Data Sheet
June 1997
CW025 Dual Output-Series Power Modules:
36 Vdc to 75 Vdc Input; 25 W
The CW025 Dual Output-Series P o wer Modules use ad v anced,
surface-mount technology and deliver high-quality, compact,
dc-dc conversion at an economical price.
Features
■
Small size: 71.1 mm x 61.0 mm x 12.7 mm
(2.80 in. x 2.40 in. x 0.50 in.)
■
Low output noise
■
Industry-standard pinout
■
Metal case
■
2:1 input voltage range
■
Remote on/off (positive logic)
■
UL
* Recognized,
CSA
†
Certified, and VDE
Licensed
■
Within FCC and CISPR Class A Radiated Limits
■
CE mark meets 73/23/EEC and 93/68/EEC direc-
tives
‡
■
Two tightly regulated outputs
Applications
■
Distributed power architectures
■
Telecommunications
Options
■
Isolated case pin
■
Higher accuracy output voltage clamp set point
■
Short pin: 2.79 mm ± 0.25 mm
(0.110 in. ± 0.010 in.)
■
Heat sink available for extended operation
■
Negative logic remote on/off
Description
The CW025 Dual Output-Series Power Modules are
a family of dc-dc converters that operate over an
input voltage range of 36 Vdc to 75 Vdc and provide
two regulated outputs. These modules off er low noise
levels with industry-standard pinouts in a small foot-
print. Each highly reliable and efficient unit features
remote on/off and current limit.
Each output is individually regulated by its own con-
trol circuit and has an independent overvoltage
clamp. With standard outputs of ±5 V, ±12 V, and
±15 V, the CW025 Dual Output-Series is flexible
enough to provide modified standard units with any
combination of output voltages from 2 V to 15 V.
Efficiency greater than 80%, a wide operating tem-
perature range, and a metal case are additional fea-
tures of these modules.
*
UL
is a registered trademark of Underwriters Laboratories, Inc.
†
CSA
is a registered trademark of Canadian Standards Associa-
tion.
‡ This product is intended for integration into end-use equipment.
All the required procedures for CE marking of end-use equip-
ment should be followed. (The CE mark is placed on selected
products.)
2 Tyco Electronics Corp
Data Sheet
June 1997
36 Vdc to 75 Vdc Input; 25 W
CW025 Dual Output-Series Power Modules:
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 operational 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.
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 (10 ms) V
I
V
I, trans
—
—80
100 Vdc
V
I/O Isolation Voltage
dc
Transient (1 minute) —
——
—500
850 V
V
Operating Case Temperature T
C
–40 100 °C
Storage Temperature T
stg
–55 125 °C
Table 1. Input Specifications
Parameter Symbol Min Typ Max Unit
Operating Input Voltage V
I
36 48 75 Vdc
Maximum Input Current
(V
I
= 0 V to 75 V; I
O
= I
O, max
; see Figure 1.) I
I, max
— — 2.0 A
Inrush Transient i
2
t — — 0.8 A
2
s
Input Reflected-ripple Current, Peak-to-peak
(5 Hz to 20 MHz, 12 µH source impedance;
T
C
= 25 °C; see Figure 11 and Design
Considerations section.)
— — 25 — mAp-p
Input Ripple Rejection (120 Hz) — — 60 — dB
Tyco Electronics Corp 3
Data Sheet
June 1997 36 Vdc to 75 Vdc Input; 25 W
CW025 Dual Output-Series Power Modules:
Electrical Specifications
(continued)
Table 2. Output Specifications
Parameter Device Symbol Min Typ Max Unit
Output Voltage
(Over all operating input voltage,
resistive load, and temperature
conditions until end of life.
See Figure 11.)
