SemiSerious

Steve Jobs may have a golden touch, but who would have ever connected Apple’s iPhone to the sixties Bond classic, Goldfinger? Well, some folks at Cambridge Silicon Radio (CSR) did. Some CSR chip designers were either great James Bond fans or not quite fans of one particular project. (I trust they weren’t talking about Steve.) The design is the Bluecore 4 chip found in the iPhone that provides the iPhone’s Bluetooth capability. One of the die markings is “Oddjob” and there is also die art of that character from Goldfinger. Being an admirer of the Bond series more than a fanatic, I have to thank CSR for adding the written reference to Oddjob.

But there are even some technically interesting features of one of the iPhone’s radio modules. The Wireless LAN (WLAN) IC is particularly interesting. The Marvell 88W8686 transceiver is the first device on the market that integrates RF functionality on a 90nm logic IC.  (The 90nm technology node is confirmed by a 6T SRAM cell size of 1.14 square microns.) The Marvell 88W8686 chip is advertised as the world’s first ultra-low-power, 90nm (WLAN) single-chip solution. The device integrates an ARM compliant CPU, and high-speed serial host interfaces. The advanced RF transceiver supports the IEEE 802.11 a/b/g standards. Marvel uses a thick Media Access Control (MAC) architecture in their design to offload the host CPU resulting in lower power consumption and increased system performance. I suppose it is no surprise that we gave it an Insight Award for innovation this year.

It is interesting to note that while both the Marvell 88W8686 and the CSR Bluecore 4 die are found separately on the iPhone, they are again bundled as a WLAN and Bluetooth system-in-package (SiP) solution in the Wi2Wi W2CBW003. The Marvell 88W8686 device provides for both traditional bond wires as well as flip-chip packaging options to allow the form factor of the SoC to be as small as possible depending on the users specific bonding requirements.

A third option allows for wafer scale packaging or mounting another packaged device directly onto the large metal areas before going ahead with wire bonding to the traditional IO ring. These bump pads are 200 microns in diameter and are placed throughout the chip. I guess it’s that package-on-package flexibility that makes it right at home in the iPhone.
 

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