SFFS277 November 2023 TMS320F280033 , TMS320F280034 , TMS320F280034-Q1 , TMS320F280036-Q1 , TMS320F280036C-Q1 , TMS320F280037 , TMS320F280037-Q1 , TMS320F280037C , TMS320F280037C-Q1 , TMS320F280038-Q1 , TMS320F280038C-Q1 , TMS320F280039 , TMS320F280039-Q1 , TMS320F280039C , TMS320F280039C-Q1
Integrity of DAC and ADC can be checked monitoring DAC output using ADC. DAC can be configured using software to provide a set of predetermined voltage levels. These voltage levels can be measured by the ADC and results thus obtained can be cross checked against the expected value to ensure proper functioning of DAC and ADC. This technique can be applied during run time as well to ensure that proper voltage levels are being driven from DAC.
For more information on the DAC channels that can be sampled by ADC without external board level connections, see the device-specific data sheet or technical reference manual. While performing the loopback checks for 12-bit differential input mode, two DACs should be used to provide input the ADC. To avoid common cause failures, it is recommended to keep the references voltages of the ADC and DAC different while performing the test. In addition, the input signal to ADC should not be driven by any other sources while the test is being performed.