Datasheet

Functional overview STM32L031x4/6
28/126 DS10668 Rev 6
3.12.1 Internal voltage reference (V
REFINT
)
The internal voltage reference (V
REFINT
) provides a stable (bandgap) voltage output for the
ADC and Comparators. V
REFINT
is internally connected to the ADC_IN17 input channel. It
enables accurate monitoring of the V
DD
value (since no external voltage, V
REF+
, is available
for ADC). The precise voltage of V
REFINT
is individually measured for each part by ST during
production test and stored in the system memory area. It is accessible in read-only mode.
3.13 Ultra-low-power comparators and reference voltage
The STM32L031x4/6 embed two comparators sharing the same current bias and reference
voltage. The reference voltage can be internal or external (coming from an I/O).
• One comparator with ultra low consumption
• One comparator with rail-to-rail inputs, fast or slow mode.
• The threshold can be one of the following:
– External I/O pins
– Internal reference voltage (V
REFINT
)
– submultiple of Internal reference voltage(1/4, 1/2, 3/4) for the rail to rail
comparator.
Both comparators can wake up the devices from Stop mode, and be combined into a
window comparator.
The internal reference voltage is available externally via a low-power / low-current output
buffer (driving current capability of 1 µA typical).
3.14 System configuration controller
The system configuration controller provides the capability to remap some alternate
functions on different I/O ports.
The highly flexible routing interface allows the application firmware to control the routing of
different I/Os to the TIM2, TIM21, TIM22 and LPTIM timer input captures. It also controls the
routing of internal analog signals to the ADC, COMP1 and COMP2 and the internal
reference voltage V
REFINT
.
Table 8. Internal voltage reference measured values
Calibration value name Description Memory address
VREFINT_CAL
Raw data acquired at
temperature of 25 °C
V
DDA
= 3 V
0x1FF8 0078 - 0x1FF8 0079
Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.