Table of Contents
Advertisement
STM32L151xC STM32L152xC
4.
t
SU(LSE)
32.768 kHz oscillation is reached. This value is measured for a standard crystal resonator and it can vary
significantly with the crystal manufacturer.
Note:
For C
and C
L1
15 pF range selected to match the requirements of the crystal or resonator (see
C
and C
L1
capacitance which is the series combination of C
Load capacitance C
C
is the pin capacitance and board or trace PCB-related capacitance. Typically, it is
stray
between 2 pF and 7 pF.
Caution:
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
L1
is the startup time measured from the moment it is enabled (by software) to a stabilized
, it is recommended to use high-quality ceramic capacitors in the 5 pF to
L2
are usually the same size. The crystal manufacturer typically specifies a load
L2,
has the following formula: C
L
= C
= 8 pF.
L2
Figure 18. Typical application with a 32.768 kHz crystal
DocID022799 Rev 10
Electrical characteristics
and C
.
L1
L2
= C
x C
/ (C
L
L1
L2
and C
(15 pF) it is strongly recommended
L1
L2
≤ 7 pF. Never use a resonator with a load
L
L
Figure
18).
+ C
) + C
where
L1
L2
stray
= 6 pF and C
= 2 pF,
stray
77/135
110
Advertisement
Table of Contents
Need help?
Do you have a question about the STM32L151CCT6 and is the answer not in the manual?