Electrical characteristics
STM32L151x6/8/B, STM32L152x6/8/B
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DocID17659 Rev 10
Figure 19. I/O AC characteristics definition
6.3.14 NRST
pin
characteristics
The NRST pin input driver uses CMOS technology. It is connected to a permanent pull-up
resistor, RPU (see
Unless otherwise specified, the parameters given in
are derived from tests
performed under ambient temperature and V
DD
supply voltage conditions summarized in
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ONP&
-AXIMUMFREQUENCYISACHIEVEDIFT
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T
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a
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Table 45. NRST pin characteristics
Symbol
Parameter
Conditions
Min
Typ
Max Unit
V
IL(NRST)
(1)
1. Guaranteed by design, not tested in production.
NRST input low level voltage
-
-
-
0.8
V
V
IH(NRST)
NRST input high level voltage
-
1.4
-
V
OL(NRST)
NRST output low level
voltage
I
OL
= 2 mA
2.7 V < V
DD
< 3.6 V
-
-
0.4
I
OL
= 1.5 mA
1.65 V < V
DD
< 2.7 V
-
-
V
hys(NRST)
NRST Schmitt trigger voltage
hysteresis
-
-
10%V
DD
(2)
2. 200 mV minimum value
mV
R
PU
Weak pull-up equivalent
resistor
(3)
3. The pull-up is designed with a true resistance in series with a switchable PMOS. This PMOS contribution to
the series resistance is around 10%.
V
IN
=
V
SS
30
45
60
k
Ω
V
F(NRST)
NRST input filtered pulse
-
-
-
50
ns
V
NF(NRST)
NRST input not filtered pulse
-
350
-
ns