Apple loses key chip executive

Dan Dobberpuhl, the PA Semi founder and CEO who came to Apple with the acquisition of his company, has apparently jumped ship to work at a chip-related start-up.

Apple acquired PA Semi in April of 2008 for $278 million. At the time, Apple CEO Steve Jobs said the company was purchased to design system-on-chips for iPhones and iPods. Dobberpuhl was the leader of the team Apple hired.

Apple did not respond to inquiries about whether Dobberpuhl was still at Apple. Several sources said Dobberpuhl's departure was not recent and may have happened as long ago as last fall or possibly before that. Sources said they believe Dobberpuhl has joined Amarjit Gill, a former PA Semi principal, at Silicon Valley start-up Agnilux.

Dobberpuhl isn't alone. Other key PA Semi team members have left Apple, including one of PA Semi's leading members, Mark Hayter.

Linley Gwennap, president and principal analyst of The Linley Group, said Dobberpuhl was the leading light at PA Semi.

"He was the CEO at PA Semi and leader of the team, and one of the guys that was driving the whole thing," Gwennap said. But "those guys are start-up kind of people, and within the structure of Apple, they may [have been] chafing."

It is not clear if the PA Semi team hired by Apple contributed to the design of the iPad's A4 chip, which Apple describes as a "custom-designed, high-performance, low-power system-on-a-chip."

Ashok Kumar, an analyst Northeast Securities, believes, like other analysts, that the central processing unit, or CPU, inside the iPad's A4 chip is based on a design from United Kingdom-based ARM, which licenses intellectual property to a number of large chip suppliers, including Qualcomm, Texas Instruments, and Nvidia.

But while some chip talent is leaving Apple, others are joining. Last year, Apple picked up Bob Drebin, former chief technology officer of the Graphics Products Group at chipmaker Advanced Micro Devices, who is now listed as a senior director at Apple.