MA-COM LW025F

Advance Data Sheet
March 1999
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Features
The LW025 Single-Output-Series Power Modules use
advanced, surface-mount technology and deliver high-quality,
compact, dc-dc conversion at an economical price.
Options
■
Choice of on/off configuration
■
Case ground pin
■
Synchronization
■
Short pins: 2.79 mm ± 0.25 mm
(0.110 in. ± 0.010 in.)
■
Short pins: 3.68 mm ± 0.25 mm
(0.145 in. ± 0.010 in.)
■
Low profile: 9.91 mm (0.390 in.) with 0.38 mm
(0.015 in.) standoffs, 9.53 mm (0.375 in.) with
standoffs recessed
■
Wide input voltage range: 36 Vdc to 75 Vdc
■
Input-to-output isolation
■
Operating case temperature range: –40 °C to
+110 °C
■
Metal case
■
Overcurrent protection
■
Remote on/off
■
Output voltage adjust: 90% to 110% of VO, nom
■
Output overvoltage protection
■
UL* 1950 Recognized, CSA† C22.2 No. 950-95
Certified, VDE 0805 (EN60950, IEC950) Licensed
■
CE mark meets 73/23/EEC and 93/68/EEC
directives‡
■
Within FCC and EN55022 (CISPR 22) Class A
radiated limits
Applications
■
Distributed power architectures
■
Telecommunications
Description
The LW025 Single-Output-Series Power Modules are low-profile dc-dc converters that operate over an input
voltage range of 36 Vdc to 75 Vdc and provide precisely regulated outputs. The output is isolated from the
input, allowing versatile polarity configurations and grounding connections. The module has a maximum power
rating of 25 W at a typical full-load efficiency of 79%.
The power modules feature remote on/off and output voltage adjustments of 90% to 110% of the nominal output voltage. Built-in filtering for both input and output minimizes the need for external filtering.
* UL is a registered trademark of Underwriters Laboratories, Inc.
† CSA is a registered trademark of Canadian Standards Association.
‡ This product is intended for integration into end-use equipment. All the required procedures for CE marking of end-use equipment should
be followed. (The CE mark is placed on selected products.)
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Advance Data Sheet
March 1999
Absolute Maximum Ratings
Stresses in excess of the absolute maximum ratings can cause permanent damage to the devices. These are
absolute stress ratings only. Functional operation of the devices is not implied at these or any other conditions in
excess of those given in the operations sections of the data sheet. Exposure to absolute maximum ratings for
extended periods can adversely affect device reliability.
Parameter
Symbol
Min
Max
Unit
VI
VI, trans
0
0
80
100
Vdc
V
Operating Case Temperature (See Figure 16.)
TC
–40
110*
°C
Storage Temperature
Tstg
–40
120
°C
I/O Isolation Voltage
—
—
1500
Vdc
Input Voltage:
Continuous
Transient (100 ms)
* Maximum case temperature varies based on power dissipation. See derating curves, Figures 15—16, for details.
Electrical Specifications
Unless otherwise indicated, specifications apply over all operating input voltage, resistive load, and temperature
conditions.
Table 1. Input Specifications
Parameter
Symbol
Min
Typ
Max
Unit
VI
36
48
75
Vdc
II, max
—
—
1.2
A
Inrush Transient
i2t
—
—
0.1
A2s
Input Reflected-ripple Current
(50 Hz to 20 MHz; 12 µH source impedance,
TC = 25 °C; see Figure 10.)
II
—
3
—
mAp-p
Input Ripple Rejection (100 Hz—120 Hz)
—
—
60
—
dB
Operating Input Voltage
Maximum Input Current
(VI = 0 V to VI, max; IO = IO, max; see Figures 1 and 2.)
Fusing Considerations
CAUTION: This power module is not internally fused. An input line fuse must always be used.
This encapsulated power module can be used in a wide variety of applications, ranging from simple stand-alone
operation to an integrated part of a sophisticated power architecture. To preserve maximum flexibility, internal fusing is not included; however, to achieve maximum safety and system protection, always use an input line fuse. The
safety agencies require a normal-blow fuse with a maximum rating of 5 A (see Safety Considerations section).
