Data Sheet
August 19 98
JC050A, JC075A, JC100A Power Modules: dc-dc Converters;
18 Vdc to 36 Vdc Input, 5 Vdc Output; 50 W to 100 W
The JC050A, JC075A, JC100A Power Modu les use adv anced ,
surface-mount technology and deliver high-quality, efficient,
compact dc-dc conversion.
Applications
■Distributed power architectures
■Workstations
■EDP equipm ent
■Telecommunications
Options
■Choice of remote on/off logic configuration
■Heat sink available for extended operation
Features
■Small size: 61.0 mm x 57.9 mm x 12.7 mm
(2.40 in. x 2.28 in. x 0.50 in.)
■High power density
■High efficiency: 85% typical
■Low output noise
■Constant frequency
■Industry-standard pinout
■Metal baseplate
■2:1 input voltage range
■Overtemperature protection (100 W only)
■Remote sense
■Remote on/off
■Adjus table output voltage
■Case ground pin
■UL* Recognized, CSA† Certified, VDE Licensed
*UL is a registered trademark of Underwriters Laboratories, Inc.
†CSA is a registered trademark of Canadian Stan dards Assn .
Description
The JC 050A, JC 07 5A , JC10 0A Powe r Modul es a r e dc -dc co nve rters that op er a t e over a n in pu t vo lt age ra nge of
18 Vdc to 36 Vdc and provide a precisely regulated dc output. The outputs are fully isolated from the inputs, allow-
ing versatile polarity configurations and grounding connections. The modules have maximum power ratings from
50 W to 100 W at typical full-load efficiency of 85%.
The sea le d mod ule s of fe r met a l ba sepl at e for exc ell en t the rmal per fo rmance . Thr ead ed -t hro ug h ho le s are pro -
vided to allow easy mounting or addition of a heat sink for high-temperature applications. The standard feature set
includes remote sensing, output trim, and remote on/off for convenient fle xibility in distributed power applications .
2Tyco Electronics Corp.
Data Sheet
August 199818 Vdc to 36 Vdc Input, 5 Vdc Output; 50 W to 100 W
JC050A, JC075A, JC100A Power Modules: dc-dc Converters;
Absolute Maximum Ratings
Stresses in excess of the absolute maximum ratings can cause permanent damage to the device. These are abso-
lute stress ratings only. Functional operation of the device is not implied at these or any other conditions in excess
of those given in the operations sections of the data sheet. Exposure to absolute maximum ratings for extended
periods can adversely affect device reliability.
Electrical Specifications
Unless otherwise indicated, specifications apply over all operating input voltage, resistive load, and temperature
conditions.
Table 1. Input Specifications
Fusing Considerations
CAUTION: This power module is not internally fused. An input line fuse must always be used.
This encapsulated power module can be used in a wide variety of applications, ranging from simple stand-alone
operation to an integrated part of a sophisticated power architecture. To preserve maximum flexibility, internal fus-
ing is not included; however, to achiev e maximum safety and system protection, always use an input line fuse. The
safety agencies require a normal-blo w , dc fuse with a maximum rating of 20 A (see Safety Considerations section).
Based on the information provided in this data sheet on inrush energ y 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 VI—50Vdc
I/O Isolation Voltage — — 1500 Vdc
Operating Case Temper ature
(See Thermal Considerations section.) TC–40 100 °C
Storage Temperature Tstg –55 125 °C
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):
JC050A (See Figure 1)
JC075A (See Figure 2)
JC100A (See Figure 3.)
II, max
II, max
II, max
—
—
—
—
—
—
3.5
5.2
6.9
A
A
A
Inru sh Transien t i2t——1.0A
2s
Input Reflected-ripple Current, Peak- to-peak
(5 Hz to 20 MHz, 12 µH source impedance;
see Figure 20.)
—— 5 —mAp-p
Input Ripple Rejection (120 Hz) — — 60 — dB
Tyco Electronics Corp. 3
Data Sheet
August 1998 18 Vdc to 36 Vdc Input, 5 Vdc Output; 50 W to 100 W
JC050A, JC075A, JC100A Power Modules: dc-dc Converters;
Electrical Specifications (continued)
Table 2. Output Specifications
Table 3. Isolation Specifications
Parameter Device Symbol Min Typ Max Unit
Output Voltage Set Point
(VI = 28 V; IO = IO, max; TC = 25 °C ) All VO, set 4.92 5.0 5.08 Vdc
Output Voltage
(Over all operating input voltage, resistive load,
and temperature conditions until end of life; see
Figure 16.)
