Data Sheet
September 1997
FW150F Power Module:
dc-dc Converter; 36 to 72 Vdc Input, 3.3 Vdc Output; 99 W
The FW150F Power Module uses advanced, surface-mount
technology and delivers high-quality, compact, dc-dc
conversion at an economical price.
Applications
■
Distributed and redundant power architectures
■
Telecommunications
Features
■
Wide input range
■
High efficiency: 75% typical
■
Parallel operation with load sharing
■
Low profile: 12.7 mm (0.5 in.)
■
Complete input and output filtering
■
Constant frequency
■
Case ground pin
■
Input-to-output isolation
■
Remote sense
■
Remote on/off
■
Short-circuit protection
■
Output overvoltage clamp
■
UL
* Recognized,
CSA
†
Certified, VDE Licensed
*
UL
is a registered trademark of Underwriters Laboratories, Inc.
†
CSA
is a registered trademark of Canadian Standards Association.
Options
■
Output voltage set-point adjustment (trim)
Description
The FW150F Po wer Module is a dc-dc conv erter that operates ov er an input v oltage r ange of 36 Vdc to 72 Vdc
and provides a precisely regulated dc output. The output is fully isolated from the input, allowing versatile polar-
ity configurations and grounding connections. The module has a maximum power rating of 99 W at a typical
full-load efficiency of 75%.
Built-in filtering, for both the input and output, 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 for high-temperature applications.
2 Lucent Technologies Inc.
Data Sheet
September 1997
dc-dc Converter; 36 to 72 Vdc Input, 3.3 Vdc Output; 99 W
FW150F Power Module:
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; ho wever, 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 20 A (see Saf ety 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
— 72 Vdc
I/O Isolation Voltage — — 500 V
Operating Case Temperature
(See Thermal Considerations section and
Figure 17.)
T
C
090
°
C
Storage Temperature T
stg
–40 125
°
C
Parameter Symbol Min Typ Max Unit
Operating Input Voltage V
I
36 48 72 Vdc
Maximum Input Current (V
I
= 0 V to 72 V): I
I, max
— — 4.2 A
Inrush Transient i
2
t — — 1.0 A
2
s
Input Reflected-ripple Current, Peak-to-peak
(5 Hz to 20 MHz, 12
µ
H source impedance)
(See Figure 8.)
— — 20 — mAp-p
Input Ripple Rejection (120 Hz) — — 60 — dB
Lucent Technologies Inc. 3
Data Sheet
September 1997 dc-dc Converter; 36 to 72 Vdc Input, 3.3 Vdc Output; 99 W
FW150F Power Module:
Electrical Specifications
(continued)
Table 2. Output Specifications
Parameter Symbol Min Typ Max Unit
Output Voltage
(Over all operating input voltage, resistive load,
and temperature conditions until end of life; see
Figure 9 and Feature Descriptions.)
V
O
3.140 — 3.460 Vdc
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 9 and
Feature Descriptions.)
PARALLEL Pin Open
V
O, set
V
O, set
3.230
3.230
3.300
3.300
3.370
3.432
Vdc
Vdc
Output Regulation:
Line (V
I
= 36 V to 72 V)
Load (I
O
= I
O, min
to I
O, max
)
Temperature (T
C
= 0
°
C to 90
°
C)
—
—
—
—
—
—
0.05
0.1
10
0.2
0.4
50
%
%
mV
Output Ripple and Noise Voltage:
RMS
Peak-to-peak (5 Hz to 20 MHz) —
——
——
—35
100 mVrms
mVp-p
Output Current
(At I
O
< I
O, min
, the modules may exceed output
ripple specifications.): I
O
1 — 30 A
Output Current-limit Inception
(V
O
= 3.0 V; see F eature Descriptions .) I
O, cli
103 — 130 % I
O, max
Output Short-circuit Current
(V
O
= 250 mV) — — 135 170 % I
O, max
External Load Capacitance
(electrolytic, total f or one unit or multiple par alleled
units)
— 0 — 4000
µ
F
Efficiency
(V
I
= 48 V; I
O
= I
O, max
; T
C
= 25
°
C; see Figure 9.)
η
72 75 — %
Dynamic Response
(
∆
I
O
/
∆
t = 1 A/10
µ
s, V
I
= 48 V, T
C
= 25
°
C):
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)
—
—
—
—
—
—
—
—
150
300
150
300
—
—
—
—
mV
µ
s
mV
µ
s
4 Lucent Technologies Inc.
Data Sheet
September 1997
dc-dc Converter; 36 to 72 Vdc Input, 3.3 Vdc Output; 99 W
FW150F Power Module:
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) 920,000 hours
Weight — — 200 (7) g (oz.)
