Data Sheet
August 1998
LW020 Single-Output-Series Power Modules:
36 Vdc to 75 Vdc Inputs; 20 W
The LW020 Single-Output-Series Power Modules use
adv anced, surface-mount technology and deliver high-quality,
compact, dc-dc conversion at an economical price.
Options
■
Choice of remote on/off configuration
■
Case ground pin
■
Synchronization
■
Short pins: 2.79 mm
±
0.25 mm
(0.110 in.
±
0.010 in.)
Features
■
Low profile: 9.91 mm (0.390 in.) with 0.38 mm
(15 mil) standoffs, 9.53 mm (0.375 in.) with
standoffs recessed
■
Wide input voltage range: 36 Vdc to 75 Vdc
■
Overcurrent protection
■
Output overvoltage protection
■
Input-to-output isolation: 1500 Vdc
■
Operating case temperature range: –40
°
C to
+110
°
C
■
Remote on/off
■
Output voltage adjustment: 90% to 110% of V
O, nom
■
UL
* 1950 Recognized,
CSA
†
C22.2 No. 950-95
Certified, EN60950, IEC950, and VDE0805
Licensed (except LW020G)
■
CE mark meets 73/23/EEC and 93/68/EEC
directives
‡
(except LW020G)
■
Within FCC and VDE Class A radiated limits
Applications
■
Distributed Power Architectures
■
Telecommunications
Description
The LW020 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 outputs are isolated from the
input, allowing versatile polarity configurations and grounding connections. Built-in filtering for both input and
output minimizes the need for external filtering. The modules hav e a maxim um po wer r ating of 20 W at a typical
full-load efficiency of up to 85%.
*
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.)
2 Lucent Technologies Inc.
Data Sheet
August 1998
36 Vdc to 75 Vdc Inputs; 20 W
LW020 Single-Output-Series Power Modules:
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.
* Maximum case temperature varies based on power dissipation. See derating curve, Figure 16, for details.
Electrical Specifications
Unless otherwise indicated, specifications apply over all operating input voltage, resistive load, and temperature
conditions.
Table 1. Input Specifications
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 fus-
ing is not included; however, to achieve maximum safety and system protection, always use an input line fuse.
The safety agencies require a normal-blow, dc 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.
Parameter Symbol Min Max Unit
Input Voltage:
Continuous
Transient (100 ms) V
I
V
I, trans
0
080
100 Vdc
V
Operating Case Temperature
(See Derating Curve, Figure 16.) T
C
–40 110*
°
C
Storage Temperature T
stg
–40 120
°
C
I/O Isolation Voltage — — 1500 Vdc
Parameter Symbol Min Typ Max Unit
Operating Input Voltage V
I
36 48 75 Vdc
Maximum Input Current
(V
I
= 0 V to V
I, max
; I
O
= I
O, max
; see Figure 1.) I
I, max
— — 1.1 A
Inrush Transient i
2
t — — 0.1 A
2
s
Input Reflected-ripple Current
(50 Hz to 20 MHz; 12
µ
H source impedance,
T
C
= 25
°
C; see Figure 11.)
I
I
— 3 — mAp-p
Input Ripple Rejection (100 Hz—120 Hz) — — 60 — dB
Lucent Technologies Inc. 3
Data Sheet
August 1998 36 Vdc to 75 Vdc Inputs; 20 W
LW020 Single-Output-Series Power Modules:
Electrical Specifications
(continued)
Table 2. Output Specifications
Parameter Device Symbol Min Typ Max Unit
Output Voltage Set Point
(V
I
= 48 V; I
O
= I
O, max
; T
C
= 25
°
C) LW020G
LW020F
LW020A
LW020B
LW020C
V
O, set
V
O, set
V
O, set
V
O, set
V
O, set
2.46
3.25
4.92
11.81
14.76
2.5
3.3
5.0
12.0
15.0
2.54
3.35
5.08
12.19
15.24
Vdc
Vdc
Vdc
Vdc
Vdc
Output Voltage
(Over all line, load, and temperature
conditions until end of life; see Figure 13.)
