Audio Hardware

Created: 5/12/2020


Audio hardware is responsible for generating, receiving, and processing audio signals, which can be either analog or digital. In this context, we limit the definition of analog signals to voltage levels. 


Analog Voltage Levels

Audio Ports

Audio Connector

Audio Playback Device

Line-Out Amplifier

Built-in Speaker Amplifier

Speakers (also known as driver or transducer)

Audio Capture Devices

For practical design example see this article:


Mic-in Pre-amplifier

Audio Processing Device

For practical design excample please this article:

Digital Signal Processor (DSP)

Main Functions of Audio Processing on DSP



Additional Features

Codec (Coder-Decoder)

A CODEC is an audio device designed to perform two main functions: encoding analog audio signals from line-in or microphone inputs to digital form, and decoding digital audio back to analog form for line-out. It interfaces with the main processor through both control and data channels. 

Detailed Analysis

Consumer Electronics: These devices often feature headphone line-out jacks and built-in microphones. The CODEC and digital amplifier are generally embedded in the system for built-in speakers. For an illustrative example, refer to Audio System block diagram

Digital MEMS Microphones: Most built-in microphones in consumer electronics are digital MEMS mics that output audio in a standard digital format, typically Pulse Density Modulation (PDM). 

Class-D Amplifiers: These are commonly used to drive built-in speakers due to their low cost and high efficiency. 

Personal Computers: PCs usually have dedicated line-in/out and microphone-in ports. These are processed by a sound card, which primarily contains a DSP, CODEC, and various audio ports. For an illustrative example, refer to Soundcard block diagram for an example.


What are the main components in audio hardware?

The primary components include Transducers, ADC (Analog-to-Digital Converters), DAC (Digital-to-Analog Converters), CODEC, and DSP (Digital Signal Processors). 

Summary and Conclusion

Overall, audio hardware components work cohesively to generate, receive, and process audio signals.

Further Reading and Practice