Based on the information provided in this data sheet on inrush energy and maximum dc input current, the same
type of fuse with a lower rating can be used. Refer to the fuse manufacturer’s data for further information.
2
Tyco Electronics Corp.
Advance Data Sheet
March 1999
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Electrical Specifications (continued)
Table 2. Output Specifications
Parameter
Device
Symbol
Min
Typ
Max
Unit
Output Voltage Set Point
(VI = 48 V; IO = IO, max; TC = 25 °C)
LW025F
LW025A
VO, set
VO, set
3.25
4.92
3.3
5.0
3.35
5.08
Vdc
Vdc
Output Voltage
(Over all line, load, and temperature conditions
until end of life; see Figure 12.)
LW025F
LW025A
VO
VO
3.17
4.85
—
—
3.43
5.15
Vdc
Vdc
Output Regulation:
Line (VI = 36 V to 75 V)
Load (IO = IO, min to IO, max)
Temperature (TC = –40 °C to +100 °C)
All
All
All
—
—
—
—
—
—
0.01
0.05
0.5
0.1
0.4
1.0
%VO
%VO
%VO
Output Ripple and Noise (See Figure 11.):
RMS
Peak-to-peak (5 Hz to 20 MHz)
All
All
—
—
—
—
—
20
40
100
mVrms
mVp-p
Output Current
(At IO < IO, min, the modules may exceed output
ripple specifications.)
All
IO
0.4
—
5.0
A
Output Current-limit Inception
(VO = 90% x VO, set; see Figures 3 and 4.)
All
IO
103
—
150
%IO, max
Output Short-circuit Current (VO = 250 mV)
All
IO
—
135
200
%IO, max
LW025F
LW025A
η
η
75
77
77
79
—
—
%
%
Switching Frequency
All
—
—
256
—
kHz
Dynamic Response
(ýIO/ýt = 1 A/10 µs, VI = VI, nom, TA = 25 °C):
Load Change from IO = 50% to 75% of IO, max:
Peak Deviation
Settling Time (VO < 10% peak deviation)
Load Change from IO = 50% to 25% of IO, max:
Peak Deviation
Settling Time (VO < 10% peak deviation)
All
All
—
—
—
—
1
0.5
—
—
%VO, set
ms
All
All
—
—
—
—
1
0.5
—
—
%VO, set
ms
Efficiency
(VI = VI, nom; IO = IO, max; TC = 25 °C; see Figures 5,
6, and 12.)
Table 3. Isolation Specifications
Min
Typ
Max
Unit
Isolation Capacitance
Parameter
—
0.002
—
µF
Isolation Resistance
10
—
—
M¾
Typ
Max
General Specifications
Parameter
Min
Calculated MTBF (IO = 80% of IO, max; TC = 40 °C)
Weight
Tyco Electronics Corp.
5,500,000
—
—
Unit
hours
54 (1.9)
g (oz.)
3
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Advance Data Sheet
March 1999
Feature Specifications
Unless otherwise indicated, specifications apply over all operating input voltage, resistive load, and temperature
conditions. See Feature Descriptions and Design Considerations for further information.
Parameter
Remote On/Off Signal Interface:
(VI = 0 V to VI, max; open collector or equivalent
compatible; signal referenced to VI(–) terminal. See
Figure 13 and Feature Descriptions.):
Negative Logic: Device Code Suffix “1”:
Logic Low—Module On
Logic High—Module Off
Positive Logic: If Device Code Suffix “1” Is Not
Specified:
Logic Low—Module Off
Logic High—Module On
Module Specifications:
On/Off Current:
Logic Low
On/Off Voltage:
Logic Low
Logic High (Ion/off = 0)
Open Collector Switch Specifications:
Leakage Current During Logic High
(Von/off = 10 V)
Output Low Voltage During Logic Low
(Ion/off = 1 mA)
Turn-on Delay and Rise Times
(at 80% of IO, max; TA = 25 °C):
Case 1: On/Off Input Is Set for Unit On and Then
Input Power Is Applied (delay from point at which
VI = 48 V until VO = 10% of VO, nom).
