Volterra Semiconductor (Nasdaq: VLTR) reported earnings on Jan. 22. Here are the numbers you need to know.

The 10-second takeaway
 For the quarter ended Dec. 31 (Q4), Volterra Semiconductor beat expectations on revenues and beat expectations on earnings per share.

Compared to the prior-year quarter, revenue expanded and GAAP earnings per share dropped significantly.

Margins shrank across the board.

Revenue details
 Volterra Semiconductor reported revenue of $40.3 million. The 12 analysts polled by S&P Capital IQ wanted to see sales of $39.4 million on the same basis. GAAP reported sales were 3.8% higher than the prior-year quarter's $38.8 million.

Source: S&P Capital IQ. Quarterly periods. Dollar amounts in millions. Non-GAAP figures may vary to maintain comparability with estimates.

EPS details
 EPS came in at $0.28. The 10 earnings estimates compiled by S&P Capital IQ predicted $0.26 per share. GAAP EPS of $0.18 for Q4 were 18% lower than the prior-year quarter's $0.22 per share.

Source: S&P Capital IQ. Quarterly periods. Non-GAAP figures may vary to maintain comparability with estimates.

Margin details
 For the quarter, gross margin was 57.3%, 100 basis points worse than the prior-year quarter. Operating margin was 13.5%, 270 basis points worse than the prior-year quarter. Net margin was 11.4%, 330 basis points worse than the prior-year quarter.

Looking ahead
 Next quarter's average estimate for revenue is $40.4 million. On the bottom line, the average EPS estimate is $0.26.

Next year's average estimate for revenue is $179.1 million. The average EPS estimate is $1.31.

Investor sentiment
 The stock has a three-star rating (out of five) at Motley Fool CAPS, with 104 members out of 119 rating the stock outperform, and 15 members rating it underperform. Among 34 CAPS All-Star picks (recommendations by the highest-ranked CAPS members), 30 give Volterra Semiconductor a green thumbs-up, and four give it a red thumbs-down.

Of Wall Street recommendations tracked by S&P Capital IQ, the average opinion on Volterra Semiconductor is outperform, with an average price target of $24.35.

Is Volterra Semiconductor the best semiconductor stock for you? You may be missing something obvious. Check out the semiconductor company that Motley Fool analysts expect to lead "The Next Trillion-dollar Revolution." Click here for instant access to this free report.