STLM20DD7F STMICROELECTRONICS [STMicroelectronics], STLM20DD7F Datasheet - Page 6

• Manufacturer Part Number: STLM20DD7F
• Description: Ultra-low current 2.4V precision analog temperature sensor
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

2
6/16
Transfer function
The STLM20’s transfer function can be described in different ways, with varying levels of
precision. A simple linear transfer function, with good accuracy near 25°C is expressed as:
Equation 1
Over the specified operating temperature range, the best accuracy can be obtained by using
the parabolic transfer function:
Equation 2
and solving for T:
Equation 3
The best fit linear transfer function for many popular temperature ranges was calculated in
Table
temperature ranges.
Table 2.
T
Temperature range
min
–55
–40
–30
–40
–10
35
20
2, where the error introduced by the linear transfer function increases with wider
(°C)
T
First order equations optimized for different temperature ranges
max
130
110
100
85
65
45
30
(°C)
V
O
T
=
– (
=
–11.79mV/°C * T + 1.8528V
–11.77mV/°C * T + 1.8577V
–11.77mV/°C * T + 1.8605V
–11.67mV/°C * T + 1.8583V
–11.71mV/°C * T + 1.8641V
–11.81mV/°C * T + 1.8701V
–11.69mV/°C * T + 1.8663V
3.88
–
V
1481.96
O
×
Linear equation
=
10
– (
–
11.69mV
6
+
V
×
O
T
2.1962
=
2
)
+
) °
(
⁄
–
×
C T
1.15
10
×
6
×
+
+
10
(
---------------------------------- -
1.8663
1.8639
3.88
–
equation from parabolic equation
2
×
Maximum deviation of linear
×
T
V
10
–
)
+
V
–
O
6
1.8639
)
±0.004
±0.004
±1.41
±0.93
±0.70
±0.65
±0.23
(°C)