QT114A-ISG Atmel, QT114A-ISG Datasheet - Page 36

• Manufacturer Part Number: QT114A-ISG
• Description: IC TOUCH SENSOR PROX 8SOIC
• Manufacturer: Atmel
• Series: QLevel™r
• Type: Liquid or Powderr

Specifications of QT114A-ISG

• Output Configuration: Open Collector: Dry-Low
• Mounting Type: Surface Mount
• Operating Temperature: -40°C ~ 85°C
• Voltage Rating: 2.45 ~ 5.25 V
• Current: 20uA
• Current - Supply: *
• Output Type: *
• Interface: *
• Input Type: *
• Operating Supply Voltage: 2.5 V to 5.25 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: SOIC-8
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Package / Case: -
• Lead Free Status / Rohs Status: Details

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