Asia Tech Wire (Sep 18) -- TSMC has begun producing Apple's A16 chips at its Arizona plant in the U.S., former Bloomberg Opinion columnist Tim Culpan said in a post on Tuesday, citing sources.

According to Culpan, TSMC is producing iPhone processor A16 SoC in "small but significant numbers" in the first phase of its Arizona plant using its enhanced version of 5nm process.

He said that this phase of production is primarily a test of the plant, with more production expected in the coming months.

Current yields at TSMC's Arizona plant are slightly lower than those in Taiwan, but the difference is not significant, Culpan said.

He added that he expects yields at the two sites to equalize in the coming months.