ICS841608I Datasheet, PDF (1/17 Pages) Integrated Device Technology – FEMTOCLOCKS CRYSTAL-TO-HCSL CLOCK GENERATOR VCO: 500MHz

FEMTOCLOCKS™ CRYSTAL-TO-HCSL
CLOCK GENERATOR
GENERAL DESCRIPTION
The ICS841608I is an optimized PCIe and sRIO
ICS
clock generator and member of the HiPerClocks™
HiPerClockS™ _{family of high-performance clock solutions from IDT.}
The device uses a 25MHz parallel crystal to
generate 100MHz and 125MHz clock signals,
replacing solutions requiring multiple oscillator and fanout buffer
solutions. The device has excellent phase jitter (<1ps rms)
suitable for clock components requiring precise and low-jitter
PCIe or sRIO or both clock signals. Designed for telecom,
networking and industrial applications, the ICS841608I can also
drive the high-speed sRIO and PCIe SerDes clock inputs of
communication processors, DSPs, switches and bridges.
ICS841608I
FEATURES
• Eight HCSL outputs: configurable for PCIe (100MHz)
and sRIO (125MHz) clock signals
• Selectable crystal oscillator interface, 25MHz,
18pF parallel resonant crystal or LVCMOS/LVTTL
single-ended reference clock input
• Supports the following output frequencies:
100MHz or 125MHz
• VCO: 500MHz
• PLL bypass and output enable
• PCI Express (2.5Gb/s) and Gen 2 (5 Gb/s) jitter compliant
• RMS phase jitter @125MHz, using a 25MHz crystal
(1.875MHz – 20MHz): 0.37ps (typical)
• Full 3.3V power supply mode
• -40°C to 85°C ambient operating temperature
• Available in both standard and (RoHs 5) lead-free (RoHS 6)
packages
BLOCK DIAGRAM
XTAL_IN
XTAL_OUT
OSC ⁰
REF_IN ^Pulldown
1
FemtoClock
PLL
VCO = 500MHz
REF_SEL ^Pulldown
IREF
M = ÷20
BYPASS ^Pulldown
FSEL ^Pulldown
1
0
÷N
÷4
÷5 (default)
MR/nOE ^Pulldown
PIN ASSIGNMENT
Q0
nQ0
32 31 30 29 28 27 26 25
Q1
XTAL_IN 1
24 VDD
nQ1
XTAL_OUT 2
23 nQ7
Q2
MR/nOE 3
VDD 4
nQ2
Q0 5
22 Q7
21 nQ6
20 Q6
nQ0 6
Q3
Q1 7
19 GND
18 nQ5
nQ3
nQ1 8
17 Q5
9 10 11 12 13 14 15 16
Q4
nQ4
Q5
ICS841608I
32-Lead VFQFN
nQ5
5mm x 5mm x 0.925mm
Q6
package body
K Package
nQ6
Top View
Q7
nQ7
IDT^™ / ICS^™ HCSL CLOCK GENERATOR
1
ICS841608AKI REV. A JUNE 18, 2008