Atmel releases false-trigger proof touch chip

Atmel Corporation has brought out the AT42QT1060 touch control chip.

The chip integrates six channels of touch sensing with the ability to drive up to seven low-current LEDs directly through a pulse-width modulated (PWM) output function.

The device operates from 5.5VDC down to 1.8VDC and consumes less than 1uA in standby mode to give long battery life.

It comes in a 4 x 4mm MLF28 package, making it suitable for use in mobile phones and other handheld devices.

An inbuilt capacitive guard channel feature helps prevent false triggering, for example, where moisture is an issue.

This feature also prevents against erroneous commands that can occur when devices such as MP3 players are carried in a pocket or when a cellular phone is held against the ear.

The integrated AT42QT1060 reduces component count, cutting design complexity and cost and enabling faster product development.

The sensor chip is based on Quantum's Qtouch charge-transfer sensing method.

This robust technology uses spread-spectrum modulation to achieve high immunity to electrical noise and adjacent key suppression (AKS) ensures only the intended key is activated by the touch of a finger.

The guard channel feature uses AKSTM to eliminate false triggering of nearby keys.

Long-term reliability is ensured because the device automatically re-calibrates on power-up, compensating for build-up of moisture or other contaminants on the touch surface.

Individual key sensitivity is host-selectable.

A host wake-up function allows the host to sleep and be woken up when a user triggers the corresponding input, providing another power-saving feature.

Additional GPIO expansion can be achieved by the use of spare IC pins.

The AT42QT1060 functions through any insulating panel, including glass or plastic, up to 3mm thick.

Electrodes can be made from copper, silver, carbon, indium tin oxide (ITO) or Orgacon conductive ink and must be 6 x 6mm or larger.

Widely different electrode sizes and shapes are possible, giving the product designer great flexibility in tailoring the user interface.

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