EFM32GG332F512 Datasheet, PDF (22/67 Pages) List of Unclassifed Manufacturers – High Performance 32-bit processor @ up to 48 MHz

3.9 Oscillators
Preliminary
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3.9.1 LFXO
Table 3.9. LFXO
Symbol
Parameter
Condition
Min
Typ
Max
Unit
f_LFXO
Supported nominal crystal
frequency
32.768
kHz
ESR_LFXO
C_LFXOL
Supported crystal equiv-
alent series resistance
(ESR)
Supported crystal external
load range
30
120 kOhm
X¹
25 pF
DC_LFXO
I_LFXO
Duty cycle
Current consumption for
core and buffer after start-
up.
ESR=30 kOhm, C_L=10 pF,
LFXOBOOST in CMU_CTRL
is 1
48
50
190
53.5 %
nA
t_LFXO
Start- up time.
ESR=30 kOhm, C_L=10 pF,
40% - 60% duty cycle has
been reached, LFXOBOOST
in CMU_CTRL is 1
400
ms
1_{See Minimum Load Capacitance (CLFXOL) Requirement For Safe Crystal Startup in energyAware Designer in Simplicity Studio}
For safe startup of a given crystal, the energyAware Designer in Simplicity Studio contains a tool to help
users configure both load capacitance and software settings for using the LFXO. For details regarding
the crystal configuration, the reader is referred to application note "AN0016 EFM32 Oscillator Design
Consideration".
3.9.2 HFXO
Table 3.10. HFXO
Symbol
f_HFXO
ESR_HFXO
g_mHFXO
C_HFXOL
DC_HFXO
I_HFXO
t_HFXO
Parameter
Supported nominal crystal
Frequency
Supported crystal equiv-
alent series resistance
(ESR)
The transconductance of
the HFXO input transistor
at crystal startup
Supported crystal external
load range
Duty cycle
Current consumption for
HFXO after startup
Startup time
Condition
Min
Crystal frequency 32 MHz
Crystal frequency 4 MHz
HFXOBOOST in CMU_CTRL
equals 0b11
4 MHz: ESR=400 Ohm,
C_L=20 pF, HFXOBOOST in
CMU_CTRL equals 0b11
32 MHz: ESR=30 Ohm,
C_L=10 pF, HFXOBOOST in
CMU_CTRL equals 0b11
32 MHz: ESR=30 Ohm,
C_L=10 pF, HFXOBOOST in
CMU_CTRL equals 0b11
Typ
4
Max
Unit
48 MHz
30
60 Ohm
400
1500 Ohm
20
mS
5
46
50
85
25 pF
54 %
µA
165
µA
400
µs
2013-06-28 - EFM32GG332FXX - d0126_Rev1.10
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