STM32L152-SK/IAR STMicroelectronics, STM32L152-SK/IAR Datasheet - Page 63

• Manufacturer Part Number: STM32L152-SK/IAR
• Description: MCU, MPU & DSP Development Tools STM32L152VBT6 IAR 32KB Workbench
• Manufacturer: STMicroelectronics
• Series: IAR Kickstartr
• Type: MCUr

Specifications of STM32L152-SK/IAR

• Contents: Board, CD
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: STM32L

STM32L151xx, STM32L152xx
Figure 16. HSE oscillator circuit diagram
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).
Table 25.
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.
t
SU(LSE)
I
Symbol
DD (LSE)
design guide for ST microcontrollers”.
small R
32.768 kHz oscillation is reached. This value is measured for a standard crystal resonator and it can vary
significantly with the crystal manufacturer.
f
I
C
t
LSE
R
LSE
g
SU(LSE)
EXT
(2)
m
F
value depends on the crystal characteristics.
(4)
S
is the startup time measured from the moment it is enabled (by software) to a stabilized
value for example MSIV-TIN32.768kHz. Refer to crystal manufacturer for more details;
Low speed external oscillator
frequency
Feedback resistor
Recommended load capacitance
versus equivalent serial
resistance of the crystal (R
LSE driving current
LSE oscillator current
consumption
Oscillator transconductance
Startup time
LSE oscillator characteristics (f
Parameter
Doc ID 17659 Rev 4
S
)
(3)
V
DD
V
LSE
= 3.3 V, V
DD
V
V
Conditions
R
V
DD
DD
DD
S
is stabilized
= 32.768 kHz)
= 30 k
= 1.8 V
= 3.0 V
= 3.6V
IN
= V
SS
Table
(1)
Electrical characteristics
Min
3
25. In the application,
32.768
Typ
450
600
750
1.2
8
1
Max
1.1
63/107
µA/V
Unit
kHz
M
pF
µA
nA
s