Industrial Environment
DC-DC Converters <40 W
IMS 7-Family
7 W DC-DC Converters
Input to output isolation test voltage 1500 V DC
Single and double outputs of 3.3, 5, 12, 15, 24 V DC
Input voltage ranges: 14...36 V DC and 36...75 V DC
•
Wide input voltage ranges
•
Galvanic isolation, single and double output units
•
High efficiency (typ. >85%)
•
Inhibit input, output voltage adjustable
•
No load and short-circuit proof
•
High reliability and no derating
•
Operating ambient temperature range –25...+71
°C
•
Emissions below EN 55 022 level B.
•
Immunity to IEC 1000- 4 -2, -3, -4, -5 and -6
•
2"
×
1" case with 10.5 mm profile
Safety according to IEC 950
LGA
C
IMS 7-Family
new
Table of Contents
Page
Electromagnetic Compatibility EMC .......................... 6 - 55
Supplementary Data ................................................. 6 - 56
Immunity to Environmental Conditions ...................... 6 - 58
Mechanical Data ....................................................... 6 - 59
Type Key and Product Marking ................................. 6 - 60
Type Survey .............................................................. 6 - 49
Description ................................................................ 6 - 49
Functional Description ............................................... 6 - 50
Safety and Installation Instructions ........................... 6 - 51
Electrical Input and Output Data ............................... 6 - 52
Description of Options ............................................... 6 - 54
Type Survey
Table 1: Type survey
Output 1
Output 2
Input Voltage Range and Efficiency
Option
η
typ
%
78
82
83
84
84
84
M
1
X
2
C
3
U
o nom
V DC
3.3
5.1
5
12
15
24
1
2
I
o nom
A
1.5
1.2
0.7
0.3
0.24
0.15
U
o nom
V DC
I
o nom
A
U
i min
...U
i max
14...36 V DC
24 IMS 7-03-7
24 IMS 7-05-7
η
typ
%
78
82
83
84
84
84
U
i min
...U
i max
36...75 V DC
48 IMS 7-03-7
48 IMS 7-05-7
48 IMS 7-05-05-7
48 IMS 7-12-12-7
48 IMS 7-15-15-7
48 IMS 7-24-24-7
5
12
15
24
0.7
0.3
0.24
0.15
24 IMS 7-05-05-7
24 IMS 7-12-12-7
24 IMS 7-15-15-7
24 IMS 7-24-24-7
3
Option M: Version for SMD mounting.
Option X: LED "U
o
present", available for double output units.
Option C: C-pinout, excludes option M as well as galvanic isola-
tion between output 1 and 2 of double output units.
Description
The IMS 7 series has been designed according to the latest
industry requirements and standards (1995) and is particu-
larly suitable for industrial and telecom applications. The
converters are ideal for use in applications where variable
input voltages or high input transients are prevalent, e.g.
mobile applications. They feature consistently high effi-
ciency over the entire input voltage range, high reliability
and good dynamic response to line and load changes.
A special feature is their small case size, 2"
×
1" with 10.5
mm height. Generous design margins have been applied.
The circuit is mounted on a single PCB, all components sol-
idly soldered without any wire connections and no potting
material is applied. The thermal design allows operation at
nominal load up to an ambient temperature of 71°C in free
air. For extremely high vibration environments the case has
holes allowing screw mounting.
Edition 2/96 - © Melcher AG
MELCHER
The Power Partners.
6 - 49
6.2
IMS 7-Family
Functional Description
DC-DC Converters <40 W
Industrial Environment
The IMS 7 DC-DC modules are feedback controlled flyback
converters using current mode PWM (Pulse Width Modula-
tion). See fig. 1 and 2.
In the case of the single output units the output is directly
monitored and fed back to the primary control circuit via a
pulse transformer, resulting in tight regulation of the output
voltage. The R-input is referenced to the secondary side
and allows for programming of the output voltages in the
range 75 to 105 % of
U
o nom
using either an external resistor
or an external voltage source.
In the case of the double output units the output voltage is
monitored by a separate transformer winding close to the
1
11
secondary windings and fed back to the control circuit. The
R-input is referenced to the primary side and allows pro-
gramming of the output voltage in the range 100 to 105 % of
U
o nom
by an external resistor or within 75 to 105 % of
U
o nom
using an external voltage source.
Current limitation is provided by the primary circuit, thus
limiting the total output current (I
o nom
for the single and
I
o1 nom
+
I
o2 nom
for the double output types).
The inhibit input allows remote converter shut down.
1
11
PWM
3
10
4
10
PWM
3
10 nF, 200V
13
2
×
2200 pF
1500 V
2
12
2
13
12
6.2
4
14
2
×
2200 pF, 1500 V
14
Fig. 1
Block diagram, single output types, standard pinout
Fig. 2
Block diagram, double output types, standard pinout
Table 2: Pin allocation, standard pinout see fig. 14 and 15
Pin
1
2
3
4
10
11
12
13
14
Single output units
Vi+
Vi–
i
n.c.
Vo –
Vo+
Vo –
R
n.c.
Double output units
Vi+
Vi–
i
R
Vo1–
Vo1+
Vo2 –
Vo2+
n.c.
Table 3: Pin allocation for C-pinout (option C) see fig. 3
and 16
Pin
1
2
3
4
5
Single output units
Vi+
Vi–
Vo+
–
Vo–
Dual output units
Vi+
Vi–
Vo+
Go
Vo–
3
1
2
4
5
Fig. 3
C-pinout
6 - 50
MELCHER
The Power Partners.