LW020G
LW020F
LW020A
LW020B
LW020C
V
O
V
O
V
O
V
O
V
O
2.4
3.20
4.85
11.64
14.55
—
—
—
—
—
2.6
3.40
5.15
12.36
15.45
Vdc
Vdc
Vdc
Vdc
Vdc
Output Regulation:
Line (V
I
= 36 V to 75 V)
Load (I
O
= I
O, min
to I
O, max
)
Temperature (T
C
= –40
°
C to +100
°
C)
All
All
All
—
—
—
—
—
—
0.01
0.05
0.5
0.1
0.2
1.0
%V
O
%V
O
%V
O
Output Ripple and Noise
(See Figure 12.):
RMS
Peak-to-peak (5 Hz to 20 MHz)
LW020A, F, G
LW020B, C
LW020A, F, G
LW020B, C
—
—
—
—
—
—
—
—
—
—
20
50
20
50
100
150
mVrms
mVrms
mVp-p
mVp-p
Output Current
(At I
O
< I
O, min
, the modules may exceed
output ripple specifications.)
LW020A, F, G
LW020B
LW020C
I
O
I
O
I
O
0.4
0.17
0.13
—
—
—
4.0
1.67
1.33
A
A
A
Output Current-limit Inception
(V
O
= 90% x V
O, set
; see Figure 2.) All I
O
103 — 150 %I
O
,
max
Output Short-circuit Current
(V
O
= 250 mV) LW020C
LW020B
LW020A, F, G
I
O
I
O
I
O
—
—
—
150
150
150
250
220
200
%I
O
,
max
%I
O
,
max
%I
O
,
max
Efficiency
(V
I, nom
; I
O
= I
O, max
; T
C
= 25
°
C; see Figures
3—7 and 13.)
LW020G
LW020F
LW020A
LW020B
LW020C
η
η
η
η
η
71
74
77
82
82
75
77
81
85
85
—
—
—
—
—
%
%
%
%
%
Switching Frequency All — — 265 — kHz
Dynamic Response
(
∆
I
O
/
∆
t = 1 A/10
µ
s, V
I
= V
I, nom
, T
A
= 25
°
C):
Load Change from I
O
= 50% to 75% of
I
O, max
:
Peak Deviation
Settling Time (V
O
< 10% peak
deviation)
Load Change from I
O
= 50% to 25% of
I
O, max
:
Peak Deviation
Settling Time (V
O
< 10% peak
deviation)
All
All
All
All
—
—
—
—
—
—
—
—
1
0.5
1
0.5
—
—
—
—
%V
O, set
ms
%V
O, set
ms
4 Lucent Technologies Inc.
Data Sheet
August 1998
36 Vdc to 75 Vdc Inputs; 20 W
LW020 Single-Output-Series Power Modules:
Electrical Specifications (continued)
Table 3. Isolation Specifications
General Specifications
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 Min Typ Max Unit
Isolation Capacitance — 0.002 — µF
Isolation Resistance 10 — — MΩ
Parameter Min Typ Max Unit
Calculated MTBF (IO = 80% of IO, max; TC = 40 °C) 4,500,000 hours
Weight — — 54 (1.9) g (oz.)
Parameter Device Symbol Min Typ Max Unit
Remote On/Off Signal Interface:
(VI = 0 V to VI, max; open collector or equivalent
compatible; signal referenced to VI(–) terminal.
See Figure 14 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)
All
All
All
All
All
Ion/off
Von/off
Von/off
Ion/off
Von/off
—
–0.7
—
—
—
—
—
—
—
—
1.0
1.2
10
50
1.2
mA
V
V
µA
V
Lucent Technologies Inc. 5
Data Sheet
August 1998 36 Vdc to 75 Vdc Inputs; 20 W
LW020 Single-Output-Series Power Modules:
Feature Specifications (continued)
Parameter Device Symbol Min Typ Max Unit
Turn-on Delay and Rise Times
(at 80% of IO, max; T A = 25 °C):
Case 1: On/Off Input Is Set f or 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)
All
All
All
All
Tdelay
Tdelay
Trise
—
—
—
—
—
27
2
1.5
—
50
10
3.0
5
ms
ms
ms
%
Output Voltage Set-point Adjustment Range LW020B
All others —
—83
90 —
—110
110 %VO, nom
%VO, nom
Output Overvoltage Protection (clamp) LW020G
LW020F
LW020A
LW020B
LW020C
VO, clamp
VO, clamp
VO, clamp
VO, clamp
VO, clamp
2.9
3.9
5.6
13.2
16.5
—
—
—
—
—
3.8
5.0
7.0
16.5
20.0
V
V
V
V
V
66 Lucent Technologies Inc.
Data Sheet
August 1998
36 Vdc to 75 Vdc Inputs; 20 W
LW020 Single-Output-Series Power Modules:
Characteristics Curves
8-1481(C).a
Figure 1. LW020 Typical Input Characteristics,
TA = 25 °C
8-1258(C).a
Figure 2. LW020A, B, C, F, and G Typical Output
Characteristics, TA = 25 °C
8-1260(C).a
Figure 3. LW020A Typical Converter Efficiency vs.
