SI-8025JF

Step-Down

to 2.5 V, 1.5 A,

DC/DC Converter

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036

Switching

Regulators

6

Layout Guideline

APPLICATIONS INFORMATION (cont.)

Thermal Protection. Circuitry turns off the switching

transistor when the junction temperature rises above 150°C.

It is intended only to protect the device from failures due to

excessive junction temperatures and should not imply that

output short circuits or continuous overloads are permitted.

Heat Radiation and Reliability. The reliability of the

IC is directly related to the junction temperature (T

operation. Accordingly, careful consideration should be

given to heat dissipation. The graph on page 2 illustrates

the effect of thermal resistance on the allowable package

power dissipation.

When mounting to a heat sink, apply silicone grease (Shin-

Etsu Chemical G746, Dow Corning Toray Silicone SC102,

or Toshiba Silicone SY6260). Recommended mounting

hardware torque: 0.588 ~ 0.686 Nm or 6.0 ~ 7.0 kgf•cm

(4.34 ~ 5.06 lbf•ft).

The junction temperature (T

either of the following equations:

T

or

T

where P

or the adjacent graph,

V