PRELIMINARY
TM
FEMTOCLOCKS
ICS843441
SAS/SATA CLOCK GENERATOR
General Description
Features
The ICS843441 is a low jitter, high performance
• Designed for use in SAS, SAS-2, and SATA systems
• Center ( 0.25%) Spread Spectrum Clocking (SSC)
• Down (-0.23% or -0.5%) SSC
S
IC
clock generator and a member of the FemtoClocks™
family of silicon timing products. The ICS843441 is
designed for use in applications using the SAS and
SATA interconnect. The ICS843241 uses an
HiPerClockS™
• Better frequency stability than SAW oscillators
• One differential 3.3V LVPECL output
external, 25MHz, parallel resonant crystal to generate four
selectable output frequencies: 75MHz, 100MHz, 150MHz, and
300MHz. This silicon based approach provides excellent
frequency stability and reliability. The ICS843441 features down
and center spread spectrum (SSC) clocking techniques.
• Crystal oscillator interface designed for 25MHz
(CL = 18pF) frequency
• External fundamental crystal frequency ensures high reliability
and low aging
• Selectable output frequencies: 75MHz, 100MHz, 150MHz,
Applications
300MHz
• SAS/SATA Host Bus Adapters
• Output frequency is tunable with external capacitors
• RMS phase jitter: 1.33ps (typical)
• SATA Port Multipliers
• SAS I/O Controllers
• 3.3V operating supply
• TapeDrive and HDD Array Controllers
• SAS Edge and Fanout Expanders
• HDDs and TapeDrives
• 0°C to 70°C ambient operating temperature
• Available in both standard (RoHS 5) and lead-free (RoHS 6)
packages
• Disk Storage Enterprise
Pin Assignment
Block Diagrams
XTAL_IN
ICS843441
25MHz
XTAL
00 = SSC Off
8-Lead SOIC, 150 Mil
3.90mm x 4.90mm x 1.375mm package body
FemtoClock™
OSC
01 = 0.5% Down-spread
10 = 0.23% Down-spread
11 = 0.5% Center-spread
Q
PLL
nQ
XTAL_OUT
M Package
Top View
SSC Output
Control Logic
Pulldown:Pulldown
SSC_SEL(1:0)
nPLL_SEL
8-Lead SOIC
VEE
F_SEL1
VEE
nPLL_SEL
nQ
Q
VCC
1
2
16
15
14
13
12
11
10
9
XTAL_OUT
XTAL_IN
Pulldown
3
4
5
6
7
8
SSC_SEL0
nc
nc
nc
XTAL_IN
FemtoClock™
25MHz
XTAL
OSC
F_SEL0
VCC
0
1
PLL
00 = 75MHz
SSC_SEL1
01 = 100MHz
Q
XTAL_OUT
10 = 150MHz (default)
11 = 300MHz
nQ
ICS843441
Pullup:Pulldown
F_SEL(1:0)
16-Lead TSSOP
4.4mm x 5.0mm x 0.925mm package body
G Package
Clock Output
Control Logic
Pulldown:Pulldown
SSC_SEL(1:0)
16-Lead TSSOP
Top View
The Preliminary Information presented herein represents a product in pre-production. The noted characteristics are based on initial product characterization
and/or qualification. Integrated Device Technology, Incorporated (IDT) reserves the right to change any circuitry or specifications without notice.
IDT™ / ICS™ SAS/SATA CLOCK GENERATOR
1
ICS843441AG REV. A JULY 17, 2008