Silicon Laboratories ( SLAB) topped earnings estimates and said its second-quarter revenue advanced 15% from last year, helping lift the microchip maker's shares Monday. Revenue rose to $123.5 million from $107.2 million a year ago, and the top line climbed 8% from the first quarter. However, Silicon Labs said its quarterly earnings fell to $10.1 million, or 18 cents a share, down from $15.6 million and 28 cents a share last year. Still, excluding items, the company would have earned 37 cents, exceeding Wall Street's consensus target by 4 cents. Analysts were also looking for revenue of $118.7 million. For the third quarter, the company anticipates revenue of $122 million to $127 million. The consensus forecast is $124.9 million, according to Thomson Financial. Shares of Silicon Labs were rising $5.38, or 18.2%, to $34.88 in recent trading. Volume was heavy. Additionally, the company said its board authorized a share repurchase program covering up to $100 million of stock during the next 12 months. Buybacks can be made in open market or privately negotiated transactions. "Product execution is our main priority, and we're starting to see the results of this in customer engagements on new products and strong demand for existing products," Necip Sayiner, president and CEO of Silicon Labs, said in a press release. "The expansion of our portfolio, the access to new markets and large customers and the potential of our R&D pipeline give me a great deal of confidence in the future growth and profitability potential of our business," he continued.