You can download a version of sqlite3 database from

https://code.google.com/archive/p/northwindextended/downloads

Advantage: It is available immediately. Click and use.

If it's simply to get a sample database for general testing, then just use what's immediately available. If you require an exact copy to match testing results (for instance), then download and convert MS data yourself to ensure exactness since the file's header indicates modifications and added foreign keys and contains no other certification of content. You really need to answer this for yourself based on your own requirements.

Without knowing anything about the conversion process, I would at least guess that the date values are not precisely the same since sqlite has no native DateTime type, rather such values would have needed to be converted to string values and/or Julian numeric values. Of course the values themselves may represent the same dates and times, but processing of query data would certainly require special handling. BLOB values for images should also produce the same images, but retrieving and using those values will likely be different than getting them from other databases. I suppose there could be other data values/types that different handling would apply since sqlite really has no distinct, strict numeric types, rather just type affinities.