Design of Multi-Channel Signal Switching Circuit for High-Resolution Thermocouple Acquisition System

Thermocouple sensor is a common temperature sensor. It is cheap and has a wide range of temperature measurement. It is widely used in industrial production. Its supporting acquisition system needs multi-channel, high precision, high resolution and supports the requirements of a variety of thermocouple typos. Therefore, this paper focuses on solving the problem of multi-channel high-precision signal acquisition and switching, and realizes a high-precision thermocouple acquisition and switching hardware architecture with 48 channels, output data rate of 1ksps/channel, temperature measurement range of -200~1820 °C, temperature accuracy of $\pm 0.25^{\circ}\mathrm{C}$ and resolution of 0.1 °C.