ICS844023I Datasheet, PDF (1/10 Pages) Integrated Circuit Systems – FEMTOCLOCKS™ CRYSTAL-TO- LVDS CLOCK GENERATOR

Integrated
Circuit
Systems, Inc.
PRELIMINARY
ICS844023I
FEMTOCLOCKS™ CRYSTAL-TO- LVDS
CLOCK GENERATOR
GENERAL DESCRIPTION
The ICS844023I is an Ethernet Clock Generator
ICS
and a member of the HiPerClocks^TM family of high
HiPerClockS™ _{performance devices from ICS. The ICS844023I}
uses an 18pF parallel resonant crystal over the
range of 24.5MHz - 34MHz. For Ethernet appli-
cations, a 25MHz crystal is used to generate 250MHz. The
ICS844023I has excellent <1ps phase jitter performance, over
the 1.875MHz - 20MHz integration range. The ICS844023I is
packaged in a small 8-pin TSSOP, making it ideal for use in
systems with limited board space.
FEATURES
• One Differential LVDS output
• Crystal oscillator interface, 18pF parallel resonant crystal
(24.5MHz - 34MHz)
• Output frequency range: 245MHz - 340MHz
• VCO range: 490MHz - 680MHz
• RMS phase jitter @ 250MHz, using a 25MHz crystal
(1.875MHz - 20MHz): 0.38ps (typical)
• 3.3V or 2.5V operating supply
• -40°C to 85°C ambient operating temperature
• Available in both standard and lead-free RoHS-compliant
packages
COMMON CONFIGURATION TABLE
Inputs
Crystal Frequency (MHz) M
25
20
Output Frequency
N
Multiplication
Value M/N
(MHz)
2
10
250
BLOCK DIAGRAM
OE ^Pullup
XTAL_IN
XTAL_OUT
OSC
Phase
Detector
VCO
490MHz - 680MHz
N = ÷2 (fixed)
Q
nQ
M = ÷20 (fixed)
PIN ASSIGNMENT
VDDA 1
GND 2
XTAL_OUT 3
XTAL_IN 4
8 VDD
7Q
6 nQ
5 OE
ICS844023I
8-Lead TSSOP
4.40mm x 3.0mm x 0.925mm
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.
844023AGI
www.icst.com/products/hiperclocks.html
REV. B JANUARY 6, 2006
1