ROHM’s 3-Axis Digital Acceleration Sensor KX123-1039 is a tri-axis +/-2g, +/-4g or +/-8g silicon micromachined accelerometer with integrated 2048byte buffer, orientation, tap/double tap, activity detecting, and Free fall algorithms. The sense element is fabricated using Kionix's proprietary plasma micromachining process technology. Acceleration sensing is based on the principle of a differential capacitance arising from acceleration-induced motion of the sense element, which further utilizes common mode cancellation to decrease errors from process variation, temperature, and environmental stress.
The sense element is hermetically sealed at the wafer level by bonding a second silicon lid wafer to the device using a glass frit. A separate ASIC device packaged with the sense element provides signal conditioning, and intelligent user-programmable application algorithms. The accelerometer is delivered in a 3 x 3 x 0.9 mm LGA plastic package operating from a 1.71 - 3.6V DC supply. Voltage regulators are used to maintain constant internal operating voltages over the range of input supply voltages. This results in stable operating characteristics over the range of input supply voltages. I2C or SPI digital protocol is used to communicate with the chip to configure and check for updates to the orientation, Directional TapTM detection, Free fall detection and activity monitoring algorithms.