DC025ABK-M - M/A-COM Technology Solutions, Inc.

Data Sheet

June 1997

DC 025 Triple Output-Series Power Mod ules:

18 Vdc to 36 Vdc Input; 25 W

Th e D C025 Trip le O u tput- Seri es Po wer Modules us e

advanced, surface-mount technology and deliver high-quality ,

co mp ac t , dc- d c conver sion at an ec onomica l pr ice.

Features

■Sm all 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

■Indust ry-standard pino ut

■Metal case with separate case ground pin

■2:1 input voltage range

■Remote on/ off (positive logic)

■

* Recognized,

CSA

† Certified, and VDE

Licensed

■Within FCC and CISPR Class A Radiated Limits

Applications

■Distributed power architectures

■Telecommunications

Options

■Higher accuracy output v oltage clamp set point

■Short pins: 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 DC025 Triple Output-Series Power Modules are

dc-dc converters that operate over an input vol tage

range of 18 Vdc to 36 Vdc and provide three outputs.

These modules offer extrem ely low noise levels with

industry-standard pinouts in a small footprint. Each

highly reliable and efficient unit f eatures remote

on/off and current limit.

The maximum total output pow er of the DC025 Triple

Output-Series Power Modules i s li mited to 25 W. The

main output (VO1) is designed to deliver the ent ire

25 W. The auxiliar y out put s (VO2 and VO3) can pro-

vide a total of 22. 5 W as long as the total output

power does not exceed 25 W.

Efficiency greater than 8 0%, a wide operating tem-

perature range, and a metal case are additional fea-

tures of these modules.

is a registered trad emark of Underwriters Laboratories, Inc.

†

CSA

is a registered trademark of Canadian Standards Associa-

tion.

22 Tyco Electronics Corp.

Data Sheet

June 1997

18 Vdc to 36 Vdc Input; 25 W

DC025 Triple Output-Series Power Modules:

Absolute Maximum Ratings

Stresses in e x cess 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 section s of the data s hee t. Exposure to absolute maximu m ratings for extend ed

period s can adverse ly affect device r eliability.

Electrical Specifications

Unless otherwise indicated, specifications apply to all modules over all operating input vol tage, resistiv e load, and

temperature conditions.

Fusing Consideration s

CAUTION: This power module is not internally fused. An inp ut line fuse must a lways be used.

This encapsulate d power m odul e can be used in a wide varie ty of applications, ranging from simple stand-alone

operation to an integrated part of a s ophisticate d power archi tecture. To preser ve maximum flexibility, internal fus-

ing is not included; how ever, to achieve maximum saf ety and system protection, alwa ys use an input line fuse . The

safety agencies require a nor mal-blow, dc fuse with a maximum rati ng of 5 A in series wit h the ungrounded input

lead. Based on the infor m at ion provided in this data sheet on inrush energy and maximum dc input current, the

same type of fuse wit h a lower rating can be used. Refer to the fuse manufacturer’s data for fur t her informat ion.

Parameter Symbol Min Max Unit

Input Voltage Continuous VI—50V

I/O Isolation Voltage:

Transient (1 minute) —

——

—500

850 V

Operating Case Temperatu re TC–40 100 °C

Storage Temperature Tstg –55 125 °C

Table 1. Input Specifications

Parameter Symbol Min Typ Max Unit

Operating Input Vo ltage VI18 28 36 Vdc

Maximum Input Current

(VI = 0 V to 36 V; IO = IO, max; see Figure 1.) II, max ——3.0A

Inrush Trans ient i2t——0.2A

Input Reflected-ripple Current, Peak-to-peak

(5 Hz to 20 MHz, 12 µH source impedance;

TC = 25 °C; see Figure 18 and Design

Considerations section.)

