MAX31913_15 Datasheet, PDF (1/17 Pages) Maxim Integrated Products – Industrial, Octal, Digital Input Translator/Serializer

MAX31913
Industrial, Octal, Digital Input
Translator/Serializer
General Description
The MAX31913 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 filter-
ing 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 optocou-
plers 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 isola-
tors, or other external 5V circuitry. Field-side LED drivers
recycle the current from the eight inputs to provide visual
input status indication without any additional current or
power consumption.
For ultra-low-power applications, and for the lowest
possible heat dissipation, Maxim Integrated offers a
pin-compatible version of this device, the MAX31912.
The MAX31912 uses patent-pending circuit techniques
to achieve further reduction of power beyond what is
possible by input current limiting alone. Contact the
factory for availability.
Ordering Information appears at end of data sheet.
Benefits and Features
●● Very Low Power and Heat Dissipation
• Low Quiescent Current (1.6mA typ)
• Highly Accurate and Stable Input Current Limiters,
Adjustable from 0.5mA to 6mA
• Energy-Less Field-Side LED Drivers
●● High Integration Reduces BOM Count, Board Size,
and System Cost
• 8 High-Voltage Input Channels (36V max)
• On-Chip 8-1 Serialization with SPI Interface
• On-Chip 5V Regulator
• On-Chip Overtemperature Indicator
• Dual On-Chip Field Supply Voltage Monitor
• Integrated Debounce Filters, Selectable From 0 to 3ms
●● Robust Features and Performance for Industrial
Environments
• Multibit CRC Code Generation and Transmission for
Error Detection and More Reliable Data Transmission
• High ESD Immunity on All Field Input Pins
●● Accepts Industry Standard Input Types
• Configurable for IEC 61131-2 Input Types 1, 2, and 3
●● Flexible Power Supply Capability Enables Usage
in 5V, 12V, 24V, and Higher Voltage Systems
• Wide Operating Field Supply Range of 7V to 36V
• Can Be Powered From the Logic-Side Using a 5V
Supply
Applications
• Digital Input Modules for PLCs
• Industrial, Building, and Process Automation
• Motor Control
19-6641; Rev 3; 4/15