ATQT600 Atmel, ATQT600 Datasheet - Page 36

• 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

10620D–AT42–04/09
Mutual-capacitance Zero-dimensional Sensors
4.2.2.8
4-4
Designs Resulting In Low Interdigitation
Figure 4-3.
As has already been stated, designs that result in a very small number of fingers should be avoided, as
such designs result in a poor SNR.
For example, if the following measurements are used in
then the calculation is as follows:
This results in the pattern shown in
T = 1.5 mm
W = 8 mm
H = 8 mm
Y
Results of Example Calculation
width
X
X
fingers
border
0.6 mm
= 0.1 mm
0.25 mm
=
=
=
= 1
= (8 - 1.5 - 0.1 - 1 x (2.25 + 0.1)) / 2
= (6.4 - 2.35) / 2
= 2.02 mm



(8 - 4.5 - 0.1) / (2.25 + 0.1)
3.4 / 2.35
1.45
Figure
10 mm


4-4.


0.5 mm
Equation
0.875 mm


4-6:
8 mm
Touch Sensors Design Guide