pip201-12m NXP Semiconductors, pip201-12m Datasheet - Page 12

• Manufacturer Part Number: pip201-12m
• Description: Pip201-12m-3 Dc-to-dc Converter Powertrain
• Manufacturer: NXP Semiconductors

Philips Semiconductors
12. Test information
9397 750 11942
Product data
printed-circuit board is approximately 5 K/W. In order to take full advantage of the low
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
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
current through the source-drain diode of the lower MOSFET. The direction of current
flow is into V
and used to calculate the power dissipation in the PIP201-12M. The case
temperature of the PIP201-12M can be measured using an infra-red thermometer.
The thermal resistance can then be calculated using the following equation:
where T
temperature ( C), I is the MOSFET current (A), and V
V
Where more than one phase is used, for example the circuit of
resistance of each PIP201-12M should be measured with current flowing in all
phases.
Figure 14
output voltage is measured using an averaging circuit. This eliminates losses in the
output inductor and the PCB tracks. The calculated power loss, using this method,
R
Fig 13. Printed-circuit board thermal via pattern.
SSO
th j
–
All holes 0.5 mm diameter with 1 mm spacing.
and V
pcb
case
shows the test circuit used to measure power loss in the PIP201-12M. The
=
DDO
SSO
is the measured case temperature ( C), T
T
------------------------------ - K W
case
(V).
I
Rev. 03 — 19 November 2003
and out of V
–
V
T
F
amb
O
. The volt drop between V
PAD1
PAD2
PAD3
Figure
DC-to-DC converter powertrain
03ag36
F
© Koninklijke Philips Electronics N.V. 2003. All rights reserved.
amb
is the voltage drop between
13. In a typical application,
SSO
PIP201-12M-3
is the ambient
and V
Figure
O
is then measured
11, the thermal
12 of 20
(3)