Delta Electronics Series E36SR Thermal Considerations, Thermal Curves, Thermal Testing Setup

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.

Thermal Derating

Heat can be removed by increasing airflow over the module. The hottest point temperature of the module is +122°C. 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.

THERMAL CURVES

The following figure shows the wind tunnel		Figure 21: Hot spot temperature measured point.
characterization setup. The power module is mounted		＊ The allowed maximum hot spot temperature is defined at 122℃
on a test PWB and is vertically positioned within the		Output Current(A)					@Vin = 24V (Transverse Orientation)
wind tunnel. The space between the neighboring PWB
				E36SR05015(Standard) Output Current vs. Ambient Temperature and Air Velocity
and the top of the power module is constantly kept at		16
6.35mm (0.25’’).		14
		12	Natural
FACING PWB	PWB		Convection
		10			100LFM
						200LFM		300LFM
	MODULE	8
								400LFM
		6							500LFM
											600LFM
		4
AIR VELOCITY		2
AND AMBIENT		0
TEMPERATURE
		20	25	30	35	40	45	50	55	60	65	70	75	80	85
MEASURED BELOW													Ambient Temperature (℃)
	50.8 (2.0”)	Figure 22: Output current vs. ambient temperature and air velocity @
THE MODULE
AIR FLOW		Vin=24V(Transverse Orientation)
		Output Current(A)		E36SR05015(Standard) Output Current vs. Ambient Temperature and Air Velocity
							@Vin = 48V (Transverse Orientation)
		16
	12.7 (0.5”)	14
		12	Natural
Note: Wind Tunnel Test Setup Figure Dimensions are in millimeters and (Inches)			Convection
					100LFM
Figure 20: Wind tunnel test setup		10					200LFM	300LFM
		8						400LFM
										500LFM
		6									600LFM
		4
		2
		0
		20	25	30	35	40	45	50	55	60	65	70	75	80	85
													Ambient Temperature (℃)

Figure 23: Output current vs. ambient temperature and air velocity @

Vin=48V(Transverse Orientation)

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