LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Data Sheet
March 22, 2000
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
Input Voltage:
Continuous
Transient (100 ms)
Operating Case Temperature
(See Thermal Considerations section.)
Storage Temperature
I/O Isolation Voltage (for 1 minute)
Symbol
Min
Max
Unit
VI
VI, trans
TC
0
0
–40
80
100
110*
Vdc
V
°C
Tstg
—
–55
—
125
1500
°C
Vdc
* Maximum case temperature varies based on power dissipation. See derating curves, Figures 24—25, for details.
Electrical Specifications
Unless otherwise indicated, specifications apply over all operating input voltage, resistive load, and temperature
conditions.
Table 1. Input Specifications
Parameter
Operating Input Voltage
Maximum Input Current
(VI = 0 V to VI, max; IO = IO, max; see Figures 1—3.)
Inrush Transient
Symbol
VI
II, max
i2t
Min
36
—
Typ
48
—
Max
75
1.2
Unit
Vdc
A
—
3
0.1
—
A2s
mAp-p
60
—
dB
Input Reflected-ripple Current
(50 Hz to 20 MHz; 12 µH source impedance,
TC = 25 °C; see Figure 19.)
II
—
—
Input Ripple Rejection (100 Hz—120 Hz)
—
—
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
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Data Sheet
March 22, 2000
Electrical Specifications (continued)
Table 2. Output Specifications
Parameter
Output Voltage Set Point
(VI = 48 V; IO = IO, max; TC = 25 °C)
Output Voltage
(Over all line, load, and temperature
conditions until end of life; see Figure 21.)
Output Regulation:
Line (VI = 36 V to 75 V)
Load (IO = IO, min to IO, max)
Temperature (TC = –40 °C to +100 °C)
Output Ripple and Noise (See Figure 20.):
RMS
Peak-to-peak (5 Hz to 20 MHz)
Output Current
(At IO < IO, min, the modules may exceed output
ripple and regulation specifications.)
Output Current-limit Inception
(VO = 90% x VO, set; see Figures 4—7.)
Output Short-circuit Current (VO = 250 mV)
Efficiency
(VI = VI, nom; IO = IO, max; TC = 25 °C; see Figures
8—11 and 21.)
Switching Frequency
Dynamic Response
(∆IO/∆t = 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)
Tyco Electronics
Device Code
Symbol
or Suffix
VO, set
LW025D
LW025G
VO, set
VO, set
LW025F
LW025A
VO, set
VO
LW025D
LW025G
VO
LW025F
VO
LW025A
VO
Min
Typ
Max
Unit
1.97
2.46
3.25
4.92
2.0
2.5
3.3
5.0
2.03
2.54
3.35
5.08
Vdc
Vdc
Vdc
Vdc
1.92
2.40
3.17
4.85
—
—
—
—
2.08
2.60
3.43
5.15
Vdc
Vdc
Vdc
Vdc
A, D, F
G
D
G
A, F
All
—
—
—
—
—
—
—
—
—
—
—
—
0.01
0.15
0.3
0.2
0.05
0.5
0.1
0.3
0.5
0.7
0.4
1.0
%VO
%VO
%VO
%VO
%VO
%VO
All
All
All
—
—
IO
—
—
0.4
—
20
—
40
100
5.0
mVrms
mVp-p
A
All
IO
103
—
150
%IO, max
D
A, F, G
LW025D
LW025G
LW025F
LW025A
All
IO
IO
—
—
150
135
220
200
η
η
η
η
—
67
70.5
75
77
—
69
73.25
77
79
256
—
—
—
—
—
%IO, max
%IO, max
%
%
%
%
kHz
D
G
A, F
All
—
—
—
—
—
—
—
—
6
3
2
1
—
—
—
—
%VO, set
%VO, set
%VO, set
ms
D
G
A, F
All
—
—
—
—
—
—
—
—
6
3
2
1
—
—
—
—
%VO, set
%VO, set
%VO, set
ms
3
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Data Sheet
March 22, 2000
Electrical Specifications (continued)
Table 3. Isolation Specifications
Parameter
Isolation Capacitance
Isolation Resistance
Min
—
10
Typ
0.002
—
Max
—
—
Unit
µF
MΩ
Min
Typ
Max
Unit
—
3,900,000
—
54 (1.9)
hours
g (oz.)