Parameter Symbol Min Typ Max Unit
Remote On/Off Signal Interface
(V
I
= 0 V to 72 V; open collector or equivalent
compatible; signal referenced to V
I
(–) terminal; see
Figure 11 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
µ
A
At V
on/off
= 15 V
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
—
—
—
—
—
—
—
—
5
1.2
1.0
15
50
10
V
mA
V
µ
A
ms
Output Voltage Adjustment
(See Feature Descriptions.):
Output Voltage Remote-sense Range
Output Voltage Set-point Adjustment Range (trim) —
——
90 —
—0.7
110 V
%V
O, nom
Parallel Operation Load Sharing
(See Feature Descriptions.) ———20% I
O, max
Output Overvoltage Clamp V
O, clamp
4.0 4.5 5.0 V
Data Sheet
September 1997
Lucent Technologies Inc. 5
dc-dc Converter; 36 to 72 Vdc Input, 3.3 Vdc Output; 99 W
FW150F Power Module:
Draft Copy Only Lucent Technologies Inc.— Proprietary Use pursuant to Company instructions
Characteristic Curves
The following figures provide typical characteristics for the FW150F Power Module.
8-1489 (C)
Figure 1. Typical FW150F Input Characteristics at
Room Temperature
8-1487 (C)
Figure 2. T ypical FW150F Output Characteristics at
Room Temperature and 48 V Input
8-1486 (C)
Figure 3. Typical FW150F Efficiency vs. Output
Current at Room Temperature
10 20 30 40 50
0.0
INPUT VOLTAGE, V
I
(V)
3.5
3.0
4.0
800
2.5
0.5
1.0
1.5
2.0
60 70
INPUT CURRENT, I
I
(A)
I
O
= 30 A
I
O
= 15 A
5 10152025
–0.5
OUTPUT CURRENT, I
O
(A)
2.5
2.0
1.5
3.0
OUTPUT VOLTAGE, V
O
(V)
3.5
400
1.0
0.5
0.0
30 35
5 10152025
70
OUTPUT CURRENT, I
O
(A)
76
75
74
77
EFFICIENCY, (%)
78
300
V
I
= 36 V
V
I
= 72 V
73
72
71
V
I
= 54 V
6 Lucent Technologies Inc.
Data Sheet
September 1997
dc-dc Converter; 36 to 72 Vdc Input, 3.3 Vdc Output; 99 W
FW150F Power Module:
Draft Copy Only Lucent Technologies Inc.— Proprietary Use pursuant to Company instructions
Characteristic Curves (continued)
8-1506 (C)
Figure 4. Typical FW150F Output Ripple Voltage at
Room Temperature, 48 V Input, and 30 A
Output
8-1504 (C)
Figure 5. Typical FW150F Transient Response to
Step Decrease in Load from 50% to 25%
of Full Load at Room Temperature and
48 V Input (Waveform Averaged to
Eliminate Ripple Component.)
8-1505 (C)
Figure 6. Typical FW150F 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-XXXX (C)
Figure 7. Typical FW150F Start-Up Transient at
Room Temperature, 48 V Input, and 30 A
Output
TIME, t (1 µs/div)
OUTPUT VOLTAGE, V
O
(V)
(50 mV/div)
TIME, t (200 µs/div)
OUTPUT VOLTAGE, V
O
(V)
(50 mV/div)
2.5
17.5
OUTPUT CURRENT, I
O
(A)
(2 A/div)
7.5
12.5
TIME, t (200 µs/div)
OUTPUT CURRENT, I
O
(A)
(5 A/div)
5
25
OUTPUT VOLTAGE, V
O
(V)
(50 mV/div)
10
15
20
3.29
3.35
Lucent Technologies Inc. 7
Data Sheet
September 1997 dc-dc Converter; 36 to 72 Vdc Input, 3.3 Vdc Output; 99 W
FW150F Power Module:
Test Configurations
8-203 (C).l
Note: Measure input reflected-ripple current with a simulated source
inductance (LTEST) of 12 µH. Capacitor CS offsets possible bat-
tery impedance. Measure current as shown above.
Figure 8. Input Reflected-Ripple Test Setup
8-683 (C).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 9. 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 80 mm (3 in.) from the module.
Figure 10. 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 8, 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 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 20 A normal-blow fuse in the ungrounded lead.
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.
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
September 1997
dc-dc Converter; 36 to 72 Vdc Input, 3.3 Vdc Output; 99 W
FW150F Power Module:
Feature Descriptions
Remote On/Off
To turn the power module on and off , the user m ust
supply a s witch to control the v oltage betw een the on/off
terminal and the V
I
(–) terminal (V
on/off
). The switch can be
an open collector or equivalent (see Figure 11). 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 s witch
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 18 V. The maximum allowable
leakage current of the switch at V
on/off
= 18 V is 50
µ
A.
