Analog Devices MAX22192 Product Info

• High Integration Reduces BOM Count and Board Space
• Eight Input Channels with Serializer
• Integrated Isolation of 600V_RMS for 60s (V_ISO)
• Operates Directly from Field Supply (7V to 65V)
• Compatible with 1.8V, 3.3V or 5V Logic
• 6mm x 10mm GQFN 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 for Error Detection

• Configurability Enables a 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 Glitch Filter
• Capable of Daisy-Chaining Other Field-Side Devices Sharing Isolated SPI

• 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 MAX22192 is an IEC 61131-2 compliant industrial digital input device with integrated digital isolation. The MAX22192 translates eight, 24V current-sinking, industrial inputs to an isolated serialized SPI-compatible output that interfaces with 1.71V to 5.5V logic voltage. A current-setting resistor allows the MAX22192 to be configured for Type 1, Type 2, or Type 3 inputs. For proximity switches, the field-wiring is verified using the wire break feature. When wire break is enabled, the active-low LFAULT output is asserted and a register flag set if the input current drops below the wire break threshold for more than 20ms. Additional diagnostics that assert active-low LFAULT include: overtemperature protection, low 24V field supply, 24V field supply missing, and CRC communication error.

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 MAX22192 has an isolated 4-pin SPI interface, and in addition uses isolated active-low LLATCH input for synchronizing input data across multiple devices in parallel, and isolated active-low LFAULT output for instantly alerting the host of any diagnostic issues. The digital signals with a name starting with L are logic-side signals, and the digital signals with a name starting with F are field-side signals.

The MAX22192 field-side accepts a single 7V to 65V supply to the V_DD24F pin. When powered by the field supply, the MAX22192 generates a 3.3V output on the V_DD3F pin from an integrated LDO regulator, which can provide up to 25mA of current for external loads in addition to powering the MAX22192. Alte