89hpes12n3a Integrated Device Technology, 89hpes12n3a Datasheet - Page 16

• Manufacturer Part Number: 89hpes12n3a
• Description: 12-lane, 3-port Pcie I/o Expansion Switch
• Manufacturer: Integrated Device Technology

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
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IDT 89HPES12N3A Data Sheet
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
J
T
T
θ
T
specified for the device. Using an ambient temperature of 70
A(allowed)
A(allowed)
J(actual)
JA
J
= (T
of 96
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 - (2.6W * 9.9W/
θ
JA(eff)
- (P *
= 70
θ
JA(effective)
o
θ
C + 2.6W * 9.9W/
JA
o
C) = 100
is:
)
J
of 125
o
C - 26
o
o
C specified for the device (shown in Table 16). Therefore, no heat sink is needed in this
C = 96
o
C = 74
16 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
o
C, then the maximum allowable T
A
is:
March 27, 2008
J
is: