EFM32WG Datasheet, PDF (684/834 Pages) List of Unclassifed Manufacturers – The EFM32WG Wonder Gecko is the ideal choice for demanding 8-, 16-, and 32-bit energy sensitive applications.

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Figure 28.3. ADC Analog Power Consumption With Different WARMUPMODE Settings
Bandgap reference warm -up
ADC warm -up
ADC enabled Conversion t rigger
Conversion t rigger
ADC conversion
Po w e r
a)
Po w e r
b)
Po w e r
c)
5 µs
5 µs
5 µs
1 µs 1 µs
NORM AL
Tim e
KEEPSCAN REFW ARM
( w SCAN REF = int e rna l ba ndga p)
Tim e
KEEPADCW ARM
( w SCAN REF = int e rna l ba ndga p)
Po w e r
d)
FASTBG
( w SCAN REF = a ny)
or
NORM AL
( w SCAN REF = e xt e rna l or VDD)
Tim e
28.3.4 Input Selection
The ADC is connected to 8 external input pins, which can be selected as 8 different single ended inputs or
4 differential inputs. In addition, 6 single ended internal inputs can be selected. The available selections
are given in the register description for ADCn_SINGLECTRL and ADCn_SCANCTRL.
For offset calibration purposes it is possible to internally short the differential ADC inputs and thereby
measure a 0 V differential. Differential 0 V is selected by writing the DIFF bit to 1 and INPUTSEL to 4 in
ADCn_SINGLECTRL. Calibration is described in detail in Section 28.3.10 (p. 689) .
Note
When VDD/3 is sampled, the acquisition time should be above a lower limit. The reader is
referred to the datasheet for minimum VDD/3 acquisition time.
28.3.4.1 Input Filtering
The selected input signal can be filtered, either through an internal low pass RC filter or an internal
decoupling capacitor. The different filter configurations can be enabled through the LPFMODE bits in
ADCn_CTRL.
The RC input filter configuration is given in Figure 28.4 (p. 684) . The resistance and capacitance values
are given in the electrical characteristics for the device, named R_ADCFILT and C_ADCFILT respectively.
Figure 28.4. ADC RC Input Filter Configuration
Input
ADC
R
C
2013-05-08 - Wonder Gecko Family - d0233_Rev0.50
684
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