General Specifications
Parameter
Calculated MTBF (IO = 80% of IO, max; TC = 40 °C)
Weight
4
Tyco Electronics
Data Sheet
March 22, 2000
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
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 22 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)
Tyco Electronics
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
LW025D
LW025G
LW025F
LW025A
—
90
2.6
2.9
3.9
5.6
—
—
—
—
—
110
3.5
3.8
5.0
7.0
%VO, nom
V
V
V
V
VO, clamp
VO, clamp
VO, clamp
VO, clamp
5
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Data Sheet
March 22, 2000
Characteristics Curves
1.2
0.7
INPUT CURRENT, II (A)
1.0
INPUT CURRENT, II (A)
0.6
0.5
IO = 5.0 A
IO = 2.6 A
IO = 0.4 A
0.4
0.3
IO = 0.4 A
IO = 2.5 A
IO = 5 A
0.8
0.6
0.4
0.2
0.2
0.0
0.1
0
10
20
0.0
0
10
20
30
40
50
60
70
30
40
50
60
70
80
INPUT VOLTAGE, VI (V)
80
8-1982(C).b
INPUT VOLTAGE, VI (V)
Figure 3. LW025A Typical Input Characteristics
8-2560(C)
Figure 1. LW025D, G Typical Input Characteristics
2.5
OUTPUT VOLTAGE, VO (V)
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
0.3
2.0
1.5
1.0
VI = 75 V
VI = 48 V
VI = 36 V
0.5
0.2
0.0
0.1
0
0.0
0
10
20
30
40
50
60
70
80
1
2
3
4
5
6
7
8
9
OUTPUT CURRENT, IO (A)
8-2667(C)
INPUT VOLTAGE, VI (V)
8-2233(C)
Figure 4. LW025D Typical Output Characteristics
Figure 2. LW025F Typical Input Characteristics
6
Tyco Electronics
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Data Sheet
March 22, 2000
Characteristics Curves (continued)
OUTPUT VOLTAGE, VO (V)
3.0
2.5
2.0
1.5
VI = 75 V
VI = 48 V
VI = 36 V
1.0
OUTPUT VOLTAGE, VO (V)
6
5
4
3
VI = 75 V
VI = 48 V
VI = 36 V
2
1
0
0.5
1
0
2
3
4
5
6
7
OUTPUT CURRENT, IO (A)
0.0
0
1
2
3
4
5
6
7
8
8-1983(C)
9
OUTPUT CURRENT, IO (A)
Figure 7. LW025A Typical Output Characteristics
8-2666(C)
Figure 5. LW025G Typical Output Characteristics
75
70
65
(%)
3.0
EFFICIENCY,
OUTPUT VOLTAGE, VO (V)
3.5
2.5
2.0
60
55
VI = 75 V
VI = 48 V
VI = 36 V
50
45
40
1.5
35
1.0
VI = 75 V
VI = 48 V
VI = 36 V
0.5
30
0.4
1
2
3
4
1.4
1.9
2.4
2.9
3.4
3.9
4.4
4.9
OUTPUT CURRENT, IO (A)
0.0
0
0.9
5
6
7
8
OUTPUT CURRENT, IO (A)
8-2234(C)
8-2650(C)
Figure 8. LW025D Typical Converter Efficiency vs.
Output Current
Figure 6. LW025F Typical Output Characteristics
Tyco Electronics
7
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Data Sheet
March 22, 2000
Characteristics Curves (continued)
85
80
(%)
76
72
EFFICIENCY,
(%)
74
EFFICIENCY,
70
68
66
60
62
60
0.4
VI = 36 V
VI = 48 V
VI = 75 V
70
65
VI = 75 V
VI = 48 V
VI = 36 V
64
75
0.5
0.9
1.4
1.9
2.4
2.9
3.4
3.9
4.4
8-2646(C)
1.5
2.0
2.5
3.0
3.5
4.0
4.5 5.0
OUTPUT CURRENT, IO (A)
4.9
OUTPUT CURRENT, IO (A)
1.0
8-1984(C)
Figure 11. LW025A Typical Converter Efficiency vs.
