VITESSE

SEMICONDUCTOR CORPORATION

Advance Product Information

VSC8151

2.488Gb/s SONET/SDH

STS-48/STM-16 Section Terminator

Page 28

© VITESSE SEMICONDUCTOR CORPORATION

741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: 805/987-5896

12/1/99

G52225-0, Rev. 2.9

Package Thermal Characteristics

The VSC8151 is packaged in an 160 pin, 28mm x 28mm thermally enhanced PQFP (EDQUAD) with an

exposed heatsink. These packages use industry-standard JDEC footprints, but have been enhanced to improve

thermal dissipation. The construction of the packages are as shown in Figure 13. A heat sink may be necessary

depending on the ambient temperature and airflow available in your system. Commercially available heatsinks

are available to improve

θ

Figure 17: Package Cross Section

Table 21: 160-Pin Enhanced PQFP Thermal Resistance

Symbol

Description

Value

Units

θ

ca-0

Thermal resistance from case to ambient, still air

24

θ

ca-1

Thermal resistance from case to ambient, 1 m/sec air

14

θ

ca-2

Thermal resistance from case to ambient, 2 m/sec air

11

θ

ca-4

Thermal resistance from case to ambient, 3 m/sec air

10

Lead

Die

Plastic Molding

Insulator

Wire Bond

Exposed Heat Slug