AP61200/AP61201/AP61202/AP61203

Document number: DS44251 Rev. 3 - 2

15 of 21

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September 2022

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AP61200/AP61201/AP61202/AP61203

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. 3

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. 4

Where:



TA is the ambient temperature of the environment

For the SOT563 package, the

θJA is 141°C/W. The actual junction temperature should not exceed the maximum recommended operating junction

temperature of +125°C when considering the thermal design. Figure 41 shows a typical derating curve versus ambient temperature.

Figure 41. Output Current Derating Curve vs. Ambient Temperature, VIN = 5V

0.00

0.25

0.50

0.75

1.00

1.25

1.50

1.75

2.00

2.25

2.50

0

20

40

60

80

100

120

140

160

Ambient Temperature (

°C)

VOUT = 1.0V

VOUT = 1.2V

VOUT = 1.5V

VOUT = 1.8V

VOUT = 2.5V

VOUT = 3.3V