Smart temperature sensors (also known as digital temperature sensors) were introduced in the mid-1990s. It is the crystallization of microelectronics, computer technology and automatic test technology (ATE). At present, the world has developed a variety of smart temperature sensor products. The temperature sensor, A / D converter, signal processor, memory (or register) and interface circuit are all included in the smart temperature sensor. Some products also include multiplexers, CPUs, RAMs and ROMs. Intelligent temperature sensor is characterized by the output temperature data and related temperature control, suitable for a variety of microcontrollers (MCU); and it is based on the hardware to achieve the test function by software, the degree of intelligence also depends on At the software development level.