ICS8536I-33 Datasheet, PDF (10/19 Pages) Integrated Device Technology – LOW SKEW, 1-TO-6, CRYSTAL OSCILLATOR/LVCMOSTO-3.3V, 2.5V LVPECL/LVCMOS FANOUT BUFFER

ICS8536I-33
LOW SKEW, 1-TO-6, CRYSTAL OSCILLATOR/LVCMOS-TO-3.3V, 2.5V LVPECL/LVCMOS FANOUT BUFFER
APPLICATION INFORMATION
RECOMMENDATIONS FOR UNUSED INPUT AND OUTPUT PINS
INPUTS:
CRYSTAL INPUTS
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 1kΩ resistor can be tied
from XTAL_IN to ground.
CLK INPUT
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.
OUTPUTS:
LVCMOS OUTPUTS
All unused LVCMOS output can be left floating. There should be
no trace attached.
LVPECL OUTPUTS
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.
LVCMOS CONTROL PINS
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.
CRYSTAL INPUT INTERFACE
The ICS8536I-33 has been characterized with 18pF parallel
resonant crystals. The capacitor values, C1 and C2, shown in
Figure 2 below were determined using an 18pF parallel resonant
crystal and were chosen to minimize the ppm error. These
same capacitor values will tune any 18pF parallel resonant
crystal over the frequency range and other parameters speci-
fied in this data sheet. The optimum C1 and C2 values can be
slightly adjusted for different board layouts.
X1
18pF Parallel Crystal
XTAL_OUT
C1
27p
XTAL_IN
C2
27p
FIGURE 2. CRYSTAL INPUt INTERFACE
IDT^™ / ICS^™ 3.3V, 2.5V LVPECL/ LVCMOS FANOUT BUFFER
10
ICS8536CGI-33 REV. B OCTOBER 27, 2008