
DATASHEET
FemtoClock Crystal-to-LVDS
Clock Generator
ICS844201I-45
ICS844201BKI-45 REVISION A OCTOBER 7, 2013
1
2013 Integrated Device Technology, Inc.
General Description
The ICS844201I-45 is a PCI ExpressTM Clock Generator. The
ICS844201I-45 can synthesize 100MHz or 125MHz reference clock
frequencies with a 25MHz crystal. The ICS844201I-45 has excellent
phase jitter performance and is packaged in a small 16-pin VFQFN,
making it ideal for use in systems with limited board space.
Features
One differential LVDS output pair
Crystal oscillator interface designed for 18pF,
25MHz parallel resonant crystal
VCO range: 490MHz – 680MHz
RMS phase jitter at 100MHz (12kHz – 20MHz): 0.792ps (typical)
RMS phase jitter at 125MHz (12kHz – 20MHz): 0.773ps (typical)
Full 3.3V output supply mode
PCI Express (2.5Gb/s) and Gen 2 (5Gb/S) jitter compliant
-40°C to 85°C ambient operating temperature
Lead-free (RoHS 6) packaging
Frequency Table
Inputs
Output Frequency Range
(MHz)
Crystal Frequency (MHz)
M
FSEL
N
Multiplication Value M/N
25
20
1
4
5
125 (default)
25
20
0
5
4
100
5
6
7
8
16 15 14 13
1
2
3
4
12
11
10
9
nc
XTAL_OUT
XTAL_IN
FSEL
Q
nQ
VDD
nc
GND
nc
GND
Pin Assignment
OSC
Phase
Detector
VCO
490MHz - 680MHz
M = ÷20 (fixed)
N = ÷5
÷4 (default)
Q
nQ
Pullup
XTAL_IN
XTAL_OUT
FSEL
Block Diagram
ICS844201I-45
16-Lead VFQFN
3mm x 3mm x 0.925mm package body
K Package
Top View