STM32F103x4, STM32F103x6
Figure 27. I/O AC characteristics definition
Electrical characteristics
90%
50%
10%
External
Output
on 50pF
tr(I O)out
10%
50%
90%
tr(I O)out
T
Maximum frequency is achieved if (t
r
+ t
f
)
≤
2/3)T and if the duty cycle is (45-55%)
when loaded by 50 pF
ai14131
5.3.14
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 ambient temperature and V
DD
supply voltage conditions summarized
in
Table 38.
Symbol
V
IL(NRST)(1)
NRST pin characteristics
Parameter
NRST Input low level voltage
Conditions
Min
–0.5
2
200
V
IN
=
V
SS
30
40
50
100
300
Typ
Max
0.8
V
V
DD
+0.5
mV
kΩ
ns
ns
Unit
V
IH(NRST)(1)
NRST Input high level voltage
V
hys(NRST)
R
PU
V
F(NRST)(1)
NRST Schmitt trigger voltage
hysteresis
Weak pull-up equivalent resistor
(2)
NRST Input filtered pulse
V
NF(NRST)(1)
NRST Input not filtered pulse
1. Guaranteed by design, not tested in production.
2. The pull-up is designed with a true resistance in series with a switchable PMOS. This PMOS contribution
to the series resistance must be minimum
(~10% order)
.
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