Data Sheet
June 1998
FE050D and FE150D Power Modules: dc-dc Converters;
38 Vdc to 60 Vdc Input, 2 Vdc Output; 20 W to 60 W
The FE050D and FE150D Power Modules use advanced,
surface-mount technology and deliver high-quality, compact,
dc-dc conversion at an economical price.
Applications
■
Redundant and distributed power architectures
■
Telecommunications
Options
■
Output voltage set-point adjustment (trim)
Features
■
High efficiency: 68% typical
■
Parallel operation with load sharing
■
Low profile: 12.7 mm (0.5 in.)
■
Complete input and output filtering
■
Within FCC requirements for Telecom
■
Constant frequency
■
Case ground pin
■
Input-to-output isolation
■
Remote sense
■
Remote on/off
■
Short-circuit protection
■
Output overvoltage clamp
■
UL
* Recognized,
CSA
†
Certified,
TÜV
‡
Licensed
*
UL
is a registered trademark of Underwriters Laboratories, Inc.
†
CSA
is a registered trademark of Canadian Standards Association.
‡
TÜV
is a registered trademark of Technischer Überwachungs-
Verein.
Description
The FE050D and FE150D Power Modules are dc-dc converters that operate over an input voltage range of
38 Vdc to 60 Vdc and provide a precisely regulated dc output. The outputs are fully isolated from the inputs,
allowing versatile polarity configurations and grounding connections. The modules have maximum power rat-
ings from 20 W to 60 W at a typical full-load efficiency of 68%.
Built-in filtering, for both the input and output of each de vice, eliminates the need f or external filters. Two or more
modules may be paralleled with forced load sharing for redundant or enhanced power applications. The
package , which mounts on a printed-circuit board, accommodates a heat sink f or high-temperature applications.
2 Lucent Technologies Inc.
Data Sheet
June 1998
38 Vdc to 60 Vdc Input, 2 Vdc Output; 20 W to 60 W
FE050D and FE150D Power Modules: dc-dc Converters;
Absolute Maximum Ratings
Stresses in excess of the absolute maximum ratings can cause permanent damage to the device. These are abso-
lute stress ratings only. Functional operation of the device 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.
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, alw ays use an input line fuse. The
safety agencies require a normal-blow, dc fuse with a maximum rating of 6 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) V
I
— 60 Vdc
I/O Isolation Voltage — — 500 V
Operating Case Temperature
(See Thermal Considerations section and
Figure 18.)
T
C
090°C
Storage Temperature T
stg
–55 125 °C
Parameter Symbol Min Typ Max Unit
Operating Input Voltage V
I
38 48 60 Vdc
Maximum Input Current (V
I
= 0 V to 60 V):
FE050D
FE150D I
I, max
I
I, max
—
——
—1
2.9 A
A
Inrush Transient i
2
t — — 1.0 A
2
s
Input Reflected-ripple Current, Peak-to-peak
(5 Hz to 20 MHz, 12 µH source impedance)
(See Figure 9.)
— — 20 — mAp-p
Input Ripple Rejection (120 Hz) — — 60 — dB
Lucent Technologies Inc. 3
Data Sheet
June 1998 38 Vdc to 60 Vdc Input, 2 Vdc Output; 20 W to 60 W
FE050D and FE150D Power Modules: dc-dc Converters;
Electrical Specifications
(continued)
Table 2. Output Specifications
Parameter Symbol Min Typ Max Unit
Output Voltage Set Point
(V
I
= 48 V; I
O
= I
O, max
; T
C
= 25 °C):
Unit Operating in Parallel or PARALLEL Pin
Shorted to SENSE(–) (See Figure 10 and
Feature Descriptions.)
PARALLEL Pin Open
V
O, set
V
O, set
1.96
1.96
2.0
2.0
2.04
2.08
Vdc
Vdc
Output Voltage
(Over all operating input voltage, resistive load,
and temperature conditions until end of life; see
Figure 10 and Feature Descriptions.)
