VCO technology and can achieve <1ps typical rms
phase jitter, easily meeting GbE/10GbE jitter requirements. The
ICS844008I-01 is packaged in a 32-pin TQFP or 32 VFQFN
packages.
FEATURES
• Eight LVDS outputs
• Crystal oscillator interface
• Supports the following output frequencies:
125MHz or 156.25MHz
• VCO: 625MHz
• RMS phase jitter @ 156.25MHz, using a 25MHz crystal
(1.875MHz - 20MHz): 0.38ps (typical)
• Full 3.3V supply mode
• -40°C to 85°C ambient operating temperature
• Available in lead-free (RoHS 6) packages
FREQUENCY SELECT FUNCTION TABLE
Input
Input Frequency (MHz)
25MHz
F_SEL
0
M Divider Value
25
25MHz
1
25
N Divider Value
4
5
Output Frequency (MHz)
156.25
125 (default)
BLOCK DIAGRAM
OEA ^Pullup
nPLL_SEL ^Pulldown
1
25MHz
XTAL_IN
OSC
XTAL_OUT
VCO
Phase
Detector
625MHz
(w/25MHz
0
Reference)
÷4
÷5
M = ÷25 (fixed)
MR ^Pulldown
F_SEL ^Pullup
OEB ^Pullup
QA0
nQA0
QA1
nQA1
QA2
nQA2
QA3
nQA3
QB0
nQB0
QB1
nQB1
QB2
nQB2
QB3
nQB3
PIN ASSIGNMENT
QA0
nQA0
VDD
QA1
nQA1
GND
QA2
nQA2
32 31 30 29 28 27 26 25
1
24
2
23
3 ^{ICS844008I-01} 22
4
32-Lead TQFP, E-Pad
7mm x 7mm x 1.0mm
21
5
package body
20
6
Y Package
19
7
Top View
18
8
17
9 10 11 12 13 14 15 16
QB3
nQB3
VDD
QB2
nQB2
GND
QB1
nQB1
ICS844008I-01
32-Lead TQFP, E-Pad
7mm x 7mm x 1.0mm
package body
Y Package
Top View
ICS844008I-01
32-Lead VFQFN
5mm x 5mm x 0.925mm
package body
K Package
Top View
IDT^™ / ICS^™ LVDS FREQUENCY SYNTHESIZER
1
ICS844008AYI-01 REV. B NOVEMBER 21, 2008