Touch Sensor Capacitive 11 Key 1.8V to 5.5V Surface Mount 32-Pin TQFP Tray

The AT42QT1111 is a digital burst mode charge-transfer (QT) capacitive sensor driver designed for any touch-key applications. The QT1111 modulates its bursts in a spread-spectrum fashion in order to suppress heavily the effects of external noise, and to suppress RF emissions. The device includes all signal processing functions necessary to provide stable sensing under a wide variety of changing conditions, and the outputs are fully debounced. Only a few external parts are required for operation.

• 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 AT42QT1111 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
• 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 (750 kHz), CHANGE pin, discrete detection outputs
• Moisture Tolerance
• Increased moisture tolerance based on hardware design and firmware tuning
• Power:
• 1.8 V – 5.5 V
• Package:
• 32-pin 5 × 5 mm QFN RoHS compliant
• 32-pin 7 × 7 mm TQFP RoHS compliant
• Signal Processing:
• Self-calibration, auto drift compensation, noise filtering, AKS technology
• Applications:
• Consumer and industrial applications, such as TV, media player