CW025AJ-M
CW025BK-M
CW025CL-M
V
O1
V
O2
V
O1
V
O2
V
O1
V
O2
4.80
–4.80
11.40
–11.40
14.25
–14.25
—
—
—
—
—
—
5.25
–5.25
12.60
–12.60
15.75
–15.75
Vdc
Vdc
Vdc
Vdc
Vdc
Vdc
Output Voltage Set Point
(V
I
= 48 V; I
O
= I
O, max
; T
C
= 25 °C) CW025AJ-M
CW025BK-M
CW025CL-M
V
O1, set
V
O2, set
V
O1, set
V
O2, set
V
O1, set
V
O2, set
4.90
–4.90
11.76
–11.76
14.70
–14.70
5.0
–5.0
12.0
–12.0
15.0
–15.0
5.10
–5.10
12.24
–12.24
15.30
–15.30
Vdc
Vdc
Vdc
Vdc
Vdc
Vdc
Output Regulation:
Line (V
I
= 36 V to 75 V)
Load (I
O1
= I
O, min
to I
O, max
, I
O2
= I
O,
max
)
Load (I
O2
= I
O, min
to I
O, max
, I
O1
= I
O,
max
)
Temperature (T
C
= –40 °C to +100
°C)
All
All
All
CW025AJ-M
CW025BK-M
CW025CL-M
—
—
—
—
—
—
—
—
—
—
—
—
0.1
0.1
0.1
15
40
40
0.2
0.4
0.4
70
150
190
%
%
%
mV
mV
mV
Output Ripple and Noise
(See Figure 12.):
RMS
Peak-to-peak (5 Hz to 20 MHz)
CW025AJ-M
CW025BK-M
CW025CL-M
CW025AJ-M
CW025BK-M
CW025CL-M
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
15
20
25
150
200
250
mVrm
s
mVrm
s
mVrm
s
mVp-p
mVp-p
mVp-p
Output Current
(At I
O
< I
O, min
, the modules may
exceed output ripple specifications.)
CW025AJ-M
CW025BK-M
CW025CL-M
I
O1
I
O2
I
O1
I
O2
I
O1
I
O2
0.20
0.20
0.10
0.10
0.08
0.08
—
—
—
—
—
—
2.50
2.50
1.04
1.04
0.83
0.83
A
A
A
A
A
A
Output Current-limit Inception
(V
O
= 90% of V
O, nom
; see Figure 2.) CW025AJ-M
CW025BK-M
CW025CL-M
—
—
—
—
—
—
3.7
1.5
1.3
6.5
2.9
2.7
A
A
A
Output Short-circuit Current
(V
O
= 250 mV) CW025AJ-M
CW025BK-M
CW025CL-M
—
—
—
—
—
—
3.5
1.0
1.0
7.0
3.0
3.0
A
A
A
Efficiency
(V
I
= 48 V; I
O
= I
O, max
; T
C
= 25 °C;
see Figures 3 and 11.)
CW025AJ-M
CW025BK-M
CW025CL-M
η
η
η
75
79
79
78
82
82
—
—
—
%
%
%
44 Tyco Electronics Corp
Data Sheet
June 1997
36 Vdc to 75 Vdc Input; 25 W
CW025 Dual Output-Series Power Modules:
General Specifications
Dynamic Response
(
∆
I
O
/
∆
t = 1 A/10 µs, V
I
= 48 V,
T
C
= 25 °C):
Load Change from I
O
= 50% to 75%
of I
O, max
(See Figures 7 to 9.):
Peak Deviation
Settling Time (V
O
< 10% peak
deviation)
Load Change from I
O
= 50% to 25%
of I
O, max
(See Figures 4 to 6.):
Peak Deviation
Settling Time (V
O
< 10% peak
deviation)
CW025AJ-M
CW025BK-M
CW025CL-M
All
CW025AJ-M
CW025BK-M
CW025CL-M
All
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
160
250
250
3
160
250
250
0.5
—
—
—
—
—
—
—
—
mV
mV
mV
ms
mV
mV
mV
ms
Table 3. Isolation Specifications
Parameter Min Typ Max Unit
Isolation Capacitance — 1200 — pF
Isolation Resistance 10 — — M
Ω
Parameter Min Typ Max Unit
Calculated MTBF (I
O
= 80% of I
O, max
; T
C
= 40 °C) 2,800,000 hours
Weight — — 113 (4.0) g (oz.)
Table 2. Output Specifications
(continued)
Parameter Device Symbol Min Typ Max Unit
Electrical Specifications
(continued)
Tyco Electronics Corp 5
Data Sheet
June 1997 36 Vdc to 75 Vdc Input; 25 W
CW025 Dual Output-Series Power Modules:
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 Device Symbol Min Typ Max Unit
Remote On/Off
(V
I
= 0 V to 75 V; open collector or equivalent
compatible; signal referenced to V
I
(–) terminal.