All VO4.85 — 5.15 Vdc
Output Regulation:
Line (VI = 18 V to 36 V)
Load (IO = IO, min to IO, max)
Temperature (TC = –40 °C to +100 °C)
All
All
All
—
—
—
—
—
—
0.01
0.05
15
0.1
0.2
50
%
%
mV
Output Ripp le and Noise Volta ge
(See Figure 14.):
RMS
Peak-to-peak (5 Hz to 20 MHz) All
All —
——
——
—40
150 mVrms
mVp-p
External Load Capacitance (electrolytic) All — 0 — 10,000 µF
Output Current
(At IO < IO, m in, the module may exceed output
ripple specifications.)
JC050A
JC075A
JC100A
IO
IO
IO
0.5
0.5
0.5
—
—
—
10
15
20
A
A
A
Output Current-limit Inception
(VO = 90% of VO, nom)JC050A
JC075A
JC100A
IO , cli
IO , cli
IO , cli
—
—
—
12.0
18.0
23.0
14
21
26
A
A
A
Output Short-circuit Current (VO = 250 mV) All — — 170 — %IO, ma x
Efficiency (VI = 28 V; IO = IO, max; TC = 70 °C) JC050A
JC075A
JC100A
η
η
η
83
83
83
84
85
85
—
—
—
%
%
%
Switching Frequency All — — 500 — kHz
Dynamic Response
(IO/t = 1 A/10 µs, VI = 28 V, TC = 25 °C):
Load Change from IO = 50% to 75% of IO, max:
Peak Deviation
Settling Time (VO < 10% of peak deviation)
Load Change from IO = 50% to 25% of IO, max:
Peak Deviation
Settling Time (VO < 10% of peak deviation)
All
All
All
All
—
—
—
—
—
—
—
—
2
300
2
300
—
—
—
—
%VO, set
µs
%VO, set
µs
Parameter Min Typ Max Unit
Isolation Capacitance — 2500 — pF
Isolation Resistance 10 — — MΩ
4Tyco Electronics Corp.
Data Sheet
August 199818 Vdc to 36 Vdc Input, 5 Vdc Output; 50 W to 100 W
JC050A, JC075A, JC100A Power Modules: dc-dc Converters;
General Specifications
Feature Specifications
Unless otherwise indicated, specifications apply over all operating input voltage, resistive load, and temperature
conditions. See Feature Descriptions for additional information.
Parameter Min Typ Max Unit
Calculated MTBF (IO = 80% of IO, max; TC = 40 °C) 2,600,000 hr.
Weight — — 100 (3.5) g (oz.)
Parameter Symbol Min Typ Max Unit
Remote On/Off Signal Interface
(VI = 0 V to 36 V; open collector or equivalent compatible;
signal referenced to VI(–) terminal; see Figure 17 and
Feature Descriptions.):
JCxx xA 1 Preferred Logi c:
Logic Low—Module On
Logic High—Module Off
JCxxxA Optional Logic
Logic Low—Module Off
Logic High—Module On
Logic Low:
At Ion/off = 1.0 mA
At Von/off = 0.0 V
Logic High:
At Ion/off = 0.0 µA
Leakage Current
Turn-on Time (See Figure 13)
(IO = 80% of IO, max; VO within ±1% of steady state)
Von/off
Ion/off
Von/off
Ion/off
—
0
—
—
—
—
—
—
—
—
20
1.2
1.0
15
50
35
V
mA
V
µA
ms
Output Voltage Adjustment (See Feature Descriptions.):
Output Voltage Remote-sense Range
Output Voltage Set-point Adjustment Range (trim) —
——
60 —
—0.5
110 V
%VO, nom
Output Overvoltage Clamp VO, clamp 5.9 — 7.0 V
Overtemperature Shutdown
(100 W only; see Feature Descriptions.) Tc — 105 — °C
Tyco Electronics Corp. 5
Data Sheet
August 1998 18 Vdc to 36 Vdc Input, 5 Vdc Output; 50 W to 100 W
JC050A, JC075A, JC100A Power Modules: dc-dc Converters;
Characteristic Curves
The following figures provide typical characteristics for the JC050A, JC075A, JC100A power modules. The figures
are identical for both on/off configurations.
