Dan Dobberpuhl, founder and CEO of P.A. Semi, has left Apple to join several other former P.A. Semi employees at a new start-up. Citing multiple anonymous sources, Cnet reports that Dobberpuhl’s departure from Apple was not recent, and may have happened as early as fall 2009. “He was the CEO at PA Semi and leader of the team, and one of the guys that was driving the whole thing,” said Linley Gwennap, a chip analyst at the Linley…