CY8CMBR2044_12 CYPRESS [Cypress Semiconductor], CY8CMBR2044_12 Datasheet - Page 15

• Manufacturer Part Number: CY8CMBR2044_12
• Manufacturer: CYPRESS [Cypress Semiconductor]

Layout Guidelines and Best Practices
Document Number: 001-57451 Rev. *E
S.No.
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Button shape
Button size
Button-button spacing
Button ground clearance
Ground flood – top layer
Ground flood – bottom layer
Trace length from button pad to
CapSense controller pins
Trace width
Trace routing
Via position for the buttons
Via hole size for button traces
No. of via on button trace
Distance of CapSense series
resistor from button pin
Distance between any CapSense
trace to ground flood
Device placement
Placement of components in two
layer PCB
Placement of components in four
layer PCB
Overlay thickness
Overlay material
Overlay adhesives
LED back lighting
Board thickness
Category
Equal to Button
Clearance
0.17 mm
Ground
0.5 mm
10 mil
5 mm
0 mm
Min
–
–
–
–
–
–
–
1
–
–
–
–
–
–
–
–
0.20 mm
450 mm
15 mm
10 mm
20 mil
2 mm
5 mm
Max
–
–
–
–
–
–
–
2
–
–
–
–
–
–
–
Solid round pattern, round with LED hole, rectangle with
round corners
Refer
8 mm
(Y dimension in
Refer
(X dimension in
Hatched ground 7 mil trace and 45 mil grid (15% filling)
Hatched ground 7 mil trace and 70 mil grid (10% filling)
Refer
0.17 mm (7 mil)
Traces should be routed on the non button side. If any
non CapSense trace crosses CapSense trace, ensure
that intersection is orthogonal
Via should be placed near the edge of the button to
reduce trace length thereby increasing sensitivity
10 mil
1
Place CapSense series resistors close to the device for
noise suppression. CapSense resistors have highest
priority; place them first
20 mil
Mount the device on the layer opposite to button. The
CapSense trace length between the device and buttons
should be minimum (see trace length above)
Top layer – buttons and
bottom layer – device, other components and traces
Top layer – buttons,
second layer – CapSense traces and V
traces below the buttons),
third layer – hatched ground,
bottom layer – CapSense IC or device, other
components, and non CapSense traces
Refer
Should be non-conductive material. Glass, ABS plastic,
formica, wood, and so on. There should be no air gap
between PCB and overlay. Use adhesive to stick the
PCB and overlay
Adhesive should be non conductive and dielectrically
homogenous. 467MP and 468MP adhesives made by
3M are recommended
Cut a hole in the button pad and use rear mountable
LEDs. Refer to
CapSense Buttons and Four LEDs on page 17
Standard board thickness for CapSense FR4 based
designs is 1.6 mm.
Design Toolbox
Design Toolbox
Design Toolbox
Design Toolbox
Recommendations / Remarks
Example PCB Layout Design with Four
Button Layout Design on page
Button Layout Design on page
CY8CMBR2044
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