If not using the remote on/off feature, short the
ON/OFF pin to V
I
(–).
8-580 (C).b
Figure 11. 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(–)]
≤
0.7 V
The voltage between the V
O
(+) and V
O
(–) terminals
must not exceed 4.0 V. This limit includes any increase
in voltage due to remote-sense compensation and out-
put voltage set-point adjustment (trim), see Figure 12.
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).e
Figure 12. Effective Circuit Configuration for
Single-Module Remote-Sense Operation
Output Voltage Set-Point 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 13
and Figure 14).
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:
The combination of the output voltage adjustment
range and the output voltage sense range given in the
Feature Specifications table cannot exceed 4.0 V
between the V
O
(+) and V
O
(–) terminals. This limit
includes any increase in voltage due to remote-sense
compensation and output voltage set-point adjustment
(trim), see Figure 12.
+
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 5.620×
VO adj, 5.2–
---------------------------------
k
Ω
=
Rtrim-down VO,
adj
1.25
–
()
5.620
×
5.2 V
O,
adj
–
----------------------------------------------------------- k
Ω
=
Lucent Technologies Inc. 9
Data Sheet
September 1997 dc-dc Converter; 36 to 72 Vdc Input, 3.3 Vdc Output; 99 W
FW150F Power Module:
Feature Descriptions
(continued)
Output Voltage Set-Point Adjustment
(Trim)
(continued)
8-717 (C).c
Figure 13. Circuit Configuration to Trim Up Output
Voltage
8-718 (C).c
Figure 14. 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 15). 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
) 944.3
Ω
8-710 (C).c
Figure 15. 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 16). 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 affect the set point of the
voltage applied to the load. For additional power
requirements, where multiple units are used to dev elop
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 proximity and
directness are necessary for good noise immunity.
When not using the parallel feature, short the
PARALLEL pin to SENSE(–).
8-581 (C)
Figure 16. Wiring Configuration for Redundant
Parallel Operation
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
VO(+)
PARALLEL
SENSE(+)
SENSE(–)
VO(–)
CASE
VI(+)
ON/OFF
VI(–)
VO(+)
PARALLEL
SENSE(+)
SENSE(–)
VO(–)
CASE
VI(+)
ON/OFF
VI(–)
1010 Lucent Technologies Inc.
Data Sheet
September 1997
dc-dc Converter; 36 to 72 Vdc Input, 3.3 Vdc Output; 99 W
FW150F Power Module:
Feature Descriptions
(continued)
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 17.
8-582 (C).c
Note: Top view, measurements shown in millimeters and (inches).
Figure 17. Case Temperature Measurement
Location
The temperature at this location should not exceed
95
°C . The maximum case temperature can be limited to
a low er value for extremely high reliability. The output
pow er of the module should not exceed the r ated power
f or the module as listed in the Ordering Information table .
F or additional information about these modules, refer 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 18. These curves can be used
to determine the appropriate airflow for a given set of
operating conditions. F or 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 18. Power Derating vs. Local Ambient
Temperature and Air Velocity
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 17. Case-to-ambient thermal resis-
tance vs. airflow for various heat sink configurations is
shown in Figure 19 and Figure 20. These curves were
obtained by experimental testing of heat sinks, which
are offered in the product catalog.
TUV Rheinland
6238
PARALLEL
+
SENSE
–
+
OUT
–
TRIM
CASE
ON/OFF
+
–IN
MEASURE CASE
TEMPERATURE HERE
18 (0.7)
76 (3.0)
FW150F9
DC-DC Power Module
IN:DC 48V, 2.9A OUT:DC 3.3V, 30A
99W
MADE IN USA
Lucent
Protected by U.S. Patents: 5,036,452 5,179,365
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.)
θca ∆TC max,
PD
--------------------- TCTA–()
P
D
------------------------
==
Lucent Technologies Inc. 11
Data Sheet
September 1997 dc-dc Converter; 36 to 72 Vdc Input, 3.3 Vdc Output; 99 W
FW150F Power Module:
Thermal Considerations (continued)
Heat Transfer with Heat Sinks (continued)
8-696 (C).a
Figure 19. Heat Sink Resistance Curves; Fins
Oriented Along Width
8-697 (C).a
Figure 20. 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 19 and
Figure 20 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 power dissipated
as heat by the unit for the particular application.
Figure 21 shows typical heat dissipation for a range of
output currents and three voltages for the FW150F.
8-924 (C)
Figure 21. Power Dissipation as Heat vs. Output
Current
Example
If an 85 °C case temperature is desired, what is the
minimum airflow necessary? Assume the FW150F
module is operating at nominal line and an output cur-
rent of 20 A, maximum ambient air temperature of
40 °C, and the heat sink is 0.5 inch.
