Currently there are four major temperature sensing technologies in the market. They are digital temperature sensors, thermistors, RTDs, and thermocouples. While RTDs and thermocouples are suitable for extreme temperature conditions, most electronic systems can benefit from either a digital temperature sensor or a thermistor. A digital temperature sensor is a self-contained complete solution, but a thermistor requires the support of external circuitry such as an analog-to-digital converter. In terms of performance, a digital temperature sensor is superior in accuracy. It is also calibration-free. On the other hand, a thermistor would require time-consuming calibration to achieve accurate measurement and thus add significant manufacturing cost. Therefore, although a themistor may have lower unit cost at first glance, a designer should consider the overall system and manufacturing cost to properly evaluate the value between the two devices.