SBAA051A January   1994  – April  2015 MSC1210Y2 , MSC1210Y3 , MSC1210Y4 , MSC1210Y5

 

  1.   Principles of Data Acquisition and Conversion
    1.     Trademarks
    2. 1 System Sampling Rate
      1. 1.1 Error Considerations
      2. 1.2 Aliasing Error
      3. 1.3 How Many Samples per Cycle?
      4. 1.4 Aperture Error
    3. 2 A Few A/D Converter Points
      1. 2.1 Accuracy
      2. 2.2 Selecting the Resolution
      3. 2.3 Resolution
    4. 3 Increasing System Throughput Rate
    5. 4 System Throughput Accuracy
    6. 5 Digital Codes
    7. 6 Summary

2.2 Selecting the Resolution

The number of bits in the A/D converter determines the resolution of the system. System resolution is determined by the channel(s) having the widest dynamic range and/or the channel(s) that require measurement of the smallest data increment. For example, assume a channel that measures pressure has a dynamic range of 4000psi that must be measured to the nearest pound. This will require an A/D converter with a minimum resolution of 4000 digital codes. A 12-bit A/D converter will provide a resolution of 212 or 4096 codes—adequate for this requirement. The actual resolution of this channel will be 4000/4096 or 0.976 psi.

The A/D converter can resolve this measurement to within ± 0.488 psi (±1/2LSB).