Overview

General Description

The MAX22000 is an industrial-grade configurable analog input/output device that can be configured on-the-fly in software as a voltage input or output, or current input or output. Additional inputs are available to measure other analog signals.

The device offers an 18-bit DAC with fast settling time, as well as a 24-bit delta-sigma ADC. The ADC and DAC can individually choose between an internal or an external reference.

The MAX22000 supports the ADC with a low-noise programmable gain amplifier (PGA), with high-voltage and low-voltage input ranges to support RTD and thermocouple measurements. Additional auxiliary inputs are provided to measure cold junction temperatures on-board.

The MAX22000 communicates through a high speed 20MHz SPI bus for all configuration and management information, as well as for conversion results. An optional 8-bit CRC enhances the reliability of the SPI interface, protecting against all 8-bit bursts and double-bit errors.

The MAX22000 operates from 2.7V to 3.6V analog and digital supplies and up to ±24V high-voltage supplies. The device is available in a 64-pin LGA package and operates over the -40°C to +125°C industrial temperature range.

Functional Block Diagram
Benefits and Features
  • Accuracy
    • ​Analog Output Voltage or Current Mode:
      • 0.02% FSR Accuracy, Room Temp​
      • 0.1% FSR Accuracy, ±50°C Temp Variation
    • 5ppm/°C Internal Reference
  • Flexibility
    • 6 Analog Inputs/1 Analog Output,  Software Configurable for Voltage and Current Mode
    • Two Auxiliary ADC Inputs for Cold Junction Measurements
    • RTD Input Mode in 2, 3, or 4-Wire Configurations
    • Thermocouple Input Mode
    • ±12.5V Input/Output Voltage Range  
    • ±25mA or ±2.5mA Output Current Range
    • ±25V, ±2.5V, ±500mV, ±250mV, and ±125mV PGA Input Voltage Ranges
    • +24V Field Supply for Current Loop
    • Optional External Reference for ADC and/or DAC
    • Six GPIOs
    • 20MHz SPI Interface
  • Robustness
    • ​±36V Protection on All Analog I/O Ports
    • Overcurrrent Protection
    • Thermal Shutdown
    • Undervoltage Interrupt on All High Voltage Supplies
    • CRC Detection
    • Open Detection on All Analog Inputs
    • 1kV HBM Protection on All Pins
  • ​-40°C to +125°C Operating Temperature Range
  • 9mm x 9.5mm 64-Pin LGA Package
Applications
  • Distributed Control Systems
  • Process Control
  • Programmable Logic Controllers (PLC)
  • Programmable Automation Controllers (PAC)


19-100526; Rev 3; 3/22