83948AYILFT IDT, Integrated Device Technology Inc, 83948AYILFT Datasheet - Page 7

• Manufacturer Part Number: 83948AYILFT
• Manufacturer: IDT, Integrated Device Technology Inc
• Type: Clock Driverr

Specifications of 83948AYILFT

• Number Of Clock Inputs: 2
• Output Frequency: 250MHz
• Output Logic Level: LVCMOS/LVTTL
• Operating Supply Voltage (min): 3V
• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (max): 3.6V
• Package Type: LQFP
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 32
• Lead Free Status / RoHS Status: Compliant

Application Information
Wiring the Differential Input to Accept Single Ended Levels
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 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
R2/R1 = 0.609.
Recommendations for Unused Input and Output Pins
Inputs:
CLK/nCLK Inputs
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 1kΩ resistor can be tied from CLK 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.
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.
IDT™ / ICS™ LVCMOS/LVTTL CLOCK GENERATOR
ICS83948I
LOW SKEW, 1-TO-12 DIFFERENTIAL-TO-LVCMOS/LVTTL FANOUT BUFFER
DD
= 3.3V, V_REF should be 1.25V and
DD
/2 is
7
Figure 1. Single-Ended Signal Driving Differential Input
Outputs:
LVCMOS Outputs
All unused LVCMOS output can be left floating. There should be no
trace attached.
Single Ended Clock Input
C1
0.1u
V_REF
ICS83948AYI REV. C NOVEMBER 7, 2008
R1
1K
R2
1K
V
DD
CLK
nCLK