Electrical characteristics
STM32F038x6
6.3.14 NRST and NPOR pin characteristics
NRST pin characteristics
The NRST pin input driver uses the CMOS technology. It is connected to a permanent pull-
up resistor, RPU.
Unless otherwise specified, the parameters given in the table below are derived from tests
performed under the ambient temperature and supply voltage conditions summarized in
Table 18: General operating conditions.
Table 47. NRST pin characteristics
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
VIL(NRST) NRST input low level voltage
VIH(NRST) NRST input high level voltage
-
-
-
-
0.445 VDD+0.398(1) -
0.3 VDD+0.07(1)
V
-
Vhys(NRST)
NRST Schmitt trigger voltage
hysteresis
-
-
200
-
mV
RPU
Weak pull-up equivalent
resistor(2)
VIN = VSS
25
40
55
kΩ
VF(NRST) NRST input filtered pulse
-
VNF(NRST) NRST input not filtered pulse
-
-
700(1)
-
100(1)
ns
-
-
ns
1. Data based on design simulation only. 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 is minimal (~10% order).
Figure 22. Recommended NRST pin protection
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1. The external capacitor protects the device against parasitic resets.
2.
The user must ensure that the level
Table 47: NRST pin characteristics.
on the NRST pin can go below
Otherwise the reset will not be
ttahkeeVnILin(NtoRSaTc)cmouanxt
level specified
by the device.
in
NPOR pin characteristics
The NPOR pin input driver uses the CMOS technology. It is connected to a permanent pull-
up resistor to the VDDA, RPU.
Unless otherwise specified, the parameters given in Table 48 below are derived from tests
performed under ambient temperature and supply voltage conditions summarized in
Table 18: General operating conditions.
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