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PCB Layout

Application Using a Multilayer PCB

PackageThermalPad

SolderPad(LandPattern)

ThermalVias

PackageOutline

PowerPad

PackageSolderPad

PackageSolderPad

(BottomTrace)

ThermalVia

ComponentTraces

ThermalIsolation

PowerPlaneOnly

1.5748mm

0.0 0.071-mmBoardBase

–

andBottomPad

0.5246 0.5606-mm

–

PowerPlane

(1-ozCu)

1.0142 1.0502-mm

–

GroundPlane

(1-ozCu)

1.5038 1.5748-mm

–

ComponentTrace

(2-ozCu)

2Plane

4Plane

Application Using a Single-Layer PCB

TPL9201

8-CHANNEL RELAY DRIVER

WITH INTEGRATED 5-V LDO AND ZERO-VOLT DETECTION

SLIS123D – JUNE 2006 – REVISED FEBRUARY 2008

To maximize the efficiency of this package for application on a single-layer or multilayer PCB, certain guidelines

must be followed when laying out this part on the PCB.

The following information is to be used as a guideline only.

For further information, see the PowerPAD concept implementation document.

In a multilayer board application, the thermal vias are the primary method of heat transfer from the package

thermal pad to the internal ground plane (see Figure 4 and Figure 5).

The efficiency of this method depends on several factors: die area, number of thermal vias, thickness of copper,

etc. (see the PowerPAD™ Thermally Enhanced Package Technical Brief, literature number SLMA002).

Figure 4. Package and PCB Land Configuration for a Multilayer PCB

Figure 5. Multilayer Board (Side View)

In a single-layer board application, the thermal pad is attached to a heat spreader (copper area) by using the low

thermal-impedance attachment method (solder paste or thermal-conductive epoxy). With either method, it is

advisable to use as much copper trace area as possible to dissipate the heat.

Copyright © 2006–2008, Texas Instruments Incorporated

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Product Folder Link(s): TPL9201