Date: 20/03/2009

Atmel's low priced touch sensor IC for mobile phone has 4 o/p channels

Atmel has launched new low cost touch sensor IC AT42QT1040 for use in mobile phones and other handheld devices. In low power mode the AT42QT1040 draws 31uA from a 1.8 VDC supply. The AT42QT1040 includes 4 digital output channels, enabling per-channel indication on touch detection. The IC can also be configured using one channel as a proximity sensor, enabling 'hidden-until-lit' user interfaces where the device detects the presence of a finger some distance away from the keypad.

This device uses Atmel's proprietary patented QTouch charge-transfer sensing method for touch sensing and spread-spectrum modulation to stay immune from electrical noise. Atmel's another patented Adjacent Key Suppression is used to ensure that only the intended key is activated by the touch of a finger. Long-term reliability is achieved because the device automatically calibrates on power-up and always stays calibrated even if there is a build-up of moisture or other contaminants on the touch surface or if the overall system is subject to aging. Individual key sensitivity can be configured to support a range of front panel thickness variations and materials including glass or plastic up to several millimeters thick. Electrodes can be made from copper, silver, carbon, indium tin oxide (ITO) or any other conductive material. Widely different electrode sizes and shapes are possible, giving the product designer great flexibility to tailor the user interface. The device has two power modes: a low power mode, which is ideal for small, battery-driven devices and a fast response mode, which provides minimum response time for applications where low touch latency is essential. To aid product development the AT42QT1040 has a debug mode in which internal data from the chip can be accessed.

Price: Each at $0.35 in quantities of 100 K units. An evaluation kit, EVK1040A, is also available, priced at $25.