Case 2: 48 V Input Is Applied for at Least One
Second, and Then the On/Off Input Is Set to Turn
the Module On (delay from point at which on/off
input is toggled until VO = 10% of VO, nom).
Output Voltage Rise Time (time for VO to rise from
10% of VO, nom to 90% of VO, nom)
Output Voltage Overshoot (at 80% of IO, max;
TA = 25 °C)
Output Voltage Set-point Adjustment Range
Output Overvoltage Protection (clamp)
4
Device
Symbol
Min
Typ
Max
Unit
All
Ion/off
—
—
1.0
mA
All
All
Von/off
Von/off
–0.7
—
—
—
1.2
10
V
V
All
Ion/off
—
—
50
µA
All
Von/off
—
—
1.2
V
All
Tdelay
—
27
50
ms
All
Tdelay
—
2
10
ms
All
Trise
—
1.5
3.0
ms
All
—
—
—
5
%
All
—
90
—
110
%VO, nom
LW025F
LW025A
VO, clamp
VO, clamp
3.9
5.6
—
—
5.0
7.0
V
V
Tyco Electronics Corp.
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Advance Data Sheet
March 1999
Characteristics Curves
3.5
OUTPUT VOLTAGE, VO (V)
3.0
0.8
INPUT CURRENT, II (A)
0.7
0.6
IO = 0.4 A
IO = 2.5 A
IO = 5 A
0.5
0.4
2.5
2.0
1.5
1.0
0.3
0.5
0.2
0.0
VI = 75 V
VI = 48 V
VI = 36 V
0
1
2
3
4
5
6
7
8
0.1
OUTPUT CURRENT, IO (A)
0.0
8-2234(C)
0
10
20
30
40
50
60
70
80
Figure 3. LW025F Typical Output Characteristics
INPUT VOLTAGE, V I (V)
8-2233(C)
Figure 1. LW025F Typical Input Characteristics
OUTPUT VOLTAGE, V O (V)
6
1.2
INPUT CURRENT, II (A)
1.0
IO = 0.4 A
IO = 2.5 A
IO = 5 A
0.8
0.6
5
4
3
VI = 75 V
VI = 48 V
VI = 36 V
2
1
0.4
0
0
0.2
1
2
3
4
5
6
7
OUTPUT CURRENT, IO (A)
0.0
0
10
20
30
40
50
60
70
80
8-1983(C)
Figure 4. LW025A Typical Output Characteristics
INPUT VOLTAGE, V I (V)
8-1982(C).b
Figure 2. LW025A Typical Input Characteristics
Tyco Electronics Corp.
5
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
OUTPUT VOLTAGE, V O (V)
(50 mV/div)
Characteristics Curves (continued)
78
76
74
72
70
68
VI = 36 V
VI = 48 V
VI = 75 V
66
64
62
60
0.4
0.9
1.4
1.9
2.4
2.9
3.4
3.9
4.4
4.9
OUTPUT CURRENT, IO (A)
OUTPUT CURRENT, IO (A)
(1.25 A/div)
EFFICIENCY, η (%)
Advance Data Sheet
March 1999
2.5A
1.25A
8-2478(C)
Figure 5. LW025F Typical Converter Efficiency vs.
Output Current
TIME, t (100 µs/div)
8-1261(C).c
Figure 7. LW025A, F Typical Output Voltage for a
Step Load Change from 50% to 25%
EFFICIENCY, η (%)
80
75
VI = 36 V
VI = 48 V
VI = 75 V
70
65
60
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5 5.0
OUTPUT CURRENT, I O (A)
8-1984(C)
Figure 6. LW025A Typical Converter Efficiency vs.
