THS6007 Datasheet, PDF (30/36 Pages) Texas Instruments – DUAL DIFFERENTIAL LINE DRIVERS AND LOW-POWER RECEIVERS

THS6007
DUAL DIFFERENTIAL LINE DRIVERS AND LOW-POWER RECEIVERS
SLOS334– DECEMBER 2000
APPLICATION INFORMATION
PCB design considerations (continued)
Thermal pad area (0.12 x 0.3)
with 10 vias
(Via diameter = 13 mils)
Figure 86. PowerPAD™ PCB Etch and Via Pattern
The actual thermal performance achieved with the THS6007 in its PowerPAD™ package depends on the
application. In the previous example, if the size of the internal ground plane is approximately 3 inches × 3 inches,
+ ǒ Ǔ ^{then the expected thermal coefficient, θJA, is about 27.9_C/W. For a given θJA, the maximum power dissipation}
is shown in Figure 87 and is calculated by the following formula:
PD
TMAX–TA
q_JA
Where:
P_D = Maximum power dissipation of THS6007 (watts)
T_MAX = Absolute maximum junction temperature (150°C)
T_A = Free-ambient air temperature (°C)
θ_JA = θ_JC + θ_CA
θ_JC = Thermal coefficient from junction to case (0.72°C/W)
θ_CA = Thermal coefficient from case to ambient
It is recommended to design the system to keep the junction temperature (T_J) at a minimum of 125°C. Junction
temperatures higher 125°C than can lead to increased output distortion. Additionally, because the heat of the
device is dissipated through the PCB, care must be taken to ensure the PCB does not become thermally
saturated. Once this happens, the power dissipation of the system (PCB and active devices) becomes very
in-efficient and the performance will suffer.
More complete details of the PowerPAD™ installation process and thermal management techniques can be
found in the Texas Instruments Technical Brief, PowerPAD™ Thermally Enhanced Package. This document can
be found at the TI web site (www.ti.com) by searching on the key word PowerPAD™. The document can also
be ordered through your local TI sales office. Refer to literature number SLMA002 when ordering.
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