8-2218 (C)
Figure 1. Typical JC050A Input Characteristics at
Room Temperature
8-1597 (C)
Figure 2. Typical JC075A Input Characteristics at
Room Temperature
8-1914 (C)
Figure 3. Typical JC100A Input Characteristics at
Room Temperature
8-2219 (C)
Figure 4. T ypical JC050A Output Characteristics at
Room Temperature
510 20
0.0
INPUT V OLTA GE, VI (A)
3.5
4.0
400
3.0
2.0
0.5
25 3015 35
1.5
IO = 10 A
2.5
1.0
IO = 5 A
INPUT CURRENT, II (V)
IO = 1 A
812162024
0
4
INPUT V OLTA GE, VI (V)
2
1
3
280
6
32
436
5
40
IO = 7.5 A
IO = 15 A
IO = 0.7 A
INPUT CURRENT, II (A)
2
48 24
28 32
0
INPUT V OLTA GE, VI (V)
3
5
1
9
0 16 20122 6 10 14 18 22 26 30 3436
7
4
6
8
INPUT CURRENT, II (A)
IO = 1 A
IO = 10 A
IO = 20 A
24 8
0
OUTPUT CURRENT, IO (A)
5
6
160
4
3
1
10 12614
2
VI = 36 V
VI = 27 V
VI = 18 V
OUTPUT VOL T AGE, VO (V)
Data Sheet
August 1998
66 Tyco Electronics Corp.
18 Vdc to 36 Vdc Input, 5 Vdc Output; 50 W to 100 W
JC050A, JC075A, JC100A Power Modules: dc-dc Converters;
Characteristic Curves (continued)
8-1598 (C)
Figure 5. T ypical JC075A Output Characteristics at
Room Temperature.
8-1599 (C)
Figure 6. T ypical JC100A Output Characteristics at
Room Temperature.
8-1600 (C)
Figure 7. Typical JC050A Converter Efficiency vs.
Output Current at Room Temperature
8-1601 (C)
Figure 8. Typical JC075A Converter Efficiency vs.
Output Current at Room Temperature
4681012
0
4
OUTPUT CURRENT, I O (A)
2
1
3
140
6
16
218
5
20
VIN = 18 V
VIN = 28 V
VIN = 36 V
OUTPUT V OLTAGE, VO (V)
5
0
4
OUTPUT CURRENT, I O (A)
2
1
3
100
6
15 20
5
25
VIN = 18 V
VIN = 28 V
VIN = 36 V
OUTPUT VOL TA GE, VO (V)
23456
74
82
OUTPUT CURRENT, I O (A)
80
76
81
EFFICIENCY, η (%)
70
84
9
19
83
10
79
78
77
75
VI = 18 V
VI = 27 V
VI = 36 V
2345 8
74
82
OUTPUT CURRENT, I
O
(A)
80
76
81
EFFICIENCY, η (%)
100 11113
83
15
79
78
77
75
67 9 12 14
V
I
= 36 V
V
I
= 28 V
V
I
= 18 V
Tyco Electronics Corp. 7
Data Sheet
August 1998 18 Vdc to 36 Vdc Input, 5 Vdc Output; 50 W to 100 W
JC050A, JC075A, JC100A Power Modules: dc-dc Converters;
Characteristic Curves (continued)
8-1602 (C)
Figure 9. Typical JC100A Converter Efficiency vs.
Output Current at Room Temperature
8-1915 (C)
Figure 10.Typical JC100A Output Ripple Voltage at
Room Temperature and 20 A Output
8-1916 (C)
Figure 11.Typical JC100A Transient Response to
Step Decrease in Load from 50% to 25%
of Full Load at Room Temperature and 28
V Input (Waveform A veraged to Eliminate
Ripple Component.)
