CM2120 digital temperature and humidity sensor is a calibration signal with a digital output of the composite temperature and humidity sensor. Using a dedicated temperature and humidity acquisition technology to ensure that products with high reliability and excellent long-term stability. The sensor includes a capacitive wet sensor and a high-precision integrated temperature sensor connected to a high-performance microprocessor. The product has excellent quality, fast response, anti-interference ability, cost-effective and so on. HM2120 communication mode using single-bus communication, standard single-bus interface, the system integration becomes simple and quick. Ultra-small size, low power consumption, signal transmission distance up to 20 meters, making it the best choice for all kinds of applications and even the most demanding applications. Adopting the direct output of temperature-compensated digital information such as humidity, temperature and calibration, users do not need to perform secondary calculation on the digital output and do not need temperature compensation for humidity to get accurate temperature and humidity information. Products for the 4-lead, easy to connect, special package can be provided according to user needs.