TPPM0304

250-mA LOW-DROPOUT REGULATOR

WITH AUXILIARY POWER MANAGEMENT

SLVS320 – OCTOBER 2000

10

POST OFFICE BOX 655303

THERMAL INFORMATION

To ensure reliable operation of the device, the junction temperature of the output device must be within the safe

operating area (SOA). This is achieved by having a means to dissipate the heat generated from the junction

of the output structure. There are two components that contribute to thermal resistance. They consist of two

The ability to efficiently dissipate the heat from the junction is a function of the package style and board layout

incorporated in the application. The operating junction temperature is determined by the operating ambient

This particular application uses the 8-pin SO package with standard lead frame with a dedicated ground

terminal. Hence, the maximum power dissipation allowable for an operating ambient temperature of 70

°C, and

a maximum junction temperature of 150

°C is determined as:

Worst case maximum power dissipation is determined by:

Normal operating maximum power dissipation is (see Figure 1):