Figure 53. Temperature Sensor And Vrefint Channel Block Diagram - ST STM32F40 Series Reference Manual

Analog-to-digital converter (ADC)
Figure 53. Temperature sensor and V
1. V
SENSE
STM23F42x 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).
289/1422
TSVREFE control bit
Temperature
sensor
Internal
power block
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)
Doc ID 018909 Rev 4
channel block diagram
REFINT
V SENSE
ADC1_IN16/
ADC1_IN18 (1)
V REFINT
ADC1_IN17
data in the ADC data register
– V ) / Avg_Slope} + 25
SENSE 25
converted data
ADC1
curve (given in mV/°C
SENSE
RM0090
MS31830V1
25