Some Infineon part numbers have a 5 digit suffix they refer to as OPN (Orderable part Number) suffix.
The Example number NTMA1 can be broken down into 3 sections.
N - The first digit will call out Hal free, RoHS compliant & Totally lead free status of the part.
TM - The Second and Third digits will call out the Packaging type, Moisture Protection Packaging and Packing size**
A1 - The Fourth and Fifth digits are designators. When all of the above is the same for a specific part, however there is a slight variance such as temperature range there will be a designator that will signify a difference.
For a full list of options for digits 1-5 Click Here