The configurable AD7147 CDC features 13 capacitance inputs and femto farad resolution, allowing mobile electronics designers to implement a touch pad, scroll wheel, slider, or up to 36 buttons per device. The addition of integrated active shield technology protects the AD7147 from capacitance-to-ground pickup and other noise sources in the system, allowing designers the freedom to place the sensor away from the main system IC.
The analog front-end of the AD7147 has been improved, yielding a threefold improvement in sensor response compared to previous AD714x products. The improved response allows end-users to experience more accurate finger navigation and improved device performance, while continuing to offer designers per-channel sensitivity adjustment for sensor-response fine tuning. The AD7147 includes on-chip sensitivity algorithms that compensate for changes in temperature and humidity, and ensure that users with different finger sizes receive the same responsive sensor performance.
The AD7147 typically consumes 1 mA in full power mode, and just 50 μA in low-power mode, a 20% reduction compared to competitive products on the market. Additionally, the AD7147 has the industry’s lowest shutdown power consumption at only 2 μA.
The AD7147 includes an SPI (serial peripheral interface)-compatible serial interface, while the AD7147-1 features an I²C (inter-integrated circuit)-compatible serial interface. Both devices are sampling now and will be available in full production quantities in July 2007. Priced at $1.30 per unit in 1,000-unit quantities, both products are housed in 24-pin 4 mm × 4 mm LFCSPs.