Atmega32u4- MU Slightly different part numbers

[Pedro147]

I purchased two lots of Atmega32u4- MU IC's from Element14 and Digikey. I searched for both parts using the manufactures part number of ATMEGA32U4-MU to identify them at the two suppliers prior to ordering them. The parts from Digikey are marked Atmel Mega32U4 - MU 1448E TH A2KHXA whereas the ones from Element14 are marked Atmel Mega32U4 - MU 1604E PH A35U3A Both are QFN44 but i am perplexed as to what the different suffix to  part numbers mean. Any help appreciated please

[wraper]

Nothing that you should care about. Apart from from the date code, manufacturing plant and lot number.

[Pedro147]

Thank you for your reply @wraper I can now sleep easy tonight   Have a great day