4-Wire-Interfaced, 2.5V to 5.5V, 20-Port and 28-Port LED Display Driver and I/O Expander

Please check latest availability status for a specific part variant.


The MAX6957 compact, serial-interfaced LED display driver general-purpose I/O (GPIO) peripheral provides microprocessors with up to 28 ports. Each port is individually user configurable to either a logic input, logic output, or common-anode (CA) LED constant-current segment driver. Each port configured as an LED segment driver behaves as a digitally controlled constantcurrent sink, with 16 equal current steps from 1.5mA to 24mA. The LED drivers are suitable for both discrete LEDs and CA numeric and alphanumeric LED digits.

Each port configured as a GPIO can be either a push-pull logic output capable of sinking 10mA and sourcing 4.5mA, or a Schmitt logic input with optional internal pullup. Seven ports feature configurable transition detection logic, which generates an interrupt upon change of port logic level. The MAX6957 is controlled through an SPI-compatible 4-wire serial interface.

The MAX6957AAX and MAX6957ATL have 28 ports and are available in 36-pin SSOP and 40-pin TQFN (6mm x 6mm) packages, respectively. The MAX6957AAI and MAX6957ANI have 20 ports and are available in 28-pin SSOP and 28-pin DIP packages, respectively.

For a 2-wire interfaced version, refer to the MAX6956 data sheet.

For a lower cost pin-compatible port expander without the constant-current LED drive capability, refer to the MAX7301 data sheet.
MAX6957: Typical Operating Circuit MAX6957: Typical Operating Circuit Enlarge+

Key Features

  • High-Speed 26MHz SPI-/QSPI-™/MICROWIRE®-Compatible Serial Interface
  • 2.5V to 5.5V Operation
  • -40°C to +125°C Temperature Range
  • 20 or 28 I/O Ports, Each Configurable as
    • Constant-Current LED Driver
    • Push-Pull Logic Output
    • Schmitt Logic Input
    • Schmitt Logic Input with Internal Pullup
  • 11µA (max) Shutdown Current
  • 16-Step Individually Programmable Current Control for Each LED
  • Logic Transition Detection for Seven I/O Ports


  • Bar Graph Displays
  • Industrial Controllers
  • Panel Meters
  • Set-Top Boxes
  • System Monitoring
  • White Goods

See parametric specs for Display Drivers (45)

Part NumberLCD or LEDDigits or Char.Output FormatDisplay TypeInterfaceVSUPPLY
minmaxSee Notes
MAX6957 LED28-SegmentAny digit typeCommon AnodeSerial SPI 26Mbit2.55.5
$4.60 @1k

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.
Product Reliability Reports: MAX6957.pdf 
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C   Material Composition  

Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

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