Output Current
78
76
EFFICIENCY,
(%)
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)
OUTPUT VOLTAGE, VO (V)
Figure 9. LW025G Typical Converter Efficiency vs.
Output Current
106%
100%
2.5 A
1.25 A
8-2478(C)
Figure 10. LW025F Typical Converter Efficiency vs.
Output Current
TIME, t (100 µs/div)
8-1261(C).f
Figure 12. LW025D Typical Output Voltage for a
Step Load Change from 50% to 25%
8
Tyco Electronics
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Data Sheet
March 22, 2000
OUTPUT VOLTAGE, VO (V)
103%
100%
OUTPUT CURRENT, IO (A)
(1.25 A/div)
OUTPUT CURRENT, IO (A)
(1.25 A/div)
OUTPUT VOLTAGE, VO (V)
Characteristics Curves (continued)
2.5 A
100%
94%
3.75 A
2.5 A
1.25 A
TIME, t (100 µs/div)
8-1262(C).f
TIME, t (100 µs/div)
8-1261(C).g
Figure 15. LW025D Typical Output Voltage for a
Step Load Change from 50% to 75%
OUTPUT VOLTAGE, VO (V)
102%
100%
OUTPUT CURRENT, IO (A)
(1.25 A/div)
OUTPUT CURRENT, IO (A)
(1.25 A/div)
OUTPUT VOLTAGE, VO (V)
Figure 13. LW025G Typical Output Voltage for a
Step Load Change from 50% to 25%
2.5 A
100%
97%
3.75 A
2.5 A
1.25 A
TIME, t (100 µs/div)
8-1262(C).g
TIME, t (100 µs/div)
8-1261(C).h
Figure 16. LW025G Typical Output Voltage for a
Step Load Change from 50% to 75%
Figure 14. LW025A, F Typical Output Voltage for a
Step Load Change from 50% to 25%
Tyco Electronics
9
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
OUTPUT VOLTAGE, VO (V)
Characteristics Curves (continued)
Data Sheet
March 22, 2000
Test Configurations
TO
OSCILLOSCOPE
CURRENT
PROBE
LTEST
VI(+)
100%
12 µH
98%
CS 220 µF
IMPEDANCE < 0.1 Ω
@ 20 °C, 100 kHz
BATTERY
33 µF
OUTPUT CURRENT, IO (A)
(1.25 A/div)
V I (–)
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.
3.75 A
2.5 A
Figure 19. Input Reflected-Ripple Test Setup
TIME, t (100 µs/div)
8-1262(C).h
Figure 17. LW025A, F Typical Output Voltage for a
Step Load Change from 50% to 75%
COPPER STRIP
VO(+)
0.1 µF
SCOPE
RESISTIVE
LOAD
REMOTE ON/OFF,
Von/off (V) (2 V/div)
VO(–)
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.
5V
Figure 20. Peak-to-Peak Output Noise
Measurement Test Setup
NORMALIZED
OUTPUT VOLTAGE, VO
0
CONTACT AND
DISTRIBUTION LOSSES
V I (+)
V O (+)
II
IO
LOAD
SUPPLY
0
V I (–)
V O (–)
CONTACT RESISTANCE
TIME, t (1 ms/div)
8-204(C)
8-1263(C).e
Figure 18. LW025A, D, F, G Typical Output Voltage
Start-Up when Signal Is Applied to
Remote On/Off
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 21. Output Voltage and Efficiency
Measurement Test Setup
10
Tyco Electronics
Data Sheet
March 22, 2000
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 19, a 33 µF
electrolytic capacitor (ESR < 0.7 Ω 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:
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
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 22). 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.
■
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
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.
■
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.
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
11
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Data Sheet
March 22, 2000
Feature Descriptions (continued)
Remote On/Off (continued)
VI(+)
VI(–)
–
Von/off
+
REMOTE
ON/OFF
Ion/off
8-758(C).a
Figure 22. 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 ∆%:
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
LW025D
LW025G
LW025F
LW025A
5.11
14.0
14.0
4.02
2.05
51.1
51.1
16.9
3.13
6.86
5.2
2.01
1.63
2.04
2.7
2.0
32.3 kΩ
77.6 kΩ
111.7 kΩ
19.3 kΩ
60.6 kΩ
86.2 kΩ
52.7 kΩ
23.3 kΩ
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.
