Electronic Design

Single-Chip 802.11a/b/g Modem Opens Up WLAN Applications

Putting a complete 802.11 physical layer, media-access controller (MAC), and baseband on one chip isn't an earth-shattering feat these days. But put 802.11b/g 2.4-GHz and 802.11a 5-GHz radios on the same chip and keep interference from compromising the MAC and baseband circuits, and you've got something to talk about.

So get ready for Atheros Communications' AR5006X. This chip includes a MAC, a baseband processor, and high-performance radios for 2.4 and 5 GHz. Built into laptops, cell phones, and other portable devices, it can connect users to virtually any current Wi-Fi access point. The chip's low cost and low power consumption extend its usefulness to new markets, including consumer electronics and wireless Voice over Internet Protocol (VoIP) via hot spots, company access points, and home networks.

The AR5006X not only puts all of the key circuitry on one chip, it also significantly reduces the external discrete components needed to make a complete modem. It specifically eliminates up to 24 separate parts required by previous two-chip solutions. With 15% fewer parts in the reference design, there's a correspondingly lower-priced bill of materials. Performance isn't compromised either, even with all three standards implemented in the chip.

Its 802.11i security feature is based on the Advanced Encryption Standard (AES). Because the AES Encryption engine is built into the chip, full real-time encryption takes place with no performance degradation. WPA and WPA2 security measures also are included. The chip supports the WiFi Multimedia (WMM) standard as well as the 801.11e Quality of Service standard, which has yet to be ratified. Also incorporated is the company's Dynamic Turbo, which captures two channels to double the data rate to 108 Mbits/s. This enables a net user throughput of more than 60 Mbits/s.

The AR5006X includes Atheros' eXtended range technology (XR), which boosts receive sensitivity to −105 dB to double the overall communications range versus typical range. Consequently, it helps eliminate dead zones in home, enterprise, and hot-spot access points. This feature alone should seriously reduce the return of consumer wireless access devices due to their inability to work everywhere in the home or over the needed range.

Atheros is sampling the chip now, with full production later in the fourth quarter. It costs $12 each in 10,000-unit lots.

Atheros Communications Inc.

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