MAX31865ATP+

Part: MAX31865 — Maxim Integrated Type: Resistance-to-Digital Converter Description: An easy-to-use resistance-to-digital converter optimized for platinum RTDs, featuring 15-bit ADC resolution, SPI-compatible interface, ±45V input protection, and integrated fault detection.

Operating Conditions:

• Supply voltage: 3.0–3.6 V
• Operating temperature: -40 to +125 °C
• Reference Resistor (R REF): 350 Ω to 10 kΩ
• Cable Resistance (per lead): 0 to 50 Ω

Absolute Maximum Ratings:

• Max supply voltage (V DD relative to GND1): +4.0 V
• Max voltage on RTDIN+, RTDIN-, FORCE+, FORCE2, FORCE- relative to GND1: ±50 V
• Max junction temperature: +150 °C

Key Specs:

• ADC Resolution: 15 Bits (No missing codes)
• Total Accuracy: 0.5 °C (0.05% of Full Scale) max
• Conversion Time (Continuous, 50Hz notch): 20 ms (typ), 21 ms (max)
• Conversion Time (Single, 60Hz notch): 52 ms (typ), 55 ms (max)
• 50/60Hz Noise Rejection: 82 dB
• Power-Supply Current (Bias on, active conversion): 2 mA (typ), 3.5 mA (max)
• SPI Clock Frequency: DC to 5 MHz
• Input Protection (FORCE+, FORCE2, FORCE-, RTDIN+, RTDIN-): ±45 V

Features:

• Handles 100 Ω to 1 kΩ (at 0°C) Platinum RTDs (PT100 to PT1000)
• Compatible with 2-, 3-, and 4-Wire Sensor Connections
• SPI-Compatible Interface
• Programmable detection of RTD and cable open and short conditions
• Fully Differential V REF Inputs
• Data-Ready Output (DRDY)

Applications:

• Industrial Equipment
• Medical Equipment
• Instrumentation

Package:

• 20-Pin TQFN
• SSOP

• Integration Lowers System Cost, Simplifies Design Efforts, and Reduces Design Cycle Time
• Simple Conversion of Platinum RTD Resistance to Digital Value
• Handles 100 Ω to 1k Ω (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 N C (Varies Due to RTD Nonlinearity)
• Total Accuracy Over All Operating Conditions: 0.5 N 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)

• Industrial Equipment
• Medical Equipment
• Instrumentation

Ordering Information appears at end of data sheet.

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(3.0V P V DD P 3.6V, T A = -40 N C to +125 N C, unless otherwise noted. Typical values are T A = +25 N C, V DD = V DVDD = 3.3V.) (Notes 2 and 3)

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• Voltage Range on BIAS, REFIN+, REFIN-, ISENSOR................................. -0.3V to (V DD + 0.3V)

• Voltage Range on FORCE+, FORCE2, FORCE-, RTDIN+, RTDIN- Relative to GND1 ....-50V to +50V

• Voltage Range on DVDD Relative to DGND........-0.3V to +4.0V

• Voltage Range on All Digital Pins Relative to DGND............................. -0.3V to (V DVDD + 0.3V)

• TQFN (derate 34.5mW/ N C above +70 N C)...............2758.6mW

• SSOP (derate 11.9mW/°C above +70° C)...............952.4mW

• ESD Protection (all pins, Human Body Model)...................±2kV

• Operating Temperature Range........................ -40 N C to +125 N C

• Junction Temperature .....................................................+150 N C

• Storage Temperature Range............................ -65 N C to +150 N C

• Soldering Temperature (reflow) ......................................+260 N C

• Lead Temperature (soldering,10s) .................................+300 N C

Stresses beyond those listed under 'Absolute Maximum Ratings' may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial .

For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages . Note that a '+', '#', or '-' in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status.