Littelfuse (LFUS -0.20%) announced better-than-expected first-quarter results last week. But following an initial surge in price, shares of the circuit protection specialist have largely given up their gains and currently sit almost exactly where they stood before the report. So what gives?

For one, both the initial jump and Littelfuse's beat were relatively modest. Quarterly revenue climbed 2% year over year (6% on a constant-currency basis) to $210.3 million, which translated to GAAP net income of $20 million, or $0.88 per diluted share. On an adjusted basis -- which means excluding items like ongoing restructuring expenses and non-operating foreign exchange losses -- earnings came in at $1.08 per share.

Analysts, on average, were only expecting revenue and adjusted earnings of $207.1 million and $1.05 per share, respectively.

"Mostly solid"
"While there was a lot of 'noise' in the first quarter related to currency fluctuations and restructuring projects," elaborated Littelfuse CEO Gordon Hunter, "the fundamental business trends and operational performance were mostly solid."

Similar to last quarter, Littelfuse's top line was driven by a 4% increase in its electronics segment to $99.4 million, a 2% gain from automotive to just under $84.1 million, and a 6% decline in its smaller electrical segment to roughly $26.9 million. Automotive, in particular, achieved its gains despite sluggish market growth in China and euro headwinds. And speaking to Hunter's "mostly solid" description, the pullback in Littelfuse's electrical business was caused by continued weakness in the mining sector and, in part, a weather-induced slow start to 2015 in industrial markets.

Speaking of which, Littelfuse also noted that for an undisclosed sum it acquired the assets of JRS Mfg. Ltd., a Canadian manufacturer of portable "e-houses" for distributing power in -- you guessed it -- mining and industrial applications, on April 16, 2015. These assets won't materially contribute to Littelfuse's financial results in 2015, but it's encouraging to know the company is willing to take advantage of short-term weakness in these markets in favor of bolstering its leadership position.

For the current quarter, Littelfuse expects revenue of $221 million to $231 million, the midpoint of which represents roughly 2% growth (7% excluding currencies) over the year-ago period. This should translate to adjusted earnings in Q2 of $1.20 to $1.35 per share, including a negative $0.13-per-share impact from foreign currencies. Analysts' consensus called for second-quarter revenue near the low end of that range at $222 million, but with earnings just slightly above Littelfuse's midpoint at $1.29 per share.

Finally, management offered some color on their full-year expectations. First, Littelfuse's full-year effective tax rate is expected to be roughly 23%, but this assumes Congress approves the R&D tax credit and the "look-through" provision this year as it did in 2014. Until that happens, Littelfuse is assuming its tax rate will be 50 to 100 basis points higher.

In addition, Littelfuse CFO Phil Franklin reminded investors that, during last quarter's report, the company stated it believed it could achieve full-year 2015 earnings of at least $5.00 per share -- and that's not necessarily the case anymore.

"Our business fundamentals have not changed since then," Franklin elaborated, "and so far execution has been good; however, currencies (particularly the euro) have moved further against us. Our current view is that at a euro-dollar rate of $1.13, $5.00 per share or more would still be achievable, but each 1% move in the euro has a full-year earnings impact of approximately $0.024 per share."

For reference, the current euro-dollar rate is 1.14.

That's fair enough; currencies inevitably ebb and flow, and Littelfuse is hardly the only business to suffer from and worry about the negative impacts of foreign exchange this quarter. Keeping in mind this doesn't signal an underlying problem with Littelfuse's core businesses, and in the absence of any big surprises this quarter, it appears Littelfuse's long-term thesis remains intact.