PRELIMINARY
CRYSTAL-TO-0.7V DIFFERENTIAL HCSL/
LVCMOS FREQUENCY SYNTHESIZER
ICS841S012I
GENERAL DESCRIPTION
FEATURES
The ICS841S012I is an optimized PCIe, sRIO and
• Tꢁo 0.7V differential HCSL outputs (Bank A), configurable for
PCIe (100MHz or 250MHz) and sRIO (100MHz or 125MHz)
clock signals
ICS
HiPerClockS™
Gigabit Ethernet Frequency Synthesizer and a
member of HiperClocks™family of high perfor-
mance clock solutions from IDT. The ICS841S012I
uses a 25MHz parallel resonant crystal to gener-
Eight LVCMOS/LVTTL outputs (Banks B/C),
15Ω typical output impedance
ate 33.33MHz - 200MHz clock signals, replacing solutions
requiring multiple oscillator and fanout buffer solution. The
device supports 0.25ꢀ center-spread, and -0.5ꢀ doꢁn-
spread clocking ꢁith tꢁo spread select pins (SSC[1:0]). The
VCO operates at frequency of 2GHz. The device has three
output banks: Bank A ꢁith tꢁo HCSL outputs, 100MHz –
250MHz; Bank B ꢁith seven 33.33MHz – 200MHz LVCMOS/
LVTTL outputs; and Bank C ꢁith one 33.33MHz – 200MHz
LVCMOS/LVTTL output.
Tꢁo REF_OUT LVCMOS/LVTTL clock outputs,
20Ω typical output impedance
• Selectable crystal oscillator interface, 25MHz, 18pF parallel
resonant crystal or one LVCMOS/LVTTL single-ended
reference clock input
• Supports the folloꢁing output frequencies:
HCSL Bank A: 100MHz, 125MHz, 200MHz and 250MHz
LVCMOS/LVTTL Bank B/C: 33.33MHz, 50MHz, 66.67MHz,
100MHz, 125MHz, 133.33MHz, 166.67MHz and 200MHz
All Banks A, B and C have their oꢁn dedicated frequency
select pins and can be independently set for the frequencies
mentioned above. The loꢁ jitter characteristic of the
ICS841S012I makes it an ideal clock source for PCIe, sRIO
and Gigabit Ethernet applications. Designed for netꢁorking and
industrial applications, the ICS841S012I can also drive the high-
speed clock inputs of communication processors, DSPs,
sꢁitches and bridges.
• VCO: 2GHz
• Spread spectrum clock: 0.25ꢀ center-spread and
-0.5ꢀ doꢁn-spread
• PLL bypass and output enable
• RMS period jitter: 15ps (typical), QB outputs
• Full 3.3V supply mode
• -40°C to 85°C ambient operating temperature
• Available in both standard (RoHS 5) and lead-free (RoHS 6)
packages
PIN ASSIGNMENT
56 55 54 53 52 51 50 49 48 47 46 45 44 43
42
41
VDD
REF_OUT0
REF_OUT1
GND
1
VDDOC
QC
2
GND
QBC_OE
VDDA
VDDA
GND
GND
IREF
QA0
3
40
39
38
37
36
35
34
33
32
31
30
29
4
5
ICS841S012I
GND
56-Lead VFQFN
6
REF_IN
VDD
8mm x 8mm x 0.925mm
package body
7
REF_SEL
XTAL_IN
XTAL_OUT
BYPASS
8
9
K Package
Top Vieꢁ
10
11
12
13
14
nQA0
QA1
nQA1
REF_OE
nMR
VDD
VDD
15 16 17 18 19 20 21 22 23 24 25 26 27 28
The Preliminary Information presented herein represents a product in pre-production.The noted characteristics are based on initial product characterization
and/or qualification.Integrated DeviceTechnology, Incorporated (IDT) reserves the right to change any circuitry or specifications ꢁithout notice.
IDT™ / ICS™ 0.7V HCSL/LVCMOS FREQUENCY SYNTHESIZER
1
ICS841S012BKI REV. A MAY 1, 2008