——30—mAp-p

Input Ripple Rejection (120 Hz) — — 60 — dB

Tyco Electronics Corp. 3
Data Sheet
June 1997 18 Vdc to 36 Vdc Input; 25 W
DC025 Triple Output-Series Power Modules:
Electrical Specifications (continued) 
Table 2. Output Speci fications
Parameter Device Symbol Min Typ Max Unit
Outp ut Vol tage
(Over all operating input voltage,  resistive 
load, and temperature conditions until end 
of life. See Figure 20.)
DC025ABK-M
DC025ACL-M
VO1
VO2
VO3
VO1
VO2
VO3
4.80
10.80
–10.80
4.80
13.77
–13.77
—
—
—
—
—
—
5.20
13.70
–13.70
5.20
17.20
–17.20
Vdc
Vdc
Vdc
Vdc
Vdc
Vdc
Output Voltage Set Point 
(VI = 28 V; TC = 25 °C; IO1 = 2.0  A, 
IO2 = IO3 = 0.5 A)
DC025ABK-M
DC025ACL-M
VO1, se t
VO2, se t
VO3, se t
VO1, se t
VO2, se t
VO3, se t
4.90
11.83
–11.83
4.90
14.84
–14.84
5.00
12.20
–12.20
5.00
15.30
–15.30
5.10
12.57
–12.57
5.10
15.76
–15.76
Vdc
Vdc
Vdc
Vdc
Vdc
Vdc
Outp ut Regulation:
Line (VI = 18 V to 36 V)
Load (See Figures 5—8.) 
(IO1 = IO, min to IO, max, IO2 = IO3 = IO, min)
Temperature (See Figures 2—4.)
(TC = –40 °C to +100 °C)
All
All
All
—
VO1
VO1
—
—
—
0.1
0.1
0.5
0.2
0.2
1.5
%
%
%
Outp ut Ripple and Noise 
(See Figure 19.):
RMS
Peak-to-peak  (5 Hz t o 20 MHz)
All
All
VO1
VO2, VO3
VO1
VO2, VO3
—
—
—
—
—
—
—
—
25
30
100
150
mVrms
mVrms
mVp-p
mVp-p
Outp ut Current
(At IO < IO,  mi n, the m odule s may exceed 
output ripple specifications.)
DC025ABK-M
DC025ACL-M
IO1
IO2, IO3
IO1
IO2, IO3
0.5
0.1
0.5
0.1
—
—
—
—
5.0
1.0
5.0
0.83
A
A
A
A
Outp ut Current-limit Inception
(VO = 90%  of VO, nom and minimum load on 
other outputs . See Figures 9—12.)
DC025ABK-M
DC025ACL-M
IO1
IO2, IO3
IO1
IO2, IO3
—
—
—
—
6
2
6
2
7.5
3.0
7.5
3.0
A
A
A
A
Outp ut Shor t -circuit Current
(VO = 1 V and minimum load on other 
outputs.)
DC025ABK-M
DC025ACL-M
IO1
IO2, IO3
IO1
IO2, IO3
—
—
—
—
8
3
8
3
10.5
4.5
10.5
4.5
A
A
A
A
Efficienc y 
(VI = 28 V; TC = 25 ° C; see Figure s 13, 14, 
and 20.):
IO1 = 2.5 A, IO2 = IO3 = 0. 5 A
IO1 = 2.0 A, IO2 = IO3 = 0. 5 A DC025ABK-M
DC025ACL-M η
η79
79 82
82 —
—%
%

44 Tyco Electronics Corp.

Data Sheet

June 1997

18 Vdc to 36 Vdc Input; 25 W

DC025 Triple Output-Series Power Modules:

General Specifications

Dynamic Respons e

(ýIO/ ýt = 1 A/10 µs, VI = 28 V, TC = 25 °C ):

Load C hange from I O = 5 0% to 75% of

IO, max:

Peak Devi ation

Settling Time (VO < 10% peak

deviation)

Load C hange from I O = 5 0% to 25% of

IO, max:

Peak Devi ation

Settling Time (VO < 10% peak

deviation)

All

VO1

—

VO1

—

0.5

—

Table 3. Isolat ion Specifications

Parameter Min Typ Max Unit

Isolation Capacitance — 0.02 — µF

Isolation Resistance 10 — — MΩ

Parameter Min Typ Max Unit

Calculated MTBF (IO = 80% of IO, max; TC = 40 °C) 2,906,000 hours

Wei g ht — — 11 3 (4.0) g (oz. )

Table 2. Output Speci fications (co ntinued)

Parameter Device Symbol Min Typ Max Unit

Electrical Specifications (continued)

Tyco Electronics Corp. 5

Data Sheet

June 1997 18 Vdc to 36 Vdc Input; 25 W

DC025 Triple Output-Series Power Modules:

Feature Specifications

Unless otherwise indicated, specifications apply over all operating input voltage, resist ive load, and temperature

conditions. See Feature Descriptions and Design Considerations for further inf ormation.

Parameter Device Symbol Min Typ Max Unit

Remote On/Off

(VI = 0 V to 36 V; open colle ctor or equivalent

compatible; signal reference d to VI(–) te rmin a l .

See Figures 17 and 21 and Feature

Descriptions.):

DC 025XX X-M (positive logic):

Logic Low—M odule Off

Logic High— M odule On

DC 025XX X1 -M (negative l ogic):

Logic Low—M odule On

Logic High— M odule Off

Module Specifications:

On/ Off Current—Log ic Low

On/Off Voltage :

Logic Low

Logic High (Ion/off = 0)

Open Coll ector Switch Specifications:

Leak age Current Dur ing Logic High

(Von/off = 10 V)

Out put Low Voltage Dur ing Logic Low

(Ion/off = 1 mA)

Turn-on Time

(IO = 80% of IO, max; VO wit hin ±1% of steady

state)

Output Volt age Overshoot (See Figure 17.)

