Ditch the headphone jack with USB Type-C

There has been a growing trend in smartphone manufacturers to get rid of the 3.5mm audio jack, which has been the standard audio connector since the early 1960s.

Although the size of the connector has differed over time, it has existed relatively in the same form since the late 1800s. With advances in digital audio quality occurring daily, and devices growing smaller and thinner; it’s about time for an update.

Micro USB has been making the conversion to USB Type-C, which was initially given mild disapproval from users due to it not being the “regular connector.” Today, it has been more or less accepted as the new standard due to the fact that most of the flagship companies have followed suit.

Now, for a bit of background on the audio jack connector as well as the USB Type-C proposals. The key characteristic that separates the two connectors is that the audio jack translates sound through stereo analog inside the socket. The significance here is that the digital conversion and speaker components need to be contained within devices such as smartphones, tablets and computers.

Interestingly, when the USB Type-C connector was being designed, the idea that digital audio should be transmitted over connection lines to save space inside smaller devices was adopted. Earphones or similar devices would instead be the analog converter, and fortunately, USB Type-C is capable of providing power to the devices on the same line.

USB Type-C can also support analog devices, meaning old headphones won’t become obsolete, at least not yet. New components were developed and included into the USB Type-C cable called sideband unit pins. Each USB Type-C connector has two of these pins that are both able to carry analog audio channels. It would be as simple as connecting an adapter to a device in order to enable analog use.

Most people listen to 44.1 KHz 16-bit stereo sound. When we listen to high definition sound, we adjust those numbers to 96 KHz 24-bit on multiple channels which delivers a much higher sound quality. High definition can be hosted through lines no larger than our current cables with the help of digital analog chips, which convert high-resolution data to sound generated in speakers. This technology is the hosting method for USB Type-C audio delivering increased sound quality.

Now you may be asking: Well if there isn’t a headphone jack on my device, and the same port for charging is used for audio, will we be able to use charge our phones while listening through a wired headset? Yes, we will be able to charge a device through the same port. The official USB Type-C standard allows for an adapter cable to be split into a charging port and a 3.5mm audio port, granting the ability to listen to music and charge a device at the same time. This cable also happens to be passive, making it cheap to obtain.

As many of us know, USB is capable of transferring more than digital audio. Using USB Type-C directly opens up development areas for advanced communication between devices. We have seen headphones incorporate things such as volume and play/pause buttons, but this can be further augmented on the communication lines. Digital processing could easily be joined and operated from apps or software on devices, allowing users to control headphone characteristics from their devices, even adding auxiliary components such as heart rate monitors. Another perk of using USB Type-C is that it can provide power to noise-cancelling headphones, as well as allowing headphones to process signals internally.

Overall, it appears to be pretty advantageous to opt into USB Type-C ports. Several companies have already produced products eliminating the audio jacks entirely such as Intel, LeEco, Lenovo, and Motorola.

Anand Kannan
Anand Kannan
Anand Kannan, Senior Product Applications Engineer, has a Masters in Electrical Engineering from University of Connecticut. Anand has been working as a Systems/Product Applications Manager since 2005. At NXP, Anand supports product definition and system implementation of Secure Interface and Power high speed products and USB TypeC/PD product lines.

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  1. […] Anand Kannan also thinks Type-C should be the dominant audio port, citing increased sound quality and […]

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