AIS2DW12 datasheet(22/60 Pages) STMICROELECTRONICS

22 / 60 page

Terminology and functionality

AIS2DW12

22/60

DocID031240 Rev 4

3.4

IC interface

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

converts the capacitive unbalancing of the MEMS sensor into an analog voltage using an

analog-to-digital converter.

The acceleration data may be accessed through an I2C/SPI interface thus making the

device particularly suitable for direct interfacing with a microcontroller.

The AIS2DW12 features a data-ready signal which indicates when a new set of measured

acceleration data is available, thus simplifying data synchronization in the digital system that

uses the device.

3.5

Factory calibration

The IC interface is factory-calibrated for sensitivity (So) and Zero-g level offset.

The trim values are stored inside the device in nonvolatile memory. Any time the device is

turned on, the trimming parameters are downloaded into the registers to be used during

active operation. This allows using the device without further calibration. If an accidental

write occurs in the registers where trimming parameters are stored, the BOOT bit in CTRL2

(21h) can help to retrieve the correct trimming parameters from nonvolatile memory without

the need to switch on/off the device. This bit is automatically reset at the end of the

download operation. Setting this bit has no impact on the control registers.

3.6

Temperature sensor

The temperature is available in OUT_T_L (0Dh), OUT_T_H (0Eh) stored as two's

complement data, left-justified in 12-bit mode and in OUT_T (26h) stored as two's

complement data, left-justified in 8-bit mode.

Refer to Table 6: Temperature sensor characteristics for the conversion factor.

AIS2DW12 Datasheet(PDF) 22 Page - STMicroelectronics