All

Ion/off

Von/off

Ion/off

Von/off

—

1.0

1.2

—

µA

Output Overvoltage Cl amp DC025 ABK-M

DC025ACL-M

VO1

VO2

VO3

VO1

VO2

VO3

—

–15

–19

6.8

–17

6.8

–21

Out put Vo ltage Set-poin t Adjustment Range All — 90 — 110 % VO, nom

6Tyco Electronics Corp.

Data Sheet

June 1997

18 Vdc to 36 Vdc Input; 25 W

DC025 Triple Output-Series Power Modules:

Characteristic Curves

8-1077(C)

Figure 1. DC025 Triple Output-Series Typical Input

Characteristics

8-1078(C)

Figure 2. DC025 Triple Output-Series Typical

Output Vol tage Variation of 5 V Output

Over Ambient Temperature Range

8-1079(C)

Figure 3. DC025 Triple Output-Series Typical

Outpu t Voltage Variation of 12 V Output

Over Am bien t Temperature Rang e

8-1080(C)

Figure 4. DC025 Triple Output-Series Typical

Outpu t Voltage Variation of 15 V Output

Over Am bien t Temperature Rang e

0 5 10 15 25

0.0

1.6

2.0

INPUT VOLTAGE, VI(V)

INPUTCURRENT,I

(A)

1.8

1.4

0.2

1.2

20 4

1.0

0.8

0.6

0.4

30 35

–40–20020406080100

4.95

4.97

4.99

5.01

CASETEMPERATURE,T (°C)

OUTPUTVOLTAGE,V

(V)

5.00

4.98

4.96

–40–200 20406080100

11.95

12.10

12.20

12.30

CASETEMPERATURE,T (°C)

OUTPUTVOLTAGE,V

(V)

12.00

12.25

12.15

12.05

–40 –20 0 2 0 40 60 80 100

15.10

15.20

15.40

15.50

15.60

CASETEMPERATURE,T(°C)

OUTPUTVOLTAGE,V

(V)

15.30

15.55

15.45

15.35

15.25

15.15

Tyco Electronics Corp. 7

Data Sheet

June 1997 18 Vdc to 36 Vdc Input; 25 W

DC025 Triple Output-Series Power Modules:

Characteristic Curves (continued)

8-1081(C)

Figure 5. DC025ABK-M Typical Load Regulation

8-1082(C)

Figure 6. DC025ABK-M Typical Cross Reg ulation

with Respect to IO1

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.8 1.0

11.0

11.5

12.5

13.0

13.5

OUTPUT CURRENT, IO2

(

)

12.0

0.7 0.9

VI=27V,IO1 =2.5A,IO3 =0.5A

VI=27V,IO1 =0.5A,IO3 =0.1A

OUTPUTVOLTAGE,V

(V)

0.0 0.5 1.0 1.5 2.0 2.5 3.0 4.0 4.5

11.0

11.5

12.5

13.0

13.5

OUTPU

CURREN

,IO1

(

)

12.0

VI=27V,IO2 =IO3 =0.1A

VI=27V,IO2 =IO3 =0.5A

3.5

OUTPUTVOLTAGE,V

(V)

8-1083(C)

Figure 7. DC025ACL-M Typical Load Regulation

8-1084(C)

Figure 8. DC025ACL-M Typical Cross Regulation

with Respect to IO1

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

13.8

14.3

15.3

15.8

16.3

OUTPUT CURRENT, IO2

(

)

14.8

VI=27V,IO1 =2.5A,IO3 =0.45A

VI=27V,IO1 =0.5A,IO3 =0.1A

OUTPUTVOLTAGE,V

(V)

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

13.8

14.3

14.8

15.8

16.3

16.8

OUTPU

CURRENT,IO1

(

)

15.3

VI=27,IO2 =IO3 =0.1A

VI=27V,IO2 =IO3 =0.45A

OUTPUTVOLTAGE,V

(V)

Note: Given the same load cond itions, Output 3 has regulation characteristics similar to Output 2, except the

polarity is negative.

8Tyco Electronics Corp.

