VSC6511 Datasheet, PDF (18/22 Pages) Vitesse Semiconductor Corporation – SMPTE-292M Serializer, Deserializer, and Deserializer/Reclocker at 1.485Gb/s

VITESSE
SEMICONDUCTOR CORPORATION
SMPTE-292M Serializer, Deserializer, and
Deserializer/Reclocker at 1.485Gb/s
Advance Product Information
VSC6511
Package Thermal Characteristics
The VSC6511 is packaged in an exposed pad, thin quad flat pack (TQFP) which adheres to industry stan-
dard EIAJ footprints for a 10x10x1.0mm body, 64 lead TQFP. The package construction is shown below. The
bottom of the lead frame is exposed so that it can be soldered to the printed circuit board and connected to the
ground plane. This provides excellent thermal characteristics and reduces electrical parasitics as well.
Figure 11: Package Cross Section
Wire Bond
Copper Lead Frame
Die
Plastic Molding Compound
Die Attach Epoxy
Ground Bond
Exposed Pad
Table 10: 64-pin, Exposed Pad TQFP Thermal Resistance
Symbol
θ_ca-0
θ_ca-100
θ_ca-200
θ_ca-400
θ_ca-600
Description
Thermal resistance from case to ambient, still air
Thermal resistance from case to ambient, 100 LFPM air
Thermal resistance from case to ambient, 200 LFPM air
Thermal resistance from case to ambient, 400 LFPM air
Thermal resistance from case to ambient, 600 LFPM air
Value
30
25
23
21
20
Units
o_C/W
o_C/W
o_C/W
o_C/W
o_C/W
The VSC6511 is designed to operate with a case temperature up to 95^oC. The user must guarantee that the
case temperature specification is not violated. With the thermal resistances shown above, the VS6511 can oper-
ate in still air ambient temperatures of 70^oC [~70^oC = 95^oC - 0.8W * 30]. If the ambient air temperature exceeds
these limits then some form of cooling through a heatsink or an increase in airflow must be provided. Additional
heat can be transferred to the printed circuit board by not using thermal reliefs on the power and ground plane
vias as well as using multiple vias to the power and ground planes.
If the exposed pad is not soldered to the printed circuit board and grounded, both thermal and electrical per-
formance will be degraded significantly.
Moisture Sensitivity Level
This device is rated with a Moisture Sensitivity Level 3 rating. Refer to Application Note AN-20 for
appropriate handling procedures.
Page 18
© VITESSE SEMICONDUCTOR CORPORATION
741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: [phone]
G52311-0, Rev 2.0
4/10/00