ICS843002I-01 Datasheet, PDF (1/15 Pages) Integrated Circuit Systems – FEMTOCLOCKS-TM CRYSTAL-TO- 3.3V, 2.5V LVPECL FREQUENCY SYNTHESIZER

Integrated
Circuit
Systems, Inc.
ICS843002I-01
FEMTOCLOCKS™ CRYSTAL-TO-
3.3V, 2.5V LVPECL FREQUENCY SYNTHESIZER
GENERAL DESCRIPTION
The ICS843002I-01 is a 2 output LVPECL
ICS
synthesizer optimized to generate Ethernet
HiPerClockS™ _{reference clock frequencies and is a member}
of the HiPerClocks^TM family of high perfor-
mance 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 ICS843002I-01 uses ICS’ FemtoClock^TM
low phase noise VCO technology and can achieve 1ps
or lower typical rms phase jitter, easily meeting Ethernet
jitter requirements. The ICS843002I-01 is packaged in a
small 20-pin TSSOP package.
FEATURES
• Two 3.3V or 2.5V LVPECL outputs
• Selectable crystal oscillator interface
or LVCMOS/LVTTL single-ended input
• Supports the following output frequencies:
156.25MHz, 125MHz and 62.5MHz
• VCO range: 560MHz - 680MHz
• RMS phase jitter @ 156.25MHz, using a 25MHz crystal
(1.875MHz-20MHz): 0.55ps (typical)
• Output skew: 30ps (maximum)
• Supply Voltage Modes
Core/Outputs
3.3/3.3
2.5/2.5
• -40°C to 85°C ambient operating temperature
• Available in both standard and lead-free RoHS-compliant
packages
FREQUENCY SELECT FUNCTION TABLE
F_SEL1
0
Inputs
F_SEL0
M Divider
Value
0
25
N Divider
Value
4
Output Frequency
(25MHz Ref.)
156.25 (default)
0
1
25
5
125
1
0
25
10
62.5
1
1
25
5
125
BLOCK DIAGRAM
F_SEL[1:0] ^Pulldown
2
nPLL_SEL ^Pulldown
REF_CLK ^Pulldown
1
25MHz
XTAL_IN
OSC
0
XTAL_OUT
nXTAL_SEL ^Pulldown
MR ^Pulldown
843002AGI-01
Phase
Detector
1
VCO
625MHz
(w/25MHz
0
Reference)
F_SEL[1:0]
0 0 ÷4 (default)
0 1 ÷5
1 0 ÷10
1 1 ÷5
M = 25 (fixed)
www.icst.com/products/hiperclocks.html
1
PIN ASSIGNMENT
nc 1
2 0 VCCO
VCCO 2
19 _Q1
Q0 3 18 nQ1
nQ0 4
17 _VEE
MR 5
16 _VCC
nPLL_SEL 6 15 nXTAL_SEL
nc 7 14 REF_CLK
VCCA 8
13 _{XTAL_IN}
F_SEL0 9 12 XTAL_OUT
VCC 10 11 F_SEL1
ICS843002I-01
20-Lead TSSOP
6.5mm x 4.4mm x 0.92mm
package body
G Package
Q0
Top View
nQ0
Q1
nQ1
REV. A JANUARY 6, 2006