Data Sheet

ADPL20502

analog.com

Rev 0

21 of 27

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Lastly, the trace used for RSEL should neither be too long nor should produce a capacitance of more than 2pF.

It is recommended to consult the ADPL20502 Evaluation board layout.

Thermal Considerations

In most applications, the IC does not dissipate much heat due to its high efficiency. But in applications where the IC

runs at high ambient temperature with heavy loads, the heat dissipated may cause the temperature to exceed +125°C

or the maximum junction temperature of the part. If the junction temperature reaches approximately +165°C (TJ

Rising), the thermal-overload protection is activated. The maximum power dissipation depends on the thermal

resistance of the IC package and the application circuit board.

The power dissipated (PD) in the device is:

������������ = ������������������ − ������������������������ − ������������������������

where PIND is power dissipated in the inductor that includes DC, AC, and core losses; POUT is power delivered to the

load.

The maximum allowed power dissipation is:

������������_������������������ =

������������������������������ − ������������

������������������

where (TJMAX - TA) is the temperature difference between the ADPL20502 maximum rated junction temperature

(+125°C) and the surrounding ambient temperature, and θJA is the thermal resistance of the junction through the

package, PCB, copper traces, and other materials to the surrounding ambient temperature.