2 2 Lineage Power
Data Sheet
April 2009
18 Vdc to 36 Vdc Input; 25 W
DC025 Triple 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 operations sections of the data shee t. Exposure to absolute maximum ratings for extended
period s can ad versely affect device r eliab ilit y.
Electrical Specifications
Unless otherwise indicated, specifications apply to all modules over all operating input voltage, resistiv e load, and
temperature conditions.
Fusing Consideration s
CAUTION: This power module is not internally fused. An input line fuse must always be used.
This encapsulate d power modul e can be used in a wide variety of applications, ranging from simple stand-alon e
operation to an integrated part of a sophisticated power architecture. To preserve maximum flexibility, internal fus-
ing is not included; how ev er, to achieve maximum saf ety and system protection, alwa ys use an input line fuse . The
safety agencies require a nor mal-blow, d c fuse with a maximum rating of 5 A in series with the ungrounded input
lead. Based on the inform at ion provided in this data sh eet on inrush energy and maximum dc input current, the
same type of fuse with a lower rat ing can be used. Refer to the fuse manufacturer’s data for furt her inform at ion.
Parameter Symbol Min Max Unit
Input Vo ltage Continuous VI—50V
I/O Isolation Voltage:
dc
Transient (1 minute) —
——
—500
850 V
V
Operating Case Temperature TC–40 100 °C
Storage Temperature Tstg –55 125 °C
Table 1. Input Spec ifications
Parameter Symbol Min Typ Max Unit
Operating Input Voltage VI18 28 36 Vdc
Maximum Input Current
(VI = 0 V to 36 V; IO = IO, max; see Figure 1.) II, max ——3.0A
Inrush Transient i2t——0.2A
2s
Input Reflected-ripple Current, Peak -to-peak
(5 Hz to 20 MHz, 12 µH source impedanc e;
TC = 25 °C; see Figure 18 and Design
Considerations section.)
——30—mAp-p
Input Ripple Rejection (120 Hz) — — 60 — dB
Lineage Power 3
Data Sheet
April 2009 18 Vdc to 36 Vdc Input; 25 W
DC025 Triple Output-Series Power Modules:
Electrical Specifications (continued)
Table 2. Ou tput Specifica tions
Parameter Device Symbol Min Typ Max Unit
Outp ut Voltage
(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, set
VO2, set
VO3, set
VO1, set
VO2, set
VO3, set
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 I O, 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 to 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, m i n, the modules may ex ceed
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 % o f 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 Figures 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 —
—%
%
4 4 Lineage Power
Data Sheet
April 2009
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 = 50% to 75% of
IO, max:
Peak Deviation
Settling Time (VO < 10% peak
deviation)
Load C hange from I O = 50% to 25% of
IO, max:
Peak Deviation
Settling Time (VO < 10% peak
deviation)
All
All
All
All
VO1
—
VO1
—
—
—
—
—
80
1
80
0.5
—
—
—
—
mV
ms
mV
ms
Table 3. Isolation 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. Ou tput Specifica tions (continued)
Parameter Device Symbol Min Typ Max Unit
Electrical Specifications (continued)
5 Lineage Power
Data Sheet
April 2009 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, resistive load, and temperature
conditions. See Feature Descriptions and Design Considerat ions for further information.
Parameter Device Symbol Min Typ Max Unit
Remote On/Off
(VI = 0 V to 36 V; open colle ctor or equivalent
compatible; signal referen ce d to VI(–) te rmina 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 logic):
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 During Logic Low
(Ion/off = 1 mA)
Tur n-on Ti me
(IO = 80% of IO, max; VO within ±1% of steady
state)
Output Voltage Overshoot (See Figure 17.)
