It is good writing practice, even in technical documents, to spell out an acronym the first time it is used in your document.

> We first designed Tensor Processing Units (TPUs) more than a decade ago motivated by Google’s...

Literally all it takes. Basically free and it helps both broaden your audience and avoid mistakes. Also, high key, it is a great opportunity for a back link to https://cloud.google.com/tpu, which you'd think Google would care about.