Analog Devices MAX22190 Product Info

• High Integration Reduces BOM Count and Board Space
  • Eight Input Channels with Serializer
  • Operates Directly from Field Supply (7V to 65V)
  • Compatible with 3.3V or 5V Logic
  • 5mm x 5mm TQFN Package
• Reduced Power and Heat Dissipation
  • Accurate Input-Current Limiters
  • Energyless Field-Side LED Drivers
• Fault Tolerant with Built-In Diagnostics
  • Input Protection to ±40V with Low-Input Leakage Current
  • Wire Break Detection
  • Integrated Field-Supply Voltage Monitors
  • Integrated Overtemperature Monitors
  • 5-Bit CRC Code Generation and Transmission for Error Detection
• Configurability Enables Wide Range of Applications
  • Configurable IEC 61131-2 Type 1, 2, 3 Inputs
  • Configurable Input Current-Limiting from 0.5mA to 3.4mA
  • Selectable Input Debounce Filtering
• Robust Design
  • ±8kV Contact ESD and ±15kV Air Gap ESD Using Minimum 1kΩ Resistor
  • ±1kV Surge Tolerant Using Minimum 1kΩ Resistor
  • -40°C to +125°C Ambient Operating Temperature

The MAX22190 is an IEC 61131-2 compliant industrial digital input device. The MAX22190 translates eight, 24V current-sinking, industrial inputs to a serialized SPI-compatible output that interfaces with 3V to 5.5V logic. A current setting resistor allows the MAX22190 to be configured for Type 1, Type 2, or Type 3 inputs. Field wiring is verified for proximity switches, by a second threshold detector on each input. When wire-break is enabled, the active-low FAULT output is asserted and a register flag is set if the input current drops below the wire-break threshold for more than 20ms. Additional diagnostics that assert the active-ow FAULT pin include: overtemperature, low 24V field supply, 24V field supply missing, CRC communication error, etc.

For robust operation in industrial environments, each input includes a programmable glitch filter. The filter delay on each channel can be independently programmed to one of eight values between 50μs and 20ms, or filter bypass.

The MAX22190 has a 4-pin SPI interface and in addition uses the active-low LATCH input for synchronizing input data across multiple devices in parallel.

MAX22190 field-side accepts a single 7V to 65V supply to V_DD24 pin. When powered by the field supply, MAX22190 generates a 3.3V output from an integrated LDO regulator, which can provide up to 25mA of current for external loads in addition to powering the MAX22190. Alternatively, MAX22190 can be powered from a 3.0V to 5.5V logic side supply connected to V_DD pin. For flexibility, the SPI interface operates at 3.3V or 5V logic levels as controlled by the V_L pin.

Design Solution: Industrial Digital Inputs: They’re Not Quite as Simple as Counting from 0 to 1 ›

Applications