STM32F103xC, STM32F103xD, STM32F103xE
Electrical characteristics
Low-speed external user clock generated from an external source
The characteristics given in
result from tests performed using an low-speed
external clock source, and under ambient temperature and supply voltage conditions
summarized in
Table 22.
Symbol
f
LSE_ext
V
LSEH
V
LSEL
t
w(LSE)
t
w(LSE)
t
r(LSE)
t
f(LSE)
C
in(LSE)
Low-speed external user clock characteristics
Parameter
User External clock source
frequency
(1)
OSC32_IN input pin high level
voltage
OSC32_IN input pin low level
voltage
OSC32_IN high or low time
(1)
OSC32_IN rise or fall time
(1)
OSC32_IN input capacitance
(1)
30
V
SS
V
IN
V
D
D
Conditions
Min
Typ
32.768
Max
1000
V
DD
Unit
kHz
0.7V
DD
V
SS
450
V
0.3V
DD
ns
50
5
70
±1
pF
%
µA
DuCy
(LSE)
Duty cycle
I
L
OSC32_IN Input leakage current
1. Guaranteed by design, not tested in production.
Figure 20. High-speed external clock source AC timing diagram
VHSEH
90%
VHSEL
10%
tr(HSE)
THSE
tf(HSE)
tW(HSE)
tW(HSE)
t
EXTER NAL
CLOCK SOURC E
fHSE_ext
OSC _IN
IL
STM32F103xx
ai14143
Doc ID 14611 Rev 7
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