
DATA SHEET
ICS843021AG REVISION D OCTOBER 12, 2010
1
2010 Integrated Device Technology, Inc.
FemtoClock Crystal-to-3.3V LVPECL
Clock Generator
ICS843021
General Description
The ICS843021 is a Gigabit Ethernet Clock Generator. The
ICS84302 uses a 25MHz crystal to synthesize 125MHz. The
ICS843021has excellent phase jitter performance, over the
1.875MHz – 20MHz integration range. The ICS843021is packaged
in a small 8-pin TSSOP, making it ideal for use in systems with
limited board space.
Features
One differential 3.3V LVPECL output
Crystal oscillator interface designed for 22.4MHz – 28MHz, 18pF
parallel resonant crystal
Output frequency range: 112MHz – 140MHz
VCO range: 560MHz – 700MHz
Output duty cycle range: 49% – 51%
RMS phase jitter at 125MHz, using a 25MHz crystal
(1.875MHz – 20MHz): 0.650ps (typical)
Offset
Noise Power
100Hz ..............-94.2 dBc/Hz
1kHz ..............-122.8 dBc/Hz
10kHz ..............-132.2 dBc/Hz
100kHz ..............-131.3 dBc/Hz
Full 3.3V supply mode
0°C to 70°C ambient operating temperature
Available in both standard (RoHS 5) and lead-free (RoHS 6)
packages
Industrial temperature information available upon request
Table 1. Frequency Table - Typical Applications
Inputs
Output Frequency Range (MHz)
Crystal Frequency (MHz)
25
125
26.6
133
Pin Assignment
ICS843021
8 Lead TSSOP
4.40mm x 3.0mm x 0.925 package body
G Package
Top View
Block Diagram
OSC
Phase
Detector
VCO
÷5
÷25
(fixed)
Q0
nQ0
XTAL_IN
XTAL_OUT
25MHz
1
2
3
4
8
7
6
5
VCCA
VEE
XTAL_OUT
XTAL_IN
VCC
Q0
nQ0
nc