Maxim > Products > Interface > MAX31911


Industrial, Octal, Digital Input Translator/Serializer

Industry's Most Robust Low-Power Industrial Digital Input Serializer
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Status Explanations for product status codes

Active: In Production.


The MAX31911 industrial interface serializer translates, conditions, and serializes the 24V digital output of sensors and switches used in industrial, process, and building automation to 5V CMOS-compatible signals required by microcontrollers. It provides the front-end interface circuit of a programmable logic controller (PLC) digital input module. The device features integrated current limiting, lowpass filtering, and channel serialization. Input current limiting allows a significant reduction in power consumed from the field voltage supply as compared to traditional discrete resistor-divider implementations. Selectable on-chip lowpass filters allow flexible debouncing and filtering of sensor outputs based on the application. On-chip serialization allows a drastic reduction in the number of optocouplers used for isolation. The device serializer is stackable so that any number of input channels can be serialized and output through only one SPI-compatible port. This reduces the number of optocouplers needed to only three, regardless of the number of input channels. For enhanced robustness with respect to high-frequency noise and fast electrical transients, a multibit CRC code is generated and transmitted through the SPI port for each 8 bits of data. The on-chip 5V voltage regulator can be used to power external optocouplers, digital isolators, or other external 5V circuitry.

For ultra-low-power applications, Maxim offers a pin-compatible version of this device, the MAX31910. The MAX31910 uses patent-pending circuit techniques to achieve further reduction of power beyond what is possible by input current limiting alone.

The future generation version of the MAX31910 and MAX31911 will include energy-less LED drivers while maintaining pin compatibility.

Data Sheet

Download this datasheet in PDF formatDownload Rev 2 (PDF, 758.5kB)
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An evaluation board is available: MAX31910EVKIT, MAX31911EVKIT MAXREFDES12

NOTE: This product uses the following:

Key Features

  • Eight High-Voltage Input Channels (36V max)
  • Configurable for IEC 61131-2 Input Types 1, 2, 3
  • Wide Operating Supply Range of 7V to 36V
  • Optional Configuration Allows 5V Supply
  • Selectable Input Filtering and Debouncing from 0ms to 3ms
  • Configurable Input Current Limiting from 0.5mA to 6mA
  • High HBM ESD Immunity on All Field Input Pins
  • On-Chip 8-to-1 Serialization with SPI Interface
  • On-Chip 5V Regulator
  • Overtemperature Indicator
  • On-Chip 24V Field Supply Voltage Monitor
  • Low Quiescent Current and Power Dissipation
  • Multibit CRC Code Generation and Transmission for Error Detection and More Reliable Data Transmission to an External Micro


  • Building Automation
  • Digital Input Modules for PLCs
  • Industrial Automation
  • Motor Control
  • Process Automation

Key Specifications:

Sensor Interface Devices
Part Number Sensor Interface Type µC Interface Type Channels VSUPPLY
Low Pwr. Shutdn Oper. Temp.
min max typ See Notes
MAX31911  IEC 61131-2 Digital Input Types 1, 2, 3 SPI 8 10 36 1400 No -40 to +125 $1.71 @1k
See All Sensor Interface Devices (10)

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.


MAX31911: Block Diagram
Block Diagram

Technical Documents

Tutorial 5518  Uptime Protects the Bottom Line
Sub-System Board 5611  Corona (MAXREFDES12#): Isolated Industrial Octal Digital Input Translator/Serializer
User Guides & Manuals 5613  Corona (MAXREFDES12#) Nexys 3 Quick Start Guide
User Guides & Manuals 5614  Corona (MAXREFDES12#) ZedBoard Quick Start Guide
App Note 5758  Analog Integration Drives Factory Integration

Product Guides

Interface (PDF)

Reliability Reports

Reliability Report: MAX31911.pdf



Ordering Information

Filters: Part Number Package: Temperature: Tape and Reel Sample
Part Number Free
Buy Status Explanations for product status codes Package:
Temp RoHS/Lead-Free?
Materials Analysis
Active TSSOP-EP;28 pin;63.7 mm²
-40°C to +125°C RoHS/Lead-Free: Lead Free
Materials Analysis
Active TSSOP-EP;28 pin;63.7 mm²
-40°C to +125°C RoHS/Lead-Free: Lead Free
Materials Analysis

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  3. Part number suffixes: T or T&R = tape and reel; + = RoHS/lead-free; # = RoHS/lead-exempt; -D = drypack; -U/+U on DS parts = cut tape. More: See Full Data Sheet or Maxim Product Naming Conventions.
  4. * Some packages have variations, listed on the drawing. "PkgCode/Variation" tells which variation the product uses. Note that "+", "#", "-" in the part number suffix describes RoHS status. Package drawings may show a different suffix character.

Similar Products by Function

MAX31910 Industrial, Octal, Digital Input Translator/Serializer
MAX31913 Industrial, Octal, Digital Input Translator/Serializer
See All Sensor Interface Devices (10Products)

Similar Products by Application

Programmable Logic Controllers (PLCs) > Binary Inputs - Digital Input/Digital Output Module

Evaluation Kits

MAX31910EVKIT, MAX31911EVKIT Evaluation Kit for the MAX31910 and MAX31911
MAXREFDES12 Corona (MAXREFDES12#): Isolated Industrial, Octal, Digital Input Translator/Serializer

Products with Similar Part Numbers

MAX31910EVKIT, MAX31911EVKIT Evaluation Kit for the MAX31910 and MAX31911

More Information

New Product Press Release   2013-08-27 ]

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Information Index

Document Ref.: 19-6441 Rev 2; 2013-10-28
This page last modified: 2013-10-29