Datasheet

Package characteristics STM8S207xx, STM8S208xx
96/103 Doc ID 14733 Rev 12
11.2.2 Selecting the product temperature range
When ordering the microcontroller, the temperature range is specified in the order code (see
Figure 49: STM8S207xx/208xx performance line ordering information scheme(1) on
page 99).
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 eight standard I/Os used at the same time in output at low level with I
OL
= 10
mA, V
OL
= 2 V
● Maximum four 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 two 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 Tab l e 57: Thermal characteristics on page 95 T
Jmax
is
calculated as follows for LQFP64 10 x 10 mm = 46 °C/W:
T
Jmax
= 82 °C + (46 °C/W x 443 mW) = 82 °C + 20 °C = 102 °C
This is within the range of the suffix 6 version parts (-40 < T
J
< 105 °C).
In this case, parts must be ordered at least with the temperature range suffix 6.