ICS8421002I-01 Datasheet, PDF (1/13 Pages) Integrated Circuit Systems – FEMTOCLOCKS™ CRYSTAL-TO-HSTL FREQUENCY SYNTHESIZER

Integrated
Circuit
Systems, Inc.
ICS8421002I-01
FEMTOCLOCKS™ CRYSTAL-TO-
HSTL FREQUENCY SYNTHESIZER
GENERAL DESCRIPTION
The ICS8421002I-01 is a 2 output HSTL
ICS
Synthesizer optimized to generate Ethernet
HiPerClockS™ _{reference clock frequencies and is a member 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
ICS8421002I-01 uses ICS’ 3^rd generation low phase
noise VCO technology and can achieve 1ps or lower typi-
cal rms phase jitter, easily meeting Ethernet jitter
requirements. The ICS8421002I-01 is packaged in a small
20-pin TSSOP package.
FEATURES
• Two HSTL outputs (VOHmax = 1.5V)
• 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): 0.44ps (typical)
• Power supply modes:
Core/Output
3.3V/1.8V
2.5V/1.8V
• -40°C to 85°C ambient operating temperature
• Available in both standard and lead-free RoHS compliant
packages
FREQUENCY SELECT FUNCTION TABLE
F_SEL1
F_SEL0
M Divider
Value
N Divider
Value
0
0
25
4
0
1
25
5
1
0
25
10
1
1
not used
Output Frequency
(25MHz Ref.)
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
VCO
M = 25 (fixed)
F_SEL[1:0]
0 0 ÷4 (default)
1
0 1 ÷5
1 0 ÷10
1 1 Not Used
0
MR ^Pulldown
8421002AGI-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
ICS8421002I-01
20-Lead TSSOP
6.5mm x 4.4mm x 0.92mm
package body
G Package
Top View
Q0
nQ0
Q1
nQ1
REV. A FEBRUARY 6, 2006