QT102 QTouch™ Sensor IC

Touch-on/off Power Control with Auto Shutoff

The QT102 capacitive touch sensor IC is a self-contained, all-digital product combining a single channel touch sensor with integrated system power management functions. The touch sensor is implemented as a toggle mode, touch on / touch off switch function and is combined with a user defined shut-off time. The shut-off function can also be overridden by external control of one of the IC pins to enhance the applications that can be addressed. This combination of functions, combined with the low impact SOT23-6 package, positions the QT102 as an ideal smart power switch for use in many consumer electronics applications.

The QT102 is a digital burst mode charge-transfer (QT) sensor designed specifically for touch controls; it includes all of the required hardware and signal processing functions necessary to provide high performance capacitive touch-sensing under the broadest range of operating conditions. Only a few passive external components are required to implement the sensor in a typical application.

The user definable auto shut-off feature of the QT102 addresses power management in applications which are battery driven and can help to provide a safety margin in, for example, small appliances. The off-timer override function can be used to integrate the chip as part of a broader system environment where an external device, such as a passive infrared sensor as part of a lighting control circuit, can determine the shut-off behaviour of the circuit.

Additionally, the QT102 is able to adapt to rapidly changing environmental conditions, compensating automatically for example as moisture or temperature changes are detected. The IC uses digital processing to reject impulse noise, using a detect integration function, or 'consensus' filter to provide fully de-bounced results for excellent discrimination of intentional operation.

The QT102 uses bursts of charge-transfer pulses to acquire the signal. Burst mode operation enables power consumption in the micro-amp range, essentially eliminates RF emissions, and reduces EMI susceptibility. All of this is achieved with no impact on the response time needed for excellent usability.

The overall cost / function / performance / package capability presented by this chip provides a unique functionality for industrial designers which opens up new application space for the increasingly popular and fashionable touch sensor market.

Evaluation Board

The E102 evaluation board has been developed to show the capabilities of the single channel, touch on/off QT102 sensor IC. It demonstrates the device in an example through-panel, toggle mode application. In addition, the evaluation shows the automatic shut off features, the delay having been preset to 90 seconds. Bond pads, located on the evaluation board, provide a convenient method to connect external sensors or to control your application using the on-board sensor.

The download table, below, provides links to the schematic diagram and evaluation board documentation. The kit includes the board and 2 additional QT102 ICs.

E102 Kit Price: US$23.50. Please contact us for availability information.

Ordering Information

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Price

‡ Price Bands (100k drop price indications, in US$, FOB UK)
A: under $0.50 | B: $0.50 - $0.80 | C: $0.80 - $1.50 | D: over $1.50