Apple iPhone 4S: How about a peek under the hood?

Friday was the first day to get your hands on an Apple iPhone 4S. I saw a photo in the San Jose Mercury News of Steve “Woz” Wozniak sitting in a lawn chair camped out at a local Apple store. He was queued up first in line to pick up one of the new phones. Meanwhile, there are several engineers around the world busily tearing apart their copies of the iPhone to give you a peek at the innards. You can see examples of this teardown work on the Chipworks and iFixit Web sites.

Of particular note to me is the analysis on that identifies the SDRAM packaged inside of the Apple A5 processor. Anandtech claims that there are two LPDDR2 SDRAM chips inside the package-on-package device for a total of 512Mbytes. Further, says the site, the A5 SoC die has two LPDDR2 channels to drive these two SDRAM die, which it infers are LPDDR2-800 parts based on the part number stamped on the A5 processor’s package. Quite a bit of detective work there.

Also of interest to me was the Chipworks analysis of the 8Mpixel camera sensor in the Apple iPhone 4S. We knew it was 8Mpixels and we also knew it was a backside-illuminated sensor, so I had assumed it was from Sony. Chipworks confirmed my assumption using an industrial infrared camera to look through the silicon of the back-illuminated sensor die. Here’s a cropped and contrast-enhanced image of that sensor logo from the Chipworks Web page:

What another great piece of detective work!

The package-on-package memory in the A5 processor and the Sony backside-illuminated sensor are both 3D IC devices. For a more comprehensive look at the current state of teardown, see the Chipworks Web site.


About sleibson2

EDA360 Evangelist and Marketing Director at Cadence Design Systems (blog at
This entry was posted in EDA360, Mobile, Silicon Realization, SoC, SoC Realization, System Realization and tagged , , , , . Bookmark the permalink.

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