LPS225HB datasheet(13/47 Pages) STMICROELECTRONICS

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LPS225HB

Functionality

The LPS225HB 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.

3.1

Sensing element

An ST proprietary process is used to obtain a mono-silicon μ-sized membrane for MEMS

pressure sensors without requiring substrate-to-substrate bonding. 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

I2C interface

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

resistance unbalancing 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 LPS225HB 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 IC interface is factory calibrated at three temperatures and two pressures for sensitivity

and accuracy.

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 normal operation which allows the device to be used without requiring any

further calibration.

LPS225HB Datenblatt(PDF) 13 Page - STMicroelectronics