LW025F871 Lineage Power, LW025F871 Datasheet - Page 10

• Manufacturer Part Number: LW025F871
• Description: CONVERTER DC/DC 3.3V 16.5W OUT
• Manufacturer: Lineage Power
• Series: LW025r
• Type: Isolated with Remote On/Offr

Specifications of LW025F871

• Output: 3.3V
• Number Of Outputs: 1
• Power (watts): 25W
• Mounting Type: Through Hole
• Voltage - Input: 36 ~ 75V
• Package / Case: 8-DIP Module
• 1st Output: 3.3 VDC @ 5A
• Size / Dimension: 2.00" L x 2.00" W x 0.39" H (50.8mm x 50.8mm x 9.9mm)
• Power (watts) - Rated: 16.5W
• Operating Temperature: -40°C ~ 110°C
• Efficiency: 77%
• Approvals: CE, CSA, UL, VDE
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• 3rd Output: -
• 2nd Output: -
• 4th Output: -

36 Vdc to 75 Vdc Inputs; 25 W
Feature Descriptions
Synchronization (Optional)
The unit is capable of external synchronization from an
independent time base with a switching rate of
256 kHz. The amplitude of the synchronizing pulse
train is TTL compatible and the duty cycle ranges
between 40% and 60%. Synchronization is referenced
to V
Thermal Considerations
Introduction
The LW025 Single-Output-Series Power Modules oper-
ate in a variety of thermal environments; however, suffi-
cient cooling should be provided to help ensure reliable
operation of the unit. Heat-dissipating components
inside the unit are thermally coupled to the case. Heat
is removed by conduction, convection, and radiation to
the surrounding environment. Proper cooling can be
verified by measuring the case temperature. Peak case
temperature (T
ure 14.
Figure 14. Case Temperature Measurement
10
10
Note: Dimensions are in millimeters and (inches). Pin locations are
I
(+).
for reference only.
Location
CASE PIN (OPTIONAL)
ON/OFF
NC
IN
-
+
C
) occurs at the position indicated in Fig-
(1.06)
MADE IN USA
OUT:DC 5.0V, 5.0A
26.9
LW025A871
DC-DC CONVERTER
IN:DC 36-75V, 1.20A
(continued)
TRIM
OUT
-
+
(0.77
19.6
8-1265(C).c
Note that the view in Figure 14 is of the metal surface
of the module—the pin locations shown are for refer-
ence. The temperature at this location should not
exceed the maximum case temperature indicated in
the derating curve shown in Figure 16. The output
power of the module should not exceed the rated
power for the module as listed in the Ordering Informa-
tion table.
Heat Transfer
Increasing airflow over the module enhances the heat
transfer via convection. Figure 16 shows the maximum
power that can be dissipated by the module without
exceeding the maximum case temperature versus local
ambient temperature (T
through 3.0 ms
Systems in which these power modules may be used
typically generate natural convection airflow rates of
0.3 ms
ponents in the system. Therefore, the natural convec-
tion condition represents airflow rates of up to 0.3 ms
(60 ft./min.). Use of Figure 16 is shown in the following
example.
Example
What is the minimum airflow necessary for a LW025A
operating at V
maximum ambient temperature of 85 °C?
Solution
Given: V
Determine P
Determine airflow (Figure 16): v = 1.0 ms
(200 ft./min.)
–1
I
(60 ft./min.) due to other heat-dissipating com-
= 75 V, I
D
I
(Figure 18): P
= 75 V, an output current of 3.5 A, and a
–1
(600 ft./min.).
O
= 3.5 A, T
A
) for natural convection
D
A
= 4.5 W
= 85 °C
Lineage Power
–1
April 2008
–1