8-1917 (C)
Figure 12.Typical JC100A Transient Response to
Step Increase in Load from 50% to 75% of
Full Load at Room Temperature and 28 V
Input (Waveform Averaged to Eliminate
Ripple Component.)
6 8 10 12 14
73
82
OUTPUT CURRENT, I
O
(A)
79
75
80
EFFICIENCY, η (%)
180 16420
83
78
77
76
74
81
V
I
= 36 V
V
I
= 18 V
V
I
= 28 V
TIME, t (1 µs/div)
OUTPUT VOLTAGE, VO (V)
(50 mV/div)
18 V
28 V
36 V
TIME, t (200 µs/div)
OUTPUT CURRENT, I
O
(A)
(2 A/div) OUTPUT VOLT A GE, V
O
(V)
(100 mV/div)
TIME, t (200 µs/div)
OUTPUT CURRENT, I
O
(A)
(2 A/div) OUTPUT VOLTAGE, V
O
(V)
(100 mV/div)
Data Sheet
August 1998
88 Tyco Electronics Corp.
18 Vdc to 36 Vdc Input, 5 Vdc Output; 50 W to 100 W
JC050A, JC075A, JC100A Power Modules: dc-dc Converters;
Characteristic Curves (continued)
8-1603 (C)
Figure 13.Typical Start-Up from Remote On/Off
JC100A1; IO = Full Load
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 14. Input Reflected-Ripple Test Setup
8-513 (C).d
Note: Use a 1.0 µF ceramic capacitor and a 10 µF aluminum or tan-
talum capacitor. Scope measurement should be made using a
BNC socket. Position the load between 51 mm and 76 mm
(2 in. and 3 in.) from the module.
Figure 15. Peak-to-Peak Output Noise
Measurement Test Setup
8-749 (C)
Note: All measurements are tak en at the module terminals. When
socketing, place Kelvin connections at module terminal s to
avoid measurement errors due to socket contact resistance.
Figure 16. Output Voltage and Efficiency
Measurement Test Setup
TIME, t (5 ms/div)
OUTPUT V OLTAGE, Vo (V)
(1 V/div) REMOTE ON/OFF
V OLTAGE, VON/OFF (V)
TO OSCILLOSCOPE
12 µH
C
S
220 µF
ESR < 0.1 Ω
@ 20 ˚C, 100 kHz
V
I
(+)
V
I
(–)
BATTERY 33 µF
CURRENT
PROBE
L
TEST
ESR < 0.7 Ω
@ 100 kHz
VO(+)
VO(–)
1.0 µF RESISTIVE
LOAD
SCOPE
COPPER STRIP
10 µF
VI(+)
IIIO
SUPPLY
CONTACT
RESISTANCE
CONTACT AND
DISTRIBUTION LOSSES
LOAD
SENSE(+)
VI(–)
VO(+)
VO(–)
SENSE(–)
η[Vo(+) – Vo(-)]Io
[Vi(+) – Vi(-)]Ii
-------------------------------------------
100×=
Tyco Electronics Corp. 9
Data Sheet
August 1998 18 Vdc to 36 Vdc Input, 5 Vdc Output; 50 W to 100 W
JC050A, JC075A, JC100A Power Modules: dc-dc Converters;
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 14, a 33 µF
electrolytic capacitor (ESR < 0.7 Ω at 100 kHz)
mounted close to the power module helps ensure sta-
bility of the unit. For other highly inductive source
impedances, consult the factory for further application
guidelines.
Safety Considerations
For safety-agency approval of the system in which the
power module is used, the power module must be
installed in compliance with the spacing and separation
requirements of the end-use safety agency standard,
i.e., UL-1950, CSA 22.2-950, and EN60950.
For the converter output to be considered meeting the
requirements of safety extra-low voltage (SELV), the
input must meet SELV requirements.
If the input meets extra-low voltage (ELV) require-
ments, then the converter’s output is considered ELV.
The input to these units is to be provided with a maxi-
mum 20 A normal-blo w 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
coutput voltage is pulled very low during a severe f ault,
the current-limit circuit can exhibit either foldback or tai-
lout characteristics (output current decrease or
increase). The unit operates normally once the output
current is brought back into its specified range.
Feature Descriptions
Remote On/Off
Two remote on/off options are available. Positive logic
remote on/off turns the module on during a logic-high
voltage on the ON/OFF pin, and off during a logic low.