See Figures 10 and 14 and Feature
Descriptions.):
CW025xx-M Positive Logic:
Logic Low—Module Off
Logic High—Module On
CW025xx1-M Negative Logic:
Logic Low—Module On
Logic High—Module Off
Module Specifications:
On/Off Current—Logic Low
On/Off Voltage:
Logic Low
Logic High (I
on/off
= 0)
Open Collector Switch Specifications:
Leakage Current During Logic High
(V
on/off
= 10 V)
Output Low Voltage During Logic Low
(I
on/off
= 1 mA)
Turn-on Time (I
O
= 80% of I
O, max
; V
O
within
±1% of steady state)
Output Voltage Overshoot
All
All
All
All
All
All
All
I
on/off
V
on/off
V
on/off
I
on/off
V
on/off
—
—
—
0
—
—
—
—
—
—
—
—
—
—
30
0
1.0
1.2
10
50
1.2
—
5
mA
V
V
µA
V
ms
%
Output Overvoltage Clamp CW025AJ
CW025BK
CW025CL
V
O1
V
O2
V
O1
V
O2
V
O1
V
O2
—
—
—
—
—
—
—
—
—
—
—
—
7
–7
16
–16
20
–20
V
V
V
V
V
V
Input Undervoltage Lockout:
Module On
Module Off All
All V
UVLO
V
UVLO
—
20 28
28 36
—V
V
66 Tyco Electronics Corp
Data Sheet
June 1997
36 Vdc to 75 Vdc Input; 25 W
CW025 Dual Output-Series Power Modules:
Characteristic Curves
8-993(C).b
Figure 1.CW025 Dual Output-Series Input Current
and Normalized Output Voltage vs. Input
Voltage at Full Load and T
C
= 25 °C
8-1022(C)
Figure 2.CW025 Dual Output-Series Normalized
Output Current vs. Normalized Output
Voltage at V
I
= 48 V and T
C
= 25 °C
8-1021(C)
Figure 3.CW025 Dual Output-Series Efficiency vs.
Normalized Output Currents (Equal Load
on Both Outputs) at V
I
= 48 V and
T
C
= 25 °C
8-1019(C)
Figure 4.CW025 Dual Output-Series Typical 5 V
Output Voltage Response to a Step Load
Change from 50% to 25% of I
O, ma x
at
V
I
= V
I, nom
and T
C
= 25 °C
0 1020304050 70
0
0.2
0.4
0.6
0.8
1.0
1.2
INPUT VOLTAGE, VI (V)
INPUT CURRENT, II (A)
0.8
0.6
0.4
0.2
0.0
1.0
1.2
VO
II
NORMALIZED OUTPUT VOLTAGE
60
0.0 0.4 0.8 1.2 1.6 2.4
0.0
0.7
0.8
0.9
1.0
1.1
OUTPUT CURRENTS NORMALIZED TO FULL LOAD
NORMALIZED OUTPUT VOLTAGE, V
O
(V)
0.6
0.5
0.4
CW025CL
CW025BK
CW025AJ
0.3
0.2
0.1
2.0
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.9 1.0
50
70
75
80
85
90
OUTPUT CURRENTS NORMALIZED TO FULL LOAD
EFFICIENCY, (%)
0.8
85
60
55
CW025AJ
CW025BK
CW025CL
0.5 A 0.5 ms
50 mV
1.0 A
0.5 A
TIME, t (0.5 ms/div)
5.0 V
∆I
O
∆t= 1 A/10 µs
OUTPUT CURRENT, I
O
(A)
(0.5 A/div) OUTPUT VOLTAGE, V
O
(mV)
(50 mV/div)
Tyco Electronics Corp 7
Data Sheet
June 1997 36 Vdc to 75 Vdc Input; 25 W
CW025 Dual Output-Series Power Modules:
Characteristic Curves
(continued)
8-1017(C)
Figure 5.CW025 Dual Output-Series Typical 12 V
Output Voltage Response to a Step Load
Change from 50% to 25% of I
O, ma x
at
V
I
= V
I, nom
and T
C
= 25 °C
8-527(C)
Figure 6.CW025 Dual Output-Series Typical 15 V
Output Voltage Response to a Step Load
Change from 50% to 25% of I
O, ma x
at
V
I
= V
I, nom
and TC = 25 °C
8-1018(C)
Figure 7.CW025 Dual Output-Series Typical 5 V
Output Voltage Response to a Step Load
Change from 50% to 75% of IO, max at
VI = VI, nom and TC = 25 °C
8-519(C)
Figure 8.CW025 Dual Output-Series Typical 12 V
Output Voltage Response to a Step Load
Change from 50% to 75% of IO, max at
VI = VI, nom and TC = 25 °C
