Datasheet

CALIBRATING FOR IMPROVED ACCURACY
0.8
0.6
0.4
0.2
0
0.2
0.4
0.6
-
-
-
TemperatureError(
C)
°
Temperature( C)°
-40 -20 0 20 40 60 130
Slope1
MAX
Slope1
MIN
Slope2
MAX
Slope2
MIN
Slope3
MIN
100 110 12080 9070503010-30 -10
Slope3
MAX
Accuracy =Acc + T SlopeD ´
(worst-case) 25°C)
uracy
(
(1)
TMP112
SBOS473B – MARCH 2009 – REVISED JUNE 2009 ......................................................................................................................................................... www.ti.com
There are many temperature monitoring applications that require better than 0.5 ° C accuracy over a limited
temperature range. Knowing the offset of a temperature sensor at a given temperature in conjunction with the
average temperature span (slope) error over a fixed range makes it possible to achieve this improved accuracy.
The TMP112 has three distinct slope regions that conservatively approximate its inherent curvature:
1. Slope1 applies over – 40 ° C to +25 ° C
2. Slope2 applies over +25 ° C to +85 ° C
3. Slope3 applies over +85 ° C to +125 ° C
These slopes are defined in Table 14 and shown in Figure 19 .It is important to note that each slope is increasing
with respect to 25 ° C.
Table 14. Specifications for User-Calibrated Systems
PARAMETER CONDITION MIN MAX UNIT
V
S
= +3.3, – 40 ° C to +25 ° C – 7 0 m ° C/ ° C
Average Slope
(Temperature Error vs V
S
= +3.3, +25 ° C to +85 ° C 0 +5 m ° C/ ° C
Temperature)
(1)
V
S
= +3.3, +85 ° C to +125 ° C 0 +8 m ° C/ ° C
(1) User-calibrated temperature accuracy can be within ± 1LSB because of quantization noise.
Figure 19. Accuracy and Slope Curves versus Temperature
Equation 1 determines the worst-case accuracy at a specific temperature:
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