The MAX6674 is a cold-junction-compensation thermocouple-to-digital converter that performs cold-junction compensation and digitizes the signal from a type-K thermocouple. The data is output in a 10-bit resolution, SPI-compatible, read-only format. This converter resolves temperatures to 0.125°C, allows readings as high as +128°C, and exhibits thermocouple accuracy of ±2°C for temperatures ranging from 0°C to +125°C. The MAX6674 is available in a small, 8-pin SO package.
The MAX6674 is a cold‑junction‑compensated K‑thermocouple‑to‑digital converter that provides 10‑bit temperature readings from 0 °C to +128 °C. It includes built‑in cold‑junction compensation, open‑thermocouple detection, and a simple SPI‑compatible serial interface for easy integration with microcontrollers.
The device is supplied in an 8‑pin SO package, operates from a 3.0 V to 5.5 V supply, and draws about 2 mA. It offers a conversion time of 0.15–0.18 s and an input impedance of 20 kΩ. Recommended layout practices include using a 0.1 pF bypass capacitor and keeping the thermocouple leads away from noisy sources.
| Temperature range | 0 °C to +128 °C |
|---|---|
| Resolution | 0.125 °C (10‑bit) |
| Supply current | 2 mA |
| Conversion time | 0.15–0.18 s |
| Thermocouple input impedance | 20 kΩ |
| Package | 8‑pin SO (SOIC) package |
The MAX6674 provides a resolution of 0.125 °C using a 10‑bit ADC.
Bit D4 goes high when the thermocouple input is open.