UPDATE 1-iPhone 5 boosts Cirrus Logic's revenue; shares jump

Oct 31 (Reuters) - Audio chipmaker Cirrus Logic Inc , whose chips were used in Apple Inc's iPhone 5, reported a 91 percent jump in second-quarter sales and its forecast for current-quarter revenue crushed analysts' estimates.

Shares of Cirrus rose as much as 11 percent in after-market trading on Wednesday before settling back near their closing level of $40.78 on the Nasdaq.

Apple, which accounted for 62 percent of Cirrus Logic's total sales last year, said on Oct. 26 that its latest iPhone was heavily backlogged. Apple shipped 26.9 million iPhones in its fourth quarter.

Audience Inc, which has been a supplier to Apple, said last month the iPhone maker was unlikely to use its technology for the latest iPhone. Speculation had swirled that Cirrus replaced Audience for the latest iPhone.

Cirrus, which makes chips that decrypt audio signals, said it expects third-quarter revenue of $270 million to $300 million, way above analysts' estimates of $237.7 million, according to Thomson Reuters I/B/E/S.

Net income rose to $35.4 million, or 51 cents per share, for the second quarter, from $11.2 million, or 17 cents per share, a year earlier.

Excluding items, earnings were 79 cents per share.

Revenue rose to $193.7 million from $101.6 million, with audio products revenue more than doubling to $178 million from $83.6 million.

Analysts on average had expected earnings of 71 cents per share on revenue of $180.8 million.