Piezo-Resistive Sensor/Accelerometer Operates in Three Axes

HDK-America has released a small, piezo-resistive three-axis acceleration sensor, the HAAM-325B, measuring 3 mm x 3 mm x 1 mm. Just one-fifth the size of the previous generation product, it offers fully comparable performance.

Based on a silicon substrate and fabricated by means of a micro-machining MEMS technology, the HAAM-325B has a high-output sensitivity of 400 mV/G (Vcc = 3 V). The device can detect even minute amounts of 3-axis dynamic acceleration in the X, Y and Z axes, and output tilt and gravitational acceleration data simultaneously. Two separate terminals of interrupt output for drop detection and shock detection are now provided, in addition to a conventional standby terminal. This helps to simplify circuit application.

If a “free-fall” condition is sensed, the HAAM-325B Sensor can signal a hard drive to “lock down” before impact. Acceleration or position can be sensed to trigger other functions, such as a screen change from portrait to landscape or an alarm to call attention to a device being dropped or moved. Another key feature is the power-saving design, typically consuming just 0.35 mA and 1 mA in standby.

Rated acceleration is +/- 2 G. Output sensitivity is 400 mV/G (at 3 V of supply voltage, ratio metric output). Offset voltage is 1.5 V +/-0.075 V (Ratio-metric to supply voltage). Sensitivity is 20 mV/N with a linearity of +/-3% FS. Operating temperature range is from 0°C to +75°C.

Shock resistance is 4000 G. HAAM-325B Three-Axis Sensors are available at $26 each in sample quantities.