
Atmel Corporation
Introduction
The AT42QT1110 (QT1110) is a digital burst mode charge-transfer (QT™) capacitive sensor driver designed for any touch-key applications.
The keys can be constructed in different shapes and sizes. Refer to the Touch Sensors Design Guide and Application Note QTAN0002, Secrets of a Successful QTouch Design, for more information on construction and design methods (both downloadable from the Atmel website).
FEATUREs
● Sensor Keys:
● Up to 11 QTouch® channels
● Data Acquisition:
● Measurement of keys triggered either by a signal applied to the SYNC pin or
at regular intervals timed by the AT42QT1110 internal clock
● Keys measured sequentially for better performance, or in parallel groups for
faster operation
● Raw data for key touches can be read as a report over the SPI interface
● Discrete Outputs:
● Configurable “Detect” outputs indicating individual key touch (7-key mode)
● Device Setup:
● Device configuration can be stored in EEPROM
● Technology:
● Patented spread-spectrum charge-transfer (direct mode)
● Key Outline Sizes:
● 6 mm × 6 mm or larger (panel thickness dependent); widely different sizes and
shapes possible, including solid or ring shapes
● Key Spacings:
● 7 mm center-to-center or more (panel thickness dependent)
● Layers Required:
● One
● Electrode Materials:
● Etched copper, silver, carbon, Indium Tin Oxide (ITO)
● Electrode Substrates:
● PCB, FPCB, plastic films, glass
● Panel Materials:
● Plastic, glass, composites, painted surfaces (low particle density metallic
paints possible)
● Panel Thickness:
● Up to 10 mm glass, 5 mm plastic (electrode size dependent)
● Key Sensitivity:
● Individually settable via simple commands over serial interface
● Adjacent Key Suppression® (AKS®)
● Patented AKS technology to enable accurate key detection
● Interface:
● Full-duplex SPI slave mode (1.5 MHz), CHANGE pin, discrete detection
outputs
● Moisture Tolerance
● Increased moisture tolerance based on hardware design and firmware tuning
● Power:
● 3 V – 5.5 V
● Package:
● 32-pin 5 × 5 mm MLF RoHS compliant
● 32-pin 7 × 7 mm TQFP RoHS compliant
● Signal Processing:
● Self-calibration, auto drift compensation, noise filtering, AKS technology
● Applications:
● Specific package qualified for automotive applications, such as radio, keyless entry, electric windows and satellite navigation