Datasheet

DS6329 Rev 16 93/184
STM32F20xxx Electrical characteristics
183
Note: For information on electing the crystal, refer to the application note AN2867 “Oscillator
design guide for ST microcontrollers” available from the ST website www.st.com.
Figure 33. Typical application with a 32.768 kHz crystal
6.3.9 Internal clock source characteristics
The parameters given in Table 32 and Table 33 are derived from tests performed under
ambient temperature and V
DD
supply voltage conditions summarized in Table 14.
High-speed internal (HSI) RC oscillator
Table 31. LSE oscillator characteristics (f
LSE
= 32.768 kHz)
(1)
1. Guaranteed by design, not tested in production.
Symbol Parameter Conditions Min Typ Max Unit
R
F
Feedback resistor - - 18.4 - MΩ
I
DD
LSE current consumption - - - 1 µA
g
m
Oscillator Transconductance - 2.8 - - µA/V
t
SU(LSE)
(2)
2. t
SU(LSE)
is the startup time measured from the moment it is enabled (by software) to a stabilized
32.768 kHz oscillation is reached. This value is measured for a standard crystal resonator and it can vary
significantly with the crystal manufacturer
startup time V
DD
is stabilized - 2 - s
DL
26&B287
26&B,1
I
/6(
&
/
5
)
670)
N+]
UHVRQDWRU
5HVRQDWRUZLWK
LQWHJUDWHGFDSDFLWRUV
%LDV
FRQWUROOHG
JDLQ
&
/
Table 32. HSI oscillator characteristics
(1)
1. V
DD
= 3.3 V, T
A
= –40 to 105 °C unless otherwise specified.
Symbol Parameter Conditions Min Typ Max Unit
f
HSI
Frequency - - 16 - MHz
ACC
HSI
HSI user-trimming step
(2)
2. Guaranteed by design, not tested in production.
---1%
Accuracy of the
HSI oscillator
T
A
= –40 to 105 °C
(3)
3. Guaranteed by characterization results.
– 8 - 4.5 %
T
A
= –10 to 85 °C
(3)
– 4 - 4 %
T
A
= 25 °C
(4)
4. Factory calibrated, parts not soldered.
– 1 - 1 %
t
su(HSI)
(2)
HSI oscillator startup time - - 2.2 4.0 µs
I
DD(HSI)
(2)
HSI oscillator power consumption - - 60 80 µA
Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.