4 Channel-to-Channel Isolated Analog Input Modules

Channel-to-channel isolated analog input modules use a separate ADC, signal and power isolator for every analog input channel, as shown in Figure 4-1. While group isolated modules offer cost efficiency, they impose restrictions on usage. The analog sensors they interface cannot have large common mode differences between them, and hence they cannot be placed in different physical regions in the factory. A channel-to-channel removes this restriction, and allows the end user maximum flexibility of usage. The common mode difference between channels can be a few kilovolts. Channel-to-channel isolation also improves robustness of the system, and brings benefits to functional safety, since any failures in the ADC or isolation in one channel will not affect the other channels.

Figure 4-1 Signal and Power Isolation in Channel-to-Channel Isolated Analog Input Modules.