MAX31856
The MAX31856 performs cold-junction compensation and digitizes the signal from any type of thermocouple. The output data is formatted in degrees Celsius. This converter resolves temperatures to 0.0078125°C, allows readings as high as +1800°C and as low as -210°C (depending on thermocouple type), and exhibits thermocouple voltage measurement accuracy of ±0.15%. The thermocouple inputs are protected against overvoltage conditions up to ±45V.
A lookup table stores linearity correction data for several types of thermocouples (K, J, N, R, S, T, E, and B). Line frequency filtering of 50Hz and 60Hz is included, as is thermocouple fault detection. A SPI-compatible interface allows selection of thermocouple type and setup of the conversion and fault detection processes.
Key Features
- Provides High-Accuracy Thermocouple Temperature Readings
- Includes Automatic Linearization Correction for 8 Thermocouple Types
- ±0.15% (max, -20°C to +85°C) Thermocouple Full-Scale and Linearity Error
- 19-Bit, 0.0078125°C Thermocouple Temperature Resolution
- Internal Cold-Junction Compensation Minimizes System Components
- ±0.7°C (max, -20°C to +85°C) Cold-Junction Accuracy
- ±45V Input Protection Provides Robust System Performance
- Simplifies System Fault Management and Troubleshooting
- Detects Open Thermocouples
- Over- and Undertemperature Fault Detection
- 50Hz/60Hz Noise Rejection Filtering Improves System Performance
- 14-Pin TSSOP Package
Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX31856.pdf
Contents
CNC.xyz MAX31856 Breakout Board
Arduino Library
You can download our Arduino Library from our Github page: https://github.com/CNCxyz/MAX31856
Bill of Materials (BOM)
| Line # | Quantity | Part Code | Description |
|---|---|---|---|
| 1 | 1 | IC1 | MAX31856 Thermocouple Chip |
| 2 | 1 | U1 | SPX3819 3.3V Voltage Regulator |
| 3 | 3 | R1, R2, R3 | 100 ohm Resistor 0603 |
| 4 | 1 | R4 | 330 ohm Resistor 0603 |
| 5 | 2 | C1, C2 | 1.0uF Capacitor 0603 |
| 6 | 5 | C3, C4, C5, C6, C7 | 0.1uF Capacitor 0603 |
| 7 | 1 | FAULT | Red LED 0603 |
| 8 | 1 | J1 | 2 Position Terminal Block |
| 9 | 1 | J2 | 9 Position Header |
Schematic
