
FEMTOCLOCK CRYSTAL-TO-
3.3V LVPECL CLOCK GENERATOR
ICS843SDN
IDT / ICS 3.3V LVPECL CLOCK GENERATOR
1
ICS843SDNAG REV. A
NOVEMBER 13, 2012
General Description
The ICS843SDN is a Gigabit Ethernet Clock Generator. The
ICS843SDN uses a 24MHz crystal to synthesize 120MHz. The
ICS843SDN uses IDT’s 3rd generation low phase noise VCO
technology, and can achieve <1ps rms phase jitter performance
over the 12kHz – 20MHz integration range. The ICS843SDN is
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 23.2MHz – 30MHz,
18pF parallel resonant crystal
Output frequency range: 116MHz – 150MHz
VCO range: 580MHz – 750MHz
Output duty cycle range: 47% – 53%
RMS phase jitter @ 120MHz, using a 24MHz crystal
(12kHz – 20MHz): 0.81ps (typical)
Full 3.3V supply mode
0°C to 70°C ambient operating temperature
Industrial temperature information available upon request
Available in lead-free (RoHS 6) package
Table 1. Frequency Table - Typical Applications
Crystal Frequency (MHz)
Output Frequency (MHz)
25
125
24
120
ICS843SDN
8 Lead TSSOP
4.40mm x 3.0mm x 0.925mm package body
G Package
Top View
Pin Assignment
1
2
3
4
8
7
6
5
VCCA
VEE
XTAL_OUT
XTAL_IN
VCC
Q
nQ
nc
OSC
Phase
Detector
VCO
÷5
÷25
(fixed)
Q
nQ
XTAL_IN
XTAL_OUT
25MHz
Block Diagram