All
All
All
All
All
All
All
Ion/off
Von/off
Von/off
Ion/off
Von/off
—
—
—
0
—
—
—
—
—
—
—
—
—
—
5
0
1.0
1.2
10
50
1.2
—
5
mA
V
V
µA
V
ms
%
Output Overvoltage Clamp DC025ABK-M
DC025ACL-M
VO1
VO2
VO3
VO1
VO2
VO3
—
—
—
—
—
—
6
15
–15
6
19
–19
6.8
17
–17
6.8
21
–21
V
V
V
V
V
V
Out put Voltage Set-point Adjustment Range All — 90 — 110 % VO, nom
6 Lineage Power
Data Sheet
April 2009
18 Vdc to 36 Vdc Input; 25 W
DC025 Triple Output-Series Power Modules:
Characteristic Curves
8-1077(C)
Figure 1. DC025 Triple Outp ut-Series Ty pical Input
Characteristics
8-1078(C)
Figure 2. DC025 Triple Outp ut-Series Ty pical
Output Voltage Va riation of 5 V Output
Over Ambient Temperature Range
8-1079(C)
Figure 3. DC025 Tri ple Output-Series Typical
Outpu t Vo ltage Variation of 12 V Output
Over Am bien t Temp eratur e Range
8-1080(C)
Figure 4. DC025 Tri ple Output-Series Typical
Outpu t Vo ltage Variation of 15 V Output
Over Am bien t Temp eratur e Range
0 5 10 15 25
0.0
1.6
2.0
INPUT VOLTAGE, VI(V)
INPUTCURRENT,I
I
(A)
1.8
1.4
0.2
1.2
20 4
0
1.0
0.8
0.6
0.4
30 35
–40–200 20406080100
4.95
4.97
4.99
5.01
CASETEMPERATURE,T (°C)
OUTPUTVOLTAGE,V
O1
(V)
5.00
4.98
4.96
–40–200 20406080100
11.95
12.10
12.20
12.30
CASETEMPERATURE, T (°C)
OUTPUTVOLTAGE,V
O
(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
O
(V)
15.30
15.55
15.45
15.35
15.25
15.15
Lineage Power 7
Data Sheet
April 2009 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 Regulation
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
(
A
)
12.0
0.7 0.9
VI=27V,IO1 =2.5A,IO3 =0.5A
VI=27V,IO1 =0.5A,IO3 =0.1A
OUTPUTVOLTAGE,V
O2
(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
T
CURREN
T
,IO1
(
A
)
12.0
VI=27V,IO2 =IO3 =0.1A
VI=27V,IO2 =IO3 =0.5A
3.5
OUTPUTVOLTAGE,V
O2
(V)
8-1083(C)
Figure 7. DC025ACL-M T y pical 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
(
A
)
14.8
VI=27V,IO1 =2.5A,IO3 =0.45A
VI=27V,IO1 =0.5A,IO3 =0.1A
OUTPUTVOLTAGE,V
O2
(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
T
CURRENT,IO1
(
A
)
15.3
VI=27,IO2 =IO3 =0.1A
VI=27V,IO2 =IO3 =0.45A
OUTPUTVOLTAGE,V
O2
(V)
Note: Given the same load cond itions, Output 3 has reg ulation character istics similar to Output 2, except the
polarity is negative.
8 Lineage Power
Data Sheet
April 2009
18 Vdc to 36 Vdc Input; 25 W
DC025 Triple Output-Series Power Modules:
Characteristic Curves (continued)
8-1085(C)
Figure 9. DC025ABK-M Typical 5 V Output Characteristics
8-1086(C)
Figure 10. DC025ABK-M Typical 12 V Output Characteristics
8-1087(C)
Figure 11. DC025A CL-M Typical 5 V Output Characteristics
0123
0
3
6
OUTPUT CURRENT, IO1 (A)
5
2
7
1
9
4
456 8
VI=36V,IO2=IO3 =0.5A
VI=27V
VI=18V
VI=36V,IO2 =IO3 =0.1A
OUTPUTVOLTAGE,V
O1
(V)
VI=27V
VI=18V
0.0 0.5 1.0 1.5 2.5
0
10
14
12
8
6
2.0
VI=18V
4
2
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
O2
(V)
0123
0.0
1.5
5.0
OUTPUT CURRENT, IO1 (A)
OUTPUTVOLTAGE,V
O1
(V)
4.5
1.0
7
0.5
9
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
April 2009
Lineage Power 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 Characteri stics
0.0 0.5 1.0 1.5
0
10
16
OUTPU
T
CURREN
T
,IO2
(
A
)
14
8
6
2.0
4
2
2.5
VI=27V
VI=18V
VI=36V,IO1 =0.5A,
IO3 =0.1A
12
VI=27V
VI=18V
VI=36V,IO1 =2.5A,
IO3 =0.45A
OUTPUTVOLTAGE,V
O2
(V)
8-1089(C)
Note: Loads varied proportionately from minimum to 50% of full
load.
