Touch Sensor Capacitive 8 Key 2V to 5.5V Surface Mount 32-Pin QFN EP T/R

The AT42QT1085 is an easy to use QTouchADC mode sensor IC based on principles for robust operation and ease of design. It is intended for any touch-key application. There are four dedicated channels configured as keys (Key 0 – Key 3). There are 12 dedicated GPIO channels (GPIO_0 – GPIO_11). Another four channels can be configured as keys or GPIO channels (Key 4 – Key 7 or GPIO 12 – GPIO 15). The QT1085 is capable of detecting proximity or touch on the channels configured as keys. Each GPIO channel may be configured as a digital input or output. In output mode, a GPIO pin may be set to output a PWM signal at any of 16 duty cycles (4-bit PWM). The QT1085 allows electrodes to project sense fields through any dielectric such as glass or plastic.

• QTouch® Sensor Channels
  • Up to eight keys
• Integrated Haptic Engine
  • Haptic events may be triggered by touch detection or controlled by a host microcontroller over SPI
• Data Acquisition
  • QTouchADC key measurement/touch detection method
  • Configurable measurement timing and averaging
  • Spread spectrum charge transfer
  • Raw data from channel measurement can be read over the SPI interface
• GPIO Pins
  • 12 dedicated bi-directional GPIO pins, plus up to 4 additional pins (replacing keys)
  • Configurable as software PWM Drive, digital inputs or outputs
• Device setup
  • Device configuration may be stored in NVRAM
• Operation
  • Power-On reset and brown-out detection
  • Internal calibrated oscillator
• Key Outline Sizes
  • 6 mm × 6 mm or larger (panel thickness dependent); widely different sizes and shapes possible, including solid or ring shapes
• Key Spacing
  • 7 mm or more, center to center (panel thickness dependent)
• Layers required
  • One
  • Electrode Materials:
  • Etched copper, silver, carbon, ITO
• Electrode Substrates:
  • PCB materials; polyamide FPCB; PET 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 configured over SPI interface
• Signal Processing:
  • Self-calibration, auto drift compensation, noise filtering
  • Patented Adjacent Key Suppression® (AKS®) technology to ensure accurate key detection
• Interface:
  • Master/Slave SPI interface, up to 750 kHz
  • Object-based communications protocol
• Power:
  • 2.0 V to 5.5 V
• Packages:
  • 32-pin 5 × 5 mm QFN RoHS compliant
  • 32-pin 7 × 7 mm TQFP RoHS compliant