MICROCHIP AT42QT1070-SSUR

The AT42QT1070 (QT1070) is a digital burst mode charge-transfer (QT) capacitive sensor driver. The device can sense from one to seven keys, dependent on mode. The QT1070 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 and no external Cs capacitors are required. The QT1070 modulates its bursts in a spread-spectrum fashion in order to heavily suppress the effects of external noise, and to suppress RF emissions. The QT1070 uses a dual-pulse method of acquisition. This provides greater noise immunity and eliminates the need for external sampling capacitors, allowing touch sensing using a single pin.

• Configurations: Comms mode · Standalone mode
• Number of Keys: Comms mode: 1 - 7 keys (or 1 - 6 keys plus a Guard Channel); Standalone mode: 1 - 4 keys plus a fixed Guard Channel on key 0
• Number of I/O Lines: Standalone mode: 5 outputs
• Technology: Patented spread-spectrum charge-transfer
• Key Outline Sizes: 6 mm×6 mm or larger (panel thickness dependent); widely different sizes and shapes possible
• Layers Required: One
• Electrode Materials: Etched copper; Silver; Carbon; Indium Tin Oxide (ITO)
• Panel Materials: Plastic; Glass; Composites; Painted surfaces (low particle density metallic paints possible)
• Panel Thickness: Up to 10 mm glass; Up to 5 mm plastic (electrode size dependent)
• Key Sensitivity: Comms mode: individually settable via simple commands over I²C-compatible interface; Standalone mode: settings are fixed
• Interface: I²C-compatible slave mode (400 kHz). Discrete detection outputs
• Signal Processing: Self-calibration; Auto drift compensation; Noise filtering; Adjacent Key Suppression (AKS) - up to three groups possible
• Power: 1.8V - 5.5V
• Package: 14-pin SOIC RoHS compliant IC; 20-pin VQFN RoHS compliant IC