MAX1457 Datasheet, PDF (11/12 Pages) Maxim Integrated Products – 0.1%-Accurate Signal Conditioner for Piezoresistive Sensor Compensation

0.1%-Accurate Signal Conditioner
for Piezoresistive Sensor Compensation
Table 1. MAX1457 Sensor Calibration and Compensation
Typical Uncompensated Input (Sensor)
Offset . . . . . . . . . . . . . . . . . . . . . . . . . .±100% FSO
FSO . . . . . . . . . . . . . . . . . . . . . .20mV/V to 30mV/V
Offset TC . . . . . . . . . . . . . . . . . . . . . . . . .20% FSO
Offset TC Nonlinearity . . . . . . . . . . . . . . . .4% FSO
FSO TC . . . . . . . . . . . . . . . . . . . . . . . . . .-20% FSO
FSO TC Nonlinearity . . . . . . . . . . . . . . . . . .5% FSO
Typical Compensated Transducer Output
Temperature Range . . . . . . . . . . .-40°C to +125°C
VOUT . . . . . . . . . . . . . . . .ratiometric to VDD at 5.0V
Offset at +25°C . . . . . . . . . . . . . . .0.500V ± 200µV
FSO at +25°C . . . . . . . . . . . . . . . . .4.000V ±200µV
Offset Accuracy Over
Temperature Range . . . . . . . . . .±4mV (0.1% FSO)
FSO Accuracy Over
Temperature Range . . . . . . . . ..±4mV (0.1% FSO)
UNCOMPENSATED RAW SENSOR OUTPUT
160
T_A = +25°C
17mV ≤ V_OUT ≤ 73mV
120
80
40
0
0
20
40
60
80 100
PRESSURE (kPa)
UNCOMPENSATED SENSOR TEMPERATURE ERROR
30
20
OFFSET
10
0
FSO
-10
-20
-50
0
50
100
150
TEMPERATURE (°C)
COMPENSATED TRANSDUCER
5
T_A = +25°C
0.5V ≤ V_OUT ≤ 4.5V
4
3
2
1
0
0
20
40
60
80 100
PRESSURE (kPa)
COMPENSATED TRANSDUCER ERROR
0.15
0.10
0.05
OFFSET
0
-0.05
FSO
-0.10
-0.15
-50
0
50
100
150
TEMPERATURE (°C)
Figure 8. Comparison of an Uncompensated Sensor (left) and a Compensated Transducer (right)
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