87354AMILFT IDT, Integrated Device Technology Inc, 87354AMILFT Datasheet - Page 9

• Manufacturer Part Number: 87354AMILFT
• Manufacturer: IDT, Integrated Device Technology Inc
• Type: Clock Dividerr

Specifications of 87354AMILFT

• Number Of Clock Inputs: 1
• Mode Of Operation: Differential
• Output Logic Level: LVPECL
• Operating Supply Voltage (min): 3V
• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (max): 3.465V
• Package Type: SOIC N
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 8
• Lead Free Status / RoHS Status: Compliant

This section provides information on power dissipation and junction temperature for the ICS87354I.
Equations and example calculations are also provided.
1. Power Dissipation.
The total power dissipation for the ICS87354I is the sum of the core power plus the power dissipated in the load(s).
The following is the power dissipation for V
NOTE: Please refer to Section 3 for details on calculating power dissipated in the load.
2. Junction Temperature.
Junction temperature, Tj, is the temperature at the junction of the bond wire and bond pad and directly affects the reliability of the
device. The maximum recommended junction temperature for the devices is 125°C.
In order to calculate junction temperature, the appropriate junction-to-ambient thermal resistance
moderate air flow of 200 linear feet per minute and a multi-layer board, the appropriate value is 103.3°C/W per Table 6 below.
Therefore, Tj for an ambient temperature of 85°C with all outputs switching is:
This calculation is only an example. Tj will obviously vary depending on the number of loaded outputs, supply voltage, air flow,
and the type of board (single layer or multi-layer).
T
87354AMI
ABLE
6. T
Single-Layer PCB, JEDEC Standard Test Boards
Multi-Layer PCB, JEDEC Standard Test Boards
NOTE: Most modern PCB designs use multi-layered boards. The data in the second row pertains to most designs.
Power (core)
Power (outputs)
Total Power
The equation for Tj is as follows: Tj =
Tj = Junction Temperature
Pd_total = Total Device Power Dissipation (example calculation is in section 1 above)
T
85°C + 0.390W * 103.3°C/W = 125°C.
JA
A
HERMAL
= Ambient Temperature
= Junction-to-Ambient Thermal Resistance
R
ESISTANCE
MAX
_MAX
MAX
= V
(3.465V, with all outputs switching) = 360mW + 30mW = 390mW
= 3.465mW/Loaded Output pair
CC_MAX
JA
* I
FOR
EE_MAX
8-
JA
PIN
CC
P
by Velocity (Linear Feet per Minute)
= 3.465V * 104mA = 360mW
= 3.465V, which gives worst case results.
SOIC, F
OWER
JA
* Pd_total + T
ORCED
C
www.idt.com
ONSIDERATIONS
C
ONVECTION
A
9
153.3°C/W
112.7°C/W
0
3.3V LVPECL C
128.5°C/W
103.3°C/W
200
÷4/÷5 D
JA
must be used. Assuming a
115.5°C/W
97.1°C/W
LOCK
ICS87354I
500
IFFERENTIAL
REV. A AUGUST 5, 2010
G
ENERATOR
-
TO
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