TDA8931 View Datasheet(PDF) - Philips Electronics

Part Name

Description

Manufacturer

TDA8931

Power comparator 1×20 W

Philips Electronics 

Philips Semiconductors

TDA8931

Power comparator 1 × 20 W

14.4.1 Thermal layout including vias

The bottom side of the double-sided PCB is used to place the SMD components including

the TDA8931T and the majority of the signal tracks. The topside is used to place the

leaded components.

The remaining area on both top and bottom layer are filled with ground plane for a proper

cooling. In this way it is possible to have a cooling area available of about:

• 40 % of the PCB area on the bottom (60 % for signal tracks and SMD components)

• 90 % of the PCB area on the top (10 % for signal tracks)

The PCB area required for a typical mono amplifier is 21.5 cm2 resulting in a cooling area

of about 28 cm2. Thermal vias should be placed close to corner leads for a proper heat

flow to the top layer of the PCB. Figure 7 is showing the thermal vias indicated as black

dots and Figure 8 is showing the heat flow to the copper area on the top layer.

20

1

top layer

bottom layer

11

10

TDA8931T

001aac239

Fig 7. Thermal vias (top view)

001aac238

Fig 8. Heat flow (cross section view)

14.4.2 Thermal considerations

To estimate the maximum junction temperature, the following equation can be used:

T j(max) = Tamb + Rth( j – a) × Pd

(5)

Where:

Tamb = ambient temperature

Pd = power dissipation in the TDA8931T

Rth(j-a) = thermal resistance from junction to ambient (24 K/W)

9397 750 13847

Preliminary data sheet

Rev. 01 — 14 January 2004

© Koninklijke Philips Electronics N.V. 2005. All rights reserved.

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