Datasheet

EXAMPLE 1: Finding Worst-Case Accuracy From – 15 ° C to +50 ° C
Accuracy =Accuracy + T Slope1D ´
MAX ( 15°Cto 25°C) (- 25°C) MAX
(2)
Accuracy =0.3 C+( 15 C 25 C)° -
MAX ( 15°Cto 25°C)-
° - °
-7
=+0.58°C
m°C
°C
(3)
Accuracy =Accuracy + T Slope2D ´
MAX (25°Cto 50°C) (25°C) MAX
(4)
Accuracy =0.3 C+(50 C 25 C)° ´
MAX (25°Cto 50°C)
° - °
5
=+0.425°C
m°C
°C
(5)
Accuracy =Accuracy + T Slope1D ´
MIN( 15°Cto 25°C) (- 25°C) MIN
(6)
Accuracy = 0.5 C+( 15 C 25 C)- ° -
MIN( 15°Cto 25°C)-
° - °
0
= 0.5- °C
m°C
°C
(7)
Accuracy =Accuracy + T Slope2D ´
MIN(25°Cto 50°C) (25°C) MIN
(8)
Accuracy = 0.5 C+(50 C 25 C)- °
MIN(25°Cto 50°C)
° - °
0
= 0.5- °C
m°C
°C
(9)
EXAMPLE 2: Finding Worst-Case Accuracy From +25 ° C to +100 ° C
Accuracy =Accuracy + T Slope2D ´
MAX (25°Cto 100°C) ( MAX
+ T Slope3D ´
25°C) MAX
(10)
Accuracy =0.3 C+(85 C 25 C)°
MAX (25°Cto 100°C)
° - °
4.5
m°C
°C
+(100 C 85 C)° - °
8
=+0.690°C
m°C
°C
(11)
Accuracy =Accuracy + T Slope2D ´
MIN(25°Cto 100°C) ( MIN
+ T Slope3D ´
25°C) MIN
(12)
Accuracy = 0.5 C+(85 C 25 C)- ° -
MIN(25°Cto 100°C)
° °
0
m°C
°C
+(100 C 85 C)° - °
0
= 0.5- °C
m°C
°C
(13)
TMP112
www.ti.com ......................................................................................................................................................... SBOS473B – MARCH 2009 – REVISED JUNE 2009
As an example, if the user is concerned only about the temperature accuracy between – 15 ° C to +50 ° C, the
worst-case accuracy could be determined by using the two slope calculations of Equation 2 and Equation 4 :
The same calculations must be applied to the minimum case:
Based on the above calculations, a user can expect a worst-case accuracy of +0.58 ° C to – 0.5 ° C in the
temperature range of – 15 ° C to +50 ° C.
If the desired temperature range falls in the region of slope 3, it is necessary to first calculate the worst-case
value from +25 ° C to +85 ° C and add it to the change in temperature multiplied by the span error of slope 3. As an
example, consider the temperature range of +25 ° C to +125 ° C as shown in Equation 10 :
Performing the same calculation for the minimum case is shown in Equation 12 :
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