This page take you to 3.5 mm Jack to USB Wiring Diagram for DIY and manufacturing purpose, which is well researched and to the point. Manufacturers are constantly working to build compact devices without compromising performance, specially in the case of multi-functional devices like mobile phones.
With USB-C, not only do you receive high-quality analog/ digital audio, but also do the function of charging and high speed data transfer. Traditional and the most popular till date, they are trying to phase out 3.5mm audio jacks with more versatile and compact USB-C port.
As a result, many modern smartphones & tablets now rely solely on USB-C for audio input and output (except for Bluetooth connection). For users who still prefer using their old, trusted analog headphones, this trend has prompted an increase in the need for 3.5mm to USB-C adapters.
DIY 3.5 mm jack to USB wiring diagram: (Passive 3.5 mm to USB Type-C Adapter)
Let’s understand the wiring and signal adaptation involved in this converter, which ensures full functionality. Whether for DIY projects or product development, the 3.5mm to USB-C wiring diagram is made available to keep the technical ischemic diagram accessible to all tech enthusiast.
The above 3.5 mm to USB C converter diagram is for the devices/ mobile phone having in built DAC converter. And in such case we are needed to use simple audio to USB C adapter for connecting earphone or headphone to a mobile, most company support this simple converter in their smartphones.
At Port 1:
-The USB-C connector utilizes 5 pins, but requires only 4 wires for connecting the 3.5 mm audio jack.
-The A5+B5 is grounded directly or connected to the ground via a 1KOhm resistor. This pin is used to detect the connection of external audio device by sending ground signal to (CC+VCONN) pin of USB controller of the host.
-The Left Channel audio out is D- (A7/B7)
-The Right Channel audio out is D+ (A6/B6)
-The A8, B8 separately used to connect Microphone and Analog Ground, and can be connected interchangeably.
Also check USB C OTG Wiring Diagram & Schematic
At Port 2:
-The Left channel Audio is Tip of female audio jack.
-The Right channel Audio is Ring 1 of female audio port.
-The Mic signal & Analog Ground can be transmitted through Ring 2 and Sleeve interchangeably.
(see the transparent audio jack below)
Above figure illustrates how a simple 3.5mm analog audio adapter can be made with simple 4 connections. In this schematics, there is a usb c plug that contains detection pins enabling or disabling digital Ground when usb is connected or disconnected respectively. This can also be done at the 3.5mm audio receptacle. At any of the end will work. Main things are ground should be detected via CC or VCONN pins. It is indicated with DT1 on the pin diagram.
Look at the USB C Pinout Diagram, for right ear signal Dp1 (A6/B6) are used while for left ear signal Dn1 (A7/B7) are used. All the A1, A12, B1, B12 are digital ground DGND and are disabled by host when external audio device is connected.
Active 3.5 mm to USB Type-C Adapter:
Unlike passive adapters, an active converter contains a built-in DAC (Digital-to-Analog Converter) that processes and converts digital audio signals from the USB-C port into analog signals for headphones or microphones. This ensures compatibility and delivers high-quality sound, even on devices lacking native analog output.
Despite devices lacking an inbuilt analog output, this active converters ensure connectivity by converting digital audio signal to analog high-quality sound.
FAQ:
Does USB-C to 3.5 mm have a DAC?
No, all the usb-c to 3.5mm jack don’t have DAC and not required to have one. The iPhones and Samsung Galaxy series phones required DAC controller IC to convert digital audio signals to analog audio signal for headphones.
How does USB-C to 3.5 mm without DAC works?
USB-C to audio converter without DAC works on the mobiles with inbuilt digital to audio converter. All or most of the phones supports this adapters and mentioned above is the circuit.