Output Current
8-1484(C)
Figure 4. LW020B Typical Converter Efficiency vs.
Output Current, TA = 25 °C
10 20 30 40 50 60
0.0
0.8
INPUT VOLTAGE, V
I
(
V
)
0.6
0.5
0.4
0.7
INPUT CURRENT, I
I
(A)
1
.
0
70 800
0.9
0.3
0.2
0.1
P
O
= 20 W
P
O
= 10 W
P
O
= 2 W
0
100%
V
O
, nom
80%
V
O
, nom
40%
V
O
, nom
20%
V
O
, nom
60%
V
O
, nom
NORMALIZED OUTPUT CURRENT, I
O
(
A
)
NORMALIZED OUTPUT VOLTAGE, V
O
(V)
V
I
= 75
V
I
= 54
V
I
= 36
50%
I
O
, max 100%
I
O
, max 150%
I
O
, max
0
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
72
73
74
75
76
77
OUTPUT CURRENT, IO (A)
78
79
80
81
EFFICIENCY, (%)
82
VI = 36
VI = 54
VI = 75
0.2 0.4 0.6 0.8 1.0 1.2
70
OUTPUT CURRENT, IO
(
A
)
84
EFFICIENCY, (%)
86
1.4 1.60.0
82
80
78
VI = 75
VI = 54
VI = 36
76
74
72
Lucent Technologies Inc. 7
Data Sheet
August 1998 36 Vdc to 75 Vdc Inputs; 20 W
LW020 Single-Output-Series Power Modules:
Characteristics Curves (continued)
8-1485(C)
Figure 5. LW020C Typical Converter Efficiency vs.
Output Current, TA = 25 °C
8-1483(C)
Figure 6. LW020F Typical Converter Efficiency vs.
Output Current, TA = 25 °C
0.2 0.4 0.6 0.8 1.0 1.2
70
OUTPUT CURRENT, I
O
(
A
)
84
EFFICIENCY, (%)
86
0.0
82
80
78 V
I
= 75
V
I
= 54
V
I
= 36
76
74
72
88
0.5 1.0 1.5 2.0 2.5 3.0
70
OUTPUT CURRENT, I
O
(
A
)
79
78
77
EFFICIENCY, (%)
80
3.5 4.00.0
76
75
74 V
I =
75
V
I =
54
V
I =
36
73
72
71
8-1483(C).a
Figure 7. LW020G Typical Converter Efficiency vs.
Output Current, TA = 25 °C
8-1262(C).a
Figure 8. LW020A, B, C, F, and G Typical Output
Voltage for a Step Load Change from
50% to 75%
1.4 1.9 2.4 2.9 3.4
60
OUTPUT CURRENT, I
O
(
A
)
74
EFFICIENCY, (%)
76
3.90.4
72
62
70
64 V
I
= 36 V
V
I
= 48 V
V
I
= 75 V
68
66
0.9
NORMALIZED
OUTPUT CURRENT, I
O
(A) NORMALIZED
OUTPUT VOLTAGE, V
O
(V)
50%
I
O
, max
100%
V
O
, nom
99%
V
O
, nom
75%
I
O
, max
TIME, t (100 µs/div)
88 Lucent Technologies Inc.
Data Sheet
August 1998
36 Vdc to 75 Vdc Inputs; 20 W
LW020 Single-Output-Series Power Modules:
Characteristics Curves (continued)
8-1261(C).b
Figure 9. LW020A, B, C, F, and G Typical Output
Voltage for a Step Load Change from
50% to 25%
8-1263(C).b
Figure 10. LW020A, B, C, F, and G Typical Output
Voltage Start-Up when Signal Applied to
Remote On/Off
Test Configurations
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 11. Input Reflected-Ripple Test Setup
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 12.Peak-to-Peak Output Noise
Measurement Test Setup
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.
