ICS8430252-45 Datasheet, PDF (1/13 Pages) Integrated Circuit Systems – FEMTOCLOCKS™ CRYSTAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER

Integrated
Circuit
Systems, Inc.
PRELIMINARY
ICS8430252-45
FEMTOCLOCKS™CRYSTAL-TO-3.3V LVPECL
FREQUENCY SYNTHESIZER
GENERAL DESCRIPTION
The ICS8430252-45 is a 2 output LVPECL and
ICS
LVCMOS/LVTTL Synthesizer optimized to gen-
HiPerClockS™ _{erate Ethernet reference clock frequencies and}
is a member of the HiPerClocks™ family of high
performance clock solutions from ICS. Using a
25MHz, 18pF parallel resonant crystal, the following fre-
quencies can be generated: 156.25MHz LVPECL output
and, 125MHz LVCMOS output. The 8430252-45 uses ICS’
3rd generation low phase noise VCO technology and can
achieve 1ps or lower typical rms phase jitter, easily meet-
ing Ethernet jitter requirements. The ICS8430252-45 is
packaged in a small 16-pin TSSOP package.
FEATURES
• One differential 3.3V LVPECL output and
One LVCMOS/LVTTL output
• Crystal oscillator interface designed for a 25MHz,
18pF parallel resonant crystal
• A 25MHz crystal generates both an output frequency of
156.25MHz (LVPECL) and 125MHz (LVCMOS)
• VCO frequency: 625MHz
• RMS phase jitter @ 156.25MHz (1.875MHz - 20MHz) using
a 25MHz crystal: 0.39ps (typical)
• Full 3.3V supply mode
• 0°C to 70°C ambient operating temperature
• Industrial temperature available upon request
• Available in both standard and lead-free RoHS compliant
packages
BLOCK DIAGRAM
OE ^Pullup
25MHz
XTAL_IN
OSC
XTAL_OUT
Phase
Detector
VCO
625MHz
Pullup
CLK_EN
Feedback Divider
÷25
÷5
QA
QB
÷4
nQB
PIN ASSIGNMENT
OE 1
VEE 2
QA 3
VCCO_A 4
nc 5
nc 6
VCCA 7
VCC 8
16 CLK_EN
15 VEE
14 QB
13 nQB
1 2 VCCO_B
11 XTAL_IN
10 XTAL_OUT
9 VEE
ICS8430252-45
16-Lead TSSOP
4.4mm x 5.0mm x 0.92mm
package body
G Package
Top View
The Preliminary Information presented herein represents a product in prototyping or pre-production. The noted characteristics are based on initial
product characterization. Integrated Circuit Systems, Incorporated (ICS) reserves the right to change any circuitry or specifications without notice.
8430252CG-45
www.icst.com/products/hiperclocks.html
REV. B DECEMBER 9, 2005
1