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AS1376

Datasheet - Application In form atio n

9.4 Power Dissipation

Maximum power dissipation (PD) of the LDO is the sum of the power dissipated by the internal series MOSFET and the quiescent current

required to bias the internal voltage reference and the internal error amplifier, and is calculated as:

Watts

(EQ 3)

Internal power dissipation as a result of the bias current for the internal voltage reference and the error amplifier is calculated as:

Watts

(EQ 4)

Total LDO power dissipation is calculated as:

Watts

(EQ 5)

9.5 Junction Temperature

Under all operating conditions, the maximum junction temperature should not be allowed to exceed 125ºC (unless the data sheet specifically

allows). Limiting the maximum junction temperature requires knowledge of the heat path from junction to case (

manufacturer), and adjustment of the case to ambient heat path (

Figure 20. Package Physical Arrangements

Figure 21. Steady State Heat Flow Equivalent Circuit

PD

MAX



I

LOAD MAX



=

V

IN MAX



V

OUT MIN



–



PD

MAX



V

IN MAX

=

PD

MAX



PD

MAX

 PD

MAX



+

Bias



=

Chip

PCB

Package

Transfer Layer

CS-WLP Package

Solder Balls

Junction

Package

PCB/Heatsink

Ambient

Chip

Power

R

R

R