Solution
Given: VI = 54 V
IO = 20 A
TA = 40 °C
TC = 85 °C
Heat sink = 0.5 inch.
Determine PD by using Figure 21:
PD = 20 W
Then solve the following equation:
Use Figure 19 and Figure 20 to determine air velocity
for the 0.5 inch heat sink. The minimum airflow neces-
sary for the FW150F module depends on heat sink fin
orientation and is shown below:
■0.25 m/s (50 ft./min.) (oriented along width)
■0.30 m/s (60 ft./min.) (oriented along length)
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
V
I
= 36 V
V
I
= 54 V
V
I
= 72 V
0 5 10 15 20 25 30
0
5
10
15
POWER DISSIPATION, P
D
(W)
20
25
30
40
OUTPUT CURRENT, I
O
(A)
35
θca TCTA–()
P
D
------------------------
=
θca 85 40–()
20
------------------------
=
θca 2.25 °C/W=
1212 Lucent Technologies Inc.
Data Sheet
September 1997dc-dc Converter; 36 to 72 Vdc Input, 3.3 Vdc Output; 99 W
FW150F Power Module:
Thermal Considerations (continued)
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 22):
8-1304 (C)
Figure 22. 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.
PDTCTSTA
cs sa
θsa TCTA–()
P
D
------------------------ θcs–=
Lucent Technologies Inc. 13
Data Sheet
September 1997 dc-dc Converter; 36 to 72 Vdc Input, 3.3 Vdc Output; 99 W
FW150F Power Module:
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).d
TUV Rheinland
6238
52.83
(2.080)
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
TRIM
63.5
(2.50)
5.3
(0.21)
55.63 (2.190) 55.63 (2.190)
121.9 (4.80)
FW150F9
DC-DC Power Module
IN:DC 48V, 2.9A OUT:DC 3.3V, 30A
99W
MADE IN USA
Lucent
Protected by U.S. Patents: 5,036,452 5,179,365
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
SIDE MARKING
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
14 Lucent Technologies Inc.
Data Sheet
September 1997
dc-dc Converter; 36 to 72 Vdc Input, 3.3 Vdc Output; 99 W
FW150F Power Module:
Recommended Hole Pattern
Component-side footprint.
Dimensions are in millimeters and (inches).
8-719 (C).d
Ordering Information
Optional TRIM pin is designated by the ending 9 in device code name. For assistance in ordering, please contact
your Lucent Technologies Microelectronics Group Account Manager or Application Engineer.
Input
Voltage Output
Voltage Output
Power Trim
Pin Device
Code Comcode
48 V 3.3 V 99 W Yes FW150F9 107050940
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
September 1997 dc-dc Converter; 36 to 72 Vdc Input, 3.3 Vdc Output; 99 W
FW150F Power Module:
Notes
Data Sheet
September 1997dc-dc Converter; 36 to 72 Vdc Input, 3.3 Vdc Output; 99 W
FW150F Power Module:
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 © 1997 Lucent Technologies Inc.
All Rights Reserved
Printed in U.S.A.
September 1997
DS96-209EPS (Replaces DS93-138EPS) Printed On
Recycled Paper
For additional information, contact your Microelectronics Group Account Manager or the following:
POWER SYSTEMS UNIT: Microelectronics Group, Lucent Technologies Inc., 3000 Skyline Drive, Mesquite, TX 75149
1-800-526-7819 (Outside U.S.A.: 972-284-2626, FAX 972-329-8202) (product-related questions or technical assistance)
INTERNET: http://www.lucent.com/micro
E-MAIL: docmaster@micro.lucent.com
U.S.A.: Microelectronics Group, Lucent Technologies Inc., 555 Union Boulevard, Room 30L-15P-BA, Allentown, PA 18103
1-800-372-2447, FAX 610-712-4106 (In CANADA: 1-800-553-2448, FAX 610-712-4106)
ASIA PACIFIC: Microelectronics Group, Lucent Technologies Singapore Pte. Ltd., 77 Science Park Drive, #03-18 Cintech III, Singapore 118256
Tel. (65) 778 8833, FAX (65) 777 7495
JAPAN: Microelectronics Group, Lucent Technologies Japan Ltd., 7-18, Higashi-Gotanda 2-chome, Shinagawa-ku, Tokyo 141, Japan
Tel. (81) 3 5421 1600, FAX (81) 3 5421 1700
EUROPE: Data Requests: MICROELECTRONICS GROUP 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 41 45 77 00 (Paris), SWEDEN: (46) 8 600 7070 (Stoc kholm), FINLAND: (358) 9 4354 2800 (Helsinki),
ITALY : (39) 2 6601 1800 (Milan), SPAIN: (34) 1 807 1441 (Madrid)
