EFM32G840F128 Datasheet, PDF (28/71 Pages) Silicon Laboratories – ARM Cortex-M3 CPU platform

3.9.2 HFXO
Table 3.10. HFXO
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Symbol
f_HFXO
ESR_HFXO
g_mHFXO
C_HFXOL
DC_HFXO
I_HFXO
t_HFXO
Parameter
Condition
Min
Supported nominal
crystal Frequency
Supported crystal Crystal frequency 32 MHz
equivalent series re-
sistance (ESR)
Crystal frequency 4 MHz
The transconduc-
tance of the HFXO
input transistor at
crystal startup
HFXOBOOST in CMU_CTRL
equals 0b11
Supported crystal
external load range
Duty cycle
Current consump-
tion for HFXO after
startup
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
Startup time
32 MHz: ESR=30 Ohm,
C_L=10 pF, HFXOBOOST in
CMU_CTRL equals 0b11
Pulse width re-
moved by glitch de-
tector
Typ
4
20
5
46
1
Max
Unit
32 MHz
30
60 Ohm
400
1500 Ohm
mS
25 pF
50
54 %
85
µA
165
µA
400
µs
4 ns
3.9.3 LFRCO
Table 3.11. LFRCO
Symbol
Parameter
Condition
f_LFRCO
Oscillation frequen-
cy , V_DD= 3.0 V,
T_AMB=25°C
t_LFRCO
Startup time not in-
cluding software
calibration
I_LFRCO
Current consump-
tion
TC_LFRCO
Temperature coeffi-
cient
VC_LFRCO
Supply voltage co-
efficient
TUNESTEP_L- Frequency step
FRCO
for LSB change in
TUNING value
Min
Typ
Max
Unit
32.768
kHz
150
µs
190
±0.02
±15
1.5
nA
%/°C
%/V
%
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