Figure 63. Temperature Sensor And Vrefint Channel Block Diagram - STMicroelectronics STM32F405 Reference Manual

Analog-to-digital converter (ADC)
1. V
SENSE
STM32F42x and STM32F43x devices.
Reading the temperature
To use the sensor:
3. Select ADC1_IN16 or ADC1_IN18 input channel.
4. Select a sampling time greater than the minimum sampling time specified in the
datasheet.
5. Set the TSVREFE bit in the ADC_CCR register to wake up the temperature sensor
from power down mode
6. Start the ADC conversion by setting the SWSTART bit (or by external trigger)
7. Read the resulting V
8. Calculate the temperature using the following formula:
–
–
Refer to the datasheet's electrical characteristics section for the actual values of V
and Avg_Slope.
Note: The sensor has a startup time after waking from power down mode before it can output
V at the correct level. The ADC also has a startup time after power-on, so to minimize
SENSE
the delay, the ADON and TSVREFE bits should be set at the same time.
The temperature sensor output voltage changes linearly with temperature. The offset of this
linear function depends on each chip due to process variation (up to 45 °C from one chip to
another).
416/1731
Figure 63. Temperature sensor and V
is input to ADC1_IN16 for the STM23F40x and STM32F41x devices and to ADC1_IN18 for the
SENSE
Temperature (in °C) = {(V
Where:
V = V value for 25° C
25 SENSE
Avg_Slope = average slope of the temperature vs. V
or µV/°C)
DocID018909 Rev 11
REFINT
data in the ADC data register
– V ) / Avg_Slope} + 25
SENSE 25
channel block diagram
curve (given in mV/°C
SENSE
RM0090
25