QT1080 / QT1101, 8 & 10-Key Touch™ Sensor ICs

For Charge-Transfer Capacitive Touch Sensing

Other features include fully debounced results, lifetime automatic calibration, adjacent key suppression, low noise operation and a fast detection mode for use in applications where a simple touch slider is needed. When used to implement individual touch keys, the sensitivity of each channel can be independently tuned simply by changing a capacitor.

Capacitive touch sensors have been notoriously prone to drift and unreliable operation. The charge-transfer chips provide automatic drift compensation over the life of the devices to suppress false detections caused by changes in temperature, humidity or other environmental effects. They also self-calibrate on power-up and automatically recalibrate after long detections so that keys never 'freeze' due to foreign objects in contact with the sensing surface or other unwanted influences.

Adjacent Key Suppression (AKS™) is an included patent-pending feature that prevents multiple keys from responding to a single touch. It works by comparing signal strengths within a group of keys and suppressing detections from those keys with signals, which are weaker than the dominant, intended key. AKS™ can operate across all 8 keys or in two groups of 4 keys, or it can be disabled.

The QT1080-ISG and QT1101-ISG operate from a single supply of between 2.8VDC and 5VDC and comes in a 1.1mm high Pb-free, QFN-32 package.

Spread spectrum, burst-mode operation ensures that external fields have minimal effect on key operation and heavily suppresses RF emissions A consensus filter that requires consecutive detections over a number of measurement cycles before a touch is confirmed, minimizes the chances of false detection due to noise. These features make EMC compliance tests simply a formality.

The devices feature a unique 'wake from low power' mode that permits extremely low current consumption while retaining excellent normal response time once a key is touched. This feature makes QT1xxx devices an excellent choice for portable applications such as MP3 players, mobile phones, and the like. There are two output modes: one pin per key, and binary coded.

Evaluation Board

The QT1080 can be assessed using Quantum's E1080 evaluation board.

Quantum recommends the use of either the QT1081 or QT1103 for new 8 or 10 channel touch sense designs. The E1080 demo board is available in limited volumes.

Please contact us in case you like to obtain one of these older boards.

Ordering Information

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‡ 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