Figure 13. DC02 5ABK-M Typical Converter
Efficiency
8-1090(C)
Not e: Loads varied proportionat ely from mini mum to 50 % of full
load.
Figure 14. DC025ACL-M Typical Con verter
Efficiency
0 20 40 60 100
55
75
85
PER
C
ENT
O
FF
U
L
L
L
O
AD
(
%
)
EFFICIENCY,η(%)
80
70
60
65
80
VI=18V
120
VI=36V
VI=27V
0 20 40 60 100
55
75
85
PER
C
ENT
O
FF
U
L
L
L
O
AD
(
%
)
EFFICIENCY,η(%)
80
70
60
65
80
VI=18V
120
VI=36V
VI=27V
10 Lineage Power
Data Sheet
April 2009
18 Vdc to 36 Vdc Input; 25 W
DC025 Triple Output-Series Power Modules:
Characteristic Curves (continued)
8-1098(C)
Figure 15. DC025 Triple Output-Series Typical
Output Voltage for a Step Load Cha ng e
from 75% to 50% of Full Load on
Outp ut 1
8-1099(C)
Figure 16. DC025 Triple Output-Series Typical
Output Voltage for a Step Load Cha ng 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
App l ied to R e mot e O n/Off
Test Configurations
8-489(C).a
Note : I np ut r ef lec ted-r i pp le cu r rent is mea su r e d wi th a si mu la ted
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
O
(V)
(%OFV
O,set
)
OUTPUTCURRENT,I
O
(A)
(%OFI
O,max
)
75%
50%
25%
99%
100%
101%
102%
TIME, t (100 µs/div)
OUTPUTVOLTAGE,V
O
(V)
(%OFV
O,set
)
OUTPUTCURRENT,I
O
(A)
(%OFI
O,max
)
101%
100%
99%
75%
50%
25%
REMOTEON/OFF
(2V/div)
TIME, t (2 ms/div)
OUTPUTVOLTAGE,V
O
(V)
(%OFV
O,set
)
6
4
2
0
0%
50%
100
%
TO OSCILLOSCOPE
CS 220 µF
IMPEDANCE < 0.1 Ω
@ 20 ˚C, 100 kHz
VI(+)
VI(–)
LTEST
BATTERY
12 µH
Lineage Power 11
Data Sheet
April 2009 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 specif ied ceramic capacitor. Sc ope meas urement
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 measuremen ts are take n at t he module termina ls. When
s ocke ting, place Kelvin connections at module terminals to
avoi d measurement errors due to socket contact r esistance.
Figure 20. Triple Output Voltage and Efficiency
Measurem ent Test Setup
Design Considerations
Input Source Impedance
The power module should be connected to a low
ac-impedance input source . Highly inductive 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 modu le helps to ensure
the stability of the unit.
Safety Considerations
For safety-agency approv al of the system in which the
power module is used, the power module must be
installed in compliance with the s pacing and separation
requirem ents of the end-use safety age ncy standard,
i.e.,
UL
-1950,
CSA
22.2-950, and EN60950 .
For the conver ter outp ut to be considered meeting the
requirem ents of safety extra-low voltage (SELV), the
input must meet SELV requirem ents.
If the input meets ex tra-low vol tage (ELV) require-
ments, then the converter’s output is considered ELV.
The input to these units is to be provided with a maxi-
mum 5 A normal-blow fuse in the ungrounded lead.
