Audio Processor with Pushbutton Interface

 

Part Number	Replacement	Explanation

Description

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The MAX5406 stereo audio processor provides a complete audio solution with volume, balance, bass, and treble controls. It features dual 32-tap logarithmic potentiometers for volume control, dual potentiometers for balance control, and linear digital potentiometers for tone control. A simple debounced pushbutton interface controls all functions. The MAX5406 advances the wiper setting once per button push. Maxim's proprietary SmartWiper™ control eliminates the need for a microcontroller (µC) to increase the wiper transition rate. Holding the control input low for more than 1s advances the wiper at a rate of 4Hz for 4s and 16Hz thereafter. An integrated click/pop suppression feature eliminates the audible noise generated by the wiper's movements.

The MAX5406 provides a subwoofer output that internally combines the left and right channels. An external filter capacitor allows for a customized cut-off frequency for the subwoofer output. A bass-boost mode enhances the low-frequency response of the left and right channels. An integrated bias amplifier generates the required (V_DD + V_SS) / 2 bias voltage, eliminating the need for external op amps for unipolar operation.

The MAX5406 also features ambience control to enhance the separation of the left- and right-channel outputs for headphones and desktop speakers systems, and a pseudostereo feature that approximates stereo sound from a monophonic signal.

The MAX5406 is available in a 7mm x 7mm, 48-pin TQFN package and in a 48-pin TSSOP package and is specified over the extended (-40°C to +85°C) temperature range.

MAX5406: Typical Operating Circuit Enlarge+

Key Features

Audio Processor Including All Op Amps and Pots for Volume, Balance, Mute, Bass, Treble, Ambience, Pseudostereo, and Subwoofer

32-Tap Volume Control (2dB Steps)

Small, 7mm x 7mm, 48-Pin TQFN and 48-Pin TSSOP Packages

Single +2.7V to +5.5V or Dual ±2.7V Supply Operation

Clickless Switching and Control

Mute Function to < -90dB (typ)

Channel Isolation > -70dB (typ)

Two Sets of Single-Ended or Differential Stereo Inputs Can Be Used for Summing/Mixing

Debounced Pushbutton Interface Works with Momentary Contact Switches or Microprocessors (µPs)

Low 0.2µA (typ) Shutdown Supply Current

Shutdown Stores All Control Settings

0.02% (typ) THD into 10kΩ Load, 25µVRMS (typ) Output Noise

Internally Generated 1/2 Full-Scale Bias Voltage for Single-Ended Applications

Power-On Volume Setting to -20dB

Internal Passive RF Filters for Analog Inputs Prevent High Frequencies from Reaching the Speakers

Applications/Uses

• Desktop Speakers
• Flat-Screen TVs
• Karaoke Machines
• PDAs or MP3 Player Docking Stations
• Portable Audio