Output Current
OUTPUT CURRENT, I O (A)
(1.25 A/div)
OUTPUT VOLTAGE, VO (V)
(50 mV/div)
85
3.75 A
2.5 A
TIME, t (100 µs/div)
8-1262(C)
Figure 8. LW025A, F Typical Output Voltage for a
Step Load Change from 50% to 75%
6
Tyco Electronics Corp.
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Advance Data Sheet
March 1999
Test Configurations
Characteristics Curves (continued)
REMOTE ON/OFF,
Von/off (V) (2 V/div)
TO OSCILLOSCOPE
LTEST
CURRENT
PROBE
VI(+)
12 µH
5V
CS 220 µF
IMPEDANCE < 0.1 Ω
@ 20 ˚C, 100 kHz
BATTERY
33 µF
VI(-)
NORMALIZED
OUTPUT VOLTAGE, V O
0
8-203(C)
Note: Input reflected-ripple current is measured with a simulated
source impedance of 12 µH. Capacitor Cs offsets possible
battery impedance. Current is measured at the input of the
module.
Figure 10. Input Reflected-Ripple Test Setup
0
TIME, t (1 ms/div)
COPPER STRIP
8-1263(C).e
V O (+)
Figure 9. LW025A, F Typical Output Voltage StartUp when Signal Is Applied to Remote
On/Off
0.1 µF
SCOPE
RESISTIVE
LOAD
V O (-)
8-513(C)
Note: Use a 0.1 µF ceramic capacitor. Scope measurement should
be made using a BNC socket. Position the load between
50 mm and 75 mm (2 in. and 3 in.) from the module.
Figure 11. Peak-to-Peak Output Noise
Measurement Test Setup
CONTACT AND
DISTRIBUTION LOSSES
V I (+)
V O (+)
II
IO
LOAD
SUPPLY
V I (-)
V O (-)
CONTACT RESISTANCE
8-204(C)
Note: All measurements are taken at the module terminals. When
socketing, place Kelvin connections at module terminals to
avoid measurement errors due to socket contact resistance.
[ V O (+) – V O (–) ]I O
η =  ------------------------------------------------ × 100
 [ V I (+) – V I (–) ]I I 
%
Figure 12. Output Voltage and Efficiency
Measurement Test Setup
Tyco Electronics Corp.
7
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Design Considerations
Grounding Considerations
For modules without the isolated case ground pin
option, the case is internally connected to the VI(+) pin.
For modules with the isolated case ground pin, device
code suffix “7,” the VI(+) pin is not connected to the
case.
Input Source Impedance
The power module should be connected to a low acimpedance input source. Highly inductive source
impedances can affect the stability of the power module. For the test configuration in Figure 10, a 33 µF
electrolytic capacitor (ESR < 0.7 ¾ at 100 kHz)
mounted close to the power module helps ensure stability of the unit. For other highly inductive source
impedances, consult the factory for further application
guidelines.
Safety Considerations
For safety-agency approval of the system in which the
power module is used, the power module must be
installed in compliance with the spacing and separation
requirements of the end-use safety agency standard,
i.e., UL 1950, CSA C22.2 No. 950-95, and VDE 0805
(EN60950, IEC950).
If the input source is non-SELV (ELV or a hazardous
voltage greater than 60 Vdc and less than or equal to
75 Vdc), for the module's output to be considered
meeting the requirements of safety extra-low voltage
(SELV), all of the following must be true:
■
The input source is to be provided with reinforced
insulation from any other hazardous voltages, including the ac mains; and
■
One VI pin and one VO pin are to be grounded or
both the input and output pins are to be kept floating;
and
■
The input pins of the module are not operator accessible; and
■
Another SELV reliability test is conducted on the
whole system, as required by the safety agencies, on
the combination of supply source and the subject
module to verify that under a single fault, hazardous
voltages do not appear at the module's output.
8
Advance Data Sheet
March 1999
Note: Do not ground either of the input pins of the
module without grounding one of the output
pins. This may allow a non-SELV voltage to
appear between the output pins and ground.
The power module has extra-low voltage (ELV) outputs
when all inputs are ELV.
