14. Package Information
391
PowerSpan II User Manual
80A1010_MA001_09
Integrated Device Technology
www.idt.com
14.2
Thermal Characteristics
The thermal performance of PowerSpan II package is represented by the following parameters:
1.
JA
, Thermal resistance from junction to ambient
JA
= (T
J
- T
A
) / P
Where,
T
J
is the junction temperature
T
A
is the ambient temperature
P is the power dissipation
JA
represents the resistance to the heat flows from the chip to ambient air. It is an index of heat
dissipation capability. Lower
JA
means better thermal performance.
2.
JT
, Thermal characterization parameter from junction-to-top center
JT
= (T
J
- T
T
) / P
Where T
T
is the temperature of the top-center of the package
JT
is used to estimate junction temperature by measuring T
T
in actual environment.
3.
3.
JC
, Thermal resistance from junction to case
JC
= (T
J
– T
C
) / P
Where,
T
C
is the case temperature
JC
is a measure of package internal thermal resistance from chip to package exterior.
The value is dependent upon package material and package geometry.
JA,
JC
and
JT
simulation are carried out to show the thermal performance of the PowerSpan II.