Silicon Inside the Asus eeePad Transformer Prime

http://www.chipworks.com/en/technical-competitive-analysis/resources/recent-teardowns/2012/01/silicon-inside-the-asus-eeepad-transformer-prime/

Silicon Inside the Asus eeePad Transformer Prime

The Silicon Story The Asus Transformer Prime presents an interesting story from many angles. The first look inside showed a general look at the chips where we saw a fairly simple circuit board with a focus on the newest and greatest in only a couple of the sockets.  You could conclude that it was those with the highest performance impact to the user. There is also an interesting IP story of sorts because Hasbro, the makers of the Transformers Optimus Prime robot toy are suing Asus for trademark infringement. We wonder if there is a functional Optimus Prime Robot that we can reverse engineer to look for electronics patent hits on IP that Asus owns. And finally, the silicon itself. And there are at least four interesting stories to be discussed: the processor, the touch screen controller, the WiFi chip, and the primary camera.

The Processor The processor in question is none other than the first proven commercial use of the nVIDIA Tegra 3. For a mobile chip this processor is very large and 60% bigger than the prior Tegra 2, at the same process generation.  Making room for more cores, room for what one nVIDIA CES 2012 presenter calls the “ninja” core, and of course all the power management and I/O.  This die is interesting in that there are 4 digital regions in the middle of the chip that are separated from the rest of the digital logic by an array of (what appears to be) capacitors. There is also a physical separation from the I/O region and the main logic and memory. We don’t tend to speculate on what blocks are what without providing specific evidence so we’ll be looking more closely at this chip in a Functional Analysis Report.  When compared to the Tegra 2 (at right), we see a lot of differences in layout, although the ratio of the die allocated to analog and digital blocks is very similar. (low resolution provided)

Broadcom Wi-Fi Chip One of the places where perhaps money was saved, or perhaps the timing for the original specification is revealed, is in the Wi-Fi module on the Asus Transformer Prime. Broadcom’s latest flagship product is the BCM 4330, and this devices uses theBCM4329. From our cataloging, the BCM4329 is the most successful WiFi chip in recent history, so from a functionality standpoint it is not really a compromise. Just a choice. The BCM4329 when compared the the BCM4330, is a larger die and does not use Bluetooth 4.0.

Touch Screen Controller The new flagship MXT768E from Atmel. Certainly new package markings versus the MXT540E we analyzed previously, but inside we see the exact same die right down to the ‘cut here’ markings. Atmel’s marketing bumph calls the mXT768E, “the industry’s first 32–bit single–chip touch controller for tablets and other large screen applications up to 12–inches. Based on Atmel’s ultra–low–power 32-bit AVR architecture, the mXT768E meets the increased demand on signal processing needed for rejecting unintended touches and maintaining responsiveness on large screens. The mXT540E and mXT384E devices, also based on the advanced 32–bit AVR architecture, offer system designers the right price–to–performance selection for their touchscreen designs, and are appropriate for smaller tablets, e–book readers and high–performance smartphones.” So the same die performing to different specifications.  This does not look like a case of binning because when you examine the bond pads in the die photos, the 768E has a number of pads with wire bonds that are not bonded in the 540E.  This approach lets Atmel incur only one set of design and die manufacturing costs, while delivering different price-performance parameters to clients. It makes good sense in many cases.

OmniVision BSI2 Hits the Street The Asus Transformer Prime’s primary image sensor is the first design win that we have found for OmniVision’s BSI2 technology. This is an 8 Mp back illuminated sensor with die markings AEQGG6 OV2B8B0 and according to the specifications the device is theOmniVision 8830. Features that show it to be BSI2 include the suspected TSVs located on either side of the bond pads (shown at right) and the copper metallization found during SEM analysis (EDS spectrum not shown). We have launched a full Imager Process Review  on this device.