Edition 2/96 - © Melcher AG
Industrial Environment
DC-DC Converters <40 W
IMS 7-Family
Safety and Installation Instructions
The converters comply with IEC 950, EN 60950 and
UL 1950 and are designed to meet EN 41003. The unit
should be connected to a secondary circuit.
Isolation
Input to output electric strength tests in accordance with the
safety standards IEC 950, EN 60950, VDE 0805 and
EN 41003 respectively are performed as factory tests and
should not be repeated in the field.
Important Advice
Melcher will not honour any guarantee/warranty claims
resulting from high voltage tests.
Safety
If the output circuit of this DC-DC converter is operator-ac-
cessible according to the IEC 950 related safety standards,
it shall be an SELV circuit (Safety Extra Low Voltage circuit,
i.e. a circuit, separated from mains by at least basic insula-
tion, that is so designed and protected that under normal
and single fault conditions, the voltage between any two
conductors and between any conductor and earth does not
exceed 60 V DC).
Cleaning Agents
In order to avoid possible damage, any penetration of
cleaning fluids is to be prevented, since the power supplies
are not hermetically sealed.
Table 4: Electric strength test voltages, clearance and
creepage distances
Characteristics
Electric strength
test voltage
Creepage
distances
Input to Output Output to Output
1.2
1.5
1.6
0.1
0.15
0.4
Unit
kV
rms
kV DC
mm
In the following table an interpretation is provided of the
IEC 950 safety standard with respect to the safety status of
the output circuit. However, it is the sole responsibility of the
installer or user to assure the compliance with the relevant
and applicable safety standards.
If table 5 is observed, the output of any IMS-family DC-DC
converter is considered to be an SELV circuit up to a nomi-
nal output voltage of 30 V (2 x 15 V in series).
6.2
Table 5: Insulation concept for SELV circuits
Nominal
mains
supply
voltage
(AC)
≤150
V
Minimum required grade
of isolation, to be
provided by the AC-DC
front end, including mains
supplied battery charger
Basic
Maximum
output
voltage
from the
front end
≤60
V
≤75
V
≤250
V
Basic
Double or reinforced
≤60
V
≤60
V
≤75
V
Minimum required
safety status of the
front end output circuit
Minimum required grade of
isolation between the input
and the output of the DC-DC
converter, provided by
the converter
Operational
Supplementary, based on
AC 150 V
Operational
Operational
Resulting safety
status of the
DC-DC converter
output circuit
SELV circuit
Earthed SELV circuit
1
Unearthed hazardous
voltage secondary circuit
2
Earthed SELV circuit
1
SELV circuit
Double or reinforced insu- Operational
lated unearthed hazardous
voltage secondary circuit,
supplying an SELV circuit
2
1
2
The earth connection has to be provided by the installer according to the relevant safety standard, e.g. IEC 950.
Has to be insulated from earth by at least basic insulation according to the relevant safety standard, based on the maximum input
voltage of the DC-DC converter.
Edition 2/96 - © Melcher AG
MELCHER
The Power Partners.
6 - 51
IMS 7-Family
DC-DC Converters <40 W
Industrial Environment
Electrical Input and Output Data
General conditions:
T
A
= 25°C, unless
T
C
is specified.
Table 6: Input Data
Input
Characteristics
Conditions
min
14
24
50
0.25
0.5
0.25
24 IMS
typ
max
36
min
36
48
100
0.5
s
48 IMS
typ
max
75
Unit
V DC
U
i
U
i nom
U
i sur
t
start up
t
rise
Input voltage range
1
Input voltage (nominal)
Repetitive surge
voltage
Converter
2
start-up time
Rise time
2
T
A min
...T
A max
I
o
= 0...I
o nom
Abs. max input (3 s)
Worst case condition at
U
i min
and full load
U
i nom
,
I
o
=
I
o nom
resistive load
capacitive load
5
12
15
30
30
B
0.8
–10...0.8
open, 2.4...U
i max
–0.5
1
<3.0
approximately 400
5
12
8
15
30
B
0.5
–10 ...0.8
open, 2.4...U
i max
–0.5
1
<3.0
approximately 400
ms
I
io
I
i rr
U
i RFI
C
i
U
ih
No load input current
Reflected
ripple current
I
o
= 0,
U
i min
...U
i max
I
o
= 0...I
o nom
mA
mA
pp
Input RFI level
EN 55022
4
conducted and radiated
Input capacitance
Inhibit voltage
3
for surge calculations
Converter operating
Converter inhibited
µF
V DC
6.2
I
ih
Inhibit current
Converter operating
Converter inhibited
mA
I
i ih
f
s
1
Input current
if unit inhibited
Switching frequency
U
i
min
...
U
i max
U
i min
...
U
i max
,
I
o
= 0...I
o nom
kHz
2
3
4
U
i min
will not be as stated if
U
o
is increased above
U
o nom
by use of the R input pin. If the output voltage is set to a higher value,
U
i min
will be proportionally increased.
Measured with a resistive or max. admissable capacitive load. (See fig. below)
Switching times are typically 10 ms for transition from one state to another.
Measured with a lead lenght of 0.1 m, leads twisted. Double output units with both outputs in parallel.
U
o
U
o nom
t
rise
t
t
start up
Fig. 4
Converter start-up and rise time
6 - 52
MELCHER
The Power Partners.
Edition 2/96 - © Melcher AG
Industrial Environment
DC-DC Converters <40 W
IMS 7-Family
Table 7a: Output data for single output units
Output
Characteristics
U
o nom
Conditions
min
3.26
3.3 V
typ max
3.34
1.5
3.0
±1
70
min
5.05
5.1 V
typ max
5.15
1.2
2.4
±1
70
%
mV
pp
Unit
V DC
A
U
o
I
o nom
I
CL
∆
U
o U
Output voltage
