Table 16. Temperature Sensor Voltage Range - ST STM32373C-EVAL User Manual

Hardware layout and configuration
Equation 2
V
OUTA1
Equation 3
V
OUTA2
Equation 4
V V
=
REF
Equation 5
V = V
Rref
The voltage on the ADC input is given in
Equation 6
V =
ADC
The measured PT100 value given by the ADC is shown in
Equation 7
R =
PT100
Where:
●
N is the value returned by the ADC corresponding to the voltage measured.
●
V
ref_ADC
If V
ref_ADC
Equation 8
R
=
PT100
Conclusion
When the JP17 jumper is closed and the external reference voltage selected (V
equals VDD, the temperature measurement becomes VDD independent.
Table 16
the STM32F373VCT6 where gain = 16.
Table 16.
VDD = 3.3 V
Rref = 1.8 KΩ
24/66
V V (since G
= +
REF OUTA2
V
=
PT100
V
–
OUTA1 PT100
⁄
= VDD 2
ref
×
V = V R
PT100 Rref PT100
16
[ × ⁄ (
V N 2 –
ref_ADC
is the ADC reference voltage (SD_VREF+ in
= VDD, the R
PT100
16
[ ⁄ ( ) ] × ×
N 2 1 2 R
–
shows the voltage range corresponding to different temperatures for the ADC IN of
Temperature sensor voltage range
Temperature (°C)
0
20
50
Doc ID 023566 Rev 1
1 )
=
A1
Equation 6.
⁄ ×
R = R VDD
ref PT100
) ] × × ⁄ ( )
1 2 R VDD
ref
value becomes as shown in
ref
Resistance (Ω)
100
107.7
119.2
⁄ ( × )
2 R
ref
Equation 7.
Figure 26).
Equation 8.
Voltage (mV)
100
107.7
119.2
UM1564
)
ref_ADC
Vin ADC (V)
1.6
1.7
1.9