EFM32-TG822F32-SK Energy Micro, EFM32-TG822F32-SK Datasheet - Page 22

• Manufacturer Part Number: EFM32-TG822F32-SK
• Description: MCU, MPU & DSP Development Tools TG822 Sample Kit
• Manufacturer: Energy Micro

Specifications of EFM32-TG822F32-SK

• Processor To Be Evaluated: EFM32
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

3.9 Oscillators
3.9.1 LFXO
2012-02-27 - EFM32TG822FXX - d0052_Rev0.95
Table 3.9. LFXO
For safe startup of a given crystal, the load capacitance should be larger than the value indicated in
Figure 3.10 (p. 22) and in Table 3.10 (p. 22) for a given LFXOBOOST setting. The minimum
supported load capacitance depends on the crystal shunt capacitance, C
vendors’ datasheet.
Figure 3.10. Minimum Load Capacitance (C
Table 3.10. Minimum Load Capacitance (C
Symbol
f
ESR
C
DC
I
t
Shunt Capacitance C
CL
LFXO
LFXO
LFXO
LFXOL
min
LFXO
LFXO
lfxoboost = 0
Symbol
Parameter
Supported nominal crystal
frequency
Supported crystal equiv-
alent series resistance
(ESR)
Supported crystal external
load range
Duty cycle
Current consumption for
core and buffer after start-
up.
Start- up time.
0
0.5
5.4
0.6
5.8
0.7
6.3
0.8
6.7
Condition
ESR=30 kOhm, C
LFXOBOOST in CMU_CTRL
is 1
ESR=30 kOhm, C
40% - 60% duty cycle has
been reached, LFXOBOOST
in CMU_CTRL is 1
0.9
7.1
LFXOL
LFXOL
1.0
7.4
...the world's most energy friendly microcontrollers
22
) Requirement For Safe Crystal Startup
) Requirement For Safe Crystal Startup
1.1
7.8
L
L
Capacitance [pF]
=10 pF,
=10 pF,
1.2
8.1
1.3
8.4
Min
1.4
8.7
48
1.5
9.0
5
0
, which is specified in crystal
Typ
32.768
1.6
9.2
www.energymicro.com
190
400
30
50
1.7
9.5
Max
1.8
9.8
53.5 %
120 kOhm
25 pF
1.9
10.0 10.2
Unit
kHz
nA
ms
2.0