Data Sheet

June 1997

18 Vdc to 36 Vdc Input; 25 W

DC025 Triple Output-Series Power Modules:

Characteristic Curves (continued)

8-1085(C)

Figure 9. DC02 5ABK-M Typical 5 V Ou tput Characteristics

8-1086(C)

Figure 10. DC02 5ABK-M Typical 12 V Ou tput Characteristics

8-1087(C)

Figure 11. DC025ACL-M Typical 5 V Output Characteristics

0123

OUTPUT CURRENT, IO1 (A)

456 8

VI=36V,IO2=IO3 =0.5A

VI=27V

VI=18V

VI=36V,IO2 =IO3 =0.1A

OUTPUTVOLTAGE,V

(V)

VI=27V

VI=18V

0.0 0.5 1.0 1.5 2.5

2.0

VI=18V

3.0 3.5

VI=27V

VI=36V,IO1 =2.5A,

IO3 =0.5A

VI=27V

VI=18V

VI=36V,IO1 =0.5A,

IO3 =0.1A

OUTPUT CURRENT, IO2 (A)

OUTPUTVOLTAGE,V

(V)

0123

0.0

1.5

5.0

OUTPUT CURRENT, IO1 (A)

OUTPUTVOLTAGE,V

(V)

4.5

1.0

0.5

2.5

456 8

4.0

3.5

3.0

2.0 VI=27V

VI=18V

VI=36V,IO2 =IO3 =0.1A

VI=36V,IO2 =IO3 =0.45A

VI=27V

VI=18V

Data Sheet

June 1997

Tyco Electronics Corp. 9

18 Vdc to 36 Vdc Input; 25 W

DC025 Triple Output-Series Power Modules:

Characteristic Curves (continued)

8-1088(C)

Figure 12. DC025ACL -M Typical 15 V Output Characteristic s

0.0 0.5 1.0 1.5

OUTPU

CURREN

,IO2

(

)

2.0

2.5

VI=27V

VI=18V

VI=36V,IO1 =0.5A,

IO3 =0.1A

VI=27V

VI=18V

VI=36V,IO1 =2.5A,

IO3 =0.45A

OUTPUTVOLTAGE,V

(V)

8-1089(C)

Note: Loads varied proportionately from minimum to 50% of full

load.

Figure 13. DC025ABK-M Typical Converter

Efficiency

8-1090(C)

Not e: Loads varied pr oporti onately fr om minimum to 50% of full

load.

Figure 14. DC025ACL-M Typical Converter

Efficiency

0 20 40 60 100

PER

ENT

(

)

EFFICIENCY,η(%)

VI=18V

120

VI=36V

VI=27V

0 20 40 60 100

PER

ENT

(

)

EFFICIENCY,η(%)

VI=18V

120

VI=36V

VI=27V

10 Tyco Electronics Corp.

Data Sheet

June 1997

18 Vdc to 36 Vdc Input; 25 W

DC025 Triple Output-Series Power Modules:

Characteristic Curves (continued)

8-1098(C)

Figure 15. DC025 Tr iple Output-Seri es Typical

Output Vol tage for a Step Load Chang e

from 75% to 50% of Full Load on

Outp ut 1

8-1099(C)

Figure 16. DC025 Tr iple Output-Seri es Typical

Output Vol tage for a Step Load Chang e

from 25% to 50% of Full Load on

Outp ut 1

8-1100(C)

Figure 17. DC025 Triple Output-Series Typical

Output Voltage Start-Up when Signal

Applied to Remot e O n/Off

Test Configurations

8-489(C).a

Note : I np ut r ef lec t e d- r i pp le curr e nt is measu red wi th a simu lated

source impedance ( LTEST) of 12 µH. Capacitor CS offsets pos-

sible battery impedance. Current is measured at the input of

the module.

Figure 18. Input Reflected-Ripple Test Setup

TIME, t (100 µs/div)

OUTPUTVOLTAGE,V

(V)

(%OFV

O,set

)

OUTPUTCURRENT,I

(A)

(%OFI

O,max

)

75%

50%

25%

99%

100%

101%

102%

TIME, t (100 µs/div)

OUTPUTVOLTAGE,V

(V)

(%OFV

O,set

)

OUTPUTCURRENT,I

(A)

(%OFI

O,max

)

101%

100%

99%

75%

50%

25%

REMOTEON/OFF

(2V/div)

TIME, t (2 ms/div)

OUTPUTVOLTAGE,V

(V)

(%OFV

O,set

)

50%

100

TO OSCILLOSCOPE

CS 220 µF

IMPEDANCE < 0.1 Ω

@ 20 ˚C, 100 kHz

VI(+)

VI(–)

LTEST

BATTERY

12 µH

Tyco Electronics Corp. 11

Data Sheet

June 1997 18 Vdc to 36 Vdc Input; 25 W

DC025 Triple Output-Series Power Modules:

Test Configurations (continued)

8-811(C).a

Not e: Use th e specified ceramic capacitor . Scope measure ment

should be made by using a BNC socket. Position the load

between 50 mm (2 in.) and 75 mm (3 in.) from the

module.

