High-Performance Low Power Touch Sensor Controller

23rd February 2009

Fujitsu

ES Admin

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Datasheet

Fujitsu Microelectronics has announced that it is distributing the FMA1127, a high-performance, low power Touch Sensor Controller (TSC) from ATLab, Inc. of South Korea. The TSC series offers a simple, reliable and aesthetic replacement for virtually all mechanical buttons, sliders and turning knobs across a variety of markets including home appliance, mobile, industrial, consumer electronics and office equipment. By enabling cost-efficient implementations and offering a high degree of design flexibility, the device provides an extremely user-friendly solution for touch-sensing applications.

Using patented technology from ATLab, Inc., the FMA1127 detects touch in the digital domain by comparing the sensor input impedances with its built-in reference impedance. The differential signal format makes the sensor resistant to outer signal disturbances and assures reliable operation. Furthermore, the FMA1127’s AIC (Automatic Impedance Calibration) function enables the sensor to maintain a consistent sensitivity even during changes to the environment caused by temperature, humidity and production tolerances. The AIC™ function can be configured easily to adjust the sensitivity for each individual channel.

Processed in standard CMOS technology, the FMA1127 features ultra-low power consumption. Typical supply current for active mode is just 120μA. In sleep mode the power consumption can be reduced down to 0.1μA. This makes the FMA1127 ideal for portable applications.

The FMA1127 makes implementing touch-sensing hardware and software fast, easy and cost-efficient. With built-in reference impedances, the sensor renders external components unnecessary for touch channels in a wide range of applications. A single electrode is sufficient for each touch channel.

Minimum software effort is required to implement basic touch functionality. Powered by the APIS™ (Adjacent Pattern Interference Suppression) function, the controller can filter-out unintentional touches made by the user. Additional filtering functions provide further pre-processing of the touch data.

The FMA1127 offers a high-level of design flexibility through the host interface (I²C) as well as up to 12 programmable general-purpose digital I/Os, which can also be used as external interrupt pins. Furthermore, the flexibility of touch-pad designs is enhanced through individual channel sensitivity and integrated pre-processing, all configurable via the host MCU. For advanced sensing, such as interpolation between discrete sensor pads, the touch strength of each sensor pad can be read by the host MCU with up to 8-bit precision.