TIME, t (0.5 ms/div)
∆I
O
∆t= 1 A/10 µs
0.416 A
0.208 A
12.0 V
0.2 A 0.5 ms
100 mV
OUTPUT VOLTAGE, V
O
(V)
(0.1 V/div)
OUTPUT CURRENT, I
O
(A)
(0.2 A/div)
∆IO
∆t= 1 A/10 µs
0.333 A
0.166 A
TIME, t (0.5 ms/div)
15.0 V
100 mV
0.2 A 0.5 ms
OUTPUT CURRENT, IO
(0.2 A/div) OUTPUT VOLTAGE, VO
(0.1 V/div)
∆I
O
∆t= 1 A/10 µs
0.5 ms
50 mV
0.5 A
1.5 A
1.0 A
TIME, t (0.5 ms/div)
5.0 V
OUTPUT CURRENT, I
O
(A)
(0.5 A/div) OUTPUT VOLTAGE, V
O
(mV)
(50 mV/div)
0.624 A
0.416 A
TIME, t (0.5 ms/div)
12.0 V
∆I
O
∆t= 1 A/10 µs
0.5 ms0.2 A
100 mV
OUTPUT CURRENT, I
O
(0.2 A/div) OUTPUT VOLTAGE, V
O
(0.1 V/div)
88 Tyco Electronics Corp
Data Sheet
June 1997
36 Vdc to 75 Vdc Input; 25 W
CW025 Dual Output-Series Power Modules:
Characteristic Curves (continued)
8-526(C)
Figure 9.CW025 Dual Output-Series Typical 15 V
Output Voltage Response to a Step Load
Change from 50% to 75% of IO, max at
VI = VI, nom and TC = 25 °C
8-1020(C)
Figure 10. CW025 Dual Output-Series Typical
Output Voltage Rise Time with Remote
On/Off at VI = VI,nom, IO = 0.8 (IO, max) and
TC = 25 °C
Test Configurations
8-489(C)
Note: Input reflected-ripple current is measured with a simulated
source impedance (LTEST) 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
8-808(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 75 mm (3 in.) from the module.
Figure 12. Output Noise Measurement Test Setup
∆I
O
∆t= 1 A/10 µs
OUTPUT VOLTAGE, V
O
(0.1 V/div)
0.500 A
0.333 A
TIME, t (0.5 ms/div)
0.2 A
100 mV
0.5 ms
OUTPUT CURRENT, I
O
(0.2 A/div)
15.0 V
∆I
O
∆t= 1 A/10 µs
2 V
0 V
TIME, t (1 ms/div)
0 V
1 ms
V
O
,
set
NORMALIZED
OUTPUT VOLTAGE, V
O
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
CURRENT
PROBE
L
TEST
V
O1
(+)
V
O2
(–)
SCOPE
0.1 µF
COPPER STRIP
0.1 µF
SCOPE
COMM
R
LOAD1
R
LOAD2
Tyco Electronics Corp 9
Data Sheet
June 1997 36 Vdc to 75 Vdc Input; 25 W
CW025 Dual Output-Series Power Modules:
Test Configurations (continued)
8-863(C).a
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 Measure-
ment Test Setup
Design Considerations
Grounding Considerations
For modules without the isolated case ground pin
option, the case is internally connected to the VI(+) pin.
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. A 33 µF electrolytic capacitor (ESR < 0.7 Ω at
100 kHz) mounted close to the power module helps
ensure stability of the unit.
Note: VI(+) is internally connected to the case for a
standard module.
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, 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 of the dc input:
■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 an SELV reli-
ability test performed on it in combination with the
converters.
The pow er module has e xtr a-low voltage (ELV) outputs
when all inputs are ELV.
The input to these units is to be provided with a maxi-
mum 5 A normal blow fuse in the ungrounded lead.
Input/Output V oltage Reversal
CAUTION: Applying a reverse voltage across the
module input or output forward biases
an internal diode. Attempting to start
the module under this condition can
damage the module.