The input to these units is to be provided with a maximum 5 A normal-blow fuse in the ungrounded lead.
Feature Descriptions
Overcurrent Protection
To provide protection in a fault (output overload) condition, the unit is equipped with internal current-limiting
circuitry and can endure current limiting for an unlimited duration. At the point of current-limit inception, the
unit shifts from voltage control to current control. If the
output voltage is pulled very low during a severe fault,
the current-limit circuit can exhibit either foldback or
tailout characteristics (output-current decrease or
increase). The unit operates normally once the output
current is brought back into its specified range.
Remote On/Off
Two remote on/off options are available. Positive logic
remote on/off turns the module on during a logic-high
voltage on the REMOTE ON/OFF pin, and off during a
logic low. Negative logic, device code suffix “1,” remote
on/off turns the module off during a logic high and on
during a logic low.
To turn the power module on and off, the user must
supply a switch to control the voltage between the
on/off terminal and the VI(–) terminal (Von/off). The
switch can be an open collector or equivalent (see Figure 13). A logic low is Von/off = –0.7 V to 1.2 V. The maximum Ion/off during a logic low is 1 mA. The switch
should maintain a logic-low voltage while sinking 1 mA.
During a logic high, the maximum Von/off generated by
the power module is 6 V. The maximum allowable leakage current of the switch at Von/off = 6 V is 50 µA.
The module has internal capacitance to reduce noise
at the ON/OFF pin. Additional capacitance is not generally needed and may degrade the start-up characteristics of the module.
Tyco Electronics Corp.
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Advance Data Sheet
March 1999
Feature Descriptions (continued)
Remote On/Off (continued)
VI(+)
VI(-)
Von/off
+
REMOTE
ON/OFF
Ion/off
8-758(C).a
Figure 13. Remote On/Off Implementation
Output Voltage Adjustment
Output voltage trim allows the user to increase or decrease the output voltage set point of a module. This is accomplished by connecting an external resistor between the TRIM pin and either the VO(+) or VO(–) pins. With an external resistor between the TRIM and VO(+) pins (Radj-down), the output voltage set point (VO, adj) decreases. With an
external resistor between the TRIM pin and VO(–) pin (Radj-up), VO, adj increases.
The following equations determine the required external resistor value to obtain an output voltage change of ý%:
c [ d ⋅ ( 1 – ∆% ) – 1 ]
R adj-down = ------------------------------------------------ – b kΩ
∆%
a
R adj-up = ----------------- – b kΩ
d ⋅ ∆%
Device
a
b
c
d
–5% VO Radj-down
+5% VO Radj-up
LW025F
LW025A
14.0
4.02
51.1
16.9
5.2
2.01
2.7
2.0
111.7 k¾
19.3 k¾
52.7 k¾
23.3 k¾
The adjusted output voltage cannot exceed 110% of the nominal output voltage between the VO(+) and VO(–) terminal.
The modules have a fixed current-limit set point. Therefore, as the output voltage is adjusted down, the available
output power is reduced. In addition, the minimum output current is a function of the output voltage. As the output
voltage is adjusted down, the minimum required output current can increase.
Output Overvoltage Protection
The output overvoltage clamp consists of control circuitry, independent of the primary regulation loop, that monitors
the voltage on the output terminals. The control loop of the protection circuit has a higher voltage set point than the
primary loop (see Feature Specifications table). In a fault condition, the overvoltage clamp ensures that the output
voltage does not exceed VO, clamp, max. This provides a redundant voltage-control that reduces the risk of output
overvoltage.
Tyco Electronics Corp.
9
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Feature Descriptions (continued)
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 VI(+).
Thermal Considerations
Introduction
The LW025 Single-Output-Series 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 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 (TC) occurs at the position indicated in Figure 14.
Note that the view in Figure 14 is of the metal surface
of the module—the pin locations shown are for reference. 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 Information 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 (TA) for natural convection
through 3.0 ms–1 (600 ft./min.).
