Teardown Reveals A Mystery Chip Inside Apple’s Lightning To 3.5mm Audio Jack Dongle


Apple's iPhone 7 was released last month that disappointingly didn't feature a headphone jack. To compensate, Apple did include a Lightning to 3.5mm audio adapter that will let you use your old headphones with the new iPhone 7 and 7 Plus. However, a teardown has been revealed by the folks over at iFixit that shows a mystery chip found inside the dongle. Let's see some more details on the teardown.

iFixit Teardown Reveals A Mystery Chip Inside The Lightning To 3.5mm Audio Jack Adapter

Other than this, Creative Electron provided an X-ray image of the audio adapter to the site. The X-ray image clearly shows the mystery chip which is most likely a DAC. What purpose could this chip boast if its not likely to be a DAC?

As expected, one end is a simple female 3.5 mm headphone jack, and the other end is a male Lightning connector. But what’s all that silicon around the Lightning connector end? Most of the retail space near the connector is taken up by a single mystery IC.

As the user oldturkey03 managed to slice open his audio adapter, the marking over it does not suggest much about the chip. It only states that the chip is from Apple.

He uncovered that mystery IC by the Lightning connector, marked 338S00140 A0SM1624 TW—which doesn’t tell us much, other than it’s an Apple part number.

According to iFixit, the exact purpose of the IC is unknown, but it is believed that it contains a ''digital-to-analog converter (DAC) and amplifier, and its counterpart, an analog-to-digital-converter (ADC).'' This is because all audio accessories need analog signals to work and unlike the antique 3.5mm headphone jack, the Lightning connector is digital. DAC is used to bridge the gap and by that it can be said to contain an ADC circuit for converting analog signals to something that can pass through the Lightning port for our iPhones.

Audio Jack

In terms of the Lightning audio adapter performance, the sound quality falls ever so slightly which will not be noticeable to some users. We can, hence, state that the audio quality on the iPhone 6s and 6s Plus is a little greater than what we will adhere to on the iPhone 7 and 7 Plus. For more details on the scenario, be sure to read the full analysis here.

This is it for now, folks. We will surely keep you updated for more details. As for now, what do you think about this teardown? Share your thoughts with us in the comments.