VSC8201DL VITESSE [Vitesse Semiconductor Corporation], VSC8201DL Datasheet - Page 20

• Manufacturer Part Number: VSC8201DL
• Description: Single Port 10/100/1000BASE-Tand 1000BASE-X PHY
• Manufacturer: VITESSE [Vitesse Semiconductor Corporation]

For the 128 pin LQFP vias which connect the nearby high frequency decoupling capacitors to the ground and power planes are sufficient
for the required heat dissipation rate. See “Local High-Frequency decoupling Capacitor Layout - LQFP package” on page 2.
For proper cooling of the 100 ball LBGA, a PCB via must be placed between the thermal BGA ball pads in a checkerboard pattern (see
Figure 13: ”Thermal Via Layout”, below). Each of these “thermal vias” should then be routed to the BGA ball pads near it with a wide
trace or solid copper fill to increase the conductive area on the surface of the PCB. In order to dissipate heat below the BGA package, the
PCB thermal vias must connect to a solid ground plane within the board. It is recommended that the ground plane have a minimum thick-
ness of one ounce (see Figure 14: ”Thermal Ground Plane Connections”, below).
Rev. 1.6.3 - 9/29/04
T
P
a
d
= Ambient temperature,
= Power dissipation.
VITESSE - CONFIDENTIAL & PROPRIETARY - DO NOT COPY WITHOUT PERMISSION
Figure 14: Thermal Ground Plane Connections
VSC8201 BGA Package
Figure 13: Thermal Via Layout
PCB Thermal Via
BGA Ball Pad
PCB Traces
BGA Balls
1-ounce Ground Plane
Thermal via
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VSC8201DL