The AS6221 is a high accurate digital temperature sensor with an accuracy of up to ±0.09°C, which is ideal for healthcare applications, wearables and devices requiring high-performance thermal information. The AS6221, is a complete digital sensor system, requires no calibration or linearization. It provides measurement outputs via a standard I²C interface. The sensor supports eight I²C addresses avoiding bus conflicts in multi-sensor use cases. The ultra-small size of the sensor (WLCSP 1.5 mm x 1.0 mm) enables accurate body/skin temperature measurements in very small health and lifestyle monitoring products. In addition to the high accuracy and the small form factor, the AS6221 offers a very low power consumption, for example measuring with 4 samples/s, the current consumption is only 6 µA. The sensor has 4 different automatic acquisition modes and keeps the high accuracy over the full supply range from 1.71 to 3.6 V. An integrated alert functionality triggers an interrupt to the micro controller when a temperature threshold is exceeded. The temperature threshold for the alert function can be adjusted in a device register.