ICS844004-104 Datasheet, PDF (1/16 Pages) Integrated Device Technology – FEMTOCLOCKS™ CRYSTAL-TO-LVDS FREQUENCY SYNTHESIZER

FEMTOCLOCKS™ CRYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER
General Description
The ICS844004-104 is a 4 output LVDS Synthesizer
ICS
optimized to generate Fibre Channel reference clock
HiPerClockS™ _{frequencies and is a member of the HiPerClocks}^TM
family of high performance clock solutions from IDT.
Using a 26.5625MHz 18pF parallel resonant crystal,
the following frequencies can be generated based on the 2
frequency select pins (F_SEL[1:0]): 212.5MHz, 187.5MHz,
159.375MHz, 106.25MHz and 53.125MHz. The ICS844004-104
uses IDT’s 3^rd generation low phase noise VCO technology and
can achieve <1ps typical rms phase jitter, easily meeting Fibre
Channel jitter requirements. The ICS844004-104 is packaged in a
32-pin VFQFN package.
ICS844004-104
Features
• Four differential LVDS outputs
• Selectable crystal oscillator interface or LVCMOS/LVTTL
single-ended input
• Supports the following output frequencies: 212.5MHz,
187.5MHz, 159.375MHz, 106.25MHz and 53.125MHz
• VCO range: 560MHz - 680MHz
• RMS phase jitter at 212.5MHz (637kHz – 10MHz), using a
26.5625MHz crystal: <1ps (typical)
• Full 3.3V or 2.5V output supply modes
• 0°C to 70°C ambient operating temperature
• Available in both standard (RoHS 5) and lead-free (RoHS 6)
packages
Table 1. Frequency Table
Inputs
Input F_SEL1
Frequency
(MHz)
F_SEL0
M
N
M/N
Output
Divider Divider Divider Frequency
Value Value Value (MHz)
26.5625
0
0
24
3
8
212.5
(default)
26.5625
0
1
24
4
6
159.375
26.5625
1
0
24
6
4
106.25
26.5625
1
1
24
12
2
53.125
23.4375
0
0
24
3
8
187.5
(default)
Pin Assignment
Q0
nQ0
MR
nPLL_SEL
nc
nc
nc
nc
32 31 30 29 28 27 26 25
1
24
2 _{ICS844004-104} 23
3 _{32 Lead VFQFN} 22
4 _{5mm x 5mm x 0.925mm} 21
5
package body
20
6
K Package
Top View
19
7
18
8
17
9 10 11 12 13 14 15 16
Q3
nQ3
GND
nc
nc
nXTAL_SEL
REF_CLK
GND
Block Diagram
F_SEL[1:0] ^Pulldown
2
nPLL_SEL ^Pulldown
REF_CLK ^Pulldown
1
26.5625MHz
XTAL_IN
OSC
0
XTAL_OUT
nXTAL_SEL ^Pulldown
Phase
Detector
1
VCO
637.5MHz
(w/26.5625MHz
0
Reference)
M = 24 (fixed)
F_SEL[1:0]
0 0 ÷3
0 1 ÷4
1 0 ÷6
1 1 ÷12
MR ^Pulldown
IDT™ / ICS™ LVDS FREQUENCY SYNTHESIZER
1
Q0
nQ0
Q1
nQ1
Q2
nQ2
Q3
nQ3
ICS844004AK-104 REV. A SEPTEMBER 15, 2008