Negative logic remote on/off turns the module off dur-
ing a logic high and on during a logic low. Negative
logic (code suffix “1”) is the factory-preferred configura-
tion.
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 17).
A logic low is Von/off = 0 V to 1.2 V. The maximum 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 modul e is 15 V. The maximum allowable
leakage current of the switch at Von/off = 15 V is 50 µA.
If not using the remote on/off feature, do one of the fol-
lowing:
■For negative logic, short ON/OFF pin to VI(-)
■For positive logic, leave ON/OFF pin open.
8-720 (C).c
Figure 17. Remote On/Off Implementation
Remote Sense
Remote sense minimizes the effects of distribution
losses by regulating the voltage at the remote-sense
connections. The voltage between the remote-sense
pins and the output terminals must not exceed the out-
put voltage sense range giv en in the Feature Specifica-
tions table, i.e.:
[VO(+) – VO(–)] – [SENSE(+) – SE N SE (–)] ≤ 0.5 V
SENSE(+)
VO(+)
SENSE(–)
VO(–)
VI(–)
+
–
Ion/off ON/OFF
VI(+)
LOAD
Von/off
Data Sheet
August 1998
1010 Tyco Electronics Corp.
18 Vdc to 36 Vdc Input, 5 Vdc Output; 50 W to 100 W
JC050A, JC075A, JC100A Power Modules: dc-dc Converters;
Feature Descriptions (continued)
Remote Sense (continued)
The voltage between the VO(+) and VO(–) terminals
must not exceed 5.9 V. This limit includes any increase
in voltage due to remote-sense compensation and out-
put voltage set-point adjustment (trim), see Figure 18.
If not using the remote-sense feature to regulate the
output at the point of load, then connect SENSE(+) to
VO(+) and SENSE(-) to VO(-) at the module.
8-651 (C).h
Figure 18. Effective Circuit Configuration for
Single-Module Remote-Sense Operation
Output Voltage Set-Point Adjustment
(Trim)
Output voltage trim allows the user to increase or
decrease the output voltage set point of a module. This
is accomplished by connecting an external resistor
between the TRIM pin and either the SENSE(+) or
SENSE(–) pins. With an external resistor between the
TRIM and SENSE(–) pins (Radj-down), th e out put v ol tage
set point (Vo, adj) decreases (see Figure 19). The follow-
ing equation determines the required external-resistor
value to obtain a percentage output voltage change of
∆%.
The test results for this configuration are displayed in
Figure 20. This figure applies to all output voltages.
With an external resistor connected between the TRIM
and SENSE(+) pins (Radj-up), the output voltage set
point (VO, adj) increases (see Figure 21).
The following equation determines the required exter-
nal-resistor v alue to obtain a percentage output v oltage
change of ∆%.
The test results for this configuration are displayed in
Figure 22.
The voltage between the VO(+) and VO(–) terminal s
must not exceed 5.9 V. This limit includes any increase
in voltage due to remote-sense compensation and out-
put voltage set-point adjustment (trim). See Figure 18.
If not using the trim f eature, leave the TRIM pin open.
8-748 (C).c
Figure 19. Circuit Configuration to Decrease
Output Voltage
8-879 (C)
Figure 20. Resistor Selection for Decreased
Output Voltage
VO(+)
SENSE(+)
SENSE(–)
VO(–)
VI(+)
VI(–)
IOLOAD
CONTACT AND
DISTRIBUTION LOSSES
SUPPLY II
CONTACT
RESISTANCE
Radj-down 100
∆%
----------2–
kΩ=
Radj-up VO100 ∆%+()
1.225∆%
-------------------------------------- 100 2∆%+()
∆%
----------------------------------
–
kΩ=
VI(+)
VI(–)
ON/OFF
CASE
VO(+)
VO(–)
SENSE(+)
TRIM
SENSE(–)Radj-down
RLOAD
010203040
100
1k
100k
1M
% CHANGE IN OUTPUT VOLTAGE (∆%)
10k
ADJUSTMENT RESISTOR VALUE (Ω)
Tyco Electronics Corp. 11
Data Sheet
August 1998 18 Vdc to 36 Vdc Input, 5 Vdc Output; 50 W to 100 W
JC050A, JC075A, JC100A Power Modules: dc-dc Converters;
Feature Descriptions (continued)
Output Voltage Set-Point Adjustment
(Trim) (continued)
8-715 (C).d
Figure 21. Circuit Configuration to Increase
Output Voltage
8-880a
Figure 22. Resistor Selection for Increased Output
Voltage
Output Overvoltage Clamp
The ouput 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 prov ides a redundant voltage control that
reduces the risk of output overvoltage.
