ICS844001I Datasheet, PDF (1/10 Pages) Integrated Circuit Systems – FEMTOCLOCKS™ CRYSTAL-TO- LVDS CLOCK GENERATOR

Integrated
Circuit
Systems, Inc.
PRELIMINARY
ICS844001I
FEMTOCLOCKS™CRYSTAL-TO- LVDS
CLOCK GENERATOR
GENERAL DESCRIPTION
The ICS844001I is a Fibre Channel Clock
ICS
Generator and a member of the HiPerClocks^TM
HiPerClockS™ _{family of high performance devices from ICS.}
The ICS844001I uses an 18pF parallel resonant
crystal over the range of 20.4MHz - 28.3MHz.
For Fibre Channel applications, a 26.5625MHz crystal is used.
The frequency select pin allows the device to generate
either 106.25MHz or 212.5MHz from a 26.5625MHz
cr ystal. To generate 187.5MHz for 12Gb Ethernet, a
23.4375MHz crystal is used. The ICS844001I uses ICS’ 3^rd
generation low phase noise VCO technology and can
achieve <1ps typical rms phase jitter, easily meeting Fibre
Channel and Ethernet jitter requirements. The ICS844001I is
packaged in a small 8-pin TSSOP, making it ideal for use in
systems with limited board space.
FEATURES
• (1) Differential LVDS output
• Crystal oscillator interface, 18pF parallel resonant crystal
(20.4MHz - 28.3MHz)
• Output frequency range: 81.66MHz - 226.66MHz
• VCO range: 490MHz - 680MHz
• RMS phase jitter @ 106.25MHz, using a 26.5625MHz crystal
(637kHz - 10MHz): 0.74ps (typical)
• 3.3V or 2.5V operating supply
• -40°C to 85°C ambient operating temperature
COMMON CONFIGURATION TABLE - FIBRE CHANNEL, 12Gb ETHERNET
Inputs
Crystal Frequency (MHz) FREQ_SEL M
26.5625
26.5625
23.4375
0
24
1
24
1
24
N
Multiplication
Value M/N
6
4
3
8
3
8
Output Frequency
(MHz)
106.25
212.5
187.5
BLOCK DIAGRAM
FREQ_SEL ^Pullup
XTAL_IN
÷3
1
XTAL_OUT
OSC
Phase
Detector
VCO
490MHz - 680MHz
÷6
0
Q
nQ
M = ÷24 (fixed)
PIN ASSIGNMENT
VDDA 1
GND 2
XTAL_OUT 3
XTAL_IN 4
8 VDD
7Q
6 nQ
5 FREQ_SEL
ICS844001I
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.
844001AGI
www.icst.com/products/hiperclocks.html
REV. A JUNE 16, 2005
1