85310AYI-11T IDT, Integrated Device Technology Inc, 85310AYI-11T Datasheet - Page 10

• Manufacturer Part Number: 85310AYI-11T
• Manufacturer: IDT, Integrated Device Technology Inc
• Type: Clock Driverr

Specifications of 85310AYI-11T

• Number Of Clock Inputs: 2
• Mode Of Operation: Differential
• Output Frequency: 700MHz
• Output Logic Level: ECL/LVPECL
• Operating Supply Voltage (min): -2.375/2.375V
• Operating Supply Voltage (typ): -2.5/-3.3/3.3V
• Operating Supply Voltage (max): -3.8/3.8V
• Package Type: LQFP
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 32
• Lead Free Status / RoHS Status: Not Compliant

ICS85310I-11 Data Sheet
Recommendations for Unused Input 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.
LVCMOS Control Pins
The control pins have an internal pullup and pulldown; additional
resistance is not required but can be added for additional protection.
A 1kΩ resistor can be used.
Termination for 3.3V LVPECL Outputs
The clock layout topology shown below is a typical termination for
LVPECL outputs. The two different layouts mentioned are
recommended only as guidelines.
The differential outputs are low impedance follower outputs that
generate ECL/LVPECL compatible outputs. Therefore, terminating
resistors (DC current path to ground) or current sources must be
used for functionality. These outputs are designed to drive 50Ω
Figure 4A. 3.3V LVPECL Output Termination
ICS85310AYI-11 REVISION F JUNE 9, 2010
RTT =
((V
3.3V
OH
LVPECL
+ V
OL
) / (V
1
CC
Z
Z
– 2)) – 2
o
o
= 50Ω
= 50Ω
* Z
R1
50Ω
o
RTT
R2
50Ω
V
+
_
CC
3.3V
- 2V
Input
LOW SKEW, 1-TO-10 DIFFERENTIAL-TO-3.3V, 2.5V LVPECL/ECL FANOUT BUFFER
10
Outputs:
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.
transmission lines. Matched impedance techniques should be used
to maximize operating frequency and minimize signal distortion.
Figures 4A and 4B show two different layouts which are
recommended only as guidelines. Other suitable clock layouts may
exist and it would be recommended that the board designers
simulate to guarantee compatibility across all printed circuit and clock
component process variations.
Figure 4B. 3.3V LVPECL Output Termination
3.3V
LVPECL
Z
Z
o
o
= 50Ω
= 50Ω
R3
125Ω
©2010 Integrated Device Technology, Inc.
R1
84Ω
3.3V
R4
125Ω
R2
84Ω
+
_
3.3V
Input