V
O
1.90 — 2.10 Vdc
Output Regulation:
Line (V
I
= 36 V to 60 V)
Load (I
O
= I
O, min
to I
O, max
)
Temperature (T
C
= 0 °C to 90 °C)
—
—
—
—
—
—
0.05
0.2
5
0.2
0.4
25
%
%
mV
Output Ripple and Noise Voltage
(See Figure 4 and Figure 11.):
RMS
Peak-to-peak (5 Hz to 20 MHz) —
——
——
—200
500 mVrms
mVp-p
Output Current
(At I
O
< I
O, min
, the modules may exceed output
ripple specifications.):
FE050D
FE150D I
O
I
O
1
1—
—1.8
5.4 A
A
Output Current-limit Inception
(V
O
= 90% of V
O
,
set
; see Figure 2 and Feature
Descriptions.)
— 103 — 130 % I
O, max
Output Short-circuit Current
(V
O
= 250 mV; see Figure 2.) — — 135 170 % I
O, max
External Load Capacitance
(electrolytic, total f or one unit or multiple par alleled
units):
FE050D
FE150D —
—0
0—
—6,000
6,000 µF
µF
Efficiency
(V
I
= 48 V; I
O
= I
O, max
; T
C
= 25 °C;
see Figure 3—Figure 9.)
η
66 68 — %
Dynamic Response
(
∆
I
O
/
∆
t = 1 A/10 µs, V
I
= 48 V, T
C
= 25 °C; see
Figure 6 and Figure 7.):
Load Change from I
O
= 50% to 75% of I
O, max
:
Peak Deviation
Settling Time (V
O
< 10% of peak deviation)
Load Change from I
O
= 50% to 25% of I
O, max
:
Peak Deviation
Settling Time (V
O
< 10% of peak deviation)
—
—
—
—
—
—
—
—
500
100
500
100
—
—
—
—
mV
µs
mV
µs
4 Lucent Technologies Inc.
Data Sheet
June 1998
38 Vdc to 60 Vdc Input, 2 Vdc Output; 20 W to 60 W
FE050D and FE150D Power Modules: dc-dc Converters;
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 for further information.
Parameter Min Typ Max Unit
Isolation Capacitance — 1700 — pF
Isolation Resistance 10 — — M
Ω
Parameter Min Typ Max Unit
Calculated MTBF (I
O
= 80% of I
O, max
; T
C
= 40 °C) 2,000,000 hours
Weight — — 200 (7) g (oz.)
Parameter Symbol Min Typ Max Unit
Remote On/Off Signal Interface
(V
I
= 0 V to 60 V; open collector or equivalent
compatible; signal referenced to V
I
(–) terminal; see
Figure 12 and Feature Descriptions.):
Logic Low—Module On
Logic High—Module Off
Logic Low:
At I
on/off
= 1.0 mA
At V
on/off
= 0.0 V
Logic High:
At I
on/off
= 0.0 µA
Leakage Current
Turn-on Time
(I
O
= 80% of I
O, max
; V
O
within ±1% of steady state)
V
on/off
I
on/off
V
on/off
I
on/off
—
0
—
—
—
—
—
—
—
—
50
1.2
1.0
18
50
100
V
mA
V
µA
ms
Output Voltage Adjustment
(See Feature Descriptions.):
Output Voltage Remote-sense Range
Output Voltage Set-point Adjustment Range (trim) —
——
90 —
—1.2
110 V
%V
O, nom
Parallel Operation Load Sharing
(See Feature Descriptions.) ———20% I
O, max
Output Overvoltage Clamp V
O, clamp
2.6 3.0 3.3 V
Lucent Technologies Inc. 5
Data Sheet
June 1998 38 Vdc to 60 Vdc Input, 2 Vdc Output; 20 W to 60 W
FE050D and FE150D Power Modules: dc-dc Converters;
Characteristic Curves
The f ollowing figures pro vide typical characteristics f or the FE150D Pow er Module. The FE050D characteristics are
similar to the FE150D characteristics provided here, scaled by power level where appropriate.
