MAX31865 PT100-PT1000 RTD Platinum Resistance Temperature Detector Module

For precise temperature sensing applications, the MAX31865 RTD Platinum Resistance Temperature Detector Module PT100-PT1000 stands out. Resistance temperature detectors (RTDs) are sensors that exhibit changes in resistance as their temperature varies, functioning akin to thermistors. In this module, the resistor comprises a small strip of platinum with a resistance of 100 ohms at 0°C, hence the designation PT100.

Compared to typical NTC/PTC thermistors, PT RTDs offer superior stability and precision, albeit at a higher cost. PT100 RTDs, in particular, have a longstanding reputation for accuracy surpassing that of thermocouples, alongside exceptional repeatability and stability. Widely employed in laboratory and industrial settings for temperature measurement, they are renowned for their reliability.

The MAX31865 serves as a straightforward thermistor-to-digital output converter designed specifically for platinum resistance temperature detectors (RTDs). An external resistor configures RTD sensitivity, while the high-precision Δ-Σ ADC converts the RTD resistor-to-reference resistor ratio into digital output. With built-in overvoltage protection up to ±45V, the MAX31865 also offers configurable detection for RTD and cable open and short-circuit conditions.

Specifications and Features:

1. Integration Lowers System Cost, Simplifies Design
2. 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
3. High Accuracy Facilitates Meeting Error Budgets
4. 15-Bit ADC Resolution; Nominal Temperature
5. Resolution 0.03125NC (Varies Due to RTD Nonlinearity)
6. Total Accuracy Over All Operating Conditions:
7. 0.5NC (0.05% of Full Scale) max
8. Fully Differential VREF Inputs
9. 21ms (max) Conversion Time
10. Integrated Fault Detection Increases System Reliability
11. ±45V Input Protection
12. Fault Detection (Open RTD Element, RTD Shorted to Out-of-Range Voltage, or Short Across RTD Element)

Package Includes:

1 x MAX31865 RTD Platinum Resistance Temperature Detector Module PT100-PT1000