Systems in which these power modules may be used
typically generate natural convection airflow rates of
0.3 ms–1 (60 ft./min.) due to other heat-dissipating components in the system. Therefore, the natural convection condition represents airflow rates of up to 0.3 ms–1
(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 VI = 75 V, an output current of 3.5 A, and a
maximum ambient temperature of 85 °C?
26.9
(1.06)
TRIM
ON/OFF
Advance Data Sheet
March 1999
Solution
19.6
(0.77)
Given: VI = 75 V, IO = 3.5 A, TA = 85 °C
Determine PD (Figure 18): PD = 4.5 W
Determine airflow (Figure 16): v = 1.0 ms–1
(200 ft./min.)
-
NC
LW025A871
OUT
- DC-DC CONVERTER
IN IN:DC 36-75V, 1.20A
+
+ OUT:DC 5.0V, 5.0A
MADE IN USA
CASE PIN (OPTIONAL)
8-1265(C).c
Note: Dimensions are in millimeters and (inches). Pin locations are
for reference only.
Figure 14. Case Temperature Measurement
Location
10
Tyco Electronics Corp.
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Advance Data Sheet
March 1999
Thermal Considerations (continued)
6
POWER DISSIPATION PD (W)
Heat Transfer (continued)
POWER DISSIPATION PD (W)
5
4
3
2
1
0
40
MAX CASE
TEMPURATURE
1.0 ms -1 (600 ft./min.)
2.0 ms -1 (400 ft./min.)
3.0 ms -1 (200 ft./min.)
NATURAL
CONVECTION
50
60
70
5
4
3
2
VI = 75 V
VI = 48 V
VI = 36 V
1
0
0.4
0.9
1.4
1.9
2.4
2.9
3.4
3.9
4.4 4.9
OUTPUT CURRENT, I O (A)
8-2479(C)
80
90
100
110
Figure 17. LW025F Power Dissipation vs. Output
Current, TA = 25 °C
MAX AMBIENT TEMPERATURE, TA (˚C)
8-2477(C)
Figure 15. LW025F Forced Convection Power
Derating; Either Orientation
POWER DISSIPATION, PD (W)
9
8
MAX CASE TEMPERATURE
7
1
VI = 75 V
VI = 48 V
VI = 36 V
5
4
3
2
1
1
1.5
2
2.5
3
3.5
4
4.5
5
OUTPUT CURRENT, IO (A)
8-1888(C).a
4
0
40
6
0.5
5
2
7
0
6
3
8
POWER DISSIPATION, PD (W)
Note: Conversion factor for linear feet per minute to meters per
second: 200 ft./min. = 1 ms–1.
NATURAL CONVECTION
1.0 ms -1 (200 ft./min.)
2.0 ms -1 (400 ft./min.)
3.0 ms -1 (600 ft./min.)
50
60
70
Figure 18. LW025A Power Dissipation vs. Output
Current, TA = 25 °C
80
90
100
110
MAX AMBIENT TEMPERATURE, TA (˚C)
8-1985(C)
Note: Conversion factor for linear feet per minute to meters per
second: 200 ft./min. = 1 ms–1.
Figure 16. LW025A Forced Convection Power
Derating; Either Orientation
Tyco Electronics Corp.
11
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Advance Data Sheet
March 1999
Thermal Considerations (continued)
Layout Considerations
Module Derating
Copper paths must not be routed beneath the power
module standoffs.
The derating curves in Figure 16 were determined from
measurements obtained in an experimental apparatus
shown in Figure 19. Note that the module and the
printed-wiring board (PWB) that it is mounted on are
vertically oriented. The passage has a rectangular
cross-section.
FACING PWB
PWB
MODULE
AIR VELOCITY
AND AMBIENT
TEMPERATURE
MEASURED
BELOW THE
MODULE
AIRFLOW
76 (3.0)
13 (0.5)
8-1126(C).d
Note: Dimensions are in millimeters and (inches).
Figure 19. Experimental Test Setup
12
Tyco Electronics Corp.