V
I
(+)
I
I
I
O
SUPPLY
CONTACT
RESISTANCE
CONTACT AND
DISTRIBUTION LOSSES
LOAD
V
I
(–)
V
O1
V
O2
COM
LOAD
η
VOJ COM–[]IOJ
J1=
2
∑
VI +() VI –()–[]II
----------------------------------------------------------------- x 100=
1010 Tyco Electronics Corp
Data Sheet
June 1997
36 Vdc to 75 Vdc Input; 25 W
CW025 Dual Output-Series Power Modules:
Feature Descriptions
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.
Current Limit
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 remote on/off, code suffix “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
Figure 14). A logic low is Von/off = 0 V to 1.2 V. The max-
imum 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 10 V. The maximum allowable
leakage current of the switch at Von/off = 10 V is 50 µA.
8-754(C)
Figure 14. Remote On/Off Implementation
COM LOAD
+
I
on/off
–
V
on/off
ON/OFF
V
I
(+)
V
I
(–)
V
O2
LOAD
V
O1
Data Sheet
June 1997
Tyco Electronics Corp 11
36 Vdc to 75 Vdc Input; 25 W
CW025 Dual Output-Series Power Modules:
Thermal Considerations
8-866(C).a
Note: Dimensions are in millimeters and (inches). Drawing is not to scale.
Figure 15. Thermal Test Setup
50.8
(2.00)
12.7 (0.50)
101.6
(4.00)
203.2 (8.00)
AIRFLOW
MEASURE CASE
TEMPERATURE AT
CENTER OF UNIT
CONNECTORS TO
LOADS, POWER
SUPPLIES, AND
DATALOGGER,
6.35 (0.25) TALL
203.2
(8.00)
9.7 (0.38)
19.1 (0.75)
WIND TUNNEL WALL
AIR VELOCITY PROBE
AMBIENT TEMPERATUR
E
THERMOCOUPLE
AIR-
FLOW
The 25 W dual output power modules are designed to
operate in a variety of thermal environments. As with
any electronic component, sufficient cooling must be
provided to help ensure reliable operation of the unit.
Heat-dissipating components inside the module are
thermally coupled to the case. Heat is removed by con-
duction, convection, and radiation to the surrounding
environment.
The thermal data presented is based on measure-
ments taken in a wind tunnel. The test setup shown in
Figure 15 was used to collect data. Actual perf ormance
can vary depending on the particular application
environment.
Basic Thermal Performance
The CW025 Dual Output-Series P ower Modules have a
separate power stage for each of the outputs. This
means that the maximum operating temperature can
be predicted quite closely by treating each output indi-
vidually and then summing the results. Figures 16
through 19 are used to predict the safe operating con-
dition for many different operating and environmental
conditions.
The method used to determine the maximum ambient
temperature at a given air velocity is a four-step pro-
cess:
1. Find the power dissipated for output 1 by using the
appropriate chart (Figures 16 through 18) for a
particular output condition (IO1).
2. Repeat step 1 for output 2 using Figures 16
through 18.
3. Find the total power dissipated by summing the
power dissipated on each of the outputs: (PDout1 +
PDout2) = PDtotal
4. Use the total power dissipated with Figure 19 to
determine the maximum ambient temperature at
different air velocities.
1212 Tyco Electronics Corp
Data Sheet
June 1997
36 Vdc to 75 Vdc Input; 25 W
CW025 Dual Output-Series Power Modules:
Thermal Considerations (continued)
Basic Thermal Performance (continued)
For example, the CW025AJ-M power module with a
54 V input and 2.5 A output on VO1 and a 1.5 A output
on V O2 will have a power dissipated of 3.6 W (from
Figure 16) plus 2.1 W (from Figure 16) or 5.7 W total.
Using Figure 19, it can be determined that the maxi-
mum ambient temperature at natural convection that
the CW025AJ-M can operate at is approximately
62 °C.
Keep in mind that these are approximations of the air
temperature and velocity required to keep the case
temperature below its maximum rating. The maximum
case temperature at the point shown in Figure 15 m ust
be kept at 100 °C or less.
Air Velocity
The air velocity required to maintain a desired maxi-
mum case temperature for a given power dissipation
and ambient temperature can be calculated by using
Figure 19 and the following equation:
where θCA is the thermal resistance from case-to-ambi-
ent air (°C/W), TC, max is the desired maximum case
temperature (°C), TA is the ambient inlet temperature
(°C), and PDtotal is the total power dissipated from the
module (W).
F or example, to maintain a maximum case temperature
of 85 °C with an ambient inlet temperature of 55 °C and
a power dissipation of 6.7 W, the thermal resistance is:
This corresponds to an air velocity greater than
0.46 ms–1 (90 fpm) in Figure 19.
