STM32L-DISCOVERY STMicroelectronics, STM32L-DISCOVERY Datasheet - Page 78

• Manufacturer Part Number: STM32L-DISCOVERY
• Description: BOARD, EVAL, STM32L-DISCOVERY
• Manufacturer: STMicroelectronics
• Series: STM32r
• Type: MCUr

Specifications of STM32L-DISCOVERY

• Kit Contents: Board, Debugger, Programmer And Compiler
• Features: 128KB Flash Plus Multiple Timers, Analogue Peripherals
• Silicon Manufacturer: ST Micro
• Core Architecture: ARM
• Core Sub-architecture: Cortex - M3
• Silicon Core Number: STM32
• Silicon Family Name: STM32F1xx
• Rohs Compliant: Yes
• Contents: Board
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: STM32L
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Electrical characteristics
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Table 25.
1. Resonator characteristics given by the crystal/ceramic resonator manufacturer.
2. Based on characterization, not tested in production.
3. The relatively low value of the RF resistor offers a good protection against issues resulting from use in a
4. t
For C
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
microcontrollers” available from the ST website www.st.com.
Figure 30. Typical application with an 8 MHz crystal
1. R
Low-speed external clock generated from a crystal/ceramic resonator
The low-speed external (LSE) clock can be supplied with a 32.768 kHz crystal/ceramic
resonator oscillator. All the information given in this paragraph are based on characterization
results obtained with typical external components specified in
the resonator and the load capacitors have to be placed as close as possible to the oscillator
pins in order to minimize output distortion and startup stabilization time. Refer to the crystal
resonator manufacturer for more details on the resonator characteristics (frequency,
package, accuracy).
t
SU(HSE
Symbol
L1
f
OSC_IN
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.
oscillation is reached. This value is measured for a standard crystal resonator and it can vary significantly
with the crystal manufacturer
SU(HSE)
R
g
and C
C
EXT
i
2
m
F
L1
Resonator with
integrated capacitors
(4)
value depends on the crystal characteristics.
and C
is the startup time measured from the moment it is enabled (by software) to a stabilized 8 MHz
L2
Oscillator frequency
Feedback resistor
Recommended load capacitance
versus equivalent serial
resistance of the crystal (R
HSE driving current
Oscillator transconductance
Startup time
. Refer to the application note AN2867 “Oscillator design guide for ST
HSE 4-26 MHz oscillator characteristics
L2
, it is recommended to use high-quality external ceramic capacitors in the
C L2
C L1
Parameter
L1
and C
8 MH z
resonator
R
EXT
Doc ID 15818 Rev 6
(1)
L2
. PCB and MCU pin capacitance must be included (10 pF
S
)
(3)
OSC_OU T
OSC_IN
V
DD
V
R F
with 30 pF load
= 3.3 V, V
DD
Conditions
R
Figure
Startup
S
is stabilized
controlled
= 30 Ω
Bias
gain
(1) (2)
IN
30). C
= V
STM32F205xx, STM32F207xx
SS
Table
L1
STM32F
and C
Min
4
5
-
-
-
-
26. In the application,
f HSE
L2
Typ
200
15
2
are usually the
-
-
-
Max
26
1
-
-
-
-
ai17530
mA/V
MHz
Unit
mA
ms
kΩ
pF