STM8S105xx
Package characteristics
Dim.
mm
Min
e
Typ
Max
1.778
inches(1)
Min
Typ
Max
0.0700
eA
10.160
0.4000
eB
12.700
0.5000
L
2.540
3.048
3.810
0.1000
0.1200 0.1500
(1) Values in inches are converted from mm and rounded to 4 decimal digits
11.3
Thermal characteristics
The maximum chip junction temperature (TJ max) must never exceed the values given in
Operating conditions
The maximum chip-junction temperature, TJmax, in degrees Celsius, may be calculated using
the following equation:
TJmax = TAmax + (PDmax x ΘJA)
Where:
• TAmax is the maximum ambient temperature in °C
• ΘJA is the package junction-to-ambient thermal resistance in ° C/W
• PDmax is the sum of PINTmax and PI/Omax (PDmax = PINTmax + PI/Omax)
• PINTmax is the product of IDD andVDD, expressed in Watts. This is the maximum chip internal
power.
• PI/Omax represents the maximum power dissipation on output pinsWhere:PI/Omax =Σ (VOL*IOL)
+ Σ((VDD-VOH)*IOH), taking into account the actual VOL/IOL and VOH/IOH of the I/Os at low
and high level in the application.
Table 58: Thermal characteristics(1)
Symbol
Parameter
Value
Unit
ΘJA
Thermal resistance junction-ambient
57
LQFP 48 - 7 x 7 mm
°C/W
ΘJA
Thermal resistance junction-ambient
54
LQFP 44 - 10 x 10 mm
°C/W
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