VITESSE
SEMICONDUCTOR CORPORATION
Data Sheet
ATM/SONET/SDH 622 Mb/s Transceiver Mux/Demux
with Integrated Clock Generation and Clock Recovery
VSC8113
The VSC8113 is manufactured in a 100PQFP package which is supplied by two different vendors. The crit-
ical dimensions in the drawing represent the superset of dimensions for both packages. The significant differ-
ence between the two packages is in the shape and size of the heatspreader which needs to be considered when
attaching a heatsink.
Package Thermal Characteristics
The VSC8113 is packaged in a thermally enhanced 100PQFP with an embedded heat sink. The heat sink
surface configurations are shown in the package drawings. With natural convection, the case to air thermal resis-
o
tance is estimated to be 27.5 C/W. The air flow versus thermal resistance relationship is shown in Table 18.
Junction to case thermal resistance is 1.2 oC/W
Table 18: Theta Case to Ambient versus Air Velocity
Air Velocity
(LFPM)
Case to air thermal resistance
oC/W
0
27.5
23.1
19.8
17.6
16
100
200
400
600
Page 22
VITESSE SEMICONDUCTOR CORPORATION
G52154-0, Rev 4.2
741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: 805/987-5896
3/19/99
VITESSE [ VITESSE SEMICONDUCTOR CORPORATION ]
