QW075A1 Lineage Power, QW075A1 Datasheet - Page 11

• Manufacturer Part Number: QW075A1
• Description: CONVERTER DC/DC 5V 75W OUT
• Manufacturer: Lineage Power
• Series: QWr
• Type: Isolated with Remote On/Offr

Specifications of QW075A1

• Output: 5V
• Number Of Outputs: 1
• Power (watts): 75W
• Mounting Type: Through Hole
• Voltage - Input: 36 ~ 75V
• Package / Case: 8-DIP Module
• 1st Output: 5 VDC @ 15A
• Size / Dimension: 2.28" L x 1.45" W x 0.50" H (57.9mm x 36.8mm x 12.7mm)
• Power (watts) - Rated: 75W
• Operating Temperature: -40°C ~ 100°C
• Efficiency: 84%
• Approvals: CE, CSA, UL, VDE
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• 3rd Output: -
• 2nd Output: -
• 4th Output: -

Data Sheet
April 2008
Thermal Considerations
Introduction
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 ther-
mally coupled to the case. Heat is removed by conduc-
tion, convection, and radiation to the surrounding
environment. Proper cooling can be verified by mea-
suring the case temperature. Peak temperature (T
occurs at the position indicated in Figure 19.
Note: Top view, pin locations are for reference only.
Figure 19. Case Temperature Measurement
The temperature at this location should not exceed
100 °C. The output power of the module should not
exceed the rated power for the module as listed in the
Ordering Information table.
Although the maximum case temperature of the power
modules is 100 °C, you can limit this temperature to a
lower value for extremely high reliability.
Heat Transfer Without Heat Sinks
Increasing airflow over the module enhances the heat
transfer via convection. Figure 22 shows the maximum
power that can be dissipated by the module without
exceeding the maximum case temperature versus local
ambient temperature (T
through 3 m/s (600 ft./min.).
Note that the natural convection condition was mea-
sured at 0.05 m/s to 0.1 m/s (10 ft./min. to 20 ft./min.);
however, systems in which these power modules may
be used typically generate natural convection airflow
rates of 0.3 m/s (60 ft./min.) due to other heat-
dissipating components in the system. The use of
Figure 22 is shown in the following example.
Lineage Power
Measurements shown in millimeters and (inches).
(0.55)
14
Location
ON/OFF
V
V
I
I
(+)
(–)
33 (1.30)
A
) for natural convection
QW050B1 and QW075B1 Power Modules; dc-dc Converters:
(+)SENSE
(–)SENSE
V
V
O
TRIM
O
(+)
(–)
8-2104 (F)
36 Vdc to 75 Vdc Input, 12 Vdc Output; 50 W to 75 W
C
)
Example
What is the minimum airflow necessary for a QW050B1
operating at V
maximum ambient temperature of 40 °C?
Solution
Given: V
Determine P
Determine airflow (v) (Use Figure 22.):
Figure 20. QW050B1 Power Dissipation vs.
Figure 21. QW075B1 Power Dissipation vs.
18
16
14
12
10
12
10
8
6
4
2
0
8
6
4
2
0
I
T
P
v = 1.0 m/s (200 ft./min.)
0.6
0.5
O
A
I
D
= 48 V
= 3.5 A
= 40 °C
Output Current at 25 °C
Output Current at 25 °C
= 8 W
D
I
(Use Figure 20.):
1.6
1.1
= 48 V, an output current of 3.5 A, and a
OUTPUT CURRENT, I
OUTPUT CURRENT, I
2.6
1.7
V
V
V
3.6
2.3
I
I
I
= 75 V
= 48 V
= 36 V
V
V
V
I
I
I
= 75 V
= 48 V
= 36 V
4.6
2.9
O
O
(A)
(A)
5.6
3.5
8-3447 (F)
8-3448 (F)
6.6
4.1
11