Datasheet

Electrical characteristics STM8S207xx, STM8S208xx
64/103 Doc ID 14733 Rev 12
10.3.3 External clock sources and timing characteristics
HSE user external clock
Subject to general operating conditions for V
DD
and T
A
.
Figure 16. HSE external clock source
HSE crystal/ceramic resonator oscillator
The HSE clock can be supplied with a 1 to 24 MHz crystal/ceramic resonator oscillator. All
the information given in this paragraph is based on characterization results with specified
typical external components. In the application, the resonator and the load capacitors have
to be placed as close as possible to the oscillator pins in order to minimize output distortion
and start-up stabilization time. Refer to the crystal resonator manufacturer for more details
(frequency, package, accuracy...).
Table 31. HSE user external clock characteristics
Symbol Parameter Conditions Min Typ Max Unit
f
HSE_ext
User external clock source
frequency
024MHz
V
HSEH
(1)
1. Data based on characterization results, not tested in production.
OSCIN input pin high level
voltage
0.7 x V
DD
V
DD
+ 0.3 V
V
V
HSEL
(1)
OSCIN input pin low level
voltage
V
SS
0.3 x V
DD
I
LEAK_HSE
OSCIN input leakage
current
V
SS
< V
IN
< V
DD
-1 1 µA
OSCIN
f
HSE
External clock
STM8
source
V
HSEL
V
HSEH