Over termperature Pro tection (Shutdown)
The 100 W module features an overtemperature pro-
tection circuit to safeguard against thermal damage.
The circuit shuts down the module when the maximum
case temperature is exceeded. The module restarts
automatically after cooling.
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,a nd radiation to the surrounding
environment. Proper cooling can be verified by mea-
suring the case temperature. Peak temperature (Tc)
occurs at the position indicated in Figure 23.
8-716 (C).f
Note: Top view, pin locations are for ref erence.
Measurements shown in millimeters and (inches).
Figure 23. C ase Temper ature Measurement
Location
The temperature at this location should not exceed
100 °C. The output power of the module should not
exceed the rated power for the module as listed in the
Ordering Information table.
Although the maximum case temperature of the power
modules is 100 °C, you can limit this temperature to a
lower value for ex tremely high reliability.
For addi ti on al info rmation on t h ese mo du les, refer t o t he
Thermal Manag emen t JC-, JF C-, JW-, and JFW-Series
50 W to 150 W Board-Mounted P ower Modules Technical
Note (TN97-008EPS).
VI(+)
VI(–)
ON/OFF
CASE
VO(+)
VO(–)
SENSE(+)
TRIM
SENSE(–)
Radj-up RLOAD
02 4 6 10
10M
%
CHANGE IN OUTPUT VOLTAGE (
∆
%)
8
1M
100k
10k
ADJUSTMENT RESISTOR VALUE (
Ω
)
38.0 (1. 50) MEASURE CASE
VI(–)
ON/OFF
CASE
+ SEN
TRIM
– SEN
VI(+)
VO(–)
VO(+)
7.6 (0.3)
TEMPERATURE HERE
Data Sheet
August 1998
1212 Tyco Electronics Corp.
18 Vdc to 36 Vdc Input, 5 Vdc Output; 50 W to 100 W
JC050A, JC075A, JC100A Power Modules: dc-dc Converters;
Thermal considerations (continued)
Heat Transfer Without Heat Sinks
Increasing airflow over the module enhances the heat
transfer via convection. Figure 24 shows the maximum
power that can be dissipated by the module without
ex ceeding the maximum case temperature v ersus local
ambient temperature (TA) for natural convection
through 4 m/s (800 ft./min.).
Note that the natural convection condition was mea-
sured at 0.05 m/s to 0.1 m/s (10 ft./min. to 20 ft./min.);
however, systems in which these power modules may
be used typicall y gen erate natural co nvection airflow
rates of 0.3 m/s (60 ft./min.) due to other heat dissipat-
ing components in the system. The use of Figure 24 is
shown in the following example.
Example
What is the minimum airflow necessary for a JC100A
operating at nominal line, an output current of 20 A,
and a maximum ambient temperature of 40 °C?
Solution
Given: VI = 28 V
IO = 20 A
TA = 40 °C
Determine PD (Use Figure 27.):
PD = 22.8 W
Determine airflow (v) (Use Figure 24.):
v = 2.7 m/s (540 ft./min.)
8-1150 (C).a
Figure 24. For ced Con vection P o wer Derating with
No Heat Sink; Either Orientation
8-2220
Figure 25. JC050A Power Dissipatio n vs.
Output Current
8-1604
Figure 26. JC075A Power Dissipatio n vs.
Output Current
8-1605
Figure 27. JC100A Power Dissipatio n vs.
Output Current
010203040 100
0
35
LOCAL AMBIENT TEMPERATURE, T
A (˚C)
POWER DISSIPATION, PD (W)
25
20
10
90
80706050
4.0 m/s (800 ft./min.)
0.1 m/s (NAT. CONV.)
(20 ft./min.)
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.)
