Datasheet

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STM32F405xx, STM32F407xx Electrical characteristics
Figure 33. Typical application with a 32.768 kHz crystal
5.3.9 Internal clock source characteristics
The parameters given in Table 34 and Table 35 are derived from tests performed under
ambient temperature and V
DD
supply voltage conditions summarized in Table 14.
High-speed internal (HSI) RC oscillator
Low-speed internal (LSI) RC oscillator
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Table 34. 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.
---1%
Accuracy of the HSI oscillator
T
A
= –40 to 105 °C
(3)
3. Guaranteed by characterization.
–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 µs
I
DD(HSI)
(2)
HSI oscillator power
consumption
- - 60 80 µA
Table 35. LSI oscillator characteristics
(1)
1. V
DD
= 3 V, T
A
= –40 to 105 °C unless otherwise specified.
Symbol Parameter Min Typ Max Unit
f
LSI
(2)
2. Guaranteed by characterization.
Frequency 17 32 47 kHz
t
su(LSI)
(3)
3. Guaranteed by design.
LSI oscillator startup time - 15 40 µs
I
DD(LSI)
(3)
LSI oscillator power consumption - 0.4 0.6 µA