Uncovering the secrets of the iPhone 4's internal chip: How did Apple engineers solve the noise interference problem?

Back in January, Google disassembled the Nexus One, and the biggest highlight was the Audience audio processor. The Audience chip integrates two advanced microphones (if you measure it , you'll find it's larger than most phones) to eliminate ambient noise. This unique design improves the quality of audio in noisy environments, making the superior performance of the microphone a major selling point for the Nexus One. (The other selling points of the Nexus One still rely on Android updates .) The design of the Nexus One was mainly completed by Audience, which brought the A1026 audio processor to the world stage. The bright yellow area in the figure below shows the chip products of Audience in the Nexus One phone:

I remember when the iPhone 4 was disassembled, it was also shown that it had two microphones. At that time, we didn't know what it was, and just analyzed it very vaguely, saying "this can effectively remove external noise and improve the sound effect." In fact, we don't know whether this is a sound processor developed by Apple itself or a technology licensed from a third party.

It was a small chip, only 3mm x 3mm, and we were unable to confirm what function it had from the disassembly. There was a white label on the chip, which meant that Apple required chip manufacturers to remove their company's brand when packaging the chip, making it impossible to identify the chip. The chip was engraved with '10C0 01S8 0077'. We racked our brains to search all databases for this data, but in the end we found nothing and ended up with nothing. However, this incident came back to haunt us in February this year. At that time, we disassembled the newly acquired Verizon (CDMA) iPhone 4 ( CDMA iPhone 4 Disassembly ). You can find the small chip to the right of the A4 processor in the picture below:

We are always looking for the unknown, just like the guy we are going to introduce below. Therefore, we decided to do a thorough investigation of this chip! A friend at Chipworks dissected this unknown chip. Guess what they found? Yes, it is a low-power audio signal processor from Audience. As the most powerful evidence, the following picture shows the word "Audience" on the chip's internal grinding scratches:

The chip's internal package is mainly an embedded digital signal processor with front-end analog . Thanks to Chipworks, we are fortunate to see the following internal package structure diagram of the chip:

The iPhone's ability to mute sounds is very impressive indeed, and as far as we know, it outperforms all phones that don't have an Audience chip.

We have to give Audience credit for this. They have a killer appeal to other smartphones. What will be interesting in the near future is whether we can see other functional sub-components embedded inside the A5 or whether we can expect Apple and Audience to be a long-term strategic partnership. Obviously, Audience is hoping for the latter - because so far, they have been doing very well in this regard.