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Parasitically Powered Digital Input

Industry's Smallest, Robust, Digital Input

Product Details

The MAX22191 is an IEC 61131-2 compliant, industrial digital input (DI) device that translates a 24V digital industrial input to a 2.4mA (typ) current for driving optical isolators. Voltage thresholds and current levels in the MAX22191 are compliant with Type 1 and Type 3 inputs, while minimizing power dissipation. The MAX22191 is also compliant with 48V inputs, with the addition of external resistors.

Operating power is derived from the input signal, eliminating the need for an external field-side power supply. A 250ns (max) fast response time is ideal for high-speed inputs. Additionally, a CMOS-compatible test input is available for safety diagnostics.

The MAX22191 features robust functionality for harsh industrial systems and is capable of normal operation with input signals ranging from -60V to +60V. Integrated thermal shutdown further protects the device when VCC is present.

The MAX22191 is available in a small, 6-lead SOT23 package and operates over the -40°C to +125°C ambient temperature range.

Design Solution: Worried About Heat in Your I/O Module? No Need to Sweat ›

Key Features

  • High Integration for Flexible Circuit Designs
    • 250ns (max) Response Time
    • Parasitically Powered from the Field Input
    • Current Sourcing Input with Optical Isolators
    • Current Sinking Input with Optical Isolators
    • Current Sinking Input with Logic Devices
    • Test Pulse Input
  • Reduced Power and Heat Dissipation
    • Current Limited Input
  • Robust Design
    • Operates from -60V to +60V Input Voltage
    • -40°C to +125°C Ambient Operating Temperature

Applications/Uses

  • Current Sourcing Inputs
  • Individually Isolated Inputs
  • Industrial Automation
  • Motor Controls
  • Process Automation
Parametric specs for Digital I/O
Digital Input/Output Digital Input
Interface Type CMOS
# Channels 1
VSUPPLY (V) (min) -60
VSUPPLY (V) (max) 60
Digital Input Type Type 1
Type 3
Min. Detectable Field Input Pulse Width (µs) 0.25
Oper. Temp. (°C) -40 to +125
Package/Pins SOT23/6
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Simplified Block Diagram

MAX22191: Simplified Block Diagram MAX22191: Simplified Block Diagram Zoom icon

Technical Docs

Design & Development

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Description

The MAX22191 evaluation kit (EV kit) is a fully assembled and tested circuit board that demonstrates the functionality of the MAX22191 digital input in an optical isolator circuit. The EV kit features two circuits: one for a 24V digital input signal and one for a 48V input signal.

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Features

  • 24V and 48V Circuits for Easy Evaluation
  • Proven PCB Layout
  • Fully Assembled and Tested

Description

The MAX22191PMB# peripheral module provides the hardware to evaluate the MAX22191 parasitically powered digital input. Refer to the MAX22191 IC data sheet for detailed information regarding operation of the IC. The PMB features two circuits: one for isolated parasitically powered circuit (using an optoisolator) and one for a 24V input signal with the circuit powered from a low-voltage logic supply.

The module can be used in various ways. Maxim sells low-cost USB2PMB1#, USB2PMB2#, and USB2GPIO# adapter boards that use the Munich GUI software for communication through a USB cable. This is not included with this board. Alternatively, any microcontroller or FPGA with a 12-pin Pmod™-compatible connector can be used. Another option for the user is to wire-wrap a temporary connection from their system to the pins on connector X1. For these later two options the user needs to write their own control software.

The Pmod PCB dimension is just 42mm long x 20mm wide, with the width determined by the size of the X1 connector.

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Features

  • Easy Evaluation of the MAX22191
  • Isolated, Paristically Powered and Logic-Powered Circuits for Easy Evaluation
  • Proven PCB Layout
  • Works with USB2PMB2# or USB2GPIO# Adapter and Munich GUI Software

/en/design/design-tools/ee-sim.html?

SIMULATION MODELS

MAX22191 IBIS Model

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Support & Training

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Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal.

Parameters

Parametric specs for Digital I/O
Digital Input/Output Digital Input
Interface Type CMOS
# Channels 1
VSUPPLY (V) (min) -60
VSUPPLY (V) (max) 60
Digital Input Type Type 1
Type 3
Min. Detectable Field Input Pulse Width (µs) 0.25
Oper. Temp. (°C) -40 to +125
Package/Pins SOT23/6

Key Features

  • High Integration for Flexible Circuit Designs
    • 250ns (max) Response Time
    • Parasitically Powered from the Field Input
    • Current Sourcing Input with Optical Isolators
    • Current Sinking Input with Optical Isolators
    • Current Sinking Input with Logic Devices
    • Test Pulse Input
  • Reduced Power and Heat Dissipation
    • Current Limited Input
  • Robust Design
    • Operates from -60V to +60V Input Voltage
    • -40°C to +125°C Ambient Operating Temperature

Applications/Uses

  • Current Sourcing Inputs
  • Individually Isolated Inputs
  • Industrial Automation
  • Motor Controls
  • Process Automation

Description

The MAX22191 is an IEC 61131-2 compliant, industrial digital input (DI) device that translates a 24V digital industrial input to a 2.4mA (typ) current for driving optical isolators. Voltage thresholds and current levels in the MAX22191 are compliant with Type 1 and Type 3 inputs, while minimizing power dissipation. The MAX22191 is also compliant with 48V inputs, with the addition of external resistors.

Operating power is derived from the input signal, eliminating the need for an external field-side power supply. A 250ns (max) fast response time is ideal for high-speed inputs. Additionally, a CMOS-compatible test input is available for safety diagnostics.

The MAX22191 features robust functionality for harsh industrial systems and is capable of normal operation with input signals ranging from -60V to +60V. Integrated thermal shutdown further protects the device when VCC is present.

The MAX22191 is available in a small, 6-lead SOT23 package and operates over the -40°C to +125°C ambient temperature range.

Design Solution: Worried About Heat in Your I/O Module? No Need to Sweat ›

Simplified Block Diagram

MAX22191: Simplified Block Diagram MAX22191: Simplified Block Diagram Zoom icon

Technical Docs

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal.