Datasheet

Electrical characteristics STM32F103xC, STM32F103xD, STM32F103xE
56/130 Doc ID 14611 Rev 8
Low-speed external user clock generated from an external source
The characteristics given in Tabl e 2 2 result from tests performed using an low-speed
external clock source, and under ambient temperature and supply voltage conditions
summarized in Table 1 0 .
Figure 20. High-speed external clock source AC timing diagram
Table 22. Low-speed external user clock characteristics
Symbol Parameter Conditions Min Typ Max Unit
f
LSE_ext
User External clock source
frequency
(1)
1. Guaranteed by design, not tested in production.
32.768 1000 kHz
V
LSEH
OSC32_IN input pin high level
voltage
0.7V
DD
V
DD
V
V
LSEL
OSC32_IN input pin low level
voltage
V
SS
0.3V
DD
t
w(LSE)
t
w(LSE)
OSC32_IN high or low time
(1)
450
ns
t
r(LSE)
t
f(LSE)
OSC32_IN rise or fall time
(1)
50
C
in(LSE)
OSC32_IN input capacitance
(1)
5pF
DuCy
(LSE)
Duty cycle 30 70 %
I
L
OSC32_IN Input leakage current
V
SS
≤ V
IN
≤ V
D
D
±1 µA
ai14143
OSC _I N
EXTERNAL
STM32F103xx
CLOCK SOURC E
V
HSEH
t
f(HSE)
t
W(HSE)
I
L
90%
10%
T
HSE
t
t
r(HSE)
t
W(HSE)
f
HSE_ext
V
HSEL