Philips Semiconductors

PIP202-12M

DC to DC converter powertrain

Product data

Rev. 01 — 15 July 2002

12 of 20

9397 750 10031

© Koninklijke Philips Electronics N.V. 2002. All rights reserved.

thermal resistance of this package, the printed-circuit board must be designed so that

heat is conducted away efficiently from the package. This can be achieved by

maximizing the area of copper around each pad, and by incorporating thermal vias to

conduct the heat to inner and/or bottom layers of the printed-circuit board.

An example of a thermal via pattern is shown in Figure 13. In a typical application,

with no forced air cooling, the use of thermal vias typically reduces the thermal

resistance from 25 K/W to 20 K/W. The additional use of a small fan can reduce this

further to approximately 15 K/W.

The thermal resistance of a particular design can be measured by passing a known

through the source-drain diode of the upper MOSFET. The direction of current flow is

and used to calculate the power dissipation in the PIP202-12M. The case

temperature of the PIP202-12M can be measured using an infra-red thermometer.

The thermal resistance can then be calculated using the following equation:

(3)

temperature (

°C), I is the MOSFET current (A), and V

Where more than one phase is used, for example the circuit of Figure 11, the thermal

resistance of each PIP202-12M should be measured with current flowing in all

phases.

All holes 0.5 mm diameter with 1 mm spacing.

Fig 13. Printed-circuit board thermal via pattern.

03ag36

PAD1

PAD2

PAD3

R

th j

pcb

–

()

T

case

T

amb

–

IV

F

×

------------------------------- KW

⁄

()

=