V
O1
(+)
SCOPE
0.1 µF
COPPER STRIP
0.47 µF
R
LOAD1
V
O3
(–)
0.47 µF SCOPE
R
LOAD2
V
O2
(+)
SCOPE
COM
R
LOAD3
VI(+)
II
IO1
SUPPLY
CONTACT
RESISTANCE
CONTACT AND
DISTRIBUTIONLOSSES
LOAD2
SENSE
VO1(+)
SENSE
COM
VO1(+)
VI(–)
COM
VO2(+)
VO3(–)
LOAD1
LOAD3
IO2
IO3
SENSE
VO2(+)
η
VOj +() VCOM–[]IOj
j1=
3
∑
VI+() VI–()–()+[]II
-----------------------------------------------------------100×=
1212 Lineage Power
Data Sheet
April 2009
18 Vdc to 36 Vdc Input; 25 W
DC025 Triple Output-Series Power Modules:
Feature Descriptions
Outp ut Overvolta ge Clam p
The output overvoltage clamp consis ts 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 v oltage set point
than the primary loop (see Feature Specifications
table). This provides a re dundant voltage control that
reduces the risk of output overvoltage.
Current Limit
To provide protection in a fault (output overload) condi -
tion, the unit is equipped with internal current-limiting
circuitr y. At the point of current-lim it inception, the unit
shifts from vo ltage control to current control. If the out-
put voltage is pulled very low during a severe f ault, the
current-limit circuit can exhibit either foldback or
tailout characteristics (output current decrease or
increase). The unit operates normally once the output
current is brought back into its specified range.
Output Voltage Set-Point Adjustment
The output voltage adjustment f eature provides the
capability of increasing or decreasing the output volt-
age set point of a module. This can be accomp lished
by using an external resistor conne cted between the
TRIM pin and either the VO1(+) or common pins. With
an ext ernal resistor between the TRIM and common
pins (Radj-up), the output voltage set point (VO, adj)
increases.
Note: The output voltage adjustment range must not
exceed 110% of the nominal output vol tage
between the VO1(+) and common ter m inals.
With an external resistor connected between the TRIM
and VO1(+) pins (Radj-down), the output voltage set point
(VO, adj) decrease s.
Note: The output voltage adjustment must be 90% or
more of the nominal output vol tage between the
VO1(+) and c om mon ter minals.
Remote On/Off
Two remote on/off options are av ai labl e. Positiv e logic
remot e on/off tur ns 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, 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 switch
can be an open collector or equivale nt (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 m A. The switch should maintain
a logic low vo ltage w hile s ink in g 1 mA.
During a logic high, the maximum Von/off generated by
the power module is 10 V. The maximum allowabl e
leakage c urrent of the sw i tch 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
April 2009
Lineage Power 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 MPER AT U RE AT
THIS POINT
CO NNECTORS T O
LOADS, POWER
SUPPLIES, AN D
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 IN USA
12.7 (0.50)
The 25 W triple output power m odules are designed to
operate in a variety of thermal en vironments. As with
any electronic component , sufficient cooling must be
provid ed to ensure reliable operation. Heat dissipating
component s inside the module are ther ma lly coupled
to the case to enable heat removal by conduc tion, con-
vection, and radiation to the surrou 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 Lineage Power
Data Sheet
April 2009
18 Vdc to 36 Vdc Input; 25 W
DC025 Triple Output-Series Power Modules:
Thermal Considerations (continued)
Ba sic Thermal Performa nce
The maximum operating temperature of the DC025 Tri-
ple Output-Serie s Power Modules at a given operating
condition can be predicted by combining the po wer dis-
sipation cur ve s (Figures 23 through 27), the power der-
ating cur ve (Figure 28), and the therm al resista nce
curve (Figure 28).
Use Figures 23 through 28 and the steps below to pre-
dict the safe operating region for many different operat-
ing and environmen tal conditi ons.
1. Calculate th e total output powe r.
POto tal = (IO1 x VO1) + (IO2 x VO2) + (IO3 x VO3)
2. Use POtotal with the appropria te figure (Figure 23
or 25) to determine the fixed 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 outp uts 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. Fi nd the total power dissipated (PDtotal) by addin g
the four power dissipations obtained in Steps 2
through 4.
PDtotal = PP + PS1 + P S2 + PS3
6. Use the estimated total power dissipated (PDtotal)
along with Figure 28 to determine the maximum
ambient temperature allo wable for a given air
velocity.