Figure 13. Output Voltage and Efficiency
Measurement Test Setup
TIME, t (100 µs/div)
NORMALIZED
OUTPUT VOLTAGE, VO (V)
NORMALIZED
OUTPUT CURRENT, IO (A)
101%
VO, nom
100%
VO, nom
50%
IO, max
25%
IO, max
TIME, t (1 ms/div)
NORMALIZED
OUTPUT VOLTAGE, V
O
(1 V/div)
0
100%
V
O
, nom
50%
V
O
, nom
5V
0
REMOTE ON/OFF,
V
on/off
(V) (2 V/div)
TO OSCILLOSCOPE
12 µH
C
S
220 µF
IMPEDANCE < 0.1 Ω
@ 20 °C, 100 kHz
V
I
(+)
V
I
(–)
BATTERY 33 µF
CURRENT
PROBE
L
TEST
V
O
(+)
V
O
(–)
RESISTIVE
LOAD
SCOPE
0.1 µF
COPPER STRIP
V
I
(+)
V
I
(–)
V
O
(+)
V
O
(–)
I
I
I
O
SUPPLY
CONTACT RESISTANCE
CO
NTA
C
T AND
DISTRIBUTION LOSSES
LOAD
ηVO(+) VO(–)–[]IO
VI(+) VI(–)–[]II
------------------------------------------------
100
×=
Lucent Technologies Inc. 9
Data Sheet
August 1998 36 Vdc to 75 Vdc Inputs; 20 W
LW020 Single-Output-Series Power Modules:
Design Considerations
Input Source Impedance
The power module should be connected to a low ac-
impedance input source. Highly inductive source
impedances can affect the stability of the power mod-
ule. For the test configuration in Figure 11, a 33 µF
electrolytic capacitor (ESR < 0.7 Ω at 100 kHz)
mounted close to the power module helps ensure sta-
bility 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
22.2 No. 950-95, EN60950, and
IEC950.
For the converter output to be considered meeting the
requirements of saf ety extr a-low v oltage (SELV), one of
the following must be true:
■All inputs are SELV and floating, with the output also
floating.
■All inputs are SELV and grounded, with the output
also grounded.
■Any non-SELV input must be provided with rein-
f orced insulation from an y other hazardous voltages,
including the ac mains, and must have a SELV reli-
ability test performed on it in combination with the
converters. Inputs must meet SELV requirements.
If the input meets extra-low voltage (ELV) require-
ments, then the converter’s output is considered ELV.
The input to these units is to be provided with a maxi-
mum 5 A normal-blow fuse in the ungrounded lead.
Feature Descriptions
Overcurrent Protection
To provide protection in a fault (output overload) condi-
tion, the unit is equipped with internal current-limiting
circuitry and can endure current limiting for an unlim-
ited 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.
Output Overvoltage Protection
The output overvoltage clamp consists of control cir-
cuitry, independent of the primary regulation loop, that
monitors the voltage on the output terminals. The con-
trol loop of the shutdown has a higher v oltage 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.
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. Negativ e logic remote on/off, device code suf-
fix “1”, 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 Fig-
ure 14). A logic low is Von/off = 0 V to 1.2 V. The maxi-
mum 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 leak-
age 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 gen-
erally needed and may degrade the start-up character-
istics of the module.
8-758(C).a
Figure 14. Remote On/Off Implementation
+
Ion/off
–
Von/off
REMOTE
ON/OFF
VI(+)
VI(–)
10 Lucent Technologies Inc.
Data Sheet
August 1998
36 Vdc to 75 Vdc Inputs; 20 W
LW020 Single-Output-Series Power Modules:
Feature Descriptions (continued)
Output V oltage Adjustment
Output voltage trim allows the user to increase or decrease the output voltage set point of a module. This is accom-
plished by connecting an external resistor between the TRIM pin and either the VO(+) or VO(–) pins. With an exter-
nal 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), V O, adj increases.
The following equations determine the required external resistor value to obtain an output voltage change of ∆%:
The adjusted output voltage cannot exceed 110% of the nominal output voltage between the VO(+) and VO(–) termi-
nal.
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.
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 LW020 Single-Output-Series power module operates 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 remo ved b y conduction, con vection, and r adiation 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 15.
Device abcd –5% VO Radj-down +5% VO Radj-up
LW020A 4.02 16.90 2.01 2.0 19.3 kΩ23.3 kΩ
LW020B 15.40 15.40 1.58 9.80 246.5 kΩ16.0 kΩ
LW020C 21.50 16.90 1.76 12.24 356.3 kΩ18.2 kΩ
LW020F 14.0 51.10 5.19 2.70 110.9 kΩ52.8 kΩ
LW020G 14.0 51.10 7.02 2.0 75.3 kΩ88.9 kΩ
Radj-down cd 1 ∆%–()1–•[]
∆%
---------------------------------------------------- b–kΩ=
Radj-up a
d∆
•%
------------------- b–kΩ=
Lucent Technologies Inc. 11
Data Sheet
August 1998 36 Vdc to 75 Vdc Inputs; 20 W
LW020 Single-Output-Series Power Modules:
Thermal Considerations (continued)
8-1265(C)
Note: Dimensions are in millimeters and (inches).
