TMS320F28069: Using of Internal or External ADC for TMS320F28069

odrigo,

I assume the question is for your application of a shunt active power filter, is the internal 12-bit ADC on the F28069 good enough, or do you need to use an external ADC.

It really comes down to the spec you need for your control algo to be stable;

1)Resolution

2)Sampling Speed

3)Total Error

4) Acceptable Latency  

All of these can be found in the F28069 DS here:

http://www.ti.com/product/TMS320F28069/datasheet/adc-electrical-characteristics-sprs6981227#SPRS6981227 

Best,
Matthew