RT9012-CMPQW datasheet(10/11 Pages) RICHTEK

10 / 11 page

RT9012

Preliminary

DS9012-06 August 2007

www.richtek.com

For recommended operating conditions specification of

RT9012, where TJ(MAX) is the maximum junction

temperature of the die (125

°C) and TA is the operated

ambient temperature. The junction to ambient thermal

resistance (

θJA is layout dependent) for WDFN-8L 2x2

package is 108

°C/W on the standard JEDEC 51-3 single-

layer thermal test board. The maximum power dissipation

at TA = 25

°C can be calculated by following formula :

PD(MAX) = ( 125

°C − 25°C ) / 108 = 0.926W for

WDFN-8L 2x2 packages

The maximum power dissipation depends on operating

ambient temperature for fixed TJ(MAX) and thermal

resistance

θJA . For RT9012 packages, the Figure 3 of

derating curves allows the designer to see the effect of

rising ambient temperature on the maximum power

allowed.

Figure 3. Derating Curves for RT9012 Packages

Power Dissipation vs. Ambient Temperature

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

100

125

Ambient Temperature (

°C)

WDFN-8L 2x2

RT9012-CMPQW Datasheet(PDF) 10 Page - Richtek Technology Corporation