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EFM32ZG210 Datasheet, PDF (29/69 Pages) Silicon image – Energy, gas, water and smart metering | |||
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3.9.4 HFRCO
Table 3.11. HFRCO
...the world's most energy friendly microcontrollers
Symbol
Parameter
Condition
Min
Typ
Max
Unit
21 MHz frequency band
20.37
21.0
21.63 MHz
fHFRCO
Oscillation frequen-
cy, VDD= 3.0 V,
TAMB=25°C
14 MHz frequency band
11 MHz frequency band
7 MHz frequency band
13.58
10.67
6.40
14.0
14.42 MHz
11.0
11.33 MHz
6.60
6.80 MHz
1 MHz frequency band
1.15
1.20
1.25 MHz
tHFRCO_settling Settling time after
start-up
fHFRCO = 14 MHz
0.6
Cycles
fHFRCO = 21 MHz
93
175 µA
IHFRCO
Current consump-
tion (Production test
condition = 14 MHz)
fHFRCO = 14 MHz
fHFRCO = 11 MHz
fHFRCO = 6.6 MHz
77
140 µA
72
125 µA
63
105 µA
fHFRCO = 1.2 MHz
22
40 µA
TUNESTEPH- Frequency step
FRCO
for LSB change in
TUNING value
0.31
%
1The 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.
Figure 3.21. Calibrated HFRCO 1 MHz Band Frequency vs Supply Voltage and Temperature
1.45
1.40
1.35
1.30
1.25
1.20
- 40°C
25°C
85°C
1.15
1.10
1.05
2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6 3.8
Vdd [V]
1.45
1.40
1.35
1.30
1.25
1.20
1.15
1.10
1.05
â4 0
2.0 V
3.0 V
3.8 V
â1 5
5
25
45
65
85
Tem perature [°C]
2015-03-06 - EFM32ZG210FXX - d0065_Rev1.10
29
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