Data Sheet
JHW250S30R2 Power Module; dc-dc Converter
36 – 75 Vdc Input; 30.2Vdc Output; 250W
October 6, 2005
300
250
200
150
Feature Descriptions (continued)
Thermal Considerations
The power modules operate in a variety of thermal
environments; however, sufficient cooling should be
provided to help ensure reliable operation of the unit.
Heat-dissipating components inside the unit are
10 0
thermally coupled to the metal case. Heat is removed by
conduction, convection, and radiation to the surrounding
environment. Proper cooling can be verified by
measuring the case temperature. Peak temperature (TC)
occurs at the position indicated in Figure 20.
50
0
20
30
40
50
60
70
80
90
100
110
CASE TEMPERATURE, TC (°C)
Considerations include ambient temperature, airflow,
module power dissipation, and the need for increased
reliability. A reduction in the operating temperature of the
module will result in an increase in reliability. The
thermal data presented here is based on physical
measurements taken in a wind tunnel.
Figure 21. Output Power Derating for JHW250S30R2
(Vo = 30.2V) vs Case Temperature
Layout Considerations
For reliable operation please refer to the power derating
guidelines shown in figure 21. Under no circumstances
should the absolute maximum temperature at this point
exceed the 100°C threshold.
The JHW250 power module series are encapsulated
aluminum case packaged style, as such; component
clearance between the bottom of the power module and
the mounting (Host) board is limited. Avoid placing
copper areas on the outer layer directly underneath the
power module. Also avoid placing via interconnects
underneath the power module.
MEASURE CASE
TEMPERATURE HERE (Tc)
For additional layout guide-lines, refer to FLTR100V20
data sheet.
VI(+)
VO(+)
+ SEN
TRIM
Post Solder Cleaning and Drying
Considerations
ON/OFF
Post solder cleaning is usually the final circuit-board
assembly process prior to electrical board testing. The
result of inadequate cleaning and drying can affect both
the reliability of a power module and the testability of the
finished circuit-board assembly. For guidance on
appropriate soldering, cleaning and drying procedures,
refer to Tyco Electronics Board Mounted Power
Modules: Soldering and Cleaning Application Note
(AP01-056EPS).
CASE
VI(-)
- SEN
30.5
(1.20)
VO(-)
29.0
(1.14)
Figure 20. Metal Case (Tc ) Temperature
Measurement Location (top view)
Although the maximum Tc temperature of the power
modules is 100°C, you can limit this temperature to a
lower value for extremely high reliability.
Tyco Electronics Power Systems
11
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