5
15
30
23 56
4
OUTPUT CURRENT, IO
(A)
10
12
101
9
5
8
6
78
11
49
7
VI = 36 V
VI = 27 V
VI = 18 V
POWER DISSIPATION, PD (W)
2345 8
0
18
OUTPUT CURRENT, I O
(
A
)
14
6
16
POWER DISSIPATION, PD (W)
100 11113
20
15
12
10
8
4
67 9 12 14
2
VI = 18 V
VI = 28 V
VI = 36 V
4681012
0
20
OUTPUT CURRENT, I
O
(A)
16
8
18
POWER DISSIPATION, P
D
(W)
140
24
16
218
22
20
14
12
10
2
6
4
V
I
= 36 V
V
I
= 28 V
V
I
= 18 V
Tyco Electronics Corp. 13
Data Sheet
August 1998 18 Vdc to 36 Vdc Input, 5 Vdc Output; 50 W to 100 W
JC050A, JC075A, JC100A Power Modules: dc-dc Converters;
Thermal Considerations (continued)
Heat Transfer with Heat Sinks
The power modules have through-threaded, M3 x 0.5
mounting holes, which enab le heat sinks or cold plates
to attach to the module. The mounting torque must not
exceed 0.56 N–m (5 in.–lb .). For a screw attachment
from the pin side, the recommended hole size on the
customer’s PWB around the mounting holes is
0.130 ± 0.005 i nches. If a larger hole is used, the
mounting torque from the pin side must not exceed
0.25 N–m (2.2 in.–lb.).
Thermal derating with heat sinks is expressed by using
the overall thermal resistance of the module. Total
module thermal resistance (θca) is defined as the max-
imum case temperature rise (∆TC, max) divided by the
module power dissipation (PD):
The location to measure case temperature (TC) is
shown in Figure 23. Case-to-ambient thermal resis-
tance vs. airflow is shown, for various heat sink config-
urations and heights, in Figure 28. Th ese curves were
obtained by experimental testing of heat sinks, which
are offered in the product catalog.
8-1153
Figure 28. Case-to-Ambient Thermal Resistance
Curves; Either Orientation
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 28 had a
thermal-conductive dry pad between the case and the
heat sink to minimize contact resistance. The use of
Figure 28 is shown in the following example
Example
If an 85 °C case temperature is desired, what is the
minimum airflow necessary? Assume the JC1 00A
module is operating at nominal line and an output cur-
rent of 20 A, maximum ambient air temper ature of
40 °C, and the heat sink is 0.5 in.
Solution
Given: VI = 28 V
IO = 20 A
TA = 40 °C
TC = 85 °C
Heat sink = 0.5 in.
Determine PD by using Figure 27:
PD = 22.8 W
Then solve the following equation:
Use Figure 28 to determine air velocity for the 0.5 inch
heat sink.
The minimum airflow necessary for the JC100A mod-
ule is 2.0 m/s (400 ft./min.).
θca ∆TCmax,
PD
---------------------TCTA
–()
PD
------------------------
==
00.5
(100) 1.0
(200) 1.5
(300) 2.0
(400) 2.5
(500) 3.0
(600)
0
1
5
6
7
8
AIR VELOCITY ME ASURED IN m/s (ft./min.)
4
3
2
CASE - TO-AMBI ENT THERMAL
RESISTANCE, RCA (°C/W)
1 1/2 IN HEAT SINK
1 IN HEAT SINK
1/2 IN HEAT SINK
1/4 IN HEAT SINK
NO HEAT SINK
θca TCTA
–()
PD
------------------------
=
θca 85 40–()
17
------------------------
=
θca 1.97 °C/W=
Data Sheet
August 1998
1414 Tyco Electronics Corp.
18 Vdc to 36 Vdc Input, 5 Vdc Output; 50 W to 100 W
JC050A, JC075A, JC100A Power Modules: dc-dc Converters;
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 29).
8-1304
Figure 29. 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
solut ion f or 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 pro-
vides a conservative estimate for such instances.
Layout Considerations
Copper paths must not be routed beneath the power
module mounting inserts.
