USB-1808X User's Guide
Specifications
19
Accuracy
Analog input DC voltage measurement accuracy
Table 2. DC accuracy components and specifications. All values are (±)
Range
Gain error
(% of
reading)
Offset
error
(mV)
INL error
(% of
range)
Absolute
accuracy at
Full Scale
(mV)
Gain
temperature
coefficient
(% reading/°C)
Offset
temperature
coefficient
(µV/°C)
±10 V
0.020
1.5
0.00076
3.576
0.00023
4
±5 V
0.020
1.0
0.00057
2.028
0.00023
4
0 V to 10 V
0.020
1.5
0.00028
3.528
0.00023
4
0 V to 5 V
0.020
1.0
0.00014
2.007
0.00023
4
Dynamic performance
Table 3. Dynamic performance specifications
Range
Condition
Specification
±10 V
Signal-to-noise ratio (SNR)
94 dB
Signal-to-noise-and-distortion ratio
(SINAD)
94 dB
Total harmonic distortion (THD)
–108 dB
Spurious free dynamic range (SFDR)
112 dB
Effective number of bits (ENOB)
15.3 bits
±5 V
SNR
91 dB
SINAD
91 dB
THD
–105 dB
SFDR
107 dB
ENOB
14.8 bits
0 V to 10 V
SNR
87 dB
SINAD
87 dB
THD
–104 dB
SFDR
109 dB
ENOB
14.5 bits
0 V to 5 V
SNR
83 dB
SINAD
83 dB
THD
–103 dB
SFDR
103 dB
ENOB
13.6 bits
Noise performance
For the peak-to-peak noise distribution test, a differential input channel is connected to AGND at the input
terminal block, and 32,000 samples are acquired at the maximum rate available at each setting.
Table 4. Noise performance specifications
Range
Counts
LSBrms
±10 V
11.6
1.77
±5 V
18.0
2.73
0 V to 10 V
23.3
3.54
0 V to 5 V
36.1
5.47
