NI USB-9237 User Guide and Specifications 18 ni.com
Stopband
Frequency........................................0.55 · fs
Rejection..........................................100 dB
Alias-free bandwidth..............................0.45 · fs
Oversample rate......................................64 · fs
Rejection at oversample rate1
50 kS/s......................................90 dB @ 3.2 MHz
10 kS/s......................................60 dB @ 640 kHz
Common-mode voltage
All signals to earth ground..............± 60 VDC
Common-mode rejection ratio (CMRR)
Relative to earth ground2.................140 dB @ 0 to 60 Hz
Relative to EX–...............................85 dB @ 0 to 1 kH
Input noise
Spurious-free dynamic
range (SFDR)..........................................106 dB,
(1 KHz, –60 dBFS)
Total harmonic distortion (fundamental @ –20 dBFS)
1 kHz...............................................100 dB
8 kHz...............................................90 dB
Excitation noise......................................0.1 mV/Vrms
1 Rejection by analog prefilter of signal frequencies at oversample rate.
2 Measured with a balanced cable. Shielded cables may be significantly unbalanced.
Excitation
Voltage
Density
(nV/Vrms per
)
Tota l
(50 kS/S)
(μV/Vrms)
0 to 1 kHz
(nV/Vrms)
2.5 V 81.3 250
3.3 V 61.0 190
5V 40.6 130
10V 20.3 65
1Hz