EFM32G222 Datasheet, PDF (29/68 Pages) Silicon Laboratories – Wake-up Interrupt Controller

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Figure 3.20. Calibrated LFRCO Frequency vs Temperature and Supply Voltage
42
40
38
- 40°C
36
25°C
85°C
34
32
30
2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6 3.8
Vdd [V]
42
40
38
36
34
32
30
–4 0
2.0 V
3.0 V
3.8 V
–1 5
5
25
45
65
85
Tem perature [°C]
3.9.4 HFRCO
Table 3.11. HFRCO
Symbol
Parameter
Condition
Min
Typ
Max
Unit
28 MHz frequency band
27.16
28
28.84 MHz
21 MHz frequency band
20.37
21
21.63 MHz
f_HFRCO
Oscillation frequen-
cy, V_DD= 3.0 V,
T_AMB=25°C
14 MHz frequency band
11 MHz frequency band
7 MHz frequency band
1 MHz frequency band
13.58
10.67
6.402
1.164
14
14.42 MHz
11
11.33 MHz
6.6¹
6.798 MHz
1.2²
1.236 MHz
t_{HFRCO_settling}
Settling time after
start-up
Settling time after
band switch
f_HFRCO = 14 MHz
0.6
Cycles
25
Cycles
f_HFRCO = 28 MHz
106
190 µA
f_HFRCO = 21 MHz
93
155 µA
I_HFRCO
Current consump- _{fHFRCO = 14 MHz}
tion (Production test
condition = 14 MHz) ^fHFRCO ^{= 11 MHz}
77
120 µA
72
110 µA
f_HFRCO = 6.6 MHz
63
90 µA
f_HFRCO = 1.2 MHz
22
32 µA
DC_HFRCO
Duty cycle
f_HFRCO = 14 MHz
48.5
50
51 %
TUNESTEP_H- Frequency step
FRCO
for LSB change in
TUNING value
0.3³
%
1_{For devices with prod. rev. < 19, Typ = 7MHz and Min/Max values not applicable.}
2_{For devices with prod. rev. < 19, Typ = 1MHz and Min/Max values not applicable.}
3_{The TUNING field in the CMU_HFRCOCTRL register may be used to adjust the HFRCO frequency. There is enough adjustment}
range to ensure that the frequency bands above 7 MHz will always have some overlap across supply voltage and temperature. By
using a stable frequency reference such as the LFXO or HFXO, a firmware calibration routine can vary the TUNING bits and the
frequency band to maintain the HFRCO frequency at any arbitrary value between 7 MHz and 28 MHz across operating conditions.
2015-05-22 - EFM32G222FXX - d0033_Rev1.90
29
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