ICS8421002I
FEMTOCLOCKS™ CRYSTAL-TO-
HSTL FREQUENCY SYNTHESIZER
Integrated
Circuit
Systems, Inc.
GENERAL DESCRIPTION
FEATURES
The ICS8421002I is a 2 output HSTL Synthesizer • Two HSTL outputs (VOHmax = 1.5V)
ICS
HiPerClockS™
optimized to generate Fibre Channel reference
• Selectable crystal oscillator interface
clock frequencies and is a member of the
or LVCMOS/LVTTL single-ended input
HiPerClocksTM family of high performance clock
solutions from ICS. Using a 26.5625MHz 18pF
• Supports the following output frequencies: 212.5MHz,
187.5MHz, 159.375MHz, 106.25MHz, 53.125MHz
parallel resonant crystal, the following frequencies can be
generated based on the 2 frequency select pins (F_SEL[1:0]):
212.5MHz, 187.5MHz, 159.375MHz, 106.25MHz and
53.125MHz. The ICS8421002I uses ICS’ 3rd generation low
phase noise VCO technology and can achieve 1ps or lower
typical rms phase jitter, easily meeting Fibre Channel jitter
requirements.The ICS8421002I is packaged in a small 20-pin
TSSOP package.
• VCO range: 560MHz - 680MHz
• RMS phase jitter @ 212.5MHz, using a 26.5625MHz crystal
(637kHz - 10MHz): 0.59ps (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 an lead-free RoHS compliant
packages
FREQUENCY SELECT FUNCTION TABLE
PIN ASSIGNMENT
nc
VDDO
Q0
VDDO
1
20
19
18
17
16
15
14
13
12
11
Inputs
Input
Frequency
(MHz)
Output
Frequency
(MHz)
Q1
2
M Divider N Divider
M/N
Divider Value
nQ1
3
F_SEL1 F_SEL0
GND
VDD
nQ0
MR
Value
24
Value
3
4
5
26.5625
26.5625
26.5625
26.5625
23.4375
0
0
1
1
0
0
1
0
1
0
8
6
4
2
8
212.5
159.375
106.25
53.125
187.5
nXTAL_SEL
REF_CLK
XTAL_IN
XTAL_OUT
F_SEL1
nPLL_SEL
nc
VDDA
F_SEL0
VDD
6
7
8
9
24
24
24
24
4
6
12
3
10
ICS8421002I
20-Lead TSSOP
6.5mm x 4.4mm x 0.92mm
package body
G Package
Top View
BLOCK DIAGRAM
F_SEL[1:0]
Pulldown
2
Pulldown
nPLL_SEL
Q0
F_SEL[1:0]
nQ0
Pulldown
REF_CLK
0 0 ÷3 (default)
0 1 ÷4
1
0
1
0
26.5625MHz
XTAL_IN
1 0 ÷6
Q1
1 1 ÷12
Phase
Detector
VCO
OSC
nQ1
XTAL_OUT
Pulldown
nXTAL_SEL
M = 24 (fixed)
Pulldown
MR
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.
8421002AGI
www.icst.com/products/hiperclocks.html
REV.A FEBRUARY 7, 2006
1