89hpes24t6zgbxg Integrated Device Technology, 89hpes24t6zgbxg Datasheet - Page 16

• Manufacturer Part Number: 89hpes24t6zgbxg
• Description: 24-lane, 6-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
this 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 89HPES24T6 Data Sheet
Table 17 lists heat sink requirements for the PES24T6 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 102
J
= T
- T
= T
= 100
o
A
A
C is well below the maximum T
J(desired)
)/P
+ P *
o
C - (3.8W * 8.5W/
θ
3.9”x6.2” (ExpressModule form factor) or larger
JA(eff)
J
- (P *
. For example, if for reliability purposes the desired T
Table 17 Heat Sink Requirements Based on Air Flow and Board Characteristics
= 70
θ
JA(effective)
o
θ
C + 3.8W * 8.5W/
JA
o
Board Size
C) = 100
is:
)
Any
Any
J
o
of 125
C - 32
o
C = 102
o
o
C = 68
C specified for the device (shown in Table 16). Therefore, no heat sink is needed in
16 of 33
o
o
C
C
o
C and assuming a system with 1m/S airflow, the actual value of T
J
in the specific system environment being considered is less than the
Board Layers
J
is 100
10 or more
14 or more
Any
o
C, then the maximum allowable T
Heat Sink Requirement
No heat sink required
No heat sink required
No heat sink required
A
April 23, 2008
is:
J
is: