The QT60325, QT60485, and QT60645 digital charge-transfer ("QT") QMatrixTM ICs are designed to detect human touch on up to 32, 48, or 64 keys respectively using a scanned, passive X-Y matrix. It will project the keys through almost any dielectric, e.g. glass, plastic, stone, ceramic, and even wood, up to thicknesses of 5 cm or more. The touch areas are defined as simple 2-part interdigitated electrodes of conductive material, like copper or screened silver or carbon deposited on the rear of a control panel. Key sizes, shapes and placement are almost entirely arbitrary; sizes and shapes of keys can be mixed within a single panel of keys and can vary by a factor of 20:1 in surface area. The sensitivity of each key can be set individually via simple functions over the SPI port, for example via Quantum's QmBtn program. Key setups are stored in an onboard eeprom and do not need to be reloaded with each power-up.