STM32L100X6 Datasheet, PDF (60/102 Pages) STMicroelectronics – Reset and supply management

Electrical characteristics
STM32L100x6/8/B-A
6.3.6
External clock source characteristics
High-speed external user clock generated from an external source
In bypass mode the HSE oscillator is switched off and the input pin is a standard GPIO. The
external clock signal has to respect the I/O characteristics in Section 6.3.13. However, the
recommended clock input waveform is shown in Figure 11.
Table 27. High-speed external user clock characteristics⁽¹⁾
Symbol
Parameter
Conditions Min Typ Max Unit
f_{HSE_ext}
User external clock source
frequency
CSS is on or
PLL is used
1
CSS is off, PLL
not used
0
8
32 MHz
V_HSEH OSC_IN input pin high level voltage
0.7V_DD -
V_DD
V_HSEL OSC_IN input pin low level voltage
V_SS
0.3V_DD
t_w(HSEH)
t_w(HSEL)
t_r(HSE)
t_f(HSE)
OSC_IN high or low time
OSC_IN rise or fall time
-
12
-
-
ns
-
-
20
C_in(HSE) OSC_IN input capacitance
-
-
2.6
-
pF
1. Guaranteed by design.
Figure 11. High-speed external clock source AC timing diagram
9+6(+
9+6(/


WU+6(
WZ+6(+
WI+6(
7+6(
WZ+6(/
W
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