If there was a complaint to be made about Broadcom's (NASDAQ:BRCM) industry-beating performance in 2009, it was that the performance was uneven, with certain key product lines performing much better than others. But if the Q4 results it released yesterday are any sign, the company is starting 2010 on more even footing.

For much of 2009, Broadcom's Mobile & Wireless division did very well. The division boasts an emerging baseband processor business that counts Nokia (NYSE:NOK) and Samsung as customers, and its spectacularly successful "combo chip" products, which integrate some combination of Bluetooth, Wi-Fi, GPS, and FM radio functionality, grew to account for over 10% of Broadcom's 2009 sales. Likewise, the company's Enterprise Networking division, after getting off to a rough start, had rebounded quite well by Q3, thanks to strong demand for Broadcom's high-margin switching chips in a variety of enterprise and telecom end-markets.

The broadband division rebounds
But going into yesterday's earnings, Broadcom's Broadband Communications division looked like it was on shakier ground. While the other divisions reported 30%+ sequential growth in a seasonally strong third quarter, Broadband Communications registered only 9% growth, with Broadcom citing competitive issues in its digital TV chip business (acquired from AMD (NYSE:AMD) in 2008) as a culprit. And the weak results and guidance delivered last week by Motorola's (NYSE:MOT) Home & Networks Mobility division, historically a major buyer of Broadcom's cable modem and set-top box chips, didn't inspire much confidence in the division's prospects either.

So it was at least a little surprising to hear Broadcom report yesterday that Broadband Communications outpaced the company's expectations by delivering 14% sequential growth in Q4, driven by cable modem and set-top box chip demand. This was just slightly below the 18% growth seen by Enterprise Networking, and well ahead of the 4% decline that Mobile & Wireless saw due to seasonal factors (manufacturers often build chip inventory in Q3 for consumer products they expect to ship in Q4).

Furthermore, along with the other divisions, Broadband Communications' sales are expected to be flat or slightly higher in a seasonally weak Q1. That's one big reason why Broadcom's implied first-quarter revenue guidance range of $1.34 to $1.41 billion blew away the $1.24 billion that Wall Street had it pegged for prior to yesterday. And with Broadcom expecting the digital TV chip business to recover and become a growth driver in 2010, there's a good chance that the division can sustain its momentum for the rest of the year.

A week of good news
Even if you ignore yesterday's earnings, this has been a pretty good news week for Broadcom. A report from Digitimes stated that the company, which already has its combo chips built into Apple's (NASDAQ:AAPL) iPhone and iPod Touch, had both a Wi-Fi/Bluetooth combo chip and a touchscreen controller designed into the iPad. Meanwhile, the company's $123 million acquisition of Teknovus quickly makes it, along with rivals PMC-Sierra (NASDAQ:PMCS) and Marvell Technology (NASDAQ:MRVL), an important player in the rapidly growing market for fiber-to-the-home chipsets -- and does so at a reasonable price.

For investors, I'd say that nothing is more important than seeing a key part of the business -- that was previously a weak link -- starting to perk up.

Eric Jhonsa has no position in any of the companies mentioned. Nokia is a Motley Fool Inside Value pick. Apple is a Motley Fool Stock Advisor recommendation. Try any of our Foolish newsletters today, free for 30 days. The Motley Fool has a disclosure policy.