Create an audio preamplifier with an attenuator using the DS1802 push-button digital potentiometer

Introduction to the DS1802 Dual Logarithmic Audio Potentiometer

The DS1802 audio potentiometer contains two digitally controlled potentiometers and features a logarithmic taper that produces a 1dB change per increment. The maximum attenuation is 63dB, but the device also contains a mute function that attenuates a signal greater than 90dB. Additionally, the DS1802 has four pushbutton inputs that can be used either as a volume/balance controller for stereo applications or for independent position control of the two potentiometers. The part also contains zero-crossing detectors, which, when used properly, can seamlessly change the volume to create a professional-sounding audio system. The part is available in 20-pin DIP, SOIC, or TSSOP packages.

The DS1802 is ideal for applications where pushbutton-controllable resistance is desired. It also has a 3-wire interface that allows a PC or microcontroller to control the potentiometers. This application note shows how to use the part, with a minimal amount of hardware, to create a preamplifier circuit with a pushbutton-controllable volume for two stereo channels.