STM32F101X6_08 STMICROELECTRONICS [STMicroelectronics], STM32F101X6_08 Datasheet - Page 42

• Manufacturer Part Number: STM32F101X6_08
• Description: Access line, advanced ARM-based 32-bit MCU with Flash memory, six 16-bit timers, ADC and seven communication interfaces
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Electrical characteristics
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Figure 19. Typical application with an 8 MHz crystal
1. R
Low-speed external clock
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 22.
1. The oscillator selection can be optimized in terms of supply current using an high quality resonator with
2.
Figure 20. Typical application with a 32.768 kHz crystal
t
SU(LSE)
Symbol
RESONATOR WITH
IN TEGRATED CAPAC ITORS
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
t
SU(LSE)
EXT
C
C
R
g
I
L1
L2
2
m
F
RESONATOR WITH
IN TEGRATED CAPAC ITORS
value depends on the crystal characteristics. Typical value is in the range of 5 to 6R
(2)
S
is the startup time measured from the moment it is enabled (by software) to a stabilized
value for example MSIV-TIN32.768 kHz. Refer to crystal manufacturer for more details
LSE oscillator characteristics (
Feedback resistor
Recommended load capacitance
versus equivalent serial
resistance of the crystal (R
LSE driving current
Oscillator transconductance
Startup time
C L2
C L1
C L2
C L1
8 MH z
resonator
Parameter
32.768 KH z
resonator
R EXT (1)
OSC_OU T
OSC_IN
OSC32_OU T
OSC32_IN
S
)
(1)
R F
R F
f
LSE
V
controlled
DD
V
controlled
Conditions
R
V
Bias
gain
DD
S
Bias
= 32.768 kHz)
gain
IN
is stabilized
= 30 KΩ
= 3.3 V
= V
SS
STM32F101xx
STM32F101xx
Table
Min
f HSE
f LSE
5
22. In the application,
Typ
5
3
S
.
STM32F101xx
Max
1.4
15
ai14128
ai14129
µA/V
Unit
MΩ
pF
µA
s