PRELIMINARY
Integrated
Circuit
Systems, Inc.
ICS83940I-01
L
OW
S
KEW
, 1-
TO
-18
LVPECL-
TO
-LVCMOS / LVTTL F
ANOUT
B
UFFER
F
EATURES
•
18 LVCMOS/LVTTL outputs, 23Ω typical output impedance
•
Selectable LVCMOS_CLK or LVPECL clock inputs
•
LVCMOS_CLK supports the following input types:
LVCMOS or LVTTL
•
PCLK, nPCLK supports the following input types:
LVPECL, CML, SSTL
•
Maximum output frequency: 250MHz
•
Output skew: 150ps (maximum)
•
Part-to-part skew: 750ps (maximum)
•
Full 3.3V, 2.5V or mixed 3.3V, 2.5V supply modes
•
-40°C to 85°C ambient operating temperature
•
Pin compatible with the MPC940L in single supply
applications
G
ENERAL
D
ESCRIPTION
The ICS83940I-01 is a low skew, 1-to-18
ICS
LVPECL-to-LVCMOS/LVTTL Fanout Buffer and a
HiPerClockS™
member of the HiPerClockS™ family of High Per-
for mance Clock Solutions from ICS. The
ICS83940I-01 has two selectable clock inputs.
The PCLK, nPCLK pair can accept LVPECL, CML or SSTL
input levels. The single ended clock input accepts LVCMOS
or LVTTL input levels. The low impedance LVCMOS/LVTTL
outputs are designed to drive 50Ω series or parallel termi-
nated transmission lines. The effective fanout can be increased
from 18 to 36 by utilizing the ability of the outputs to drive two
series terminated lines.
The ICS83940I-01 is characterized at full 3.3V, full 2.5V and
mixed 3.3V input and 2.5V output operating supply modes. Guar-
anteed output and part-to-part skew characteristics make the
ICS83940I-01 ideal for those clock distribution applications de-
manding well defined performance and repeatability.
B
LOCK
D
IAGRAM
P
IN
A
SSIGNMENT
GND
V
DDO
Q3
Q4
Q5
Q0
Q1
Q2
32 31 30 29 28 27 26 25
GND
CLK_SEL
PCLK
nPCLK
LVCMOS_CLK
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16
Q17
Q16
Q15
GND
Q14
Q13
Q12
V
DDO
24
23
22
Q6
Q7
Q8
V
DDO
Q9
Q10
Q11
GND
GND
LVCMOS_CLK
0
18
Q0:Q17
CLK_SEL
PCLK
nPCLK
V
DD
V
DDO
ICS83940I-01
21
20
19
18
17
1
32-Lead LQFP
Y Pacakge
7mm x 7mm x 1.4mm package body
Top View
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.
83940DYI-01
www.icst.com/products/hiperclocks.html
1
REV. A MARCH 1, 2004
ICS [ INTEGRATED CIRCUIT SYSTEMS ]