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Advance Data Sheet
March 1999
Outline Diagram
Dimensions are in millimeters and (inches).
Tolerances: x.x ± 0.5 mm (0.02 in.), x.xx ± 0.25 mm (0.010 in.). Pin-to-pin tolerances are not cumulative.
Note: For standard modules, VI(+) is internally connected to the case.
Top View
50.8 (2.00)
Pin
Function
1
Remote
On/Off
2
No Connection (sync feature optional)
3
VI(–)
4
VI(+)
5
Case Pin
(pin optional)
6
Trim
TRIM
ON/OFF
NC
50.8
(2.00)
IN
+
LW025A871
DC-DC CONVERTER
IN:DC 36-75V, 1.20A
OUT:DC 5.0V, 5.0A
OUT
+
MADE IN USA
7
– Output
8
+ Output
CASE PIN
(OPTIONAL)
Side View
0.38 ± 0.13
(0.015 ± 0.005)
9.91 ± 0.38
(0.390 ± 0.015)
Bottom View
STANDOFFS
1.78 x 0.51 THICK
(0.070 x 0.020),
4 PLACES
4.70 (0.185)
MIN
22.9
(0.90)
1.02 (0.040) DIA
SOLDER-PLATED
BRASS, ALL PINS
5.08
(0.200)
20.3 (0.80)
5
8
4
5.08 (0.200)
5.08 (0.200)
10.16 (0.400)
3
7
2
1
10.16 (0.400)
5.08
(0.200)
2.5
(0.10)
6
45.72 ± 0.38
(1.800 ± 0.015)
2.5 (0.10)
REF
8-1198(C).f
Tyco Electronics Corp.
13
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Advance Data Sheet
March 1999
Recommended Hole Pattern
Component-side footprint. Dimensions are in millimeters and (inches).
2.5
(0.10)
12.7
(0.50)
20.32
(0.800)
15.24
(0.600)
50.8 (2.00)
45.72 (1.800)
5.08
(0.200)
2.54 (0.100)
12.4
(0.49)
50.8
(2.00)
7.62 (0.300)
10.16
(0.400)
17.78
(0.700)
37.8
(1.49)
3.43
(0.135)
38.86
(1.530)
CASE OUTLINE
DRILL HOLE OF APPROX.
2.54 (0.100) DIAMETER
TO RECESS STANDOFFS
IF LOWER HEIGHT IS NEEDED
8-1198(C).f
Ordering Information
Table 4. Device Codes
Input Voltage
Output Voltage
Output Power
Device Code
Comcode
48 V
3.3 V
48 V
5V
16.5 W
LW025F
108448234
25 W
LW025A
TBD
Optional features may be ordered using the device code suffixes shown below. To order more than one option, list
suffixes in numerically descending order. Please contact your Tyco Electronics’ Account Manager or Field Application Engineer for pricing and availability.
Table 5. Option Codes
Option
Short pins: 2.79 mm ± 0.25 mm
(0.110 in. ± 0.010 in.)
Case ground pin
Short pins: 3.68 mm ± 0.25 mm
(0.145 in. ± 0.010 in.)
Synchronization
Negative logic on/off
14
Device Code Suffix
8
7
6
3
1
Tyco Electronics Corp.
Advance Data Sheet
March 1999
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Notes
Tyco Electronics Corp.
15
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Advance Data Sheet
March 1999
Tyco Electronics Power Systems, Inc.
3000 Skyline Drive, Mesquite, TX 75149, USA
+1-800-526-7819 FAX: +1-888-315-5182
(Outside U.S.A.: +1-972-284-2626, FAX: +1-972-284-2900)
http://power.tycoelectronics.com
Tyco Electronics Corporation reserves the right to make changes to the product(s) or information contained herein without notice. No liability is assumed as a result of their use or application.
No rights under any patent accompany the sale of any such product(s) or information.
© 2001 Tyco Electronics Corporation, Harrisburg, PA. All International Rights Reserved.
Printed in U.S.A.
March 1999
DS98-052EPS
Printed on
Recycled Paper