Microchip AT42QT1110-AZ

The Microchip AT42QT111x standarized capacitive touch controller with configurable 11-key QTouch buttons with guard channels for reliable capacitive user interfaces. It can be used in any application that requires buttons. Its keys can be constructed in different shapes and sizes. The device includes all signal processing functions necessary to provide stable sensing under a wide variety of changing conditions. The outputs are fully debounced. Only a few external components are required for operation.

The 42AT1110 operates from 3V - 5.5V, whereas the 42QT1111 operates from 1.8V - 5.5V

The 42AT1110 features an "Extended Pulse Time" configuration

• Up to 11 QTouch® channels
• Measurement of keys triggered either by a signal applied to the SYNC pin or at regular intervals timed by the AT42QT111x 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, configurable “Detect” outputs indicating individual key touch (7-key mode)
• Device configuration can be stored in EEPROM
• 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)
• PCB 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 configurable via simple commands over serial interface
• Patented Adjacent Key Suppression® (AKS®) technology to enable accurate key detection
• Interface: Full-duplex SPI slave mode (1.5 MHz), CHANGE pin, discrete detection outputs
• Increased moisture tolerance based on hardware design and firmware tuning
• AT42QT1110: 3V – 5.5V
• AT42QT1111: 1.8V – 5.5V
• 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