8-774 (C)
Figure 1. Typical FE150D Input Characteristics at
Room Temperature
8-775 (C)
Figure 2. Typical FE150D Output Characteristics
at Room Temperature and 48 V Input
8-777 (C)
Figure 3. Typical FE050D Efficiency vs. Output
Current at Room Temperature
8-776 (C)
Figure 4. Typical FE150D Efficiency vs. Output
Current at Room Temperature
3.0
INPUT CURRENT, I
I
(A)
–0.5010203040
INPUT VOLTAGE, V
I
(V)
1.0
0.0
50
2.5
60
0.5
1.5
2.0
I
O
= 30 A
I
O
= 15 A
2.5
OUTPUT VOLTAGE, V
O
(V)
0.00 5 10 15 20
OUTPUT CURRENT, I
O
(A)
1.5
0.5
25
2.0
40
1.0
30 35
75
EFFICIENCY, η (%)
55
5012345 7
OUTPUT CURRENT, I
O
(A)
65
60
6
70
891
0
V
I
= 38 V
V
I
= 60 V
V
I
= 48 V
72
EFFICIENCY, η (%)
62
600 5 10 15 20
OUTPUT CURRENT, I
O
(A)
68
64
25
70
30
66
V
I
= 38 V
V
I
= 60 V
V
I
= 48 V
66 Lucent Technologies Inc.
Data Sheet
June 1998
38 Vdc to 60 Vdc Input, 2 Vdc Output; 20 W to 60 W
FE050D and FE150D Power Modules: dc-dc Converters;
Characteristic Curves
(continued)
8-778 (C)
Figure 5. T ypical FE150D Output Ripple Voltage at
Room Temperature, 48 V Input, and 30 A
Output
8-779 (C)
Figure 6. Typical FE150D Transient Response to
Step Decrease in Load from 50% to 25%
of Full Load at Room Temperature and
48 V Input (Waveform Averaged to Elimi-
nate Ripple Component.)
TIME, t (1 µs/div)
20 mV 1 µs
OUTPUT
CURRENT
,
V
O
(V)
(20 mV/div)
50 µs
50 mV
7.5
15.5
TIME, t (50 µs/div)
OUTPUT CURRENT, IO (A)
(2 A/div) OUTPUT VOLTAGE, VO (V)
(50 mV/div)
8-780 (C)
Figure 7. Typical FE150D Transient Response to
Step Increase in Load from 50% to 75% of
Full Load at Room Temperature and 48 V
Input (Waveform Averaged to Eliminate
Ripple Component.)
8-1955 (C)
Figure 8. Typical FE150D Start-Up Transient at
Room Temperature, 48 V Input, and
30 A Output
7.5
15.5
OUTPUT VOLTAGE, VO (V)
(50 mV/div)
OUTPUT CURRENT, IO (A)
(2 A/div)
TIME, t (50 µs/div)
50 mV 50 µs
TIME, t
(
1 ms/div
)
OUTPUT VOLTAGE, VO (V)
(500 mV/div)
Lucent Technologies Inc. 7
Data Sheet
June 1998 38 Vdc to 60 Vdc Input, 2 Vdc Output; 20 W to 60 W
FE050D and FE150D Power Modules: dc-dc Converters;
Test Configurations
8-203 (C).l
Note: Measure input reflected-ripple current with a simulated source
inductance (L
TEST
) of 12 µH. Capacitor CS offsets possible bat-
tery impedance. Measure current as shown above.
Figure 9. Input Reflected-Ripple Test Setup
8-683 (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 10. Output Voltage and Efficiency
Measurement 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 (2 in.) and 76 mm (3 in.) from the module.
Figure 11. Peak-to-Peak Output Noise
Measurement Test Setup
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 9, 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
22.2-950, and EN60950.
For the converter output to be considered meeting the
requirements of safety extra-low voltage (SELV), the
input 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 6 A normal-blow fuse in the ungrounded lead.
