The MAX5456/MAX5457 dual, logarithmic taper digital
potentiometers feature a simple pushbutton interface
that controls volume and balance in audio applications.
Each potentiometer has 32 tap points and replaces
mechanical potentiometers. Refer to the MAX5408–
MAX5411 data sheet for SPI? versions of the MAX5456/
MAX5457.
Use the MAX5456/MAX5457 digital inputs with momentary
contact single-pole/single-throw (SPST) pushbutton
switches. Each input includes internal debounce circuitry
and a 50kΩ pullup resistor.
The MAX5456/MAX5457 advance the wiper setting once
per button push. Maxim’s proprietary SmartWiper? control
eliminates the need for a microcomputer 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 per second thereafter.
The MAX5456/MAX5457 provide temperature coefficients
of 50ppm/°C end-to-end and 5ppm/°C ratiometric
and a nominal resistance of 10kΩ per potentiometer.
An integrated click/pop suppression feature minimizes
the audible noise generated by wiper transitions. The
typical total harmonic distortion plus noise (THD+N) for
these devices is 0.01%.
The MAX5457 features a 3-button interface with a
MODE input that toggles between volume- and balancecontrol
modes. An LED output indicates volume or balance
mode. The MAX5456 features a 4-button interface
with separate inputs for up and down volume controls
and left and right balance controls.
The MAX5456/MAX5457 are available in 16-pin QSOP
and 16-pin TQFN packages and are specified over the
extended (-40°C to +85°C) temperature range.