MXMMAX31865AAP+

The MAX31865 is an easy-to-use resistance-to-digital converter optimized for platinum resistance temperature detectors (RTDs). An external resistor sets the sensitivity for the RTD being used and a precision delta-sigma ADC converts the ratio of the RTD resistance to the reference resistance into digital form. The MAX31865"s inputs are protected against overvoltage faults as large as ±45V. Programmable detection of RTD and cable open and short conditions is included.

• Integration Lowers System Cost, Simplifies Design Efforts, and Reduces Design Cycle Time
  • Simple Conversion of Platinum RTD Resistance to Digital Value
  • Handles 100O to 1kO (at 0°C) Platinum RTDs (PT100 to PT1000)
  • Compatible with 2-, 3-, and 4-Wire Sensor Connections
  • SPI-Compatible Interface
  • 20-Pin TQFN and SSOP Packages

High Accuracy Facilitates Meeting Error Budgets

• 15-Bit ADC Resolution; Nominal Temperature Resolution 0.03125°C (Varies Due to RTD Nonlinearity)
• Total Accuracy Over All Operating Conditions: 0.5°C (0.05% of Full Scale) max
• Fully Differential V_REF Inputs
• 21ms (max) Conversion Time

Integrated Fault Detection Increases System Reliability

• ±45V Input Protection
• Fault Detection (Open RTD Element, RTD Shorted to Out-of-Range Voltage, or Short Across RTD Element)