TMS320F28377D: The question about the ADC conversion time of TMS320F28377D,pls help

Part Number:TMS320F28377D

Dears

We are evaluating the TMS320F28377D and TMS320F28335 recently,but there is one problem has been bothering us for several days.We need your urgent help now,pls and thanks.

Pls refer to the pic as below,we found that the ADC conversation time of 28335 is shorter than 28377D,and we think 28377D is higher performance device with the better ADC module,but the truth is that 28377 integrated one slower ADC module.We could not understand the reason now.For our 24GHZ Radar project,28377D and 28335,how to choosing?

Thank you for help