Figure 19. Output Noise Measurement Test Setup

8-749(C).b

Note: All measurements are taken at the module termina ls. When

s ock eting, pla c e Kelvin connections at module terminals to

avoid measurement errors due to socket contact resistance.

Figure 20. Triple Output Voltage an d Efficiency

Measurem ent Test Setup

Design Considerations

Input So urce Impedance

The power module should be connected to a low

ac-impedance input source . Highl y inductiv e source i m-

pedances can affec t the stability of the power module. A

33 µF electrolytic capacitor (ESR < 0.7 ¾ at 100 kHz)

mounted c lose to the power module helps to ensure

the stability of the unit.

Safety Considerations

For safety-agency approval of the system in which the

power module is used, t he power module must be

installed in compliance with the s pacing and separation

requirem ents of the end-use safety agency standard,

i.e.,

-1950,

CSA

22.2-950, and EN60950 .

For t he converter output to be considered meeting the

requirem ents 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 t o be provided with a maxi-

mum 5 A normal-blow fuse in the ungrounded lead.

(+)

SCOPE

0.1 µF

COPPER STRIP

0.47 µF

LOAD1

(–)

0.47 µF SCOPE

LOAD2

(+)

SCOPE

COM

LOAD3

VI(+)

IO1

SUPPLY

CONTACT

RESISTANCE

CONTACT AND

DISTRIBUTIONLOSSES

LOAD2

SENSE

VO1(+)

SENSE

COM

VO1(+)

VI(–)

COM

VO2(+)

VO3(–)

LOAD1

LOAD3

IO2

IO3

SENSE

VO2(+)

VOj +() VCOM–[]IOj

j1=

∑

VI+() VI–()–()+[]II

-----------------------------------------------------------100×=

1212 Tyco E lectron ics Corp.

Data Sheet

June 1997

18 Vdc to 36 Vdc Input; 25 W

DC025 Triple Output-Series Power Modules:

Feature Descriptions

Outp ut Overvoltage Clam p

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 volt age set point

than the primary loop (see Feature Specifications

table). T his provides a redundant vo lta ge control that

reduces the risk of output overvoltage.

Current Limit

To provide protect ion in a fault (output over load ) condi-

tion, the unit is equi pped with internal current-limiting

circuitr y. At the point of c urrent-limit inception, the unit

shifts from v oltage control to current control. If the out-

put voltage is pulled very low during a severe f ault, the

current-limit circuit c an exhibit eith er 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 Voltage Set-Point Adjustment

The output voltage adjustment feature provides the

capability of increasing or decreasing the output v olt-

age set point of a module. Th is can be accomp lished

by u sing an ext ernal resistor conne cted between the

TRIM pin and either the VO1(+) or common pins . With

an external resistor between the TRIM and common

pins (Radj-up), the output voltage set point (VO, adj)

increases.

Note: T he out put volt age adju stment range must not

exceed 110% of the nominal output voltage

between the VO1(+) and com mon ter m inals.

With an external resistor connected between the TRIM

and VO1(+) pins (Radj-down), the output voltage set point

(VO, adj) decreases.

Note: T he out put volt age adju stment must be 90% or

more of the nominal output vol tage between the

VO1(+) and common ter mi nals.

Remote On/Off

Two remote on/off options are avai lab le. Positive logic

remote on/o ff tur ns the module on during a logic high

voltage on the REMOT E ON/OFF pin, and off during a

logic low. Negative logic remot e on/off, suffix code “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 vol tage between the on/

off ter m inal and the VI(–) terminal (Von/off). The switc h

can be an open collector or equival ent (see Figure 21).

A logic low is Von/off = 0 V to 1.2 V. The maxi mum Ion/off

durin g a logic low is 1 mA. The sw itch should maintain

a logic low voltage w h ile s in k ing 1 mA.

During a logic high, the maximum Von/off generated by

the po wer module is 10 V. The maximum allowable

leakage c urrent of the switch at Von/off = 10 V is 50 µA.

8-758(C).a

Figure 21. Remote On/Off Implementation

Radj-up 42.35

VO, adj VO, nom–

----------------------------------





kΩ=

Radj-down VO, adj 2.5–()16.94×

VO, nom VO, adj–

--------------------------------------------------





kΩ=

Ion/off

–

Von/off

REMOTE

ON/OFF

VI(+)

VI(–)

Data Sheet

June 1997

Tyco Electronics Corp. 13

18 Vdc to 36 Vdc Input; 25 W

DC025 Triple Output-Series Power Modules:

Thermal Considerations

8-866(C).b

Note: Dimensions are in millimeters and (inches). Drawing is not to scale.

