Datasheet

Electrical characteristics STM32F103xC, STM32F103xD, STM32F103xE
94/143 DS5792 Rev 13
Figure 46. I/O AC characteristics definition
5.3.15 NRST pin characteristics
The NRST pin input driver uses CMOS technology. It is connected to a permanent pull-up
resistor, R
PU
(see Table 46).
Unless otherwise specified, the parameters given in Table 49 are derived from tests
performed under ambient temperature and V
DD
supply voltage conditions summarized in
Table 10 .
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Table 49. NRST pin characteristics
Symbol Parameter Conditions Min Typ Max Unit
V
IL(NRST)
(1)
1. Guaranteed by design.
NRST Input low level voltage - –0.5 - 0.8
V
V
IH(NRST)
(1)
NRST Input high level voltage - 2 - V
DD
+0.5
V
hys(NRST)
NRST Schmitt trigger voltage
hysteresis
- - 200 - mV
R
PU
Weak pull-up equivalent resistor
(2)
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).
V
IN
= V
SS
30 40 50 kΩ
V
F(NRST)
(1)
NRST Input filtered pulse - - - 100 ns
V
NF(NRST)
(1)
NRST Input not filtered pulse - 300 - - ns