8-987a(C)
Figure 16. 5 V Output Power Dissipation vs. Output
Current
8-1000(C)
Figure 17. 12 V Output Power Dissipation vs.
Output Current
θCA TC max,TA–
PDtotal
---------------------------------
=
θCA 85°C55°C–
6.7W
----------------------------------
≤4.5°CW⁄=
0 0.5 1.0 1.5 2.0 2.5
0
0.5
1.0
1.5
2.0
4.0
OUTPUT CURRENT, I
O
(
A
)
2.5
3.0
3.5
POWER DISSIPATION, P
D
(W)
V
I
= 54 V
V
I
= 72 V
V
I
= 36 V
0.0 0.2 0.4 0.6 0.8 1.2
0.0
0.5
1.0
1.5
2.0
3.0
OUTPUT CURRENT, IO (A)
2.5
VI = 36 V
VI = 54 V
VI = 72 V
1.0
POWER DISSIPATION, PD (W)
Tyco Electronics Corp 13
Data Sheet
June 1997 36 Vdc to 75 Vdc Input; 25 W
CW025 Dual Output-Series Power Modules:
Thermal Considerations (continued)
Air Velocity (continued)
8-999(C)
Figure 18. 15 V Output Power Dissipation vs.
Output Current
8-988(C)
Figure 19. Total Power Dissipation vs. Local
Ambient Temperature and Air Velocity
8-989(C)
Figure 20. Case-to-Ambient Thermal Resistance vs.
Air Velocity
Use of Heat Sinks and Cold Plates
The CW025 Dual Output-Series case includes through-
threaded M3 x 0.5 mounting holes allowing attachment
of heat sinks or cold plates from either side of the mod-
ule. The mounting torque must not exceed 0.56 N/m
(5 in-lb.).
The following thermal model can be used to determine
the required thermal resistance of the sink to provide
the necessary cooling:
where PD is the power dissipated by the module, θCS
represents the interfacial contact resistance between
the module and the sink, and θSA is the sink-to-ambient
thermal impedance (°C/W). For thermal greases or
foils, a value of θCS = 0.1 °C/W to 0.3 °C/W is typical.
The required θSA is calculated from the following equa-
tion:
Note that this equation assumes that all dissipated
power must be shed by the sink. Depending on the
user-defined application environment, a more accur ate
model including heat transf er from the sides and rear of
the module can be used. This equation provides a con-
servative estimate in such instances.
For further information, refer to the
Thermal Energy
Management CC-, CW-, DC-Series 25 W to 30 W
Board-Mounted Power Modules
Technical Note.
0.0 0.1 0.2 0.3 0.7 0.9
0.0
0.5
1.0
1.5
2.0
3.0
OUTPUT CURRENT, IO (A)
2.5
VI = 36 V
VI = 54 V
VI = 72 V
0.80.4 0.5 0.6
POWER DISSIPATION, PD (W)
40 50 60 90 100
0.0
4.0
5.0
6.0
10.0
LOCAL AMBIENT TEMPERATURE, T
A
(°C)
7.0
8.0
9.0
70 80
3.0
2.0
1.0
2.03 ms
–1
(400 ft./min)
NATURAL
CONVECTION
1.02 ms
–1
(200 ft./min)
TOTAL POWER DISSIPATION, P
D
(W)
0.51 ms
–1
(100 ft./min)
0.31 ms
–1
(60 ft./min)
NAT
CONV 0.25
(50) 0.51
(100) 0.76
(150) 1.78
(350) 2.03
(400)
0.0
1.0
2.0
3.0
7.0
VELOCITY ms
–1
(ft./min.)
4.0
5.0
6.0
1.02
(200) 1.27
(250) 1.52
(300)
THERMAL RESISTANCE CASE
TO AMBIENT (°C/W)
PDθCS
T ATc
l
Ts
θSA
θSA TCTA–
PDtotal
----------------- θCS–=
14 Tyco Electronics Corp
Data Sheet
June 1997
36 Vdc to 75 Vdc Input; 25 W
CW025 Dual Output-Series Power Modules:
Outline Diagrams
Dimensions are in millimeters and (inches).
Copper paths must not be routed beneath the power module standoffs.
Tolerances: x.x ± 0.5 mm (0.02 in.), x.xx ± 0.25 mm (0.010 in.).
