MAX31865

<span id="page-0-0"></span>Typical Application Circuits

The MAX31865 is an electronic component from Analog Devices Inc./Maxim Integrated. <span id="page-0-0"></span>Typical Application Circuits. View the full MAX31865 datasheet below including electrical characteristics, absolute maximum ratings.

Manufacturer

Analog Devices Inc./Maxim Integrated

Overview

Part: MAX31865 from Maxim Integrated

Type: Resistance-to-Digital Converter

Key Specs:

RTD Range: 100Ω to 1kΩ (at 0°C)
ADC Resolution: 15-Bit
Nominal Temperature Resolution: 0.03125°C
Total Accuracy: 0.5°C max
Max Conversion Time: 21 ms (50Hz notch, continuous conversion)
Input Protection: ±45V
Operating Temperature Range: -40°C to +125°C
Supply Voltage (VDD/DVDD): 3.0V to 3.6V
SPI Clock Frequency: 5.0 MHz max

Features:

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
15-bit ADC resolution
Total accuracy over all operating conditions: 0.5°C max
Fully differential VREF inputs
Integrated fault detection (Open RTD element, RTD shorted to out-of-range voltage, or short across RTD element)
Programmable detection of RTD and cable open and short conditions
±45V input protection

Applications:

Industrial Equipment
Medical Equipment
Instrumentation

Package:

20-Pin TQFN
SSOP

Features

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 0.03125NC (Varies Due to RTD Nonlinearity)
- Total Accuracy Over All Operating Conditions: 0.5NC (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)

Ordering Information appears at end of data sheet.

Applications

Industrial Equipment
Medical Equipment
Instrumentation

Pin Configuration

Electrical Characteristics

(3.0V P VDD P 3.6V, TA = -40NC to +125NC, unless otherwise noted. Typical values are TA= +25NC, VDD = VDVDD = 3.3V.) (Notes 2 and 3)

PARAMETER	SYMBOL	CONDITIONS	MIN	TYP	MAX	UNITS
ADC Resolution				15		Bits

Absolute Maximum Ratings

Voltage Range on VDD Relative to GND1-0.3V to +4.0V	Continuous Power Dissipation (TA = +70NC)
Voltage Range on BIAS, REFIN+,	TQFN (derate 34.5mW/NC above +70NC)2758.6mW
REFIN-, ISENSOR -0.3V to (VDD + 0.3V)	SSOP (derate 11.9mW/°C above +70° C)952.4mW
Voltage Range on FORCE+, FORCE2,	ESD Protection (all pins, Human Body Model)±2kV
FORCE-, RTDIN+, RTDIN- Relative to GND1 -50V to +50V	Operating Temperature Range -40NC to +125NC
Voltage Range on DVDD Relative to DGND-0.3V to +4.0V	Junction Temperature +150NC
Voltage Range on All Digital Pins	Storage Temperature Range -65NC to +150NC
Relative to DGND -0.3V to (DVDD + 0.3V)	Soldering Temperature (reflow) +260NC
	Lead Temperature (soldering,10s) +300NC
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation

(Note 1) Package Thermal Characteristics

TQFN
SSOP

Junction-to-Ambient Thermal Resistance (qJA) ..........29°C/W Junction-to-Case Thermal Resistance (qJC).................2°C/W SSOP

Thermal Information

TQFN
SSOP

Junction-to-Ambient Thermal Resistance (qJA) ..........29°C/W Junction-to-Case Thermal Resistance (qJC).................2°C/W SSOP

Typical Application

Absolute Maximum Ratings

Voltage Range on VDD Relative to GND1-0.3V to +4.0V	Continuous Power Dissipation (TA = +70NC)
Voltage Range on BIAS, REFIN+,	TQFN (derate 34.5mW/NC above +70NC)2758.6mW
REFIN-, ISENSOR -0.3V to (VDD + 0.3V)	SSOP (derate 11.9mW/°C above +70° C)952.4mW
Voltage Range on FORCE+, FORCE2,	ESD Protection (all pins, Human Body Model)±2kV
FORCE-, RTDIN+, RTDIN- Relative to GND1 -50V to +50V	Operating Temperature Range -40NC to +125NC
Voltage Range on DVDD Relative to DGND-0.3V to +4.0V	Junction Temperature +150NC
Voltage Range on All Digital Pins	Storage Temperature Range -65NC to +150NC
Relative to DGND -0.3V to (DVDD + 0.3V)	Soldering Temperature (reflow) +260NC
	Lead Temperature (soldering,10s) +300NC
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation

(Note 1) Package Thermal Characteristics

TQFN
SSOP

Junction-to-Ambient Thermal Resistance (qJA) ..........29°C/W Junction-to-Case Thermal Resistance (qJC).................2°C/W SSOP

Package Information

+Denotes a lead(Pb)-free/RoHS-compliant package. T = Tape and reel. *EP = Exposed pad.

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.

PACKAGE TYPE	PACKAGE CODE	OUTLINE NO.	LAND PATTERN NO.
20 TQFN-EP	T2055+5	21-0140	90-0010
20 SSOP	A20+1	21-0056	90-0094

Related Variants

The following components are covered by the same datasheet.

Part Number	Manufacturer	Package
MAX31865AAP	Analog Devices Inc./Maxim Integrated	—
MAX31865ATP	Analog Devices Inc./Maxim Integrated	—
MAX31865ATP+T	Analog Devices Inc./Maxim Integrated	20-WQFN Exposed Pad

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