Integration Lowers System Cost, Simplifies Design Efforts, and Reduces Design Cycle Time
Simple Conversion of Platinum RTD Resistance to Digital Value
Handles 100Ω to 1kΩ (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 VREF 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)
MAX31865 Applications
Industrial Equipment
Instrumentation
Medical Equipment
MAX31865 Description
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.
