Touch controller runs buttons and sliders

Ideal for use as a multimedia HMI controller in mobile phones, where it saves space, minimises design time and allows the designer creative flexibility in laying out control keys.

New from Atmel, the AT42QT2160 touch controller IC combines touch key and touch slider functions in a single device.

The AT42QT2160 can control up to 16 individual touch keys with a slider comprising between two and eight of the touch key channels.

In addition, the chip can also control up to 11 LEDs through a PWM output function that is controlled by the host, eliminating the need for an external LED controller.

With this combination of functions, this device is ideal for use as a multimedia HMI controller in mobile phones and consumer applications, such as personal media players, where it saves space, minimises design time and allows the designer creative flexibility in laying out control keys.

With its wide voltage range (1.8 to 5.5V DC) and low power requirements, it is well suited for other battery-driven applications, such as digital still cameras, PDAs or handheld gaming devices.

The AT42QT2160 uses Quantum Research Group's (acquired by Atmel in March 2008) patented charge-transfer technology.

This provides robust and reliable performance, high immunity to EMI through spread-spectrum modulation and filtering algorithms, calibration of the device over life and user-defined sensitivity thresholds for individual keys.

An additional patented function, adjacent key suppression (AKS), intelligently suppresses signals present from nearby keys so that only intended keys register a touch.

The AT42QT2160 has three GPIOs with PWM capability and a further eight shared output ports that provide additional standard outputs for the host without adding cost or using an extra I/O expansion device with PWM capability.

Host configurability is achieved via a two-wire interface (I2C compatible).

To save system power, the chip provides a system multi-input wake-up (MIWU) function.

This can trigger a reaction from the host or other system components via the two-wire interface, or using a dedicated output pin when predefined input signals levels are reached.

Touch button sensor electrodes, of arbitrary sise (larger than 6 x 6mm) and shape, are usually formed from copper pads on the printed circuit board or a flexible circuit.

The touch surface can be made from glass up to 3mm in thickness or plastic, up to 2.5mm thick.

According to Peter Jones, Managing Director of Atmel's MCU Business Unit: "This is the first of many new products that we will launch in the next year as we accelerate our R and D in touch technology to capitalise on one of the fastest growing embedded applications".

"We expect to see up to 60 models of mobile phone adopting our technology over the next 12 months and the increasing use of touch controls in everything from laptop PCs to consumer electronics".

"It's a very exciting time to be in this business".

The AT42QT2160 is the latest addition to Atmel's comprehensive range of capacitive touch controllers based on Quantum Research Group's charge-transfer technology.

These include QTouch controllers for single and multiple touch buttons, touch sliders and touch wheels, together with QMatrix devices for higher density matrix key panels.

Samples of the AT42QT2160 IC are available now in 28-pin 4 x 4mm QFN packages.

Pricing for the part is US $0.98 each for quantities of 100,000 units per year.

A demonstration board for development support is also available.

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