TO OSCILLOSCOPE
12 µH V
I
(+)
V
I
(–)
CURRENT
PROBE
L
TEST
BATTERY C
S
220 µF
ESR < 0.1 Ω
@ 20 °C, 100 kHz 33 µF
ESR < 0.7 Ω
@ 100 kHz
V
I
(–)
V
O
(+)
PARALLEL
SENSE(+)
SENSE(–)
V
O
(–)
V
I
(+) I
O
LOAD
CONTACT AND
DISTRIBUTION LOSSES
SUPPLY I
I
CONTACT
RESISTANCE
ηVO+()
–
V
O
–
()[]
I
O
V
I
+
()
–
V
I
–
()[]
I
I
--------------------------------------------------
x
100=
V
O
(+)
V
O
(–)
RESISTIVE
LOAD
SCOPE
0.1 µF
COPPER STRIP
88 Lucent Technologies Inc.
Data Sheet
June 1998
38 Vdc to 60 Vdc Input, 2 Vdc Output; 20 W to 60 W
FE050D and FE150D Power Modules: dc-dc Converters;
Electrical Descriptions
Current Limit
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.
Feature Descriptions
Remote On/Off
To turn the pow er module on and off , the user m ust
supply a s witch to control the v oltage between the on/off
terminal and the V
I
(–) terminal (V
on/off
). The switch can be
an open collector or equivalent (see Figure 12). A logic
low is V
on/off
= 0 V to 1.2 V, during which the module is on.
The maximum I
on/off
during a logic low is 1 mA. The switch
should maintain a logic-low v oltage while sinking 1 mA.
During a logic high, the maximum V
on/off
generated by
the power module is 15 V. The maximum allowable
leakage current of the switch at V
on/off
= 15 V is 50 µA.
If not using the remote on/off feature, short the
ON/OFF pin to V
I
(–).
8-580 (C).b
Figure 12. Remote On/Off Implementation
Remote Sense
Remote sense minimizes the effects of distribution
losses by regulating the voltage at the remote-sense
connections. For single-unit operation, the PARALLEL
pin should be connected to SENSE(–). The voltage
between the remote-sense pins and the output termi-
nals must not exceed the output voltage sense range
given in the Feature Specifications table, i.e.:
[V
O
(+) – V
O
(–)] – [SENSE(+) – SENSE(–)]
≤
2.8 V
The voltage between the V
O
(+) and V
O
(–) terminals
must not exceed the minimum output overvoltage
clamp voltage as indicated in the Feature Specifica-
tions table. This limit includes any increase in voltage
due to remote-sense compensation and output voltage
set-point adjustment (trim), see Figure 13.
If not using the remote-sense f eature to regulate the out-
put at the point of load, connect SENSE(+) to V
O
(+) and
SENSE(–) to V
O
(–) at the module.
8-651 (C)
Figure 13. Effective Circuit Configuration for
Single-Module Remote-Sense Operation
Output Voltage Set-P oint Adjustment (Trim)
When not using the trim feature , leav e the TRIM pin open.
Adjustment with TRIM Pin
Output voltage adjustment allows the output voltage
set point to be increased or decreased by adjusting an
external resistor connected between the TRIM pin and
either the SENSE(+) or SENSE(–) pins (see Figure 14
and Figure 15).
