SFFS779 December 2024 TMS320F28P550SJ
The open and short detection circuit allows customers to detect faults in the ADC input channel. This capability is valid only in single-ended mode. For system integrators using differential mode, the ADC must be configured in 12-bit single-ended mode to perform this test. Error response, diagnostic testability, and any necessary software requirements are defined by the software implemented by the system integrator. This capability is deprecated in few part numbers. Confirm the availability of the feature before using this diagnostic.
The following circuit and configuration, selected by programmable register bits to control switches S1, S2, S3, and S4, allows controlling input ADC channel to test for open and short conditions.
ADCOSDETECT.DETECTCFG | Source Voltage | S4 | S3 | S2 | S1 | Drive Impedance |
---|---|---|---|---|---|---|
0 | Off | Open | Open | Open | Open | Open |
1 | Zero Scale | Closed | Open | Open | Closed | 5K || 7K |
2 | Full Scale | Open | Closed | Closed | Open | 5K || 7K |
3 | 5/12 VDDA | Open | Closed | Open | Closed | 5K || 7K |
4 | 7/12 VDDA | Closed | Open | Closed | Open | 5K || 7K |
5 | Zero Scale | Open | Open | Open | Closed | 5K |
6 | Full Scale | Open | Open | Closed | Open | 5K |
7 | Zero Scale | Closed | Open | Open | Open | 7K |