STM8S105x4/6
Electrical characteristics
HSE crystal/ceramic resonator oscillator
The HSE clock can be supplied with a 1 to 16 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 startup stabilization time. Refer to the crystal resonator manufacturer for more details
(frequency, package, accuracy...).
Table 32. HSE oscillator characteristics
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
fHSE
External high speed
oscillator frequency
-
1
-
16
MHz
RF
Feedback resistor
-
C(1)
Recommended load
capacitance(2)
-
-
220
-
-
-
k
20
pF
IDD(HSE)
HSE oscillator power
consumption
C = 20 pF
fOSC = 16 MHz
C = 10 pF
fOSC = 16 MHz
-
-
-
6 (start up)
1.6 (stabilized)(3)
mA
-
6 (start up)
1.2 (stabilized)(3)
gm
Oscillator
transconductance
-
5
-
-
mA/V
tSU(HSE)(4) Startup time
VDD is stabilized
-
1
-
ms
1. C is approximately equivalent to 2 x crystal Cload.
2. The oscillator selection can be optimized in terms of supply current using a high quality resonator with small Rm value.
Refer to crystal manufacturer for more details
3. Data based on characterization results, not tested in production.
4.
rtSeUa(cHhSeEd).isThthise
start-up
value is
time measured
measured for a
from the
standard
moment it is enabled
crystal resonator and
(by software) to a stabilized
it can vary significantly with
16 MHz oscillation is
the crystal manufacturer.
DocID14771 Rev 15
67/121
90