ICS843021 Datasheet, PDF (1/13 Pages) Integrated Circuit Systems – FEMTOCLOCKS-TM CRYSTAL-TO- 3.3V LVPECL CLOCK GENERATOR

Integrated
Circuit
Systems, Inc.
ICS843021
FEMTOCLOCKS™ CRYSTAL-TO-
3.3V LVPECL CLOCK GENERATOR
GENERAL DESCRIPTION
ICS
The ICS843021 is a Gigabit Ethernet Clock
Generator and a member of the HiPerClocks^TM
HiPerClockS™ _{family of high performance devices from ICS. The}
ICS843021 uses a 25MHz crystal to synthesize
125MHz. The ICS843021 has excellent phase jitter
performance, over the 1.875MHz – 20MHz integration range.
The ICS843021 is packaged in a small 8-pin TSSOP, making it
ideal for use in systems with limited board space.
FEATURES
• 1 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 to 700MHz
• Output duty cycle range: 49% - 51%
• RMS phase jitter @ 125MHz, using a 25MHz crystal
(1.875MHz - 20MHz): 0.37ps (typical)
• RMS phase noise at 125MHz (typical)
Offset
Noise Power
100Hz ............... -94.2 dBc/Hz
1KHz .............. -122.8 dBc/Hz
10KHz .............. -132.2 dBc/Hz
100KHz .............. -131.3 dBc/Hz
• 3.3V operating supply
• 0°C to 70°C ambient operating temperature
• Industrial temperature information available upon request
• Lead-Free package fully RoHS compliant
FREQUENCY TABLE - TYPICAL APPLICATIONS
Inputs
Crystal Frequency (MHz)
25
26.6
Output Frequency (MHz)
125
133
BLOCK DIAGRAM
25MHz
XTAL_IN
OSC
Phase
VCO
÷5
XTAL_OUT
Detector
÷25
(fixed)
PIN ASSIGNMENT
nQ0
Q0
VCCA 1
VEE 2
XTAL_OUT 3
XTAL_IN 4
8 VCC
7 Q0
6 nQ0
5 nc
ICS843021
8-Lead TSSOP
4.40mm x 3.0mm x 0.925mm package body
G Package
Top View
843021AG
www.icst.com/products/hiperclocks.html
1
REV. C MARCH 31, 2005