MEMS targets handhelds

STMicroelectronics has developed a three-axis linear accelerometer that combines a MEMS-based sensor and interface chip in a single package.

The LIS3L02 Three-Axis Linear Accelerometer from STMicroelectronics houses a one-chip three-axis MEMS accelerometer sensor plus an interface chip in a QFN package.

In mobile phones, PDAs and other handheld battery-powered products, the LIS3L02 can be used to implement new intuitive user interfaces based on the movement of the user. This approach allows one-handed operation without styluses, thumb keyboards or other input devices.

Movement or inclination in three axes causes small displacements of moving silicon structures in the MEMS sensor die, changing the capacitance between moving and fixed parts. The interface chip, which is in the same package, translates these minute capacitance changes into calibrated analog voltages proportional to the movement. The interface chip is factory trimmed to ensure repeatable performance without production line adjustment in the end product.

Three versions of the LIS3L02 are currently available: type LIS3L02A provides an analog output; LIS3L02P provides both an analog voltage output and PWM output; type LIS3L02D provides a serial digital I2C output. All types operate on a 3.3-5V supply and have an equivalent noise acceleration of better than 500 millionths of one g.

During transport and service it can withstand accelerations up to 1500g without damage, making it sufficiently shock resistant for mobile phone applications.

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