Connecting the external resistor (R
trim-up
) between the
TRIM and SENSE(–) pins (V
O , adj
) increases the output
voltage set point as defined in the following equation:
Connecting the external resistor (R
trim-down
) between
the TRIM and SENSE(+) pins (V
O
,
adj
) decreases the
output voltage set point as defined in the following
equation:
+
Ion/off
–
Von/off
CASE
ON/OFF
VI(+)
VI(–)
PARALLEL
SENSE(+)
SENSE(–)
VO(+)
VO(–)
V
O
(+)
PARALLEL
SENSE(+)
SENSE(–)
V
O
(–)
V
I
(+)
V
I
(–)
I
O
LOAD
CONTACT AND
DISTRIBUTION LOSSES
SUPPLY I
I
CONTACT
RESISTANCE
Rtrim-up 1.25 6.810×
VO adj,2–
---------------------------------
k
Ω
=
Rtrim-down VO,
adj
1.25
–
()
6.810
×
2V
O,
adj
–
-----------------------------------------------------------
k
Ω
=
Lucent Technologies Inc. 9
Data Sheet
June 1998 38 Vdc to 60 Vdc Input, 2 Vdc Output; 20 W to 60 W
FE050D and FE150D Power Modules: dc-dc Converters;
Feature Descriptions
(continued)
Output V oltage Set-Point Adjustment (T rim)
(continued)
Adjustment with TRIM Pin
(continued)
The voltage between the V
O
(+) and V
O
(–) terminals
must not exceed the minimum output overvoltage
clamp voltage as indicated in the Feature Specifica-
tions table. This limit includes any increase in voltage
due to remote-sense compensation and output voltage
set-point adjustment (trim), see Figure 13.
8-717 (C).c
Figure 14. Circuit Configuration to Trim Up Output
Voltage
8-718 (C).c
Figure 15. Circuit Configuration to Trim Down
Output V oltage
Adjustment Without TRIM Pin
The output voltage can be adjusted by placing an
external resistor (R
adj
) between the SENSE(+) and
V
O
(+) terminals (see Figure 16). By adjusting R
adj
, the
output voltage can be increased b y 10% of the nominal
output voltage. The equation below shows the
resistance required to obtain the desired output
voltage.
R
adj
= (V
O, adj
– V
O, nom
) 2775
Ω
8-710 (C).c
Figure 16. Circuit Configuration to Adjust Output
Voltage
Forced Load Sharing (Parallel Operation)
For either redundant operation or additional power
requirements, the po wer modules can be configured for
parallel operation with forced load sharing (see Figure
17). For a typical redundant configuration, Schottky
diodes or an equivalent should be used to protect
against short-circuit conditions. Because of the remote
sense, the forward-voltage drops across the Schottky
diodes do not aff ect the set point of the voltage applied
to the load. For additional power requirements, where
multiple units are used to develop combined power in
excess of the rated maximum, the Schottky diodes are
not needed.
Good layout techniques should be observed for noise
immunity. To implement forced load sharing, the follow-
ing connections must be made:
■
The parallel pins of all units must be connected
together. The paths of these connections should be
as direct as possible.
■
All remote-sense pins should be connected to the
power bus at the same point, i.e., connect all
SENSE(+) pins to the (+) side of the power b us at the
same point and all SENSE(–) pins to the (–) side of
the power b us at the same point. Close pro ximity and
directness are necessary for good noise immunity.
V
O
(+)
PARALLEL
SENSE(+)
SENSE(–)
V
O
(–)
V
I
(+)
V
I
(–)
I
O
LOAD
CONTACT AND
DISTRIBUTION LOSSES
SUPPLY I
I
CONTACT
RESISTANCE
TRIM R
trim-up
V
O
(+)
PARALLEL
SENSE(+)
SENSE(–)
V
O
(–)
V
I
(+)
V
I
(–)
I
O
LOAD
CONTACT AND
DISTRIBUTION LOSSES
SUPPLY I
I
CONTACT
RESISTANCE
TRIM R
trim-down
V
O
(+)
PARALLEL
SENSE(+)
SENSE(–)
V
O
(–)
V
I
(+)
V
I
(–) I
O
LOAD
CONTACT AND
DISTRIBUTION LOSSES
SUPPLY I
I
CONTACT
RESISTANCE
R
adj
1010 Lucent Technologies Inc.
Data Sheet
June 1998
38 Vdc to 60 Vdc Input, 2 Vdc Output; 20 W to 60 W
FE050D and FE150D Power Modules: dc-dc Converters;
Feature Descriptions
(continued)
Forced Load Sharing (Parallel Operation)
(continued)
When not using the parallel feature, short the
PARALLEL pin to SENSE(–).