Figure 22. Thermal Test Setup

50.8

(2.00)

12.7 (0.50)

101.6

(4.00)

203.2 (8.00)

AIRFLOW

MEASURE CASE

TE MPERATU RE AT

THIS POINT

CO NNECTO RS TO

LOADS, POWER

SUPP LIES, 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 TEMPERATURE

THERMOCOUPLE

AIR-

FLOW

27.9

(1.1)

27.9

(1.1)

dc-dc POWER MODULE

MADE I N USA

12.7 (0.50)

The 25 W triple output power module s are designed to

operate in a variety of thermal en vi ronments. As with

any electronic component , sufficient cooling must be

provided to ensure reliable operatio n. Heat dissipating

component s inside the module are ther ma lly coupled

to the case to enable heat removal by conduction, con-

vection , and radiation to the s urrou nding environme nt.

The thermal data presented is based on measure-

ments taken in a wind tunnel. The test setup shown in

Figure 22 was used to collect data. Actual performance

can vary depending on the particular application

environment.

1414 Tyco E lectron ics Corp.
Data Sheet
June 1997
18 Vdc to 36 Vdc Input; 25 W
DC025 Triple Output-Series Power Modules:
Thermal Considerations (continued)
Ba sic Thermal Performance
The maximum operating temperature of the DC025 Tri-
ple Output-Serie s Power M odu les at a given opera ting 
condition can be predicted by combining the power dis-
sipation cur ves (Figures 23 through 27), the power der-
ating cur ve (Figure 28), and t he ther m al resistance 
curve (Figure 28).
Use Figures 23 through 28 and the steps below to pre-
dict the safe operating region for ma ny different operat-
ing and environ men tal  conditions.
1. Calculate the total output power. 
POto tal = (IO1 x VO1) + (IO2 x VO2) + (IO3 x VO3)
2. Use POtotal with the appropriate figure (Figure 23 
or 25) to determine the fix ed losses (PP) associ-
ated with operating at POtotal. These losses are 
independent  of which output the load is being 
drawn from.
3. Use the desired output current (IO1) with  Figure 25 
to determ ine P S1, which is the additional power 
being dissipated due to loading of the main output.
4. Repeat Step 3 for outputs 2 and 3 using the appro-
priate figure (Figure 23 or 27) to determine PS2 and 
PS3, which is the power dissipated due to loading of 
the auxiliary outputs .
5. Find the total power dissipated (PDtot al) by adding 
the four power dissipations obtained in Steps 2 
through 4. 
PDtotal = P P + PS1 + PS2 + PS3
6. Use the estimated total power dissipated (PDtotal) 
along with Figure 28 to determine the maxim um 
ambient temperature allowable for a given air 
velocity.
For example, cons ider  th e  DC02 5 ABK p o wer module 
operating with 27 V input and output currents 
IO1 = 2.5 A, IO2 = 0.5 A, IO3 = 0.5 A. 
T he tot al ou tp ut pow er (P Ototal) is 24.5 W. The total 
po wer dissipation  is PDtotal = 4.86 W,  which is obtained 
by adding:
PP= 4.5 W (from Fig ure 23)
PS1 = 0.22 W (from Figure 25)
PS2 = 0.07 W (from Figure 23)
PS3 = 0.07 W (from Figure 23)
Figure 28 shows that in natural c onvec tion the maxi-
mum operating ambient temperature for this module is 
approximately 66 °C.
Keep in mind that the procedure above provides 
approximations of the te mperature and air velocities 
required to keep the c ase t emp erature below i ts maxi-
mum rating. The maximum case temperature, as moni-
tored at the point shown in Fig ure 22, should be 
main tained at 100 °C or less under all conditions.
Air Ve locity
The air velocity required to maint ain a desired maxi-
mum case temperature  for a given power dissipation 
and ambient temperature can be calculated using 
Figure 28 and the following equation:
where:
■θCA is the thermal resistance from case-to-ambient 
air (°C/W) 
■TCmax is the desired maximum case temperature (°C) 
■TA is the ambient inlet temperature (°C)
■PDtotal is the total power dissipated by the module 
(W) at the desired operating condition
F or example, to maintain a maximum case temperature
of 85 °C with an ambient i nlet temperature of 65 °C and
a power dissipation of 4.86 W,  the thermal resist ance is:
This correspo nds to an airflow greater than 0.38 ms–1 
(75 fpm) in Figure 28. 
θCA TCmax TA–
PDtotal
----------------------------
=
θCA ð 85 °C65 °C–
4.86 W
------------------------------------- 4.1°C/W=

Tyco Electronics Corp. 15

Data Sheet

June 1997 18 Vdc to 36 Vdc Input; 25 W

DC025 Triple Output-Series Power Modules:

