ics8536-01 Integrated Device Technology, ics8536-01 Datasheet - Page 11

• Manufacturer Part Number: ics8536-01
• Description: Xtal, Lvcmos, Differential Input Lvpecl Output 1 6 266-mhz Buffer
• Manufacturer: Integrated Device Technology

LVCMOS
The XTAL_IN input can accept a single-ended LVCMOS signal
through an AC coupling capacitor. A general interface diagram is
shown in Figure 3. The XTAL_OUT pin can be left floating. The
input edge rate can be as slow as 10ns. For LVCMOS inputs, it is
recommended that the amplitude be reduced from full swing to
half swing in order to prevent signal interference with the power
rail and to reduce noise. This configuration requires that the output
R
I
C
For applications not requiring the use of the crystal oscillator input,
both XTAL_IN and XTAL_OUT can be left floating. Though not
required, but for additional protection, a 1k
from XTAL_IN to ground.
CLK I
For applications not requiring the use of the test clock, it can be
left floating. Though not required, but for additional protection, a
1k
CLK/nCLK I
For applications not requiring the use of the differential input,
both CLK and nCLK can be left floating. Though not required, but
for additional protection, a 1k
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 1k
IDT
NPUTS
RYSTAL
ECOMMENDATIONS FOR
ICS8536-01
LOW SKEW, 1-TO-6, CRYSTAL/LVCMOS/DIFFERENTIAL-TO-3.3V, 2.5V LVPECL FANOUT BUFFER
™
resistor can be tied from the CLK input to ground.
/ ICS
NPUT
:
I
NPUT
™
:
3.3V, 2.5V LVPECL FANOUT BUFFER
ONTROL
NPUT
TO
:
XTAL I
:
resistor can be used.
P
INS
:
NTERFACE
F
U
IGURE
NUSED
resistor can be tied from CLK to
3. G
VDD
Ro
I
NPUT AND
ENERAL
resistor can be tied
D
IAGRAM FOR
O
Rs
Zo = Ro + Rs
UTPUT
P
Zo = 50
LVCMOS D
INS
11
impedance of the driver (Ro) plus the series resistance (Rs) equals
the transmission line impedance. In addition, matched termination
at the crystal input will attenuate the signal in half. This can be
done in one of two ways. First, R1 and R2 in parallel should equal
the transmission line impedance. For most 50
and R2 can be 100 . This can also be accomplished by removing
R1 and making R2 50 .
O
LVPECL O
All unused LVPECL outputs can be left floating. We recommend
that there is no trace attached. Both sides of the differential output
pair should either be left floating or terminated.
UTPUTS
VDD
RIVER TO
R1
R2
:
.1uf
UTPUT
XTAL I
XTAL_IN
XTAL_OUT
NPUT
ICS8536AG-01 REV. B NOVEMBER 3, 2006
I
NTERFACE
PRELIMINARY
applications, R1