What happened

Shares of Littelfuse (LFUS -0.40%) surged on Wednesday after the company reported its first-quarter results, easily beating analyst estimates for both revenue and earnings. Strong organic revenue growth across all the company's segments, as well as additional revenue from acquisitions, drove Littelfuse's impressive results. As of 12:15 p.m. EDT, the stock was up 14.3%.

So what

Littelfuse reported first-quarter revenue of $417.8 million, up 46% year over year and $26.3 million higher than the average analyst estimate. Most of this growth was driven by the acquisition of IXYS, which the company completed in January. But even excluding that extra revenue, organic revenue grew by 10% year over year.

A Littelfuse Industrial Shock-Block SB6100

Littelfuse Industrial Shock-Block SB6100. Image source: Littelfuse.

Electronics sales jumped 72%, or 10% organically; automotive sales rose 17%, or 10% organically; and industrial sales surged 14%, or 13% organically.

Non-GAAP earnings per share came in at $2.38, up 41% year over year and a whopping $0.58 higher than analysts were expecting. EPS was $1.45 on a GAAP basis, down from $1.69 in the prior-year period. The decline was due to charges and costs related to the IXYS acquisition.

Littelfuse CEO Dave Heinzmann summed up the company's results:

We are off to a strong start integrating the IXYS business, and have taken initial steps to drive synergy realization. Leveraging the broad-based demand across our businesses, we expect robust top-line growth and consistent operating margins in the second quarter. We are focused on the right growth opportunities to continue executing our long-term strategy and driving double digit sales and earnings growth.

Now what

Littelfuse expects to generate between $450 million and $462 million of revenue during the second quarter, up 45% year over year on a reported basis and up 8% organically at the midpoint of that range. Non-GAAP EPS is expected between $2.39 and $2.53, up 17% at the midpoint.

With Littelfuse blowing analyst estimates out of the water and providing guidance calling for continued organic revenue and earnings growth in the second quarter, investors have no shortage of reasons to bid up the stock.