Delta Electronics Series DNS manual Thermal Curves Thermal Considerations, Thermal Testing Setup

THERMAL CURVES

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					Figure 44: Temperature measurement location
equipment. This type of	equipment commonly uses				The allowed maximum hot spot temperature is defined at 125℃
vertically mounted circuit cards in cabinet racks in which
the power modules are mounted.						DNS04S0A0R06(Standard) Output Current vs. Ambient Temperature and Air Velocity
					7	Output Current(A)		@ Vin = 5V, Vo = 3.3V (Either Orientation)
The following figure shows the wind tunnel					6
characterization setup. The power module is mounted
on a test PWB and is vertically positioned within the					5
wind tunnel. The height of this fan duct is constantly kept
at 25.4mm (1’’).					4
Thermal Derating					3				Natural
									Convection
Heat can be removed by increasing airflow over the					2
module. To enhance system reliability, the power					1
module should always be operated below the maximum
operating temperature. If the temperature exceeds the					0
maximum module temperature, reliability of the unit may					60		65	70	75	80	85
										Ambient Temperature (℃)
be affected.		PWB			Figure 45: DNS04S0A0R06 (Standard) Output current vs.
FACING PWB					ambient temperature and air velocity@Vin=5V, Vo=3.3V (Either
			MODULE		Orientation)
						DNS04S0A0R06(Standard) Output Current vs. Ambient Temperature and Air Velocity
					7	Output Current(A)		@ Vin = 5.0V, Vo = 1.5V (Either Orientation)
AIR VELOCITY					6
AND AMBIENT
TEMPERATURE					5
MEASURED BELOW			50.8 (2.0”)						Natural
THE MODULE
					4				Convection
	AIR FLOW
					3
				12.7 (0.5”)	2				100LFM
				25.4 (1.0”)
Note: Wind Tunnel Test Setup Figure Dimensions are in millimeters and (Inches)					1
Figure 43: Wind tunnel test setup					60		65	70	75	80	85
					0
										Ambient Temperature (℃)
					Figure 46: DNS04S0A0R06 (Standard)Output current vs.
DS_DNS04SIP06A_07172008					ambient temperature and air velocity@Vin=5V, Vo=1.5V (Either
											13
					Orientation)