QHW075F1-Q Lineage Power, QHW075F1-Q Datasheet - Page 12

• Manufacturer Part Number: QHW075F1-Q
• Description: CONVRTR DC/DC 3.3V 49.5W OUT
• Manufacturer: Lineage Power
• Series: QHWr
• Type: Isolated with Remote On/Offr

Specifications of QHW075F1-Q

• Output: 3.3V
• Number Of Outputs: 1
• Power (watts): 50W
• Mounting Type: Through Hole
• Voltage - Input: 36 ~ 75V
• Package / Case: 8-DIP Module
• 1st Output: 3.3 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: 50W
• Operating Temperature: -40°C ~ 100°C
• Efficiency: 81%
• Approvals: CE, CSA, UL, VDE
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• 3rd Output: -
• 2nd Output: -
• 4th Output: -

QHW050F1-Q, QHW075F1-Q, and QHW100F1-Q Power Modules;
dc-dc Converters: 36 to 75 Vdc Input, 3.3 Vdc Output; 33 W to 66 W
Feature Descriptions
Output Overvoltage Protection
The output overvoltage protection consists of circuitry
that monitors the voltage on the output terminals. If the
voltage on the output terminals exceeds the overvolt-
age protection threshold, then the module will shut
down and latch off. The overvoltage latch is reset by
either cycling the input power for one second or by tog-
gling the on/off signal for one second. If the auto-restart
option is chosen, the unit will “hiccup” until the tempera-
ture is within specification.
Overtemperature Protection
These modules feature an overtemperature protection
circuit to safeguard against thermal damage. The cir-
cuit shuts down and latches off the module when the
maximum case temperature is exceeded. The module
can be restarted by cycling the dc input power for at
least one second or by toggling the remote on/off signal
for at least one second. If the auto-restart option is cho-
sen, the unit will “hiccup” until the temperature is within
specification.
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 24.
Note: Top view, pin locations are for reference only.
Figure 24. Case Temperature Measurement
12
12
Measurements shown in millimeters and (inches).
(0.55)
14
Location
V
ON/OFF
V
I
I
(+)
(–)
33 (1.30)
(continued)
(+)SENSE
(–)SENSE
V
V
TRIM
O
O
(+)
(–)
8-2104(F)
C
)
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. Figures 25 and 26 show the
maximum power that can be dissipated by the module
without exceeding the maximum case temperature ver-
sus local ambient temperature (T
tion 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 dissipat-
ing components in the system. The use of Figure 25 is
shown in the following example.
Example
What is the minimum airflow necessary for a
QHW100F1-Q operating at V
of 15 A, transverse orientation, and a maximum ambi-
ent temperature of 40 °C?
Solution
Given: V
Determine P
Determine airflow (v) (Use Figure 25):
I
T
P
v = 0.5 m/s (100 ft./min.)
O
A
I
D
= 15 A
= 48 V
= 40 °C
= 7.75 W
D
(Use Figure 29):
I
= 48 V, an output current
A
) for natural convec-
Lineage Power
Data Sheet
April 2008