For example, con sider the DC025ABK power module
operating with 27 V input and output currents
IO1 = 2.5 A, IO2 = 0.5 A, IO3 = 0.5 A.
T he total output power (POtotal) is 24.5 W. The total
po wer dissipation is PDtotal = 4.86 W, which is obtained
by adding:
PP= 4.5 W (from Figure 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 convection the maxi-
mum operating ambient temperature f or this module is
approximately 66 °C.
Keep in mind that the procedure abov e provides
approximations of the temperature and air velocities
required to keep the case t emp erature below its maxi-
mum rating. The maximum case temperature, as moni-
tored at the point shown in Figure 22, should be
main tained at 100 °C or less u nder all conditions.
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 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 temperatur e (°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 resistance is:
This correspo nds to an airflow grea ter 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=
Lineage Power 15
Data Sheet
April 2009 18 Vdc to 36 Vdc Input; 25 W
DC025 Triple Output-Series Power Modules:
Thermal Considerations (continued)
Air Velocity (continued)
8-1091(C)
Figure 23. DC025ABK-M Fixed Losses, PP
8-1092(C)
Figure 24. DC025ACL-M Fixe d 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 30
1.0
4.0
5.0
6.0
OUTPUTPOWER, PO(W)
1.5
5.5
4.5
3.5
2.0
2.5
3.0
POWERDISSIPATION,P
D
(W)
20
36V
27 V
0 5 10 15 25 30
1.0
4.0
5.0
6.0
OUTPUTPOWER, PO(W)
1.5
5.5
4.5
3.5
2.0
2.5
3.0
POWERDISSIPATION,P
D
(W)
20
36 V
27V
18V
0.0 0.5 1.0 1.5 2.5 3.0
0.0
0.8
1.2
1.6
OUTPUT CURRENT,I
O1 (A)
POWERDISSIPATION,P
D
(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 (A)
0.35
0.25
0.15
0.05
0.10
0.4 0.7 0.9 1.00.8
POWERDISSIPATION,P
D
(W)
1616 Lineage Power
Data Sheet
April 2009
18 Vdc to 36 Vdc Input; 25 W
DC025 Triple Output-Series Power Modules:
Thermal Considerations (continued)
Air Velocity (continued)
8-1095(C)
Figure 27. DC025ACL-M Losses Associa ted with
±15 V Output, PS2/PS3
8-1130(C)
Figu re 28. To ta l Power Di ss i pat i on vs. Local
Ambient Tempe rature and Air Vel ocity
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 e xc eed
0.56 N/m (5 i n.-lb).
The following thermal model can be used 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 module, 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 thermal greases or
foil s, a value of θCS = 0 .1 °C/W t o 0. 3 °C/W is ty p i c a l.
The required θSA is calculated from the following equa-
tion:
Note that this equation assumes th at all dissipated
power must be shed by the sink. Depend ing 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 estimat e in such instances.
F or further thermal inf ormation on these modules, ref er
to the
Thermal Management f or CC-, CW, DC, DW-
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
(
A
)
0.5
0.3
0.1
0.4 0.7 0.90.8
POWERDISSIPATION,P
D
(W)
40 50 100
0.0
2.0
8.0
LOCALAMBIENTTEMPERATURE, TA(°C)
3.0
4.0
5.0
6.0
7.0
70
1.0
9060 80
TOTALPOWERDISSIPATION,P
D
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–=
Lineage Power 17
Data Sheet
April 2009 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 e rs and (in ches ).
Copper paths must not be routed beneath the power modu le 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 CHINA
71.1 (2.80) MAX
61.0
(2.40)
MAX
PIN 1 INDICATOR
M3
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)
10.16 (0.400)
VI(–) COM
1
2
4
3
9
8
6
7
5
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 Lineage Power
Data Sheet
April 2009
18 Vdc to 36 Vdc Input; 25 W
DC025 Triple Output-Series Power Modules:
Recommended Hole Pattern
Component-s ide footpr int.
Dim e ns io ns a r e in mi llimet e r s and (inc h es).
Recommen ded hole size for pin: 1.2 7 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)
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)
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
3
1
2
5
6
8
7
9
