Apple Shuffle Non-DRM Chip Undressed

Contributed by Gary Tomkins

The new iPod shuffle has caused quite the “tempest in a teapot” over the last couple of weeks with the knowledge that the iPod contains no controls in the main body, only in the headphone cable. And standard headphones will not work with the iPod.

First off let me state . . . what a daft idea,  a sure way for most of us to avoid buying one! I say this as someone who loves his Macbook, an owner of four Macs (and a working version of the original Mac-only iPod, and Shuffle). I am probably regarded as a “Mac Fanboy” here at Chipworks. Steve Jobs what were you thinking? I am pretty sure when my current Shuffle dies, it will not be replaced by one of these . . . end of rant.

Anyway, back to the chip – the now infamous 8A83E3 (or 89S3E3 seen in some versions). Early speculation suggested that it was a DRM chip, which clearly would be a very, very bad thing. Fortunately this has been refuted by Apple, and it is just a proprietary control chip. Apparently part of a “made for iPod” licensing program that will incur additional charge to manufacturers wanting to make headphones for the iPod. So, it’s just a bad thing. Obviously some circuitry is required to control the iPod, and if you have no interface with the iPod, it has to be in the cable somewhere.

One long-shot rumour is that the chip actually contains a microphone. As Apple does sell headphones with microphones, it’s just possible that they are using the same device and activating the microphone through software. So I thought I would throw our labs at this part and take a peek at what is inside this chip.

Here is the black “Apple goodness” with the Apple headphones that I would typically throw out, as they don’t fit my ears.

The small board with the actual headphone wires passing through the controller.

Our chip is not the 8A83E3 or 89S3E3 that has been posted elsewhere; ours is the 8CT3E3. So we have an 8xx3E3. The 8xx is likely a date code or wafer identifier.

The packaging is actually pretty unusual. It is a chip-scale bare die assembly, where the die has an RDL (metal redistribution layer) and solder balls directly flip chipped to the board. The die marking is a laser marking on the back of the silicon die.

Here is the die “undressed.”

It’s a small, 1.35 mm x 0.85 mm, die made by Texas Instruments with die markings of CDPS3271C.

The die markings clarify the part number, which is actually a typical TI date code. The 8x represents the year and month, and the next four characters are the lot code. Therefore, our three parts were made in September ’08 (89), October ’08 (8A), and December ’08 (8C).

Taking a peek at it down the microscope, it looks like it is fabricated with a three metal BiCMOS process, likely 0.25 µm or 0.18 µm. There is not really a lot of circuitry on the die, but then again how much is really needed to relay the button commands to the processor chip – just the volume controller and the interface for the capacitative sensors on the back of the board.

So no DRM, no microphone; just a high volume design win for Texas Instruments.