Package characteristics
STM8S207xx, STM8S208xx
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 TAmax= 82 °C (measured according to JESD51-2)
● IDDmax = 15 mA, VDD = 5.5 V
● Maximum eight standard I/Os used at the same time in output at low level with IOL = 10
mA, VOL= 2 V
● Maximum four high sink I/Os used at the same time in output at low level with IOL = 20
mA, VOL= 1.5 V
● Maximum two true open drain I/Os used at the same time in output at low level with
IOL = 20 mA, VOL= 2 V
PINTmax = 15 mA x 5.5 V = 82.5 mW
PIOmax = (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: PINTmax = 82.5 mW and PIOmax 360 mW:
PDmax = 82.5 mW + 360 mW
Thus: PDmax = 443 mW
Using the values obtained in Table 57: Thermal characteristics on page 95 TJmax is
calculated as follows for LQFP64 10 x 10 mm = 46 °C/W:
TJmax = 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 < TJ < 105 °C).
In this case, parts must be ordered at least with the temperature range suffix 6.
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