What is the meaning of the 51/52 of NRF51/52?

[Andrew]

I am just curious, do the numbers 51 and the 52 have any meaning? Does the base of 50 imply anything? Are these just arbitrary numbers for the sake of good marketing?

[Nguyen Hoan Hoang]

51 or nRF51 refers to the nRF51822, nRF51422 series SoC (Cortex-M0) 52 or nRF52 refers to the nRF52832, nRf2840, nRF52180 series SoC (Cortex-M4F)

They represent 2 different family of Soc

[endnode]

i guess only Nordic can answer (and I believe they won't tell you that 5 is favorite number of their CEO even if it is true so I'm not sure what are you hoping for) but you've noticed that before nRF5x fully flexible 2.4GHz SoCs they had/have nRF2x series and that they are now working on LTE based low-power cellular network chip in nRF9x series? So the probable answer seems to be "just to distinguish clearly product families and key common features to bring them to market";)

[Joakim Jakobsen]

Hi Andrew!

Like the previous answers stated, I'm afraid the numbers in nRF51 and nRF52 does not have any special meaning to them. They are simply product names, made to clearly distinguish between Nordic's product series.

Best regards
Joakim