TPPM0111DWPR datasheet(9/10 Pages) TI

9 / 10 page

TPPM0111

DUAL LOW-DROPOUT LINEAR REGULATOR

SLVS414 – DECEMBER 2001

POST OFFICE BOX 655303

• DALLAS, TEXAS 75265

TYPICAL THERMAL CHARACTERISTICS

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 providing 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

paths in series. The first is the junction-to-case thermal resistance, RθJC; the second is the case-to-ambient

thermal resistance, RθCA. The overall junction-to-ambient thermal resistance, RθJA, is determined by:

RθJA = RθJC + RθCA

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

temperature, TA, and the junction power dissipation, PJ.

The junction temperature, TJ, is determined by the following thermal equation:

TJ = TA + PJ (RθJC) + PJ (RθCA)

TJ = TA + PJ (RθJA)

This particular application uses the 20-pin DWP power pad package with a standard lead frame with a dedicated

ground terminal. Using a multilayer printed-circuit board (PCB), the power pad is mounted as recommended

in the TI packaging application. The power pad is electrically connected to the ground plane of the board through

a dedicated ground pin and the die mount power pad. This provides a means for heat spreading through the

copper plane associated within the PCB (ground layer). The thermal resistance from junction to ambient, RθJA,

is dependent of several factors, the implemented method of package attachment to the heat spreading material

and the air flow in the system application.

TPPM0111DWPR Datasheet(PDF) 9 Page - Texas Instruments