Figure 15. Case Temperature Measurement
Location
Note that the view in Figure 15 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 T ransfer
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
e xceeding 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 com-
ponents in the system. Therefore, the natural convec-
tion 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 LW020A
operating at nominal line, an output current of 3.6 A,
and a maximum ambient temperature of 85 °C?
Solution:
Given: VI = 48 V, IO = 3.6 A, TA = 85 °C
Determine PD (Figure 17): PD = 4.5 W
Determine airflow (Figure 16): v = 1.0 ms–1
(200 ft./min.)
8-1264(C).a
Note: Conversion factor for linear feet per minute to meters per
second: 200 ft./min. = 1 ms–1.
Figure 16. Forced Convection Power Derating;
Either Orientation
8-1275(C).a
Figure 17. LW020A Power Dissipation vs. Output
Current
19.6
(0.77)
TRIM
–
+
OUT
ON/OFF
NC
+
–
IN LW020A81
DC-DC CONVERTER
MADE IN USA
IN:DC 36-75V, 1.1A
OUT:DC 5.0V, 4A
Lucent
CASE PIN
(
OPTIONAL
)
26.9
(1.06)
TUV Rheinland
40 60 100
0
2
MAX AMBIENT TEMPERATURE, TA (°C)
POWER DISSIPATION, PD (W)
50 70 80 90
1
3
4
5
110 120
6
7
3.0 ms –1 (600 ft./min.)
2.0 ms –1 (400 ft./min.)
MAX CASE
TEMPERATURE
NATURAL
CONVECTION
1.0 ms –1 (200 ft./min.)
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
0
1
OUTPUT CURRENT, IO (A)
2
3
4
5
POWER DISSIPATION, PD (W)
6
VI = 75
VI = 48
VI = 36
1212 Lucent Technologies Inc.
Data Sheet
August 1998
36 Vdc to 75 Vdc Inputs; 20 W
LW020 Single-Output-Series Power Modules:
Thermal Considerations (continued)
Heat T ransfer (continued)
8-1479(C)
Figure 18. LW020B Power Dissipation vs. Output
Current, TA = 25 °C
8-1477(C)
Figure 19. LW020C Power Dissipation vs. Output
Current, TA = 25 °C
8-1478(C).a
Figure 20. LW020F and G Power Dissipation vs.
Output Current, TA = 25 °C
Thermal Measurements
The derating curves in Figure 16 were obtained from
measurements obtained in an experimental apparatus
shown in Figure 21. 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.
8-1126(C).d
Note: Dimensions are in millimeters and (inches).
Figure 21. Experimental Test Setup
0.80.4
OUTPUT CURRENT, IO
(
A
)
2
1
5
1.0 1.60.0 0.6
VI = 54
3
0.2
4
VI = 36
VI = 75
1.2 1.4
6
0
POWER DISSIPATION, PD (W)
0.80.4
0.0
OUTPUT CURRENT, I
O
(
A
)
3.0
2.5
2.0
POWER DISSIPATION, P
D
(W)
4
.5
1.0 1.20.0
1.5
1.0
0.5
0.6
V
I
= 54
3.5
0.2
4.0
V
I
= 36
V
I
= 75
1.4 1.9 2.4 2.9 3.4
0.5
OUTPUT CURRENT, I
O
(
A
)
4.0
POWER DISSIPATION, P
D
(W)
4.5
3.90.4
3.5
1.0
3.0
1.5 V
I
= 36 V
V
I
= 48 V
V
I
= 75 V
2.5
2.0
0.9
AIR VELOCITY
AND AMBIENT
TEMPERATURE
MEASURED
BELOW THE
MODULE
AIRFLOW
13 (0.5)
FACING PWB
MODULE
76 (3.0)
PWB
Lucent Technologies Inc. 13
Data Sheet
August 1998 36 Vdc to 75 Vdc Inputs; 20 W
LW020 Single-Output-Series Power Modules:
Outline Diagram
Dimensions are in millimeters and (inches). Copper paths must not be routed beneath the pow er module standoffs.
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.
