STM32F103C4H6ATR STMICROELECTRONICS [STMicroelectronics], STM32F103C4H6ATR Datasheet - Page 46

• Manufacturer Part Number: STM32F103C4H6ATR
• Description: Low-density performance line, ARM-based 32-bit MCU with 16 or 32 KB Flash, USB, CAN, 6 timers, 2 ADCs, 6 communication interfaces
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Note:
Caution:
5.3.7
46/80
Table 23.
1. Based on characterization, not tested in production.
2. Refer to the note and caution paragraphs below the table, and to the application note AN2867 “Oscillator
3. The oscillator selection can be optimized in terms of supply current using an high quality resonator with
4.
For C
15 pF range selected to match the requirements of the crystal or resonator. C
usually the same size. The crystal manufacturer typically specifies a load capacitance which
is the series combination of C
Load capacitance C
C
between 2 pF and 7 pF.
To avoid exceeding the maximum value of C
to use a resonator with a load capacitance C
capacitance of 12.5 pF.
Example: if you choose a resonator with a load capacitance of C
then C
Figure 21. Typical application with a 32.768 kHz crystal
Internal clock source characteristics
The parameters given in
temperature and V
t
SU(LSE)
Symbol
stray
design guide for ST microcontrollers.
small R
kHz oscillation is reached. This value is measured for a standard crystal resonator and it can vary
significantly with the crystal manufacturer
C
t
R
g
SU(LSE)
I
(2)
2
m
F
L1
is the pin capacitance and board or trace PCB-related capacitance. Typically, it is
L1
Resonator with
integrated capacitors
(4)
and C
S
= C
is the startup time measured from the moment it is enabled (by software) to a stabilized 32.768
value for example MSIV-TIN32.768kHz. Refer to crystal manufacturer for more details
Feedback resistor
Recommended load capacitance
versus equivalent serial
resistance of the crystal (R
LSE driving current
Oscillator Transconductance
startup time
LSE oscillator characteristics (f
L2
L2
C L2
= 8 pF.
C L1
it is recommended to use high-quality ceramic capacitors in the 5 pF to
DD
L
Parameter
has the following formula: C
supply voltage conditions summarized in
32.768 kH z
resonator
Table 24
L1
Doc ID 15060 Rev 3
and C
are derived from tests performed under ambient
OSC32_OU T
OSC32_IN
S
)
(3)
L2
.
V
R F
DD
L1
L
V
= 3.3 V, V

DD
LSE
and C
Conditions
R
controlled
S
7 pF. Never use a resonator with a load
Bias
is stabilized
L
gain
= 30 k
= 32.768 kHz)
= C
L2
L1
IN
(15 pF) it is strongly recommended
= V
x C
SS
L2
STM32F103xx
Table
/ (C
f LSE
Min
L
(1)
5
= 6 pF, and C
L1
9.
+ C
Typ
5
3
L2
) + C
L1
Max
and C
1.4
15
stray
stray
ai14146
= 2 pF,
L2,
where
µA/V
Unit
M
µA
pF
s
are