ICS844002I-01 Datasheet, PDF (1/12 Pages) Integrated Circuit Systems – FEMTOCLOCKS™ CRYSTAL-TO-LVDS FREQUENCY SYNTHESIZER

Integrated
Circuit
Systems, Inc.
ICS844002I-01
FEMTOCLOCKS™ CRYSTAL-TO-
LVDS FREQUENCY SYNTHESIZER
GENERAL DESCRIPTION
The ICS844002I-01 is a 2 output LVDS
ICS
Synthesizer optimized to generate Ethernet
HiPerClockS™ _{reference clock frequencies and is a mem-}
ber of the HiPerClocks^TM family of high
performance clock solutions from ICS. Using a
25MHz, 18pF parallel resonant crystal, the following
frequencies can be generated based on the 2 frequency
select pins (F_SEL[1:0]): 156.25MHz, 125MHz and
62.5MHz. The ICS844002I-01 uses ICS’ 3^rd generation
low phase noise VCO technology and can achieve <1ps
typical rms phase jitter, easily meeting Ethernet jitter
requirements. The ICS844002I-01 is packaged in a small
20-pin TSSOP package.
FEATURES
• Two LVDS outputs
• Selectable crystal oscillator interface
or LVCMOS/LVTTL single-ended input
• Supports the following output frequencies: 156.25MHz,
125MHz, 62.5MHz
• VCO range: 560MHz - 680MHz
• RMS phase jitter @ 156.25MHz, using a 25MHz crystal
(1.875MHz - 20MHz): 0.41ps (typical)
• Full 2.5V supply mode
• -40°C to 85°C ambient operating temperature
• Available in both, standard and RoHS/Lead-Free compliant
packages
FREQUENCY SELECT FUNCTION TABLE
F_SEL1
0
0
1
1
F_SEL0
0
1
0
1
M Divider N Divider
Value
Value
25
4
25
5
25
10
Not Used
Output Frequency (MHz)
(25MHz Reference)
156.25
125
62.5
Not Used
BLOCK DIAGRAM
F_SEL[1:0] ^Pulldown
nPLL_SEL ^Pulldown
REF_CLK ^Pulldown
1
25MHz
XTAL_IN
OSC
0
XTAL_OUT
nXTAL_SEL ^Pulldown
2
Phase
Detector
1
VCO
625MHz
0
(w/25MHz
Reference)
M = 25 (fixed)
F_SEL[1:0]
0 0 ÷4
0 1 ÷5
1 0 ÷10
1 1 not used
MR ^Pulldown
844002AGI-01
www.icst.com/products/hiperclocks.html
1
PIN ASSIGNMENT
nc ₁
2 0 ^VDDO
VDDO ₂
19 ^Q1
Q0 _{3 18} nQ1
nQ0 4 17 GND
MR 5
16 ^VDD
nPLL_SEL 6 15 nXTAL_SEL
nc 7 14 REF_CLK
VDDA 8
13 ^XTAL_IN
F_SEL0 9 12 XTAL_OUT
VDD 10 11 F_SEL1
ICS844002I-01
20-Lead TSSOP
6.5mm x 4.4mm x 0.92mm
package body
G Package
Top View
Q0
nQ0
Q1
nQ1
REV. A JANUARY 5, 2006