RT8901

9

DS8901-03 October 2013

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Copyright 2013 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

For recommended operating conditions specification, the

maximum junction temperature is 125

°C. The junction to

ambient thermal resistance

SOP-8 package, the thermal resistance

on the standard JEDEC 51-7 four layers thermal test board.

°C can be

calculated by following formula :

°C - 25°C ) / (120°C/W) = 0.833W for

SOP-8 package

The maximum power dissipation depends on operating

resistance

designer to see the effect of rising ambient temperature

on the maximum power dissipation allowed.

Figure 7. Derating Curve

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0

15304560

7590

105 120 135

Ambient Temperature (°C)

Four Layers PCB