AT42QT1040-MMH Atmel, AT42QT1040-MMH Datasheet - Page 61

• Manufacturer Part Number: AT42QT1040-MMH
• Description: IC TOUCH SENSOR 4KEY 20-VQFN
• Manufacturer: Atmel
• Series: QTouch™r
• Type: Resistiver

Specifications of AT42QT1040-MMH

• Touch Panel Interface: 4, 2-Wire
• Number Of Inputs/keys: 4 Key
• Data Interface: I²C, Serial
• Data Rate/sampling Rate (sps, Bps): 200k
• Voltage Reference: Internal
• Voltage - Supply: 1.8 V ~ 5.5 V
• Current - Supply: 10mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 20-VQFN Exposed Pad, 20-HVQFN, 20-SQFN, 20-DHVQFN
• Output Type: Logic
• Input Type: Logic
• Supply Voltage: 1.8 V to 5.5 V
• Dimensions: 3 mm L x 3 mm W x 0.8 mm H
• Output Voltage: 0.7 V to 0.8 V
• Temperature Range: - 40 C to + 85 C
• Termination Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Interface: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: AT42QT1040-MMH; AT42QT1040-MMHTR

6.3.4.3
Touch Sensors Design Guide
Wheel
To form a wheel, the design is simply is wrapped around to form a circle, with the X segments becoming
wedge shaped (see
many Y “circles” as necessary to ensure a maximum gap of 4 mm between them.
Figure 6-5.
Center diameter depends on
the number of Y traces,
the spacing of Y traces,
the number of X electrodes, etc.
Note the maximum outer arc length
0.1–0.5 mm
Gap Between
X Electrodes
Two-layer Small Wheel: Multiple Y Traces (Spatially Interpolated)
Figure
1.5–4 mm
X5
X6
2–4 mm
6-5). Note that, as with the Y “stripes” in the slider design, there should be as
X4
Y, 0.1
–0.5
X7
mm Width
Mutual-capacitance One-dimensional Sensors
X0
Y should connect on layer
below X if possible
X3
X2
Outer Arc
<8 mm
X1
10620D–AT42–04/09
6-7