Thermal Considerations (continued)

Air Ve locity (continued)

8-1091(C)

Figure 23. DC025ABK-M Fixed Losses, PP

8-1092(C)

Figure 24. DC025ACL-M Fixed Losses, PP

8-1093(C)

Figure 25. DC025ABK-M, DC025ACL-M Losses,

Associ ated with 5 V Output, PS1

8-1094(C)

Figure 26. DC025ABK-M, Losses Associated with

±12 V Output, PS2/PS3

18 V

0 5 10 15 25 3

1.0

4.0

5.0

6.0

OUTPU

POWER, PO

(

)

1.5

5.5

4.5

3.5

2.0

2.5

3.0

POWERDISSIPATION,P

(W)

36V

27 V

0 5 10 15 25 3

1.0

4.0

5.0

6.0

OUTPU

POWER, PO

(

)

1.5

5.5

4.5

3.5

2.0

2.5

3.0

POWERDISSIPATION,P

(W)

36 V

27V

18V

0.0 0.5 1.0 1.5 2.5 3.0

0.0

0.8

1.2

1.6

PUT CURREN

,IO1

(

)

POWERDISSIPATION,P

(W)

1.4

1.0

0.6

0.2

0.4

2.0

VI=18V

VI=27V

3.5 4.5 5.0

4.0

VI=36V

0.0 0.1 0.2 0.3 0.5 0.6

0.00

0.20

0.30

0.40

OUTPUT CURRENT, IO2OR IO3

(

)

0.35

0.25

0.15

0.05

0.10

0.4 0.7 0.9 1.00.8

POWERDISSIPATION,P

(W)

1616 Tyco E lectron ics Corp.

Data Sheet

June 1997

18 Vdc to 36 Vdc Input; 25 W

DC025 Triple Output-Series Power Modules:

Thermal Considerations (continued)

Air Ve locity (continued)

8-1095(C)

Figure 27. DC025ACL-M Losses Associa ted with

±15 V Output, PS2/PS3

8-1130(C)

Figu re 28. Tota l Power D i ss i pat i on vs. Local

Ambient Temperature and Air Velocity

8-1101(C)

Figure 29. Case-to-Ambient Thermal Resistance vs.

Air Velocity

Use of Heat Sinks and Cold Plates

The DC025 Tr iple Output-Seri es case includes

through-threaded M3 x 0.5 mounting holes allowing

attachment of heat sinks or cold plates from either side

of the module. The mounting torque must not exceed

0.56 N/m (5 i n.-lb).

The following thermal model can be us ed to determine

the required ther m al resistance of the sink to provide

the necess ary cooling:

where PD is the power dissipated by the m odule, θCS

represen ts the interfacial contact resistance between

the module and the sink, and θSA is the sink-to-ambient

ther m al impedance (° C/W ). For therm al greases or

foil s, a value of θCS = 0 .1 °C/W t o 0. 3 °C/W i s typi c a l.

The required θSA is calculated from the fol lowing equa-

tion:

Note that this equation assumes th at all dissipated

power must be shed by the si nk . Depending on the

user-defined application environment, a more accurate

model including heat transfer from the sides and rear of

the module can be used. This equation provides a con-

ser vative estim at e in such instances.

F or further thermal information on these modules, ref er

to the

Thermal Management for CC-, CW, DC , D W-

Ser ies 25 W to 30 W Board-Moun ted Power Modules

Technical Note.

0.0 0.1 0.2 0.3 0.5 0.6

0.0

0.2

0.4

0.6

OUTPUT CURRENT, IO2OR IO3

(

)

0.5

0.3

0.1

0.4 0.7 0.90.8

POWERDISSIPATION,P

(W)

40 50 100

0.0

2.0

8.0

LOCALAMBIENTTEMPERATURE, TA(°C)

3.0

4.0

5.0

6.0

7.0

1.0

9060 80

TOTALPOWERDISSIPATION,P

TOTAL(W)

0.51 ms –1 (100 ft./min.)

1.02 ms –1 (200 ft./min.)

2.03 ms –1 (400 ft./min.)

NATURAL

CONVECTION

NAT

CONV 0.25

(50.0) 0.51

(100.0) 2.03

(400.0)

0.0

8.0

VELOCITY,ms–1 (ft./min.)

0.76

(150.0) 1.78

(350.0)

1.0

6.0

7.0

1.02

(200.0) 1.27

(250.0) 1.52

(300.0)

5.0

4.0

3.0

2.0

THERMALRESISTANCE(°C/W)

CASE-TO-AMBIENT

PDθCS

TATc Ts

θSA

•

θSA TCTA–

PDtotal

----------------- θCS–=

Tyco Electronics Corp. 17

Data Sheet

June 1997 18 Vdc to 36 Vdc Input; 25 W

DC025 Triple Output-Series Power Modules:

Outline Diagram

Dim e ns io ns are in millim e t er s an d (in ches ).

