Datasheet

DocID14611 Rev 10 57/136
STM32F103xC, STM32F103xD, STM32F103xE Electrical characteristics
129
Low-speed external user clock generated from an external source
The characteristics given in Table 22 result from tests performed using an low-speed
external clock source, and under ambient temperature and supply voltage conditions
summarized in Table 10.
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)
-5-pF
DuCy
(LSE)
Duty cycle 30 - 70 %
I
L
OSC32_IN Input leakage current V
SS
≤V
IN
≤V
DD
--±1µA
ai14143
OSC _I N
EXTER NAL
STM32F103xx
CLOCK SO URC 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