Inphi Corp., the Santa Clara-based chip firm with a large engineering force in Thousand Oaks, ousted its CEO on Feb. 1 as it announced that profits plummeted by 93 percent in 2011.

Inphi designs chips aimed at packing more memory into Internet servers and increasing bandwidth in the Internet backbone. The company announced that Ford Tamer, a former venture capitalist who helped Khosla Ventures invest in several companies and has served as a turnaround executive, has become CEO effectively immediately.

Current CEO and President Young K. Sohn is retiring from the company and will not seek reelection to its board of directors at Inphi’s upcoming annual shareholder meeting, the company said. Sohn will stay on as a senior adviser through the transition.

The abrupt leadership change came just as Inphi said its revenues for 2011 declined to $79.3 million, a nearly 5 percent drop from the year before. Net income cratered, dropping from $26.1 million to $1.9 million – a decline of 93 percent.

Tamer, the new CEO, is no stranger to the Tri-Counties. He was involved in early investments in Kaai, a cleantech LED lighting startup founded on technology produced by UC Santa Barbara professors Shuji Nakamura and Steve DenBaars. It eventually combined with another firm and moved to Silicon Valley.

More recently, Tamer has been tapped as a fix-it CEO. He took the helm at Telegent, a Sunnyvale-based mobile television chip design firm.

That firm had filed for an initial public offering with more than $100 million in revenues and almost $40 million in profits, but later pulled the filing as it faced crushing pressure on its margins from Chinese competitors, according to EE Times, an electronic engineering industry magazine. The company was sold to a Chinese firm on Tamer’s watch.

Inphi’s own initial public offering in late 2010 was hailed as a success, with shares rising nearly 30 percent to the $15 to $16 range out of the gate. But its shares have taken a beating as the young firm ran into shipping delays for its products and lower-than-anticipated orders. But in the past two months, shares have rebounded to above the $14 mark.

“Inphi’s core competencies in advanced analog circuit design, signal integrity, power management, packaging, and process technologies should bolster the company’s ability to pursue solid growth in the years ahead,” Tamer said in a release.