Camarillo-based semiconductor firm Semtech plans to buy a Canadian chipmaker for $494 million.

The agreement to buy Burlington, Ontario-based Gennum is Semtech’s second large acquisition since 2009, when it closed a deal to buy Irvine-based Sierra Monolithics for $180 million.

The Gennum deal fits neatly into the strategic plan put in place by Semtech’s leadership in the past five years: A focus on Internet bandwidth, energy efficiency and miniaturization, paired with a turn toward commercial products that sell at lower volumes but better margins than chips that go into consumer devices.

Gunnum makes chips that allow video, data and multimedia content to be transmitted at high speed over long distances. Its focus is on the commercial and infrastructure markets in big cities and at big companies. Semtech’s leaders said they also expect Gennum to make the firm a player in the broadcast and HD transmission markets.

“I’ve set a goal now of becoming a billion-dollar company,” Mohan Maheswaran, CEO of Semtech, told the Business Times in 2011. The company’s most recently reported full-year revenue was $454 million, and it has about $250 million in cash on its balance sheet.

Semtech said it expects to finance the acquisition through a combination of cash on hand and new bank financing. In a release, it said it has received a financing commitment of up to $400 million from Jefferies Finance.

The deal will need the approval of two-thirds of Gennum shareholders and from Canadian authorities. Semtech shares were up more than 8 percent to $29.22 the day after the deal was announced.