Atmel Xplained Evaluation Board AT32UC3L0-XPLD AT32UC3L0-XPLD Data Sheet
Product codes
AT32UC3L0-XPLD
73
32099G–06/2011
AT32UC3L016/32/64
8.
Mechanical Characteristics
8.1
Thermal Considerations
8.1.1
Thermal Data
summarizes the thermal resistance data depending on the package.
8.1.2
Junction Temperature
The average chip-junction temperature, T
J
, in °C can be obtained from the following:
1.
2.
where:
•
θ
JA
= package thermal resistance, Junction-to-ambient (°C/W), provided in
•
θ
JC
= package thermal resistance, Junction-to-case thermal resistance (°C/W), provided in
.
•
θ
HEAT SINK
= cooling device thermal resistance (°C/W), provided in the device datasheet.
• P
D
= device power consumption (W) estimated from data provided in the
.
• T
A
= ambient temperature (°C).
From the first equation, the user can derive the estimated lifetime of the chip and decide if a
cooling device is necessary or not. If a cooling device is to be fitted on the chip, the second
equation should be used to compute the resulting average chip-junction temperature T
cooling device is necessary or not. If a cooling device is to be fitted on the chip, the second
equation should be used to compute the resulting average chip-junction temperature T
J
in °C.
Table 8-1.
Thermal Resistance Data
Symbol
Parameter
Condition
Package
Typ
Unit
θ
JA
Junction-to-ambient thermal resistance
Still Air
TQFP48
63.2
°
C/W
θ
JC
Junction-to-case thermal resistance
TQFP48
21.8
θ
JA
Junction-to-ambient thermal resistance
Still Air
QFN48
28.3
°
C/W
θ
JC
Junction-to-case thermal resistance
QFN48
2.5
θ
JA
Junction-to-ambient thermal resistance
Still Air
TLLGA48
30.06
°
C/W
θ
JC
Junction-to-case thermal resistance
TLLGA48
TBD
T
J
T
A
P
D
θ
JA
×
(
)
+
=
T
J
T
A
P
(
D
θ
(
HEATSINK
×
θ
JC
) )
+
+
=