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15

20

25

30

35

40

0

0.01

0.1

1

10

100

THERMAL RESISTANCE

vs

COPPER HEATSINK AREA

Copper Heatsink Area – cm2

No Air Flow

150 LFM

250 LFM

1 oz. Copper

Power Plane

1 oz. Copper

Ground Plane

2 oz. Copper Solder Pad

With 25 Thermal Vias

Thermal Vias, 0.3 mm

Diameter, 1.5 mm Pitch

TPS75601, TPS75615

TPS75618, TPS75625

TPS75633

SLVS329C – JUNE 2001 – REVISED MARCH 2004

THERMAL INFORMATION (continued)

Figure 25.

Figure 26.

From the data in Figure 25 and rearranging Equation 4, the maximum power dissipation for a different ground

plane area and a specific ambient temperature can be computed (see Figure 27).

16