Delta Electronics 4.5V~13.8Vin, 20A manual Thermal Consideration, Thermal Curves NE12S0A0V20

THERMAL CONSIDERATION

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 test PWB 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’’).

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.

THERMAL CURVES (NE12S0A0V20)

Figure 25: Temperature measurement location* The allowed maximum hot spot temperature is defined at 130℃

NE12S0A0V20(standard) Output Current vs. Ambient Temperature and Air Velocity

Output Current (A) @Vin=12V Vout=5.0V (Through PWB Orientation)

20
18
16
14			Natural
			Convection	100LFM	200LFM
12						300LFM
10							400LFM
								500LFM
8
6								600LFM
4
2
0
25	30	35	40	45	50	55	60	65	70	75	80	85
										Ambient Temperature (℃)

Figure 26: Output current vs. ambient temperature and air velocity @Vin=12V, Vout=5.0V (Through PWB Orientation)

FACING PWB

AIR VELOCITY

AND AMBIENT

TEMPERATURE

MEASURED BELOW

THE MODULE

AIR FLOW

PWB

MODULE

50.8 (2.0”)

11 (0.43”)

22 (0.87”)

NE12S0A0V20(standard) Output Current vs. Ambient Temperature and Air Velocity

Output Current (A) @Vin=12V Vout=2.5V (Through PWB Orientation)

20
18
16
			Natural
14			Convection	100LFM	200LFM
						300LFM
12							400LFM
10								500LFM
8								600LFM
6
4
2
0
25	30	35	40	45	50	55	60	65	70	75	80	85
										Ambient Temperature ( )

Note: Wind tunnel test setup figure dimensions are in millimeters and (Inches)

Figure 24: Wind tunnel test setup

Preliminary DS_NE12S20A_07272007

℃

Figure 27: Output current vs. ambient temperature and air velocity@ Vin=12V, Vout=2.5V (Through PWB Orientation)

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