Datasheet

UnitMaxTypMinConditionsParameterSymbol
kΩ-220-
Feedback resistorR
F
pF20--
Recommended load
capacitance
(2)
C
(1)
mA
6 (startup)
--
C = 20 pF,
HSE oscillator power
consumption
I
DD(HSE)
1.6 (stabilized)
(3)
f
OSC
= 16 MHz
6 (startup)
--
C = 10 pF,
1.2 (stabilized)
(3)
f
OSC
=16 MHz
mA/V--5
Oscillator
transconductance
g
m
ms-1-
V
DD
is stabilizedStartup timet
SU(HSE)
(4)
(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 R
m
value. Refer to crystal manufacturer for more details
(3)
Data based on characterization results, not tested in production.
(4)
t
SU(HSE)
is the start-up time measured from the moment it is enabled (by software) to a stabilized 16
MHz oscillation is reached. This value is measured for a standard crystal resonator and it can vary
significantly with the crystal manufacturer.
Figure 19: HSE oscillator circuit diagram
OSCOUT
OSCIN
f
HSE
to core
C
L1
C
L2
R
F
STM8
Resonator
Consumption
control
g
m
R
m
C
m
L
m
C
O
Resonator
HSE oscillator critical g
m
equation
g
mcrit
= (2 × Π × f
HSE
)
2
× R
m
(2Co + C)
2
DocID15590 Rev 866/116
STM8S903K3 STM8S903F3Electrical characteristics