8-1198(C).g
T op View Pin Function
1 Remote
On/Off
2 No Connec-
tion (sync fea-
ture optional)
3V
I(–)
4V
I(+)
5 Case Pin
(pin optional)
6Trim
7 – Output
8 + Output
Side View
Bottom View
TRIM
–
ON/OFF
NC
LW020A81
DC-DC CONVERTER
+
OUT
Lucent
50.8
(2.00)
50.8 (2.00)
CASE PIN (OPTIONAL)
+
–
MADE IN USA
IN:DC 36-75V, 1.1A
OUT:DC 5.0V, 4A
IN
4
1
2
3
6
7
8
5
2.5 (0.10)
22.9
(0.90)
5.08 (0.200)
5.08 (0.200)
5.08
(0.200)
2.5 (0.10) REF
20.3 (0.80)
10.16 (0.400)
10.16 (0.400)
45.72 ± 0.38
(1.800 ± 0.015)
5.08
(0.200)
1.02 (0.040) DIA
SOLDER-PLATED BRASS,
ALL PINS
9.91 ± 0.38
(0.390 ± 0.015)
STANDOFFS
4.70 (0.185)
MIN 1.78 x 0.51 THICK
(0.070 x 0.020),
4 PLACES
0.38 ± 0.13
(0.015 ± 0.005)
TUV Rheinland
14 Lucent Technologies Inc.
Data Sheet
August 1998
36 Vdc to 75 Vdc Inputs; 20 W
LW020 Single-Output-Series Power Modules:
Recommended Hole Pattern
Component-side footprint.
Dimensions are in millimeters and (inches).
8-1198(C).g
Ordering Information
Table 4. Device Codes
Optional f eatures may be ordered using the de vice code suffix es sho wn. To order more than one option, list suffix es
in numerically descending order. Please contact your Lucent Technologies Network Products Group Account Man-
ager or Application Engineer for pricing and availability of options.
Table 5. Options
Input V oltage Output V oltage Output Power Device Code Comcode
48 V 2.5 V 10 W L W020G 108258195
48 V 3.3 V 13.2 W L W020F 107640807
48 V 5 V 20 W L W020A 107314304
48 V 12 V 20 W L W020B 107681033
48 V 15 V 20 W L W020C 107640799
Option Device Code Suffix
Short pin: 2.79 mm ± 0.25 mm
(0.110 in. ± 0.010 in.) 8
Case ground pin 7
Synchronization 3
Negative remote on/off logic 1
CASE OUTLINE
DRILL HOLE OF APPROX.
2.54 (0.100) DIAMETER
TO RECESS STANDOFFS
IF LOWER HEIGHT IS NEEDED
5.08
(0.200)
12.7
(0.50) 2.54 (0.100)
50.8 (2.00)
10.16
(0.400)
20.32
(0.800)
37.8
(1.49)
3.43
(0.135) 38.86
(1.530)
7.62 (0.300)
12.4
(0.49)
17.78
(0.700)
50.8
(2.00)
45.72 (1.800)
15.24
(0.600)
2.5
(0.10)
Lucent Technologies Inc. 15
Data Sheet
August 1998 36 Vdc to 75 Vdc Inputs; 20 W
LW020 Single-Output-Series Power Modules:
Notes
Data Sheet
August 1998
36 Vdc to 75 Vdc Inputs; 20 W
LW020 Single-Output-Series Power Modules:
Copyright © 1998 Lucent Technologies Inc.
All Rights Reserved
Printed in U.S.A.
August 1998
DS97-280EPS (Replaces DS94-171EPS) Printed On
Recycled Paper
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 +1-972-284-2900) (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., 750A Chai Chee Road #05-01, Chai Chee Industrial Park, Singapore 469001
Tel. (65) 240 8041, FAX (65) 240 8053
JAPAN: Lucent Technologies Japan Ltd., 7-18, Higashi-Gotanda 2-chome, Shinagawa-ku, Tokyo 141-0022, Japan
Tel. (81) 3 5421 1600, FAX (81) 3 5421 1700
LATIN AMERICA: Lucent Technologies Inc., Room 9N128, One Alhambra Plaza, Coral Gables, FL 33134, USA
Tel. +1-305-569-4722, FAX +1-305-569-3820
EUROPE: Data Requests: DATALINE: Tel. (44) 1189 324 299, FAX (44) 1189 328 148
Technical Inquiries:GERMANY: (49) 89 95086 0 (Munich), UNITED KINGDOM: (44) 1344 865 900 (Bracknell),
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.
