Electrical characteristics
STM32F105xx, STM32F107xx
5.3.6
External clock source characteristics
High-speed external user clock generated from an external source
The characteristics given in Table 20 result from tests performed using an high-speed
external clock source, and under ambient temperature and supply voltage conditions
summarized in Table 9.
Table 20. High-speed external user clock characteristics
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
External user clock source
frequency(1)
fHSE_ext
1
8
50
MHz
VHSEH
VHSEL
tw(HSE)
OSC_IN input pin high level voltage
OSC_IN input pin low level voltage
0.7VDD
VSS
VDD
V
0.3VDD
OSC_IN high or low time(1)
OSC_IN rise or fall time(1)
16
45
tw(HSE)
ns
tr(HSE)
tf(HSE)
20
Cin(HSE) OSC_IN input capacitance(1)
DuCy(HSE) Duty cycle
5
pF
%
55
1
IL
OSC_IN Input leakage current
VSS ~ VIN ~ VDD
µA
1. Guaranteed by design, not tested in production.
Low-speed external user clock generated from an external source
The characteristics given in Table 21 result from tests performed using an low-speed
external clock source, and under ambient temperature and supply voltage conditions
summarized in Table 9.
Table 21. Low-speed external user clock characteristics
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
User External clock source
frequency(1)
fLSE_ext
32.768 1000
VDD
kHz
OSC32_IN input pin high level
voltage
VLSEH
0.7VDD
V
OSC32_IN input pin low level
voltage
VLSEL
tw(LSE)
VSS
0.3VDD
OSC32_IN high or low time(1)
OSC32_IN rise or fall time(1)
450
tw(LSE)
ns
tr(LSE)
tf(LSE)
50
Cin(LSE) OSC32_IN input capacitance(1)
DuCy(LSE) Duty cycle
5
pF
%
30
70
1
IL
OSC32_IN Input leakage current VSS ~ VIN ~ VDD
µA
1. Guaranteed by design, not tested in production.
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