Analog Devices Inc.

Category: Integrated Circuits (ICs)

For new designs, please refer to MAX22195 ›The MAX31914 translates and conditions the 24V digitaloutput of sensors and switches used in industrial,process, and building automation to 5V CMOS-compatiblesignals required by microcontrollers. It provides the frontendinterface circuit of a programmable logic controller(PLC) digital input module.The signal voltage translation is performed in conjunctionwith input current limiting and lowpass filtering. Inputcurrent limiting allows a significant reduction in powerconsumed from the field-supply voltage, as comparedto traditional discrete resistor-divider implementations.To achieve the lowest in-class power dissipation, the ICuses patent-pending circuit techniques to achieve furtherreduction of power dissipation beyond what is possibleby input current limiting alone. This special low-poweroperating mode is automatically activated when on-chiplowpass filtering is selected.Selectable on-chip lowpass filters allow flexible debouncingand filtering of sensor inputs based on the application.When no filtering is selected, the IC is capable of detectingpulses as short as 0.75μs at its field inputs.All 8 input channels are translated to CMOS logic levels andpresented in parallel on the eight output pins for direct orgalvanically isolated interface with a controller ASIC ormicro.The on-chip 5V voltage regulator can be used to powerexternal optocouplers, digital isolators, or other external5V circuitry.For low-cost applications, Maxim Integrated offers a pincompatible version of this device, the MAX31915, whichdoes not include the current-switching circuitry includedin the MAX31914.ApplicationsDigital Input Modules for Programmable Logic Controllers (PLCs)Industrial Automation, Building AutomationProcess Automation

* $4.60 - $4.35