THS6007

DUAL DIFFERENTIAL LINE DRIVERS AND LOW-POWER RECEIVERS

SLOS334– DECEMBER 2000

30

POST OFFICE BOX 655303

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,

then the expected thermal coefficient,

is shown in Figure 87 and is calculated by the following formula:

P

D +

T

MAX

–T

A

q

JA

Where:

= Maximum power dissipation of THS6007 (watts)

= Free-ambient air temperature (

°C)

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.