EVALUATION KIT AVAILABLE MAX31914 Ultra-Low Power Industrial, Octal, Digital Input Translator General Description Benefits and Features The MAX31914 translates and conditions the 24V digi- Flexible Supply Options Enables Usage in 24V, 12V, tal output of sensors and switches used in industrial, and 5V Supplied Systems process, and building automation to 5V CMOS-compatible 7V to 36V Wide Operating Field-Supply Range signals required by microcontrollers. It provides the front- Device Can Be Optionally Powered from the Logic- end interface circuit of a programmable logic controller Side Using a 5V Supply (PLC) digital input module. Low Power and Low Heat Dissipation Very Low Quiescent Current The signal voltage translation is performed in conjunction with input current limiting and lowpass filtering. Input Extremely Accurate and Stable Input Current Limiters Special Ultra-Low-Power Operating Mode with current limiting allows a significant reduction in power consumed from the field-supply voltage, as compared Switched Current Limiters to traditional discrete resistor-divider implementations. Configurability Enables a Wide Range of Standard To achieve the lowest in-class power dissipation, the IC and Custom Applications uses patent-pending circuit techniques to achieve further Configurable Inputs for IEC 61131-2 Input Types 1, reduction of power dissipation beyond what is possible 2, and 3 or for Standard CMOS Logic Levels by input current limiting alone. This special low-power 0.5mA to 6mA Configurable Input Current Limiting operating mode is automatically activated when on-chip Selectable Input Filtering and Debounce: 0, 25s, lowpass filtering is selected. 0.75ms, and 3ms Settings Selectable on-chip lowpass filters allow flexible debouncing High Integration Reduces BOM Count and Board and filtering of sensor inputs based on the application. Space When no filtering is selected, the IC is capable of detecting 8 High-Voltage Input Channels (36V Max) pulses as short as 0.75s at its field inputs. 8 CMOS Logic Outputs for High-Speed Simultaneous Transfer of All Input States to the Controller All 8 input channels are translated to CMOS logic levels and On-Chip 5V Regulator presented in parallel on the eight output pins for direct or On-Chip Overtemperature Indicator galvanically isolated interface with a controller ASIC or On-Chip Field-Supply Voltage Monitor micro. High HBM ESD Immunity on all Field Input Pins The on-chip 5V voltage regulator can be used to power (15kV HBM) external optocouplers, digital isolators, or other external 5V circuitry. For low-cost applications, Maxim Integrated offers a pin compatible version of this device, the MAX31915, which does not include the current-switching circuitry included in the MAX31914. Applications Ordering Information appears at end of data sheet. Digital Input Modules for Programmable Logic Controllers (PLCs) Industrial Automation, Building Automation Process Automation 19-7474 Rev 1 4/15MAX31914 Ultra-Low Power Industrial, Octal, Digital Input Translator Block Diagram 24V 5V MAX31914 5VOUT V 5V REGULATOR CC24V V REF SUPPLY MONITOR UVFAULT SENSORS FAULT TEMPERATURE MONITOR DB0 RIREF SWITCHED DB1 RT1 CURRENT LIMITER IN1 LOWPASS OP1 FILTER CONTROLLER VOLTAGE OR VTSELECT COMP ISOLATION V REF INPUT CHANNEL 0 RT8 IN8 INPUT CHANNEL 7 OP8 GND