ics83940dyi-01t Integrated Device Technology, ics83940dyi-01t Datasheet - Page 9

• Manufacturer Part Number: ics83940dyi-01t
• Description: Lvpecl/lvcmos-input Lvcmos-output 1 18 250-mhz Clock Buffer
• Manufacturer: Integrated Device Technology

IDT™ / ICS™ LOW SKEW, 1-TO-18 LVPECL-TO-LVCMOS/LVTTL FANOUT BUFFER
ICS83940-01
LOW SKEW, 1-TO-18 LVPECL-TO-LVCMOS/LVTTL FANOUT BUFFER
W
Figure 1 shows how the differential input can be wired to accept
single ended levels. The reference voltage V_REF = V
generated by the bias resistors R1, R2 and C1. This bias circuit
should be located as close as possible to the input pin. The ratio
R
I
CLK I
For applications not requiring the use of a clock input, it can
be left floating. Though not required, but for additional
protection, a 1kΩ resistor can be tied from the CLK input to
ground.
PCLK/nPCLK I
For applications not requiring the use of a differential input,
both the PCLK and nPCLK pins can be left floating. Though
not required, but for additional protection, a 1kΩ resistor can
be tied from PCLK to ground.
LVCMOS C
All control pins have internal pull-ups or pull-downs; additional
resistance is not required but can be added for additional
protection. A 1kΩ resistor can be used.
83940DY-01
NPUTS
ECOMMENDATIONS FOR
IRING THE
NPUT
:
:
ONTROL
D
NPUT
Integrated
Circuit
Systems, Inc.
IFFERENTIAL
P
:
INS
:
U
NUSED
I
F
NPUT TO
IGURE
Single Ended Clock Input
I
NPUT AND
1. S
A
A
www.icst.com/products/hiperclocks.html
PPLICATION
CCEPT
INGLE
O
E
C1
0.1u
S
NDED
UTPUT
INGLE
V_REF
LVPECL-
DD
/2 is
S
IGNAL
P
E
INS
9
9
I
NDED
of R1 and R2 might need to be adjusted to position the V_REF in
the center of the input voltage swing. For example, if the input
clock swing is only 2.5V and V
and R2/R1 = 0.609.
NFORMATION
O
LVCMOS O
All unused LVCMOS output can be left floating. We
recommend that there is no trace attached.
D
1K
UTPUTS
R1
1K
R2
RIVING
VDD
TO
L
EVELS
-LVCMOS / LVTTL F
nPCLK
D
PCLK
:
UTPUT
IFFERENTIAL
:
I
NPUT
DD
= 3.3V, V_REF should be 1.25V
L
OW
S
ANOUT
KEW
REV. A NOVEMBER 18, 2005
, 1-
B
TO
UFFER
ICS83940-01
-18
TSD