40W Class-D Audio Amplifier with Digital Master Volume Control

The OPA1688 device used in this design belongs to the SoundPlus family of Texas Instruments. It is a low-noise operational amplifier designed for audio applications. It can either operate using a single voltage supply or a split voltage supply. The MAX5486, which is also used in this project, is a dual 40kΩ digital logarithmic potentiometer that has a debounced pushbutton interface ideal to control the volume and balance the left and right channel of this project. It has 32 log-spaced tap points with a buffered wiper. The power amplifier in this design is the TPA3106D1, which is a 40W class-D audio power amplifier with 92% efficiency that eliminates the need for an external heat sink. Read more