8-581 (C)
Figure 17. Wiring Configuration for Redundant
Parallel Operation
Output Overvoltage Clamp
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 clamp has a higher voltage set point
than the primary loop (see Feature Specifications
table). This provides a redundant voltage-control that
reduces the risk of output overvoltage.
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 occurs
at the position indicated in Figure 18.
8-582 (C).m
Note: Top view, measurements shown in millimeters and (inches).
Figure 18. Case Temperature Measurement
Location
The temperature at this location should not exceed
95 °C. The maximum case temper ature can be limited to
a lower value for extremely high reliability. The output
power of the module should not exceed the rated power
f or the module as listed in the Ordering Information table.
For additional information about these modules, ref er to
the Lucent Technologies
Thermal Management for
High-Power Board-Mounted Power Modules
Technical
Note (TN97-009EPS).
Heat Transfer Without Heat Sinks
Derating curves for forced-air cooling without a heat
sink are shown in Figure 19. These curv es can be used
to determine the appropriate airflow for a given set of
operating conditions. For e xample , if the unit dissipates
20 W of heat, the correct airflow in a 40 °C en vironment
is 1.0 m/s (200 ft./min.).
8-587 (C)
Figure 19. Power Derating vs. Local Ambient
Temperature and Air Velocity
V
O
(+)
PARALLEL
SENSE(+)
SENSE(–)
V
O
(–)
CASE
V
I
(+)
ON/OFF
V
I
(–)
V
O
(+)
PARALLEL
SENSE(+)
SENSE(–)
V
O
(–)
CASE
V
I
(+)
ON/OFF
V
I
(–)
+
SENSE
–
+
OUT
–
CASE
ON/OFF
+
–IN
FE150D9
DC-DC Power Module
MADE IN USA
MEASURE CASE
TEMPERATURE HERE
76 (3.0)
18 (0.7)
Lucent
IN:DC 48V, 2.0A OUT:DC 2V, 30A
60W
Protected by U.S. Patents: 5,036,452 5,179,365
TRIM
PARALLEL
TUV Rheinland
30
POWER DISSIPATION, PD (W)
LOCAL AMBIENT TEMPERATURE, TA (°C)
20
10
020406080
40
100
0
0.1 m/s (20 ft./min.)
NATURAL CONVECTION
0.5 m/s (100 ft./min.)
1.0 m/s (200 ft./min.)
1.5 m/s (300 ft./min.)
2.0 m/s (400 ft./min.)
2.5 m/s (500 ft./min.)
3.0 m/s (600 ft./min.)
3.5 m/s (700 ft./min.)
4.0 m/s (800 ft./min.)
Lucent Technologies Inc. 11
Data Sheet
June 1998 38 Vdc to 60 Vdc Input, 2 Vdc Output; 20 W to 60 W
FE050D and FE150D Power Modules: dc-dc Converters;
Thermal Considerations (continued)
Heat Transfer with Heat Sinks
The power modules have threaded #4-40 fasteners,
which enable heat sinks or cold plates to be attached to
the module. The mounting torque must not exceed
0.56 N-m (5 in.-lb.).
Thermal derating with heat sinks is expressed b y using
the ov er all thermal resistance of the module. Total mod-
ule thermal resistance (θca) is defined as the maximum
case temperature rise (∆TC, max) divided by the module
power dissipation (PD):
The location to measure case temperature (TC) is
shown in Figure 18. Case-to-ambient thermal resis-
tance vs. airflow for various heat sink configurations is
shown in Figure 20 and Figure 21. These curves were
obtained by experimental testing of heat sinks, which
are offered in the product catalog.
8-696 (C).a
Figure 20. Heat Sink Resistance Curves; Fins
Oriented Along Width
8-697 (C).a
Figure 21. Heat Sink Resistance Curves; Fins
Oriented Along Length
These measured resistances are from heat transfer
from the sides and bottom of the module as well as the
top side with the attached heat sink; therefore, the
case-to-ambient thermal resistances shown are gener-
ally lower than the resistance of the heat sink by itself.
