PA Semi helped in the development the chips and engines that run the iPhone, iPad and iPod. At the time of the acquisition in 2008, PA Semi was working on chips based on the Power architecture, but that was abandoned and the new personnel were moved over to work on Apple's ARM-based chips.
"We will do more [acquisitions], we are constantly looking in the market," Cook said. "Cash is not burning a hole in our pocket."
The company is not under pressure to acquire new revenue streams and will look to acquire companies with complementary skill sets and offerings, Cook said. Apple has a cash reserve of $137 billion.