Chapter3 HardwareOverview
©NationalInstruments Corporation 3-11 ATE Series User Manual
Figure3-7. Dither
Youcannot disable dither on the AT-MIO-16XE-10, AT-AI-16XE-10,or
AT-MIO-16XE-50.This is because the resolutionof the ADC is so fine that
theADC and the PGIA inherently produce almost 0.5 LSBrms of noise. This
is equivalentto having a dither circuit that is always enabled.
Multiple-Channel Scanning Considerations
All of the AT E Series devices can scan multiple channels at the same
maximum rate as their single-channel rate; however, you should pay
careful attention to the settling times for each of the devices. The settling
time for most of the AT E Series devices is independent of the selected
gain, even at the maximum sampling rate. The settling time for the high
channel count and very high-speed devices is gain dependent, which can
affect the useful sampling rate for a given gain. No extra settling time is
necessary between channelsas long as the gain is constant and source
impedances are low. Refer to Appendix A, Specifications, for a complete
listing of settling timesfor each of theAT E Series devices.
100 200 400
a. Dither disabled; no averaging b. Dither disabled; average of 50 acquisitions
c. Dither enabled; no averaging
100 200 300 4000 500
–4.0
–2.0
0.0
2.0
4.0
–6.0
d. Dither enabled; average of 50 acquisitions
LSBs
LSBs
LSBs
LSBs
6.0
100 200 300 4000 500
–4.0
–2.0
0.0
2.0
4.0
–6.0
6.0
100 200 300 4000 500
–4.0
–2.0
0.0
2.0
4.0
–6.0
6.0
100 200 300 4000 500
–4.0
–2.0
0.0
2.0
4.0
–6.0
6.0