LPS33HW datasheet(14/50 Pages) STMICROELECTRONICS

14 / 50 page

Functionality

LPS33HW

14/50

DocID030522 Rev 1

Functionality

The LPS33HW is a high-resolution, digital output pressure sensor packaged in a CCLGA

package with metal lid. 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.

3.1

Sensing element

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

sensors. When pressure is applied, the membrane deflection induces an imbalance in the

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

3.2

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/SPI interface thus

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

The LPS33HW 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.

3.3

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.

LPS33HW Datasheet(PDF) 14 Page - STMicroelectronics