89hpes16t4 Integrated Device Technology, 89hpes16t4 Datasheet - Page 14

• Manufacturer Part Number: 89hpes16t4
• Description: 16-lane, 4-port Pcie I/o Expansion Switch
• Manufacturer: Integrated Device Technology

Heat Sink
most cases.
Thermal Usage Examples
heat sink. The general formula to determine
maximum T
scenario. The formula is also useful from a system design perspective. It can be used to determine if a heat sink should be added to the device based
on some desired value of T
[e-mail] for further assistance.
IDT 89HPES16T4 Data Sheet
Table 17 lists heat sink requirements for the PES16T4 under three common usage scenarios. As shown in this table, a heat sink is not required in
.
The junction-to-ambient thermal resistance is a measure of a device’s ability to dissipate heat from the die to its surroundings in the absence of a
Thermal reliability of a device is generally assured when the actual value of T
The actual T
An appropriate level of increased air flow and/or a heat sink can be added to achieve this lower ambient temperature. Please contact
1 m/S or more
Air Flow
J
T
T
θ
T
Zero
Zero
specified for the device. Using an ambient temperature of 70
A(allowed)
A(allowed)
J(actual)
JA
J
= (T
of 98
J
= T
- T
o
= T
= 100
C is well below the maximum T
A
A
J(desired)
)/P
+ P *
J
. For example, if for reliability purposes the desired T
o
C - (2.9W * 9.6W/
θ
3.9”x6.2” (ExpressModule form factor) or larger
JA(eff)
- (P *
Table 17 Heat Sink Requirements Based on Air Flow and Board Characteristics
= 70
θ
JA(effective)
o
θ
C + 2.9W * 9.6W/
JA
o
Board Size
C) = 100
is:
)
Any
Any
J
of 125
o
C - 28
o
o
C specified for the device (shown in Table 16). Therefore, no heat sink is needed in this
C = 98
o
C = 72
14 of 31
o
C
o
C
o
C and assuming a system with 1m/S airflow, the actual value of T
J
J
in the specific system environment being considered is less than the
is 100
Board Layers
o
C, then the maximum allowable T
10 or more
6 or more
Any
Heat Sink Requirement
No heat sink required
No heat sink required
No heat sink required
A
is:
March 25, 2008
J
is: