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Q54SG Datasheet, PDF (22/26 Pages) Delta Electronics, Inc. – Industry standard, DOSA compliant pin out
FEATURES DESCRIPTIONS (CON.)
3. To ensure the parallel module can start up
monotonically without trigging the OCP, below design
guideline should be followed:
a) Before all the parallel modules finish start up, the total
load current should be lower than the rated current of a
single module.
b) The ON/OFF pin of the converters should be
connected together to keep the parallel modules start up
at the same time.
c) Since theinput under voltage lockout set point varies
slightly from module to module, the dv/dt of the rising
edge of the input source voltage must be greater than
1V/ms to ensure the parallel modules start up at the
same time.
THERMAL CONSIDERATIONS
Thermal management is an important part of the system
design. To ensure proper, reliable operation, sufficient
cooling of the power module is needed over the entire
temperature range of the module. Convection cooling is
usually the dominant mode of heat transfer.
Hence, the choice of equipment to characterize the
thermal performance of the power module is a wind
tunnel.
Thermal Testing Setup
Delta’s DC/DC power modules are characterized in
heated vertical wind tunnels that simulate the thermal
environments encountered in most electronics
equipment. This type of equipment commonly uses
vertically mounted circuit cards in cabinet racks in which
the power modules are mounted.
The following figure shows the wind tunnel
characterization setup. The power module is mounted
on a 185mmX185mm,70μm (2Oz),6 layers test board
and is vertically positioned within the wind tunnel. The
space between the neighboring PWB and the top of the
power module is constantly kept at 6.35mm (0.25’’).
FANCING PWB
PWB
MODULE
DS_Q54SG12050_09092016
AIR VELOCITY
AND AMBIENT
TEMPERATURE
SURED BELOW
THE MODULE
AIR FLOW
Note: Wind Tunnel Test Setup Figure Dimensions are in millimeters and (Inches)
Figure 22: Wind tunnel test setup
Thermal Derating
Heat can be removed by increasing airflow over the
module. To enhance system reliability; the power
module should always be operated below the maximum
operating temperature. If the temperature exceeds the
maximum module temperature, reliability of the unit may
be affected.
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