Question: How is the comparator in the PSoC® 4000 family different? What are its limitations?
The comparator in the PSoC 4000 family is the CapSense® block’s comparator exposed for general-purpose use. Because the CapSense comparator performs a compare operation only with the internal reference voltage, one of its inputs (negative terminal) is tied to the internal reference (1.2 V) and cannot be changed. The positive input of the comparator connects to either Analog MUX bus A (AMUXA) or Analog MUX bus B (AMUXB) so any GPIO having analog MUX bus support can be connected to the positive input. The output of the comparator can be routed to P0, P0 or P1 and is always asynchronous. Because the comparator is a part of the CapSense block, it cannot be used along with CapSense in a project. Refer to the “1.2 Volt Comparator (CSD Comp)” Creator Component for the PSoC 4000 family datasheet for more information. Figure 1 provides an overview of the comparator connections.
Figure 1. Comparator Connections