Pcb layout recommendations, Package diagrams, Minimize stubs to minimize reflected signals – Cypress Perform CY7C68013 User Manual
Page 59: Continued)
CY7C68013A, CY7C68014A
CY7C68015A, CY7C68016A
Document #: 38-08032 Rev. *L
Page 59 of 62
13. PCB Layout Recommendations
Follow these recommendations to ensure reliable high perfor-
mance operation:
■
Four layer impedance controlled boards are required to
maintain signal quality.
■
Specify impedance targets (ask your board vendor what they
can achieve).
■
To control impedance, maintain trace widths and trace spacing.
■
Minimize stubs to minimize reflected signals.
■
Connections between the USB connector shell and signal
ground must be near the USB connector.
■
Bypass and flyback caps on VBus, near connector, are recom-
mended.
■
DPLUS and DMINUS trace lengths should be kept to within 2
mm of each other in length, with preferred length of 20 to
30 mm.
■
Maintain a solid ground plane under the DPLUS and DMINUS
traces. Do not allow the plane to split under these traces.
■
Do not place vias on the DPLUS or DMINUS trace routing.
■
Isolate the DPLUS and DMINUS traces from all other signal
traces by no less than 10 mm.
Package Diagrams
(continued)
TOP VIEW
PIN A1 CORNER
0.50
3.50
5.00±0.10
BOTTOM VIEW
0.10(4X)
3.50
5.00±0.10
0.50
Ø0.15 M C A B
Ø0.05 M C
Ø0.30±0.05(56X)
A1 CORNER
-B-
-A-
1.0
m
ax
0.160
~
0.260
0.080
C
0.45
SEATING PLANE
0.21
0.10
C
-C-
SIDE VIEW
5.00±0.10
5.00±0.10
REFERENCE JEDEC: MO-195C
PACKAGE WEIGHT: 0.02 grams
E
G
H
F
D
C
B
A
1
3
2
6
5
4
8
6
7
8
5
6
2
3
4
1
E
G
H
F
D
C
B
A
001-03901-*B
Figure 39. 56 VFBGA (5 x 5 x 1.0 mm) 0.50 Pitch, 0.30 Ball BZ56 (001-03901)
Note
24. Source for recommendations: EZ-USB FX2™PCB Design Recommendations, http://www.cypress.com/cfuploads/support/app_notes/FX2_PCB.pdf and
High-Speed USB Platform Design Guidelines, http://www.usb.org/developers/docs/hs_usb_pdg_r1_0.pdf.