Functionality

HTS221

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DocID026333 Rev 4

3

Functionality

The HTS221 is a digital humidity and temperature sensor, packaged in an HLGA holed

package.The device includes the sensing element and an IC (integrated circuit) interface

able to take information from the sensing element and provide a digital signal to the

application, communicating through I²C/SPI interfaces with the host controller.

3.1

IC interface

The complete measurement chain consists of a low-noise capacitive amplifier, which

converts the capacitive imbalance of the humidity sensor into an analog voltage signal, and

an analog-to-digital converter is used to generate the digital information.

The converter is coupled with a dedicated hardware (HW) averaging filter to remove the

high-frequency component and reduce the serial interface traffic.

The relative humidity and temperature data can be accessed through an I²C/SPI interface,

making the device particularly suitable for direct interfacing with a microcontroller.

3.2

Factory calibration

The IC (integrated circuit) interface is factory calibrated and the coefficients required to

convert the ADC 16-bit values into rH% or degrees Celsius can be read through the internal

registers of the sensor. Further calibration by the user is not required.