12
Tyco Electronics
Data Sheet
March 22, 2000
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Feature Descriptions (continued)
26.9
(1.06)
Output Overvoltage Protection
tyco
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.
TRIM
ON/OFF
19.6
(0.77)
–
NC LW025A871
OUT
– DC-DC CONVERTER
IN IN:DC 36-75V, 1.20A
+
+ OUT:DC 5.0V, 5.0A
MADE IN USA
VDE
TUV Rheinland
CASE PIN (OPTIONAL)
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 23.
8-1265(C).c
Note: Dimensions are in millimeters and (inches). Pin locations are
for reference only.
Figure 23. Case Temperature Measurement
Location
Note that the view in Figure 23 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 curves shown in Figures 24—25. 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. Figures 24—25 show the maximum power that can be dissipated by the modules
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 25 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?
Tyco Electronics
13
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Data Sheet
March 22, 2000
Thermal Considerations (continued)
6
POWER DISSIPATION, PD (W)
Heat Transfer (continued)
Solution
Given: VI = 75 V, IO = 3.5 A, TA = 85 °C
Determine PD (Figure 29): PD = 4.5 W
Determine airflow (Figure 25): v = 1.0 ms–1
(200 ft./min.)
3
VI = 36 V
VI = 48 V
VI = 75 V
2
1
0.9
1.4
4
1.9
2.4
2.9
3.4
3.9
4.4
4.9
OUTPUT CURRENT, IO (A)
8-2649(C)
3
2
1
0
40
MAX CASE
TEMPERATURE
3.0 ms –1 (600 ft./min.)
2.0 ms –1 (400 ft./min.)
1.0 ms –1 (200 ft./min.)
NATURAL
CONVECTION
Figure 26. LW025D Power Dissipation vs. Output
Current
6
50
60
70
80
90
100
110
MAX AMBIENT TEMPERATURE, TA (°C)
8-2477(C)
Note: Conversion factor for linear feet per minute to meters per
second: 200 ft./min. = 1 ms–1.
Figure 24. LW025D, F, G Forced Convection Power
Derating; Either Orientation
5
4
3
8
MAX CASE TEMPERATURE
VI = 75 V
VI = 48 V
VI = 36 V
2
1
0
0.4
9
POWER DISSIPATION, PD (W)
4
0
0.4
POWER DISSIPATION, PD (W)
POWER DISSIPATION, PD (W)
5
5
0.9
1.4
1.9
2.4
2.9
3.4
3.9
4.4
4.9
OUTPUT CURRENT, IO (A)
8-2645(C)
7
6
Figure 27. LW025G Power Dissipation vs. Output
Current
5
4
3
2
1
0
40
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
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 25. LW025A Forced Convection Power
Derating; Either Orientation
14
Tyco Electronics
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Data Sheet
March 22, 2000
Thermal Considerations (continued)
Module Derating
Heat Transfer (continued)
The derating curves in Figures 24—25 were determined from measurements obtained in an experimental
apparatus shown in Figure 30. 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.
POWER DISSIPATION, PD (W)
6
5
4
FACING PWB
3
PWB
2
VI = 75 V
VI = 48 V
VI = 36 V
1
0
0.4
0.9
1.4
1.9
2.4
2.9
MODULE
3.4
3.9
4.4 4.9
OUTPUT CURRENT, IO (A)
8-2479(C)
Figure 28. LW025F Power Dissipation vs. Output
Current, TA = 25 °C
AIR VELOCITY
AND AMBIENT
TEMPERATURE
MEASURED
BELOW THE
MODULE
POWER DISSIPATION, PD (W)
8
AIRFLOW
76 (3.0)
7
6
VI = 75 V
VI = 48 V
VI = 36 V
5
13 (0.5)
8-1126(C).d
4
Note: Dimensions are in millimeters and (inches).
3
Figure 30. Experimental Test Setup
2
1
0
0.5
Layout Considerations
1
1.5
2
2.5
3
3.5
4
4.5
5
OUTPUT CURRENT, IO (A)
8-1888(C).a
Copper paths must not be routed beneath the power
module standoffs.