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.).

8-846(C)

Top View

Side View

Bottom View

DC-DC Power Module

MADEIN USA

71.1 (2.80) MAX

61.0

(2.40)

MAX

PIN 1 INDICATOR

ON/OFF

CASE

VI(+)

VO1(+)

TR IM

VO3(–)

VO2(+)

5.1 (0.20)

4.8 (0.19)

11.4 (0.45)

3.8 (0.15)

MOUNTING INSERTS

M3 x 0.5 THROUGH,

4PLACES

STAND-OFF,

4PLACES

10.16 (0.400)

48.3 (1.90)

63.50 ± 0.38 (2.500 ± 0.015)

10.16 (0.400)

50.8

(2.00)

20.32

(0.800)

20.32

(0.800)

20.32

(0.800)

30.5

(1.20)

7.1 (0.28)

10.16 (0.400)

VI(–) COM

1.02 (0.040) ± 0.08 (0.003) DIA

TIN-PLATED

BRASS, 9 PLACES

12.7 (0.50)

MAX

5.1(0.20)

MIN

0.51

(0.020)

18 Tyco Electronics Corp.

Data Sheet

June 1997

18 Vdc to 36 Vdc Input; 25 W

DC025 Triple Output-Series Power Modules:

Recommended Hole P attern

Component-s ide footprint.

Dim e ns io ns a r e in mi llimet e r s and (inc hes).

Recommen ded hole size for pin: 1.27 mm (0.050 in.)

8-846(C)

11.4 (0.45)

3.8 (0.15)

5.1 (0.20)

CASE OUTLINE

10.16 (0.400)

48.3 (1.90)

63.50 ± 0.38 (2.500 ± 0.015)

71.1 (2.80) MAX

M3 x 0.5 CLEARANCE HOLE

4 PLACES(OPTIONAL)

10.16 (0.400)

50.8

(2.00)

20.32

(0.800)

20.32

(0.800)

30.5

(1.20)

20.32

(0.800)

61.0

(2.40)

MAX 4

Tyco Electronics Corp. 19

Data Sheet

June 1997 18 Vdc to 36 Vdc Input; 25 W

DC025 Triple Output-Series Power Modules:

Ordering Information

Tabl e 4. Orderi ng Inform a ti on Ta ble

Optional f eatures may be ordered using the de vice code suffixes shown below. To order more than one option, list

suffix es in numerically descending or der f ol lo wed by the -M suffix, indicating metric (M3 x 0.5 heat sink hardware).

The heat sinks designed for th is package have an M prefix, i .e., MHSTxxx45 and M HSL xxx45 (see

Thermal

Energy M anag eme nt 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 pricin g and availability of

options.

Input

Voltage Output

Power Remote

On/Off Logi c Device

Code Comcode

18 V — 36 V +5 V, ±12 V 25 W positive DC025ABK-M 107587313

18 V—36 V +5 V, ±15 V 25 W positive DC025ACL-M 107587339

Option Device Code

Suffix

Short pins : 2.79 m m ± 0.25 mm

(0.110 in. ± 0.010 in.) 8

Negative on/off logic 1

Data Sheet

June 1997

18 Vdc to 36 Vdc Input; 25 W

DC025 Triple Output-Series Power Modules:

Printed on

Recycled Paper

World W id e Headquarter s

Tyco Electronics Power Systems, Inc.

3000 S kyline Driv e, Me squit e, TX 75149, USA

+1-800-526-7819 FAX: +1-888-315-5182

(Out side U.S.A .: +1-972-284-2626, FAX: +1-972-284-2900)

www.power.tycoelectronics.com

e-m ail : te chsupport1@ty coelectro ni cs.com

Tyco Electronics Corporation reserves the right to make changes to the product(s) or information contained herein without noti ce. 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.

Pri nt ed in U.S.A.

June 19 97

DS96-1 28EPS (Rep laces DS94-054EPS )

Europe, Middle- E ast and Africa Headquarters

Tyco Electr onics (UK ) Ltd

Tel: +44 (0) 1344 469 300, Fax: +44 (0) 1344 469 301

Central America-Latin America Headquar ters

Tyco Electronics P o wer Systems

Tel: +54 11 43 16 2866, Fax: +5 4 11 4312 9508

Asia-Pacific Headquar ters

Tyco Electro nics Singapore Pte Ltd

Tel: +65 482 0311, F ax: 65 480 9299