Filter
Top Products
A single ended input has no common mode range because there is only one LOW
wire, which is assumed to be at the same level at the signal and at the A/D board.
Figure 6-3. Single-Ended Input
The maximum difference which may be rejected is the CMR.
For example, the CIO-SSH16 has a common mode plus signal range of 11.5 volts,
common mode not to exceed 10 volts.
This specification is illustrated graphically here and will be referred to as Cumulative
Signal Range (CSR).
Figure 6-4. CSR
Most manufactures of A/D boards specify the CMR directly from the component data
sheet, ignoring the effect of the board level system on that specification. A data sheet
of that type might claim 10 volts of CMR. Although this is a factual specification and
19