Figure 29. LW025A Power Dissipation vs. Output
Current, TA = 25 °C
Tyco Electronics
15
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Data Sheet
March 22, 2000
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)
tyco
50.8
(2.00)
–
IN
+
Function
1
Remote
On/Off
2
No Connection (sync feature optional)
TRIM
ON/OFF
NC
Pin
LW025A871
DC-DC CONVERTER
IN:DC 36-75V, 1.20A
OUT:DC 5.0V, 5.0A
3
VI(–)
4
VI(+)
5
Case Pin
(pin optional)
6
Trim
7
– Output
8
+ Output
–
OUT
+
MADE IN USA
VDE
TUV Rheinland
CASE PIN
(OPTIONAL)
Side View
0.38 ± 0.13
(0.015 ± 0.005)
9.91 ± 0.38
(0.390 ± 0.015)
Bottom View
1.02 (0.040) DIA
SOLDER-PLATED BRASS,
ALL PINS
STANDOFFS
1.78 x 0.51 THICK
(0.070 x 0.020),
4 PLACES
4.70 (0.185)
MIN
22.9
(0.90)
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
16
Tyco Electronics
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Data Sheet
March 22, 2000
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
50.8 (2.00)
(2.00)
45.72 (1.800)
12.4
(0.49)
5.08
(0.200)
2.54 (0.100)
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
48 V
48 V
48 V
48 V
Output Voltage
2.0 V
2.5 V
3.3 V
5V
Output Power
10 W
12.5 W
16.5 W
25 W
Device Code
LW025D
LW025G
LW025F
LW025A
Comcode
108413477
108485145
108448234
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 Application Engineer for pricing and availability of options.
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
Tyco Electronics
Device Code Suffix
8
7
6
3
1
17
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Data Sheet
March 22, 2000
Notes
18
Tyco Electronics
Data Sheet
March 22, 2000
Tyco Electronics
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
19
LW025 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 25 W
Data Sheet
March 22, 2000
For additional information, contact your Lucent Technologies Account Manager or the following:
POWER SYSTEMS UNIT: Network Products Group, Lucent Technologies Inc., 3000 Skyline Drive, Mesquite, TX 75149, USA
+1-800-526-7819 (Outside U.S.A.: +1-972-284-2626, FAX +1-888-315-5182) (product-related questions or technical assistance)
INTERNET:
http://www.lucent.com/networks/power
E-MAIL:
techsupport@lucent.com
ASIA PACIFIC:
Lucent Technologies Singapore Pte. Ltd., 750D Chai Chee Road #07-06, Chai Chee Industrial Park, Singapore 469004
Tel. (65) 240 8041, FAX (65) 240 8438
CHINA:
Lucent Technologies (China) Co. Ltd., SCITECH Place No. 22, Jian Guo Men Wai Avenue, Beijing 100004, PRC
Tel. (86) 10-6522 5566 ext. 4187, FAX (86) 10-6512 3634
JAPAN:
Lucent Technologies Japan Ltd., Mori Building No. 21, 4-33, Roppongi 1-Chome, Minato-ku, Tokyo 106-8508, Japan
Tel. (81) 3 5561 5831, FAX (81) 3 5561 1616
LATIN AMERICA: Lucent Technologies Inc., Room 416, 2333 Ponce de Leon Blvd., Coral Gables, FL 33134, USA
Tel. +1-305-569-4722, FAX +1-305-569-3820
EUROPE:
Data Requests: DATALINE: Tel. (44) 7000 582 368, FAX (44) 1189 328 148
Technical Inquiries:GERMANY: (49) 89 95086 0 (Munich), UNITED KINGDOM: (44) 1344 865 900 (Ascot),
FRANCE: (33) 1 40 83 68 00 (Paris), SWEDEN: (46) 8 594 607 00 (Stockholm), FINLAND: (358) 9 4354 2800 (Helsinki),
ITALY: (39) 02 6608131 (Milan), SPAIN: (34) 91 807 1441 (Madrid)
Lucent Technologies Inc. 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.
Copyright © 2000 Lucent Technologies Inc.
All Rights Reserved
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March 22, 2000
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