DocID022799 Rev 10
89/135
STM32L151xC STM32L152xC
Electrical characteristics
110
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, R
PU
(see
Unless otherwise specified, the parameters given in
are derived from tests
performed under the conditions summarized in
.
AIC
TR)/ OUT
/54054
%84%2.!,
/.P&
-AXIMUMFREQUENCYISACHIEVEDIFTRTF
4ANDIFTHEDUTYCYCLEIS
WHENLOADEDBYP&
4
TF)/ OUT
Table 46. NRST pin characteristics
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
V
IL(NRST)
(1)
NRST input low level
voltage
-
-
-
0.3 V
DD
V
V
IH(NRST)
NRST input high
level voltage
-
0.39V
DD
+0.59
-
-
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)
-
mV
R
PU
Weak pull-up
equivalent resistor
(3)
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
1. Guaranteed by design, not tested in production.
2. With a minimum of 200 mV.
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%.