5.1.2.1 Internal Power Dissipation

Internal power dissipation, junction temperature rise, junction temperature and maximum power dissipation are calculated in the following example. The power dissipation as a result of ground current is small enough to be neglected.

Equation 5-7. Power Dissipation Example

Package:

Package Type = 5-Lead SOT-223

Input Voltage:

V_IN = 14V±5%

LDO Output Voltage and Current:

V_OUT = 5V

I_OUT = 100 mA

Maximum Ambient Temperature:

T_A(MAX) = +60°C

Internal Power Dissipation:

P_{LDO(MAX)} = (V_{I N (M A X)} - V_{O U T (M I N)}) \times I_{O U T (M A X)}

P_{L D O} = (14.7 - 4.9) \times 100 mA

P_{L D O} = 0.98 Watts