MAX5440

Stereo Volume Control with Rotary Encoder Interface

Rotary Encoder Interface Uses Gray Scale Encoding to Control Volume and Balance in Audio Applications


Description

The MAX5440 dual, 40kΩ logarithmic taper volume control features a debounced up/down interface for use with a simple rotary encoder without using a microcontroller (µC). Each potentiometer has 32 log-spaced tap points with a buffered wiper output and replaces mechanical potentiometers. An integrated bias generator provides the required ((VDD + VSS) / 2) bias voltage, eliminating the need for costly external op-amp circuits in unipolar audio applications. A mode-indicator LED output specifies volume or balance control. Five integrated LED drivers indicate volume level or balance settings, depending on the status of the mode indicator.

The MAX5440 includes debounced pushbutton inputs for mute and mode. The mute input allows a single pushbutton to change between volume control and the -90dB (typ) mute setting. The mode input toggles between volume and balance control. A click-and-pop suppression feature minimizes the audible noise generated by wiper transitions. The MAX5440 provides a nominal temperature coefficient of 35ppm/°C end-to-end and 5ppm/°C, ratiometrically. The MAX5440 is available in a 24-pin SSOP package and is specified for operation over the -40°C to +85°C extended temperature range.
MAX5440: Typical Operating Circuit MAX5440: Typical Operating Circuit Enlarge+

Key Features

  • Logarithmic Taper Volume Control with (31) 2dB Steps
  • Low-Power Wiper Buffers Provide 0.003% THD
  • Single +2.7V to +5.5V or Dual ±2.7V Supply Voltage Operation
  • Low 0.5µA Shutdown Supply Current
  • Integrated Bias Voltage Generator
  • Five-Segment LED Volume/Balance Indicator
  • Clickless Switching
  • 40kΩ End-to-End Fixed Resistance Value
  • Mute Function Toggles to -90dB (typ)
  • Power-On Reset to -12dBFS Wiper Position

Applications/Uses

  • Desktop Speakers
  • Multimedia Docking Stations
  • Set-Top Boxes
  • Stereo Volume Control
Part Number Taper POTs Control Interface Wiper Memory Steps REND-TO-END
(kΩ)
Res. Tol.
(%)
Temp. Coeff.
(ppm/°C)
Wiper Resistance
(Ω)
ICC @5V
(µA)
Budgetary
Price
typ typ max See Notes
MAX5440  Log 2 Rotary Encoder Volatile 32 40 30 35 1 1.4 $1.54 @1k
See All Digital Potentiometers (127)
Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

Technical Documents

Tutorial 4262 Improve Stereo Performance with Active Biasing

Quality and Environmental Data

Request Reliability Report for: MAX5440 
Lead-Free Package Tin (Sn) Whisker Reports
 

Related Resources