ATQT600 Atmel, ATQT600 Datasheet - Page 27

• Manufacturer Part Number: ATQT600
• Description: KIT EVAL TOUCH FOR QT600
• Manufacturer: Atmel
• Series: QTouch™r

Specifications of ATQT600

• Sensor Type: Touch Screen
• Interface: USB
• Embedded: Yes, Other
• Utilized Ic / Part: ATtiny88, ATmega324PA, ATxmega128A1
• Processor To Be Evaluated: ATtiny88, ATmega324, ATxmega128
• Data Bus Width: 8 bit, 16 bit
• Interface Type: USB
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Operating Supply Voltage: 1.6 V to 3.6 V
• Silicon Manufacturer: Atmel
• Kit Application Type: Sensor
• Application Sub Type: Touch Sensor
• Kit Contents: USB Bridge, MCU Cards, Touchpad Cards
• Svhc: No SVHC (15-Dec-2010)
• Mcu Supported Families: ATtiny88,
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Supply: -
• Sensitivity: -
• Sensing Range: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

3.2.7
3.3
Touch Sensors Design Guide
Conductive Paints
Non-planar Construction
Figure 3-9.
Remember that any type of conductive item can cause this effect. Examples of such items include
decorative logos created using metallic paints or foils, paints with a high carbon black content, and paints
containing metallic particles.
Refer to QTAN0021, Materials and Coatings Selection for Atmel Capacitive-touch Control Panels
(available under a non-disclosure agreement only), for details of selecting conductive paints and
coatings.
The underlying principle of a non-planar construction method is to form the electrodes on the inner
surface of the touch panel, with the rest of the touch sensing circuitry on the main capacitive touch circuit
board and remote from the electrodes.
This non-planar approach can be desirable in that it offers several advantages:



The rules for the interconnecting traces are identical to those already described in
“Interconnection” on page
method of construction, and so careful consideration must be given as to how the two halves of the
circuit will be connected together.
It allows for more flexibility and creativity in product shape and size, as the touch sensing circuitry
does not need to be placed on the under surface of a sloping or curved front panel.
The physical separation of the sensor and the front panel allows LEDs to be easily incorporated in the
product.
It can aid in the assembly and testing of the product, as the sensor assembly and the circuit assembly
are built and tested as separate items.
Touch Sensor
Behind Panel
becomes partly touch-sensitive
The Effect of a Floating Conductive Item
Floating conductive item
(here, a metal bezel)
3-4. However, the methods for interconnection are tightly coupled with the
Panel
prevents it from becoming partly touch-sensitive
Self-capacitance Zero-dimensional Sensors
Grounding the floating conductive item
10620D–AT42–04/09
Section 3.2.4
3-7