EFR32FG12P432F Datasheet, PDF (73/183 Pages) Silicon Laboratories – EFR32FG12 Flex Gecko Proprietary Protocol SoC Family Data Sheet

4.1.12.2 High-Frequency Crystal Oscillator (HFXO)
EFR32FG12 Flex Gecko Proprietary Protocol SoC Family Data Sheet
Electrical Specifications
Table 4.34. High-Frequency Crystal Oscillator (HFXO)
Parameter
Symbol
Test Condition
Min
Typ
Max
Unit
Crystal frequency
f_HFXO
38
38.4
40
MHz
Supported crystal equivalent ESR_{HFXO_38M4} Crystal frequency 38.4 MHz
series resistance (ESR)
—
—
60
Ω
Supported range of crystal
load capacitance ¹
C_{HFXO_CL}
6
—
12
pF
On-chip tuning cap range ^{2 C}HFXO_T
On each of HFXTAL_N and
HFXTAL_P pins
9
20
25
pF
On-chip tuning capacitance SS_HFXO
step
—
0.04
—
pF
Startup time
t_HFXO
38.4 MHz, ESR = 50 Ohm, C_L =
—
300
—
μs
10 pF
Frequency tolerance for the FT_HFXO
38.4 MHz, ESR = 50 Ohm, C_L =
-40
—
40
ppm
crystal
10 pF
Note:
1. Total load capacitance as seen by the crystal.
2. The effective load capacitance seen by the crystal will be C_{HFXO_T} /2. This is because each XTAL pin has a tuning cap and the
two caps will be seen in series by the crystal.
4.1.12.3 Low-Frequency RC Oscillator (LFRCO)
Table 4.35. Low-Frequency RC Oscillator (LFRCO)
Parameter
Symbol
Test Condition
Min
Typ
Max
Unit
Oscillation frequency
f_LFRCO
ENVREF² = 1
31.3
32.768
33.6
kHz
ENVREF² = 0
31.3
32.768
33.4
kHz
Startup time
t_LFRCO
—
500
—
μs
Current consumption ¹
I_LFRCO
ENVREF = 1 in
CMU_LFRCOCTRL
—
370
—
nA
ENVREF = 0 in
CMU_LFRCOCTRL
—
520
—
nA
Note:
1. Block is supplied by AVDD if ANASW = 0, or DVDD if ANASW=1 in EMU_PWRCTRL register.
2. In CMU_LFRCOCTRL register.
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