Atmel QTouch AT42QT2120 Manual

Features
•
Number of Keys:
– Comms Mode: 1 to 12 keys (1 to 9 if wheel or slider option enabled)
– Standalone Mode: 1 to 5 keys
•
Technology:
– Patented spread-spectrum QTouchADC charge-transfer
•
Number of Output Lines:
– Comms Mode: Up to 10 channels can be configured as outputs (but they will
replace the keys)
– Standalone Mode: 1 to 5 channels can be configured as outputs
•
Key Outline Sizes:
– 5 mm x 5 mm or larger (panel thickness dependent)
•
Key Spacings:
– 6 mm or wider, center to center (panel thickness, human factors dependent)
•
Key Design:
– Single solid or ring shaped electrodes; widely different sizes and shapes possible
•
Proximity Electrode Design:
– Single solid electrodes; Key Design, Loop, PCB Trace - different sizes and shapes
possible
•
Wheel Size:
– Typically 30 mm – 50 mm diameter
•
Wheel Electrode Design:
– Spatially interpolated wheel up to 80 mm diameter
– Typical width of segments 12 mm
•
Slider Electrode Design:
– Spatially interpolated, resistorless design
– Typical length 50 mm – 100 mm, typical width 12 mm
– Can be an arc or other irregular shape
•
Substrates:
– FR-4, low cost CEM-1 or FR-2 PCB materials; polyamide FPCB; PET films, glass
•
Adjacent Metal:
– Compatible with grounded metal immediately next to keys
•
Layers Required:
– One; electrodes and components can be on same side
•
Electrode Materials:
– Etched copper, silver, carbon, indium tin oxide (ITO), PEDOT
•
Panel Materials:
– Plastic, glass, composites, painted surfaces (nonconductive paints)
•
Key Panel Thickness:
– Up to 15 mm glass (key size dependent)
– Up to 10 mm plastic (key size dependent)
•
Wheel/slider Panel Thickness:
– Up to 4 mm glass
– Up to 3 mm plastic
•
Key Sensitivity:
– Comms Mode – individually settable via simple commands over I
– Standalone mode – settings are fixed
•
Interface:
2
I
– C slave mode (400 kHz)
– CHANGE status indication pin
•
Signal Processing:
– Self-calibration, Auto drift compensation, Noise filtering, Adjacent Key
®
Suppression (AKS
•
Power:
– 1.8 V to 5.5 V
•
Packages:
– 20-pin SOIC/TSSOP RoHS compliant IC
– 20-pad VQFN RoHS compliant IC
®
)
QTouch
12-channel
Touch Sensor
IC
AT42QT2120
2
C interface
9634E–AT42–06/12