Note: For standard modules, VI(+) is internally connected to case.
8-755(C).b
T op View
Side View
Bottom View
61.0
(2.40)
MAX
PIN 1
INDICATOR
DC-DC POWER MODULE
71.1 (2.80) MAX
MADE IN USA
Lucent
M3
ON/OFF
VI(+)
VI(–)
VO2(–)
COM
VO1(+)
12.70 (0.500)
5.08 (0.200)
50.8
(2.00)
61.0
(2.40)
MAX
10.16 (0.400)
15.24 (0.600)
25.40
(1.000)
4.8 (0.19)
24.1
(0.95)
20.32
(0.800)
48.3 (1.90)
63.50 ± 0.38 (2.500 ± 0.015)
71.1 (2.80) MAX
11.4 (0.45)
3.8 (0.15)
5.1 (0.20)
STAND-OFF,
4 PLACES
MOUNTING INSERTS
M3 x 0.5 THROUGH
4 PLACES
7.1 (0.28)
CASE PIN
OPTIONAL
3
2
1
4
5
6
7
1.02 (0.040) ± 0.08 (0.003) DI
A
SOLDER-PLATED BRASS,
6 PLACES
(7 PLACES WITH OPTIONAL
CASE GROUND)
12.7 (0.50)
MAX
5.8 (0.23)
0.51
(0.020)
Tyco Electronics Corp 15
Data Sheet
June 1997 36 Vdc to 75 Vdc Input; 25 W
CW025 Dual Output-Series Power Modules:
Recommended Hole Pattern
Component-side footprint.
Dimensions are in millimeters and (inches).
Recommended hole size for pin: 1.27 mm (0.050 in.).
8-755(C).b
12.70 (0.500)
5.08 (0.200)
61.0
(2.40)
MAX
10.16 (0.400)
15.24 (0.600)
25.40
(1.000)
24.1
(0.95) 20.32
0.800
48.3 (1.90)
63.50 ± 0.38 (2.500 ± 0.015)
71.1 (2.80) MAX
11.4 (0.45)
3.8 (0.15)
5.1 (0.20)
CASE OUTLINE
1
2
3
4
7
6
5
M3 x 0.5 CLEARANCE HOLE
4 PLACES (OPTIONAL)
CASE PIN
OPTIONAL
50.8
(2.00)
Data Sheet
June 1997
36 Vdc to 75 Vdc Input; 25 W
CW025 Dual Output-Series Power Modules:
Printed on
Recycled Paper
Tyco Electronics Power Systems, Inc.
3000 Skyline Drive, Mesquite, TX 75149, USA
+1-800-526-7819 FAX: +1-888-315-5182
(Outside U.S.A.: +1-972-284-2626, FAX: +1-972-284-2900
http://power.tycoeleectronics.com
Tyco Electronics Corportation reserves the right to make changes to the product(s) or information contained herein without notice. No liability is assumed as a result of their use or application.
No rights under any patent accompany the sale of any such product(s) or information.
© 2001 Tyco Electronics Corporation, Harrisburg, PA. All International Rights Reserved.
Printed in U.S.A.
June 1997
DS96-050EPS (Replace DS93-224EPS)
Ordering Information
Table 4. Ordering Information Table
Optional features may be ordered using the device code suffixes shown below. To order more than one option, list
suffixes in numerically descending order followed by the -M suffix, indicating metric (M3 x 0.5 heat sink hardware).
The heat sinks designed f or this package ha ve an M prefix, i.e ., MHSTxxx45 and MHSLxxx45 (see
Thermal Energy
Management CC-, CW-, DC-, and DW-Series 25 W to 30 W Board-Mounted Power Modules
Technical Note).
Table 5. Options Table
Please contact your Tyco Electronics’ Account Manager or Field Application Engineer for pricing and availability.
Input Voltage Output Voltage Output Power Remote On/Off Logic Device Code Comcode
36 V—75 V ±5 V 25 W positive CW025AJ-M 107587230
36 V—75 V ±12 V 25 W positive CW025BK-M 107587248
36 V—75 V ±15 V 25 W positive CW025CL-M 107587255
36 V—75 V ±12 V 25 W negative CW025BK1-M 107637761
Option Device Code Suffix
Short pin: 2.79 mm ± 0.25 mm
(0.110 in. ± 0.010 in.) 8
Isolated case ground pin 7
Negative logic remote on/off 1
