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MGC3130 – Sabrewing Single-Zone Evaluation Kit User’s Guide
DS41685A-page 20

2013 Microchip Technology Inc.
In a target system design the GND layer is not required. It is added for the Sabrewing
Board as a shielding layer and shall simulate the presence of static components which
are placed in the target device underneath the sensing electrodes. In order to keep
ground capacitances (C
TxGND,
C
RxGND
) below 1nF, the GND layer is structured in a
way that 40% of the area is covered with copper.
The sensing area of the Sabrewing board, depicted in Figure 3-5, is defined as the area
enclosed by the four frame electrodes. Depending on the parameterization, it can differ
from the physical dimensions of the electrodes.
FIGURE 3-5: SENSING AREA
Note 1: Please refer to the “ MGC3130 Single-Zone 3D Gesture Controller Data
Sheet” (DS41667) for the electrodes equivalent circuitry, capacitances
(C
RxTx
, C
RxGND,
C
TxGND
) and their typical values.
2: The integration of GestIC
®
technology into a target device does not require
the GND layer. If no shielding is needed, or if the device already contains
grounded planes, a two layer design is preferable.
TABLE 3-1: ELECTRODE DESIGN
Length Width Coverage
Horizontal Electrodes (Rx) 131.7 mm 5 mm solid
Vertical Electrodes (Rx) 98.7 mm 5 mm solid
Center Electrode (Rx) 118 mm 68.7 mm 5% structured
Tx Electrode (refer to Figure 3-3 )
Part I (under center Electrode)
Part II (outside Part I)
148 mm
118 mm
148 mm
98.7 mm
68.7 mm
98.7 mm
50% structured
20% structured
Ground Area 180 mm 126.6 mm 40% structured
Center electrode
North electrode
South electrode
West electrode
Ea
st electro
de
Sensing Area