AN1790 - APPLICATION NOTE

2/8

RESET THRESHOLDS

The STM8xx Reset Circuit devices have different reset threshold levels. Table 1, lists the thresholds,

When considering the threshold level required for an application, it is also necessary to consider the max-

imum transient duration, not causing a reset pulse, with respect to voltage threshold overdrive. A large

transient voltage overdrive needs less time to generate the Reset pulse, than a small transient voltage

overdrive, which needs much longer. Refer to the characterization graph shown in Figure 1.

Table 1. Reset Thresholds

Figure 1. Max Transient Duration NOT Causing Reset Pulse vs. Reset Comparator Overdrive

Part

Temperature Range (

° C)

Min

Typ

Max

STM8xxL

25

4.54

4.63

4.72

-40 to 80

4.50

4.75

STM8xxM

25

4.30

4.38

4.46

-40 to 80

4.25

4.50

STM8xxT

25

3.03

3.08

3.14

-40 to 80

3.00

3.15

STM8xxS

25

2.88

2.93

2.98

-40 to 80

2.85

3.00

STM8xxR

25

2.58

2.63

2.68

-40 to 80

2.55

2.70

AI07883

0.00

100.00

200.00

300.00

400.00

500.00

600.00

700.00

1

10

100

1000

R/S/T

L/M