Datasheet

DocID14771 Rev 15 107/121
STM8S105x4/6 Thermal characteristics
107
12.2 Selecting the product temperature range
When ordering the microcontroller, the temperature range is specified in the order code (see
Section 13: Ordering information).
The following example shows how to calculate the temperature range needed for a given
application.
Assuming the following application conditions:
Maximum ambient temperature T
Amax
= 82°C (measured according to JESD51-2),
I
DDmax
= 15 mA, V
DD
= 5.5 V
Maximum 8 standard I/Os used at the same time in output at low level with
I
OL
= 10 mA, V
OL
= 2 V
Maximum 4 high sink I/Os used at the same time in output at low level with
I
OL
= 20 mA, V
OL
= 1.5 V
Maximum 2 true open drain I/Os used at the same time in output at low level with
I
OL
= 20 mA, V
OL
= 2 V
P
INTmax
= 15 mA x 5.5 V= 82.5 mW
P
IOmax
= (10 mA x 2 V x 8) + (20 mA x 2 V x 2) + (20 mA x 1.5 V x 4) = 360 mW
This gives: P
INTmax
= 82.5 mW and P
IOmax
= 360 mW:
P
Dmax
= 82.5 mW + 360 mW
Thus: P
Dmax
= 443 mW.
Using the values obtained in Table 56: Thermal characteristics T
Jmax
is calculated as
follows:
For LQFP32 60°C/W
T
Jmax
= 82°C + (60°C/W x 443 mW) = 82°C + 27°C = 109 °C
This is within the range of the suffix 6 version parts (-40 < T
J
< 131°C).
Parts must be ordered at least with the temperature range suffix 3.
Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.