P
D
T
C
T
S
T
A
θcs θsa
→
θsa TCTA
–()
PD
-------------------------θcs–=
15 Tyco Electronics Corp.
Data Sheet
August 199818 Vdc to 36 Vdc Input, 5 Vdc Output; 50 W to 100 W
JC050A, JC075A, JC100A Power Modules: dc-dc Converters;
Outline Diagram
Dimensions are in millimeters and (inches).
Tolerances: x.x mm ± 0.5 mm (x.xx in. ± 0.02 in.)
x.xx mm ± 0.25 mm (x.xxx in. ± 0.010 in.)
Top View
Side View
Bottom View
8-1945
* Side labels include Tyco name, product designation, saf ety agency markings, input/output v oltage and current ratings, and bar code.
57.9 (2.28) MAX
61.0
(2.40)
MAX
5.1 (0.20) MIN
12.70 ± 0.5
(0.500 ± 0.020) 2.06 (0.081) DIA
SOLDER-PLATED BRASS,
2 PLACES–(OUTPUT AND
+OUTPUT)
1.02 (0.0 40 ) DIA
SOLDER-PLATED
BRASS, 7 PLCS
SIDE LABEL*
10.16
(0.400)
–SEN
TRIM
+SEN
CASE
ON/OFF
MOUNTING INSERTS
M3 x 0.5 THROUGH,
4 PLACES
10.16
(0.400)
5.1 (0.20)
48.3 (1.90)
48.26
(1.900)
12.7 (0. 50)
4.8
(0.19)
17.78
(0.700)25.40
(1.000)
35.56
(1.400)
25.40
(1.000)
50.8
(2.00)
35.56
(1.400)
VI (–)V
O (–)
VO (+)VI (+)
Data Sheet
August 199818 Vdc to 36 Vdc Input, 5 Vdc Output; 50 W to 100 W
JC050A, JC075A, JC100A Power Modules: dc-dc Converters;
Printed on
Recycled Paper
World Wide Headquarters
Tyco Electronics Pow er Systems, Inc.
3000 S kyline Drive , Me squite, TX 7514 9, US A
+1-800-526-7819 FAX: +1-888-315-5182
(Outside U .S.A.: +1-972-284-2626, FA X: + 1-9 7 2 -28 4 -2 9 00)
www.power.tycoelectronics.com
e-mail: techsupport1@tycoelectronics.com
Tyco Electronics Co rporation 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 Power Systems, Inc. (Mesquite, Texas) All International Rights Reserved.
Printed in U.S.A.
August 1998
DS97-550EPS
Europe, Middle-East and A frica Headquarters
Tyco E lectronics (UK) Ltd
Te l: +44 (0) 1344 469 30 0, Fax: +44 (0) 1344 4 69 30 1
Cen tral Am erica-Latin America Head qu arters
Tyco E lectronics Power Systems
Tel: +54 11 4316 28 66, Fax: +54 11 43 12 9508
Asia - Pac ific He a dquarte r s
Tyco E lectronics Singapore Pte Ltd
Tel: +65 482 0311, Fax: 65 480 9299
Recommended Hole Patter n
Component-side footprint.
Dimensions are in millimeters and (inches).
8-1945
Ordering Information
10.16
(0.400)
10.16
(0.400)
12.7 (0.50)
48.3 (1.90)
48.26
(1.900)
4.8
(0.19)
MOUNTING INSERTS
MODULE OUTLINE
5.1 (0.20)
57.9 (2.28) MAX
17.78
(0.700)
25.40
(1.000)
35.56
(1.400)
25.40
(1.000)
50.8
(2.00)
35.56
(1.400)
61.0
(2.40)
MAX
–SEN
TRIM
+SEN
CASE
ON/OFF
VI (+) VO (+)
VO (–)
VI (–)
3.30 ± 0.15 (0.130 ± 0.005)
Input
Voltage Output
Voltage Output
Power Remote On/
Off Logic Device
Code Comcode
28 V 5.0 V 50 W negative JC050A1 107201634
28 V 5.0 V 75 W negative JC075A1 107309999
28 V 5.0 V 100 W negative JC100A1 107201675
28 V 5.0 V 50 W positive JC050A 107309858
28 V 5.0 V 75 W positive JC075A 107430340
28 V 5.0 V 100 W positive JC100A 107309924
