Apple is buying part of European chipmaker Dialog Semiconductor in an effort to bring more of its silicon design in-house. The deal includes $300 million in cash to license some of Dialog’s power management technologies, acquihire 300 engineers, and take control of some assets. A further $300 million is being committed for products from Dialog over the next three years.

As TechCrunch notes, this is Apple’s biggest acquisition ever when it comes to headcount. While Apple isn’t acquiring Dialog outright, the 300 engineers make up 16 percent of its total workforce, and are said to have been working closely with Apple on chip design for years.

Apple’s biggest acquisition ever in terms of new headcount

“Dialog has deep expertise in chip development, and we are thrilled to have this talented group of engineers who’ve long supported our products now working directly for Apple,” hardware SVP Johny Srouji says in a statement. “Our relationship with Dialog goes all the way back to the early iPhones, and we look forward to continuing this long-standing relationship with them.”

Last year the Nikkei reported that Apple was looking to design its own power management chips and move away from Dialog; earlier this year Dialog said Apple had cut orders, and teardowns suggest that Apple may have started using its own design in place of a certain Dialog chip in the iPhone XS Max. This acquihire is likely a way to bring Dialog’s R&D under Apple’s umbrella, with future designs becoming Apple IP that the company is free to use and modify at will.