The module used to collect the data in Figure 20 and
Figure 21 had a thermal-conductive dry pad between
the case and the heat sink to minimize contact resis-
tance.
To choose a heat sink, determine the pow er dissipated
as heat by the unit for the particular application.
Figure 22 shows typical heat dissipation for a range of
output currents and three voltages for the FE050D and
FE150D.
θca ∆TC max,
PD
---------------------TCTA–()
PD
------------------------
==
5.0
4.0
3.0
2.0
1.0
0.0
NAT
CONV 0.5
(100) 1.0
(200) 1.5
(300) 2.0
(400) 2.5
(500)
THERMAL RESISTANCE, (°C/W)
AIR VELOCITY MEASURED IN m/s (ft./min.)
NO HEAT SINK
0.5 in. HEAT SINK
1 in. HEAT SINK
0.25 in. HEAT SINK
5.0
4.0
3.0
2.0
1.0
0.0
NAT
CONV 0.5
(100) 1.0
(200) 1.5
(300) 2.0
(400) 2.5
(500)
THERMAL RESISTANCE, (°C/W)
AIR VELOCITY MEASURED IN m/s (ft./min.)
NO HEAT SINK
0.5 in. HEAT SINK
1 in. HEAT SINK
0.25 in. HEAT SINK
1212 Lucent Technologies Inc.
Data Sheet
June 1998
38 Vdc to 60 Vdc Input, 2 Vdc Output; 20 W to 60 W
FE050D and FE150D Power Modules: dc-dc Converters;
Thermal Considerations (continued)
Heat Transfer with Heat Sinks (continued)
8-1954 (C)
Figure 22. Power Dissipation vs. Output Current
Example
If an 85 °C case temperature is desired, what is the
minimum airflow necessary? Assume the FE150D
module is operating at nominal line and an output cur-
rent of 25.5 A, maximum ambient air temperature of
40 °C, and the heat sink is 0.5 inch.
Solution
Given: VI = 49 V
IO = 25.5 A
TA = 40 °C
TC = 85 °C
Heat sink = 0.5 inch.
Determine PD by using Figure 22:
PD = 24 W
Then solve the following equation:
Use Figure 20 and Figure 21 to determine air velocity
for the 0.5 inch heat sink. The minimum airflow neces-
sary for the FE150D module depends on heat sink fin
orientation and is shown below:
■0.4 m/s (80 ft./min.) (oriented along width)
■0.45 m/s (90 ft./min.) (oriented along length)
Custom Heat Sinks
A more detailed model can be used to determine the
required thermal resistance of a heat sink to provide
necessary cooling. The total module resistance can be
separated into a resistance from case-to-sink (θcs) and
sink-to-ambient (θsa) shown below (Figure 23.):
8-1304 (C)
Figure 23. Resistance from Case-to-Sink and Sink-
to-Ambient
For a managed interface using thermal grease or foils,
a value of θcs = 0.1 °C/W to 0.3 °C/W is typical. The
solution for heat sink resistance is:
This equation assumes that all dissipated power must
be shed by the heat sink. Depending on the user-
defined application environment, a more accurate
model, including heat transfer from the sides and bot-
tom of the module, can be used. This equation provides
a conservative estimate for such instances.
Layout Considerations
Copper paths must not be routed beneath the power
module standoffs.
5 10152025
0
25
OUTPUT CURRENT, I
O
(
A
)
15
10
20
POWER DISSIPATION, P
D
(W)
35
3
0
0
30
5
V
I
= 60 V
V
I
= 49 V
V
I
= 38 V
θca TCTA–()
PD
------------------------
=
θca 85 40–()
24
------------------------
=
θca 1.88 °C/W=
PDTCTSTA
cs sa
θsa TCTA–()
PD
-------------------------θcs–=
Lucent Technologies Inc. 13
Data Sheet
June 1998 38 Vdc to 60 Vdc Input, 2 Vdc Output; 20 W to 60 W
FE050D and FE150D Power Modules: dc-dc Converters;
Outline Diagram
Dimensions are in millimeters and (inches).
Tolerances: x.x mm ± 0.5 mm (x.xx in. ± 0.02 in.),
x.xx mm ± 0.25 mm (x.xxx in. ± 0.010 in.)
T op View
Side View
Bottom View
8-719 (C).p
TUV Rheinland
121.9 (4.80)
52.83
(2.080)
55.63 (2.190)
5.3
(0.21)
FOR OPTIONAL HEAT SINK MOUNTING
#4-40 THD 4.6 (0.18) DEEP
6 PLCS
PARALLEL
+
SENSE
–
+
OUT
–
CASE
ON/OFF
+
–IN
FE150D9
DC-DC Power Module
MADE IN USA
TRIM
Lucent
5.3
(0.21)
63.5
(2.50) IN:DC 48V, 2.0A OUT:DC 2V, 30A
60W
Protected by U.S. Patents: 5,036,452 5,179,365
55.63 (2.190)
TRIM OPTION ONLY
3.8 (0.15)
TYP 8 PLCS
12.7
(0.50)
4.1
(0.16 )
1.0 (0.04)
1.57 (0.062) ± 0.05 (0.002) DIA
TIN-PLATED BRASS
TYP 12 PLCS
S
IDE MARKIN
G
12.2
(0.48)
4.3 (0.17)
5.08
(0.200)
10.16
(0.400)
15.24
(0.600)
113.54 (4.470)
30.48
(1.200) 35.56
(1.400)
25.40
(1.000)
20.32
(0.800)
TRIM OPTION ONLY
1414 Lucent Technologies Inc.
Data Sheet
June 1998
38 Vdc to 60 Vdc Input, 2 Vdc Output; 20 W to 60 W
FE050D and FE150D Power Modules: dc-dc Converters;
Recommended Hole Pattern
Component-side footprint.
Dimensions are in millimeters and (inches).
8-719 (C).p
Ordering Information
This family of modules is not recommended f or ne w designs . For ne w designs w e recommend the JFW f amily
of power modules. Please refer to the Lucent Technologies Power Systems Selection Guide or to individual data
sheets. For further assistance you may call the Lucent Technologies Power Systems Technical Hotline
(1-800-526-7819 or 972-284-2626).
Optional TRIM pin is designated by the ending 9 in device code name.
Input
Voltage Output
Voltage Output
Power Trim Device
Code Comcode
48 V 2 V 20 W Yes FE050D9 Not Available
48 V 2 V 60 W Yes FE150D9 Not Available
48 V 2 V 20 W No FE050D 106468244
48 V 2 V 60 W No FE150D 106258338
12.2
(0.48)
4.3 (0.17)
10.16
(0.400)
15.24
(0.600)
5.08
(0.200)
113.54 (4.470)
20.32
(0.800)
25.40
(1.000)
30.48
(1.200)
35.56
(1.400)
TRIM OPTION ONLY
PARALLEL
+
SENSE
–
+
OUT
–
TRIM
CASE
ON/OFF
+
–IN
Lucent Technologies Inc. 15
Data Sheet
June 1998 38 Vdc to 60 Vdc Input, 2 Vdc Output; 20 W to 60 W
FE050D and FE150D Power Modules: dc-dc Converters;
Notes
Data Sheet
June 1998
38 Vdc to 60 Vdc Input, 2 Vdc Output; 20 W to 60 W
FE050D and FE150D Power Modules: dc-dc Converters;
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 +1-972-329-8202) (product-related questions or technical assistance)
INTERNET: http://www.lucent.com
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 48 83 68 00 (Paris), SWEDEN: (46) 8 600 7070 (Stoc kholm), FINLAND: (358) 9 4354 2800 (Helsinki),
ITALY : (39) 2 6608131 (Milan), SPAIN: (34) 1 807 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 © 1998 Lucent Technologies Inc.
All Rights Reserved
Printed in U.S.A.
June 1998
DS97-534EPS (Replaces DS92-059EPS) Printed On
Recycled Paper
