EFM32G290 Datasheet, PDF (27/72 Pages) Silicon Laboratories – Wake-up Interrupt Controller

3.9 Oscillators
3.9.1 LFXO
Table 3.8. LFXO
...the world's most energy friendly microcontrollers
Symbol
Parameter
Condition
Min
Typ
Max
Unit
f_LFXO
Supported nominal
crystal frequency
32.768
kHz
ESR_LFXO
C_LFXOL
Supported crystal
equivalent series re-
sistance (ESR)
Supported crystal
external load range
30
120 kOhm
X¹
25 pF
I_LFXO
Current consump-
tion for core and
buffer after startup.
ESR=30 kOhm, C_L=10 pF,
LFXOBOOST in CMU_CTRL is
1
190
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 Configurator in Simplicity Studio}
For safe startup of a given crystal, the Configurator tool 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".
2015-05-22 - EFM32G290FXX - d0007_Rev1.90
27
www.silabs.com