Industry's Most Integrated Stereo Audio Processor From Maxim Provides Volume, Balance, and Treble Control Without a Microcontroller

SUNNYVALE, Calif.--May 30, 2006--Maxim Integrated Products introduces the MAX5406, a complete audio processor with a simple, debounced pushbutton interface. The MAX5406 integrates all the op amps and potentiometers necessary for implementing and controlling standard audio functions: balance, volume, tone, treble, bass, bass boost, and ambience. For ultimate design flexibility and space savings, the MAX5406 eliminates the need for an external microcontroller to control functions or respond to the pushbuttons.

The Historical Design Problem

Traditionally audio products combined all the necessary user interfaces, e.g., the display, controls, and speakers into one package. The recent design of media players such as the MP3 players, however, has disconnected the 'brains' (i.e., the microcontroller) from the output. Consequently, docks or dock-enabled boom boxes need not duplicate the higher level functions already present in the media player. The basic boom box now only needs power, speakers, and a few simple controls to function up to specification.

The MAX5406 accommodates the new multimedia applications that use a microcontroller for functions other than audio control. The MAX5406 processes audio signals without using a microcontroller to control the volume advance rate, balance, or tone. The device's debounced pushbutton interface can be used with any momentary contact pushbutton switch, thus saving board space and overall system cost by eliminating costly debounce circuitry. While Maxim designed this device to alleviate microcontroller requirements for audio processing and control, the MAX5406 can still be controlled with a microcontroller.

Unmatched Integration in an Audio Processor

The MAX5406 intelligently controls the wiper advance rate using the Company's proprietary Smart Wiper(TM) technology. The wiper advances at a rate of 4Hz after the user presses the button continuously for 1 second, and at 16Hz after the button has been pressed for 4 seconds. A mute toggle function sets all wipers to maximum attenuation and returns the wipers to their previous position when deactivated.

The MAX5406 makes the microcontroller or GPIO optional by integrating the audio processor controls into a debounced pushbutton interface. The SmartWiper control increases the wiper advance rate using simple momentary contact switches, further eliminating the need for microcontroller intervention. Although the MAX5406 does not require a microcontroller for audio processing, the debounced pushbutton interface can be controlled by a microcontroller.

Many remote-controlled applications like WLAN, BT, or mobile phones have RF signals on board. The MAX5406 utilizes integrated passive filters to automatically reject any RF interference that can couple into the audio path of these types of products.

Integrated bass and treble filter circuitry implements the well-known Baxandall response. The bass and treble corner frequencies are set using small external ceramic capacitors.

The MAX5406 provides signal paths so the user can change the stereo separation or add delayed signals to improve the product's sound. This 'ambience' function toggles on or off. For greater design flexibility, this signal-processing path can also be used to create pseudo-stereo, thus generating a stereo signal from a monophonic source. The integrated bass-boost feature and a subwoofer output improve the low-frequency sound.

Each potentiometer includes integrated suppression circuitry that ensures clickless and popless operation through all control changes such as tone, volume, power-up, and power-down. A shutdown feature reduces supply current to 1.5mA to extend battery life while maintaining the volume, balance, and tone settings.

Versatile for a Broad Range of Applications

The MAX5406 is primarily targeted as a complete solution for multimedia boom boxes when paired with power amps like the MAX9769. The device is also designed for multimedia-focused handheld devices such as stereo PDA/MP3 players and stereo cell phones, where the microcontroller can be used for functions other than simple audio control. Other applications include rear-seat entertainment controls, portable stereos, video game consoles, and karaoke machines.

Available in a 4mm x 4mm TQFN package, the MAX5406 is significantly smaller than a discrete implementation. Total harmonic distortion is less than 0.01% and the output noise is less than 25mVrms. This low-power audio processor operates from a +2.7V to +5.25V single supply or +/-2.7V dual supply, and requires less than 0.5 microamps in shutdown. Prices start at $2.17 (1000-up, FOB USA) and samples are available now. For more information, please visit http://www.maxim-ic.com/MAX5406info.

Maxim Integrated Products is a leading international supplier of quality analog and mixed-signal products for applications that require real world signal processing. For more information, contact Maxim at 120 San Gabriel Dr., Sunnyvale, CA 94086. Telephone: 408-737-7600 or our URL: www.maxim-ic.com.

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