Table of Contents
Advertisement
Electrical characteristics
Symbol
f
OSC_IN
R
F
C
I
HSE
I
DD(HSE)
g
m
t
SU(HSE)
(4)
1. Resonator characteristics given by the crystal/ceramic resonator manufacturer.
2. Based on characterization results, not tested in production.
3. The relatively low value of the RF resistor offers a good protection against issues resulting from use in a
humid environment, due to the induced leakage and the bias condition change. However, it is
recommended to take this point into account if the MCU is used in tough humidity conditions.
4. t
SU(HSE)
oscillation is reached. This value is measured for a standard crystal resonator and it can vary significantly
with the crystal manufacturer.
For C
and C
L1
5 pF to 25 pF range (typ.), designed for high-frequency applications, and selected to match
the requirements of the crystal or resonator (see
same size. The crystal manufacturer typically specifies a load capacitance which is the
series combination of C
can be used as a rough estimate of the combined pin and board capacitance) when sizing
C
and C
L1
microcontrollers" available from the ST website www.st.com.
70/129
Table 28. HSE oscillator characteristics
Parameter
Oscillator frequency
Feedback resistor
Recommended load
capacitance versus
equivalent serial resistance
(3)
of the crystal (R
)
S
HSE driving current
HSE oscillator power
consumption
Oscillator transconductance
Startup time
is the startup time measured from the moment it is enabled (by software) to a stabilized 8 MHz
, it is recommended to use high-quality external ceramic capacitors in the
L2
and C
L1
. Refer to the application note AN2867 "Oscillator design guide for ST
L2
DocID17659 Rev 10
STM32L151x6/8/B, STM32L152x6/8/B
Conditions
-
-
= 30 Ω
R
S
V
= 3.3 V, V
= V
DD
IN
SS
with 30 pF load
C = 20 pF
f
= 16 MHz
OSC
C = 10 pF
f
= 16 MHz
OSC
Startup
V
is stabilized
DD
Figure
. PCB and MCU pin capacitance must be included (10 pF
L2
(1)(2)
Min Typ
Max
1
24
200
-
-
20
-
-
-
3
2.5 (startup)
-
-
0.7 (stabilized)
2.5 (startup)
-
-
0.46 (stabilized)
3.5
-
-
-
1
-
17). C
and C
are usually the
L1
L2
Unit
MHz
kΩ
pF
mA
mA
mA
/V
ms
Advertisement
Table of Contents
Need help?
Do you have a question about the STM32L151CB and is the answer not in the manual?