The MAX22194 is an industrial quad digital input that translates four industrial 24V or TTL level inputs to logic level outputs. The device has a serial interface allowing configuration and reading of serialized data through SPI. The input channels are individually configurable as sinking (p-type) or sourcing (n-type) inputs. Current limiters on each digital input minimize power dissipation while ensuring compliance with the IEC 61131-2 standard. With a single current-setting resistor, the inputs are individually configurable for Type 1/3, Type 2, TTL, or HTL (high-impedance 24V levels). The current sinks or sources can be individually disabled. Every input channel has a programmable glitch/debounce filter. The MAX22194 can be powered from a field supply from 8V up to 36V for sink/source operation and has an integrated 5V linear regulator that can provide up to 20mA of load current. APPLICATIONS * Programmable Logic Controllers * Factory Automation * Process Control * Software Configurable * Four Inputs Individually Configurable as Sink or Source * Type 1/3, Type 2, TTL, and Hi-Z (HTL) Modes * Wide Resistor-Settable Accurate Input Current Ranging from 0.5mA to 6.75mA * Programmable Glitch Filters * Extensive Diagnostics (Supply Voltage Monitoring, Temperature Alarms, PCB Fault Alarms, Thermal Shutdown) * Addressable or Daisy-Chain SPI to Reduce Isolation Channels * Robust Solution * IEC 61000-4-2 ESD Airgap ±15kV and Contact ±8kV with Minimum 680Ω Pulse Resistor at Field Inputs * IEC 61000-4-5 Surge ±1.2kV/42Ω with Minimum 680Ω Pulse Resistor at Field Inputs * CRC Error Detection on SPI * -40°C to +125°C Operating Temperature