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STM32F031x4 STM32F031x6
Electrical characteristics
86
Low-speed external user clock generated from an external source
In bypass mode the LSE oscillator is switched off and the input pin is a standard GPIO.
The external clock signal has to respect the I/O characteristics in
. However,
the recommended clock input waveform is shown in
Figure 15. Low-speed external clock source AC timing diagram
Table 32. Low-speed external user clock characteristics
Symbol
Parameter
(1)
1.
Guaranteed by design, not tested in production.
Min
Typ
Max
Unit
f
LSE_ext
User external clock source frequency
-
32.768
1000
kHz
V
LSEH
OSC32_IN input pin high level voltage
0.7 V
DDIOx
-
V
DDIOx
V
V
LSEL
OSC32_IN input pin low level voltage
V
SS
-
0.3 V
DDIOx
t
w(LSEH)
t
w(LSEL)
OSC32_IN high or low time
450
-
-
ns
t
r(LSE)
t
f(LSE)
OSC32_IN rise or fall time
-
-
50
069
9/6(+
WI/6(
7/6(
W
WU/6(
9/6(/
WZ/6(+
WZ/6(/
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http://www.vicor.top/
021-31660491