What is the difference between STM32WB55 and ES32WB55?

[e.li1]

Hi, I have two types of MCUs that I am building a board with. One is labeled as STM32WB55, while the other one is ES32WB55. Is there any difference between the two? I could not find any information on the ES32 chip in my Googling. I am having trouble connecting to the chip using an ST-Link. Does it have anything to do with the fact that I am using an ES chip?

Thanks.

[BRYAN SPEED]

ES , I think means Engineering Sample

[e.li1]

Thanks Bryan. That makes sense.

[Remi QUINTIN]

​Yes it is an engineering sample, which means it is a very early sample of STM32WB product which was not fully validated and may have some issues corrected in the final STM32WB devices delivered on the market.