SAMPLE ERROR CALCULATION
RTD value at 4mA Output (RRTD MIN):
RTD Measurement Range:
Ambient Temperature Range (∆TA):
Supply Voltage Change (∆V+):
100Ω
200°C
20°C
5V
Common-Mode Voltage Change (∆CM):
0.1V
ERROR
(ppm of Full Scale)
SAMPLE
ERROR CALCULATION(1)
ERROR SOURCE
ERROR EQUATION
UNADJ.
ADJUST.
INPUT
Input Offset Voltage
vs Common-Mode
Input Bias Current
Input Offset Current
VOS/(VIN MAX) • 106
CMRR • ∆CM/(VIN MAX) • 106
IB/IREF • 106
100µV/(800µA • 0.38Ω/°C • 200°C) • 106
50µV/V • 0.1V/(800µA • 0.38Ω/°C • 200°C) • 106
0.025µA/800µA • 106
1645
82
31
0
82
0
I
OS • RRTD MIN/(VIN MAX) • 106
3nA • 100Ω/(800µA • 0.38Ω/°C • 200°C) • 106
5
0
Total Input Error:
1763
82
EXCITATION
Current Reference Accuracy
vs Supply
I
REF Accuracy (%)/100% • 106
0.2%/100% • 106
25ppm/V • 5V
0.1%/100% • 800µA • 100Ω/(800µA • 0.38Ω/°C • 200°C) • 106
2000
125
1316
0
125
0
(IREF vs V+) • ∆V+
Current Reference Matching
I
REF Matching (%)/100% • 800µA •
R
RTD MIN/(VIN MAX) • 106
vs Supply
(IREF Matching vs V+) • ∆V+ •
RTD MIN/(VIN MAX
10ppm/V • 5V • 800µA • 100Ω/(800µA • 0.38Ω/°C • 200°C)
66
66
R
)
Total Excitation Error:
3507
191
GAIN
Span
Nonlinearity
Span Error (%)/100% • 106
Nonlinearity (%)/100% • 106
0.2%/100% • 106
0.01%/100% • 106
Total Gain Error:
2000
100
2100
0
100
100
OUTPUT
Zero Output
vs Supply
(IZERO – 4mA) /16000µA • 106
(IZERO vs V+) • ∆V+/16000µA • 106
25µA/16000µA • 106
0.2µA/V • 5V/16000µA • 106
Total Output Error:
1563
63
1626
0
63
63
DRIFT (∆TA = 20°C)
Input Offset Voltage
Input Bias Current (typical)
Input Offset Current (typical)
Current Reference Accuracy
Drift • ∆TA/(VIN MAX) • 106
Drift • ∆TA/800µA • 106
Drift • ∆TA • RRTD MIN/(VIN MAX) • 106
Drift • ∆TA
1.5µV/°C • 20°C/(800µA • 0.38Ω/°C • 200°C) • 106
20pA/°C • 20°C/800µA • 106
5pA/°C • 20°C • 100W/(800µA • 0.38Ω/°C • 200°C) • 106
35ppm/°C • 20°C
493
0.5
493
0.5
0.2
0.2
700
395
500
626
2715
700
395
500
626
2715
Current Reference Matching Drift • ∆TA • 800µA • RRTD MIN/(VIN MAX
)
15ppm/°C • 20°C • 800µA • 100Ω/(800µA • 0.38Ω/°C • 200°C)
25ppm/°C • 20°C
Span
Drift • ∆TA
Drift • ∆TA/16000µA • 106
Zero Output
0.5µA/°C • 20°C/16000µA • 106
Total Drift Error:
NOISE (0.1Hz to 10Hz, typ)
Input Offset Voltage
Current Reference
Zero Output
vn/(VIN MAX) • 106
0.6µV/(800µA • 0.38Ω/°C • 200°C) • 106
3nA • 100Ω/(800µA • 0.38Ω/°C • 200°C) • 106
0.03µA/16000µA • 106
10
5
2
10
5
2
I
REF Noise • RRTD MIN/(VIN MAX) • 106
I
ZERO Noise/16000µA • 106
Total Noise Error:
17
17
TOTAL ERROR:
11728
3168
NOTE (1): All errors are min/max and referred to input unless otherwise stated.
(1.17%)
(0.32%)
TABLE II. Error Calculation.
XTR105
SBOS061B
11
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