Datasheet

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STM32F37xxx Electrical characteristics
114
Figure 15. Typical application with a 32.768 kHz crystal
Note: An external resistor is not required between OSC32_IN and OSC32_OUT and it is forbidden
to add one.
6.3.8 Internal clock source characteristics
The parameters given in Table 42 are derived from tests performed under ambient
temperature and supply voltage conditions summarized in Table 22.
The provided curves are chararacterization results, not tested in production.
High-speed internal (HSI) RC oscillator
MS30253V1
OSC32_OU T
OSC32_IN
f
LSE
C
L1
32.768 kHz
resonator
C
L2
Resonator with
integrated capacitors
Drive
programmable
amplifier
Table 42. HSI oscillator characteristics
(1)
1. V
DDA
=3.3 V, T
A
= –40 to 105 °C unless otherwise specified.
Symbol Parameter Conditions Min Typ Max Unit
f
HSI
Frequency - 8 - MHz
TRIM HSI user trimming step - - 1
(2)
2. Guaranteed by design, not tested in production.
%
DuCy
(HSI)
Duty cycle 45
(2)
-55
(2)
%
ACC
HSI
Accuracy of the HSI
oscillator (factory
calibrated)
T
A
= –40 to 105 °C –3.8
(3)
3. Data based on characterization results, not tested in production.
-4.6
(3)
%
T
A
= –10 to 85 °C –2.9
(3)
-2.9
(3)
%
T
A
= 0 to 70 °C –2.3
(3)
-–2.2
(3)
%
T
A
= 25 °C –1 - 1 %
t
su(HSI)
HSI oscillator startup
time
1
(3)
-2
(3)
µs
I
DD(HSI)
HSI oscillator power
consumption
- 80 100
(3)
µA