CCS/TMS320F28069: Generating square wave from sine wave using ADC

Ayushi,
Here are my thoughts on testing the ADC pins on this device:

If you need a very finite guarantee that all the pins are proper, then you will need to provide an input to each of them and convert each channel to verify operation. There is not a direct way to do this on the device, however, you could potentially route a PWM pin to a RC filter to create a analog output that changes based on the PWM duty cycle. You would still need to deal with the presence of that RC on each pin when they are used in the system, however.

There is another option, that would not need any external connections, but would be less complete in terms of performance guarantee.

Using the temp sensor on ADCINA5 as well as the VREFLO connection on ADCINB5, you could convert these options and then convert the open channel A5/B5 and note that the ADC converted value moves. This will be due to the internal voltage nets of the ADC (assuming nothing is driving the pin); and while there is no spec on this voltage, it will be different than the VREFLO conversions, and almost certainly different than the conversion of the temp sensor.

This would at least tell you both S/H capacitors are working and can charge to different values. There is no check of precision here, just function.

Best,
Matt

Thank you sir for suggestions!

I tested ADCINA5 on one of the board , i think it gives accurate values on eval board but not on customize board.

But is there any example which I can follow for converting analog signals to digital in TMS320F28069?

and if possible can you explain in brief about function of adc_soc example, by reading I understood after soc adcina2 and adcina4 wait for interrupts and starts to get convert in digital in steps but o/p doesnot make any sense. how can I verify outputs?

Ayushi,
As you mentioned that example is using ADCINA2 and ADCINA4 pins to sample a voltage. Now, on the control CARD or LaunchPAD there is not a votlage connected to the pin, so an external source would need to be connected to those pins to get a reliable reading.

If nothing else is done then the ADC is sampling floating pins will be non-deterministic.

Best,
Matthew