STM32F103xx
Electrical characteristics
Figure 16. I/O AC characteristics definition
90%
10 %
50%
50%
90%
10%
t
EXTERNAL
OUTPUT
ON 50pF
t
r(IO)out
r(IO)out
T
Maximum frequency is achieved if (t + t ) £ 2/3)T and if the duty cycle is (45-55%)
r
f
when loaded by 50pF
ai14131
5.3.13
NRST pin characteristics
The NRST pin input driver uses CMOS technology. It is connected to a permanent pull-up
resistor, R (see Table 29).
PU
Unless otherwise specified, the parameters given in Table 32 are derived from tests
performed under ambient temperature and V supply voltage conditions summarized in
DD
Table 7.
(1)
Table 32. NRST pin characteristics
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
VIL(NRST) NRST Input low level voltage
VIH(NRST) NRST Input high level voltage
–0.5
2
0.8
V
VDD+0.5
NRST Schmitt trigger voltage
Vhys(NRST)
hysteresis
200
40
RPU
Weak pull-up equivalent resistor(2)
VIN = VSS
30
50
kΩ
ns
µs
VF(NRST) NRST Input filtered pulse(3)
VNF(NRST) NRST Input not filtered pulse(3)
1. TBD stands for to be determined.
100
300
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).
3. Values guaranteed by design, not tested in production.
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STMICROELECTRONICS [ ST ]
