LPS22DF datasheet(9/54 Pages) STMICROELECTRONICS

9 / 54 page

Functionality

The LPS22DF is a high-resolution, digital output pressure sensor packaged in an HLGA full-mold package. The

complete device includes a sensing element based on a piezoresistive Wheatstone bridge approach, and an IC

interface which communicates a digital signal from the sensing element to the application.

4.1

Sensing element

An ST proprietary process is used to obtain a silicon membrane for MEMS pressure sensors. This silicon

membrane is surrounded by a silicon spring structure and it contributes to isolate the membrane from mechanical

and thermal stress in applications. When pressure is applied, the membrane deflection induces an imbalance in

the Wheatstone bridge piezoresistances whose output signal is converted by the IC interface.

4.2

IC interface

The complete measurement chain is composed of a low-noise amplifier which converts the resistance unbalance

of the MEMS sensors (pressure and temperature) into an analog voltage using an analog-to-digital converter.

The pressure and temperature data may be accessed through an I²C/MIPI I3CSM/SPI interface thus making the

device particularly suitable for direct interfacing with a microcontroller.

The LPS22DF features a Data-Ready signal which indicates when a new set of measured pressure and

temperature data are available, thus simplifying data synchronization in the digital system that uses the device.

4.3

Factory calibration

The trimming values are stored inside the device in a non-volatile structure. When the device is turned on, the

trimming parameters are downloaded into the registers to be employed during the normal operation which allows

the device to be used without requiring any further calibration.

LPS22DF

Functionality

DS13316 - Rev 1

page 9/54

LPS22DF Datasheet(PDF) 9 Page - STMicroelectronics