Separate module
The second National Semiconductor part resides within a separate surface-mount module that forms the radio interface. The modular radio subsystem integrates the National LMX4270C radio transceiver and associated discretes within a shielded module whose design parallels that found within the Xbox 360 console itself. Here again, the die photograph reveals a combination of analog RF circuitry and logic, which likely implements the digital aspects of the radio architecture. FCC filings clearly indicate an ISM-band 2.4-GHz center frequency for the transceiver.

Related FCC filings also lead to some confusion about the part indicated as a delay line or MOSFET, a site unpopulated in the FCC photos. Similarly, a small regulator is shown in the FCC filing, although this same part was not present in the unit we analyzed.

The most likely explanation for this is a board design whose layout allows flexibility in features that were an uncertain element of the SC14470C during its development.

The presence of a large coil and tantalum capacitor certainly points to the presence of a dc/dc converter, for example, but it seems the semiconductor aspects of same must have made it into the SC14470C, given the lack of a discrete regulator. Mystery solvers, drop me a line of you figure this one out.

Bill-of-material estimates for the wireless controller come in at around $11, or 22 percent of the retail price for the product--a far cry from the negative margin of the console itself. While Call of Duty and Madden NFL 2006 may be examples of the obvious profit play, the add-ons in the hardware arena certainly help in the overall equation. Play on!

By David Carey, president of Portelligent. The Austin, Texas, company produces teardown reports and related industry research on wireless, mobile and personal electronics (www.teardown.com).

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