ATMega328P-MUR /AUR /MMHR /ANR what is the difference?

What is the difference between these ATMega328P chips and how do I choose the right one for my application? I take Digikey as an example after searching for ATMega328P the following micro controller IC’s come up:

ATMEGA328P-AUR
ATMEGA328P-MUR
ATMEGA328P-MMHR
ATMEGA328P-ANR
also some chips are marked as ATMEGA328PB-MUR etc.

I am simply trying move my Arduino Nano project onto a PCB have have a bunch of them produced. After which I want to flash the Arduino boot loader onto the produced PCB’s and program them through the Arduino IDE.

Are the letters after the hyphen of relevance in this situation?

Is there something in particular I should look out for?

I see the official Arduino Nano schematic references the ATMega328P-MUR

I have also seen this project and schematic which references the ATMega328P-AU

TheAliw1:
ATMEGA328P-AUR
ATMEGA328P-MUR
ATMEGA328P-MMHR
ATMEGA328P-ANR

The information is all available to you in table 38.8 of the ATmega328P datasheet:

Unfortunately the absolute dummies seem to have used white on white text for the table that cross references their package code to the description of what that code means.

This tells you several things about the part, including: IC package, and the operational range of temperatures the chip is rated for:
ATMEGA328P-AUR: TQFP-32, -40C to 85C, packaged as tape and reel
ATMEGA328P-MUR: QFN-32, -40C to 85C, packaged as tape and reel
ATMEGA328P-MMHR: QFN-28, -40C to 85C, packaged as tape and reel, NiPdAu Lead Finish
ATMEGA328P-ANR: TQFP-32, -40C to 105C, packaged as tape and reel

TheAliw1:
also some chips are marked as ATMEGA328PB-MUR etc.

The ATmega328PB is a different microcontroller from the ATmega328P. In many ways (but not all), it is an upgrade from the ATmega328P, while remaining pin compatible so it can act as a "drop in replacement". See the datasheet for details:

Thanks Pert for the excellent reply!

I didn't get to page 635 of the data sheet yet :cold_sweat:

As always, the data sheet seems to be the answer :cold_sweat:

I found the answer to my followup questions but I want to address them here for completeness as I imagine people new to electronics might have the same questions coming up like me:

What are TQFP-32, QFN-32, QFN-28 and 32A 28M1 28M1 32M1-A 28P3?
Theses are:
32A = 32-lead, Thin (1.0mm) Plastic Quad Flat Package (TQFP)
28M1 = 28-pad, 4 x 4 x 1.0 body, Lead Pitch 0.45mm Quad Flat No-Lead/Micro Lead Frame Package (QFN/MLF)
28P3 = 28-lead, 0.300” Wide, Plastic Dual Inline Package (PDIP)
32M1-A = 32-pad, 5 x 5 x 1.0 body, Lead Pitch 0.50mm Quad Flat No-Lead/Micro Lead Frame Package (QFN/MLF)

pert:
Unfortunately the absolute dummies seem to have used white on white text for the table that cross references their package code to the description of what that code means.

Black text on a white background is much better here :slight_smile:

Section 39: "Packaging Information" goes through the package and solder pad size in much more detail. These are the following pages in the data sheet.