VSC7126 Datasheet, PDF (15/16 Pages) Vitesse Semiconductor Corporation – 1.0625 Gbits/sec Fibre Channel Transceiver

VITESSE
SEMICONDUCTOR CORPORATION
Datasheet
VSC7126
1.0625 Gbits/sec Fibre
Channel Transceiver
Package Thermal Characteristics
The VSC7126 is packaged in a 14 mm PQFP with an integrated heat spreader. These packages use indus-
try-standard EIAJ footprints, but have been enhanced to improve thermal dissipation. The construction of the
packages is as shown in Figure 11.
Figure 11: Package Cross Section - 14 mm package
Plastic Molding Compound
Copper Heat Spreader
Lead
Bond Wire
Die
Table 5: Thermal Resistance
Symbol
θ_jc
θ_ca
θ_ca-100
θ_ca-200
θ_ca-400
θ_ca-600
Description
Thermal resistance from junction to case
Thermal resistance from case to ambient in still air including
conduction through the leads.
Thermal resistance from case to ambient with 100 LFM airflow
Thermal resistance from case to ambient with200 LFM airflow
Thermal resistance from case to ambient with 400 LFM airflow
Thermal resistance from case to ambient with 600 LFM airflow
14mm Value
17
32
28
25
22
20
Units
o_C/W
o_C/W
o_C/W
o_C/W
o_C/W
o_C/W
The VSC7126 is designed to operate with a case temperature up to 90^oC. The user must guarantee that the
temperature specification is not violated. With the Thermal Resistances shown above, the 14x14 PQFP can
operate in still air ambient temperatures of 40^oC (40°C = 90°C - 1.56W * 32°C/W). If the ambient air tempera-
ture exceeds these limits, then some form of cooling through a heatsink or an increase in airflow will be needed.
Moisture Sensitivity Level
This device is rated with a moisture sensitivity level 3 rating. Refer to Application Note AN-20 for appro-
priate handling procedures.
G52148-0, Rev. 4.3
3/4/99
© VITESSE SEMICONDUCTOR CORPORATION
741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: [phone]
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