SLAU847E October 2022 – May 2025 MSPM0L1105 , MSPM0L1106 , MSPM0L1116 , MSPM0L1117 , MSPM0L1227 , MSPM0L1227-Q1 , MSPM0L1228 , MSPM0L1228-Q1 , MSPM0L1303 , MSPM0L1304 , MSPM0L1304-Q1 , MSPM0L1305 , MSPM0L1305-Q1 , MSPM0L1306 , MSPM0L1306-Q1 , MSPM0L1343 , MSPM0L1344 , MSPM0L1345 , MSPM0L1346 , MSPM0L2227 , MSPM0L2227-Q1 , MSPM0L2228 , MSPM0L2228-Q1
The output of the comparator can be used with or without internal filtering. Output filtering can only be enabled while Comparator is in fast mode (COMPx.CTL1.MODE = 0). When FLTEN bit in COMPx.CTL1 register is set, the output is filtered with an on-chip analog filter. The delay of the filter can be adjusted in four different steps using the FLTDLY bits in COMPx.CTL1 register (see Table 16-1).
| FLTDLY bit in COMPx.CTL1 | Typical filter delay |
|---|---|
| 0 | 70ns |
| 1 | 500ns |
| 2 | 1200ns |
| 3 | 2700ns |
The comparator output oscillates if the voltage difference across the input terminals is small (see Figure 16-2 ). Internal and external parasitic effects and cross coupling on and between signal lines, power supply lines, and other parts of the system result in this behavior. The comparator output oscillation reduces the accuracy and resolution of the comparison result. Selecting the output filter can reduce errors associated with comparator oscillation.
The output filter only works for the comparator when it operates in fast mode.