MAX6675 K-Type Thermocouple Module – Digital Temperature Sensor for High Temp Measurement (0 to 1024°C), Arduino Compatible

Description

The MAX6675 is a cold-junction compensated K-type thermocouple-to-digital converter designed for high-temperature measurement in appliances, HVAC systems, and industrial equipment . It performs signal amplification, cold-junction compensation, linearization, and 12-bit analog-to-digital conversion internally, outputting temperature data via a simple SPI-compatible serial interface .

The device resolves temperature to 0.25°C and can read up to +1024°C, with specified thermocouple accuracy of 8 LSBs over the 0°C to +700°C range . It includes open-thermocouple detection (bit D2 goes high if the probe is disconnected) and operates from a 3.0V to 5.5V supply . The MAX6675 is available in an 8-pin SO package; breakout modules add a screw terminal for the thermocouple and 0.1″ header pins for Arduino connection.

Critical limitations: The MAX6675 measures only positive temperatures—it cannot read below 0°C . It is susceptible to power-supply noise, and a 0.1µF ceramic bypass capacitor close to the supply pin is recommended . Self-heating can degrade accuracy; a large ground plane helps . For negative temperature measurement or higher precision, consider the MAX31855 (which supports negative temperatures).

Features

• Direct K-Type Thermocouple Interface: Integrates cold-junction compensation and digitization in one chip .

• 12-Bit, 0.25°C Resolution: Fine-grained temperature readings .

• SPI-Compatible Read-Only Interface: Simple 3-wire connection to any microcontroller .

• Open-Thermocouple Detection: Bit D2 flags a disconnected probe .

• Wide Temperature Range: 0°C to +1024°C (accuracy specified to +700°C) .

• Low Power Consumption: Operates from 3.0V to 5.5V .

• Compact 8-Pin SO Package: Small footprint for space-constrained designs .

• Arduino Library Support: Widely available libraries simplify integration .

Technical Specifications