AP64060Q

Document number: DS44124 Rev. 3 - 2

13 of 19

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September 2022

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AP64060Q

Application Information (continued)

8

Power Derating Characteristics

To prevent the regulator from exceeding the maximum recommended operating junction temperature, some thermal analysis is required. The

regulator’s temperature rise is given by:

������������������������������ = ������������ ∙ (������������������)

Eq. 2

Where:



PD is the power dissipated by the regulator



θJA is the thermal resistance from the junction of the die to the ambient temperature

The junction temperature, TJ, is given by:

������������ = ������������ + ������������������������������

Eq. 3

Where:



TA is the ambient temperature of the environment

For the TSOT26 package, the

θJA is 80°C/W. The actual junction temperature should not exceed the maximum recommended operating junction

temperature of 150°C when considering the thermal design. Figure 25 shows a typical derating curve versus ambient temperature.

Figure 25. Output Current Derating Curve vs. Ambient Temperature, VIN = 12V

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

0

20

40

60

80

100

120

140

160

Ambient Temperature (

°C)

VOUT = 1.2V, 1.5V, 1.8V, 2.5V, 3.3V, 5V