EVALUATION KIT AVAILABLE MAX31915 Industrial, Octal, Digital Input Translator General Description Benefits and Features The MAX31915 translates and conditions the 24V Flexible Supply Options Enables Usage in 24V, 12V, digital 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 conjunc- tion with input current limiting and lowpass filtering. Input Extremely Accurate and Stable Input Current Limiters current-limiting allows a significant reduction in power Configurability Enables a Wide Range of Standard consumed from the field-supply voltage, as compared to and Custom Applications traditional discrete resistor-divider implementations. Configurable Inputs for IEC 61131-2 Input Types 1, 2, and 3 or for Standard CMOS Logic Levels Selectable on-chip lowpass filters allow flexible debouncing and filtering of sensor inputs based on the application. 0.5mA to 6mA Configurable Input Current Limiting Selectable Input Filtering and Debounce: 0, 25s, When no filtering is selected, the IC is capable of detecting 0.75ms, and 3ms Settings pulses as short as 0.75s at its field inputs. High Integration Reduces BOM Count and Board Space All 8 input channels are translated to CMOS logic levels and 8 High-Voltage Input Channels (36V Max) are presented in parallel on the eight output pins for direct 8 CMOS Logic Outputs for High-Speed Simultaneous or galvanically-isolated interface with a controller ASIC or Transfer of All Input States to the Controller micro. On-Chip 5V Regulator The on-chip 5V voltage regulator can be used to power On-Chip Overtemperature Indicator external optocouplers, digital isolators, or other external On-Chip Field-Supply Voltage Monitor 5V circuitry. High HBM ESD Immunity on all Field Input Pins For ultra-low-power applications and lowest possible heat (15kV HBM) dissipation, Maxim Integrated plans to offer a pin-compati- ble version of this device the MAX31914. The MAX31914 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. Applications Digital Input Modules for Programmable Logic Controllers (PLCs) Industrial Automation, Building Automation Process Automation Ordering Information appears at end of data sheet. 19-7472 Rev 1 4/15MAX31915 Industrial, Octal, Digital Input Translator Block Diagram 24V 5V MAX31915 5VOUT V 5V REGULATOR CC24V V REF SUPPLY MONITOR UVFAULT SENSORS FAULT TEMPERATURE MONITOR DB0 RIREF DB1 CURRENT LIMITER RT1 IN1 LOWPASS OP1 FILTER VOLTAGE VTSELECT COMP V CONTROLLER REF INPUT CHANNEL 0 OR ISOLATION RT8 IN8 INPUT CHANNEL 7 OP8 GND