
Analog-to-digital converter (ADC)
RM0453
534/1454
RM0453 Rev 2
18.3.2 ADC
voltage
regulator (ADVREGEN)
The ADC has a specific internal voltage regulator which must be enabled and stable before
using the ADC.
The ADC internal voltage regulator can be enabled by setting ADVREGEN bit to 1 in the
ADC_CR register. The software must wait for the ADC voltage regulator startup time
(t
ADCVREG_SETUP
) before launching a calibration or enabling the ADC. This delay must be
managed by software (for details on t
ADCVREG_SETUP
, refer to the device datasheet).
After ADC operations are complete, the ADC is disabled (ADEN = 0). To keep power
consumption low, it is important to disable the ADC voltage regulator before entering low-
power mode (LPRun, LPSleep or Stop mode). Refer to
Section : ADC voltage regulator
Note:
When the internal voltage regulator is disabled, the internal analog calibration is kept.
Analog reference from the power control unit
The internal ADC voltage regulator internally uses an analog reference delivered by the
power control unit through a buffer. This buffer is always enabled when the main voltage
Table 101. ADC internal input/output signals
Internal signal
name
Signal type
Description
V
IN
[x]
Analog Input
channels
Connected either to internal channels or to ADC_IN
i
external channels
TRGx
Input
ADC conversion triggers
V
TS
Input
Internal temperature sensor output voltage
V
REFINT
Input
Internal voltage reference output voltage
V
BAT/3
Input
VBAT pin input voltage divided by 3
dac_out1
Input
DAC internal channel1 input
ADC_AWDx_OUT
Output
Internal analog watchdog output signal connected to on-
chip timers (x = Analog watchdog number = 1,2,3)
Table 102. External triggers
Name
Source
EXTSEL[2:0]
TRG0
TIM1_TRGO2
000
TRG1
TIM1_CC4
001
TRG2
TIM2_TRGO
010
TRG3
TIM2_CH4
011
TRG4
Reserved
100
TRG5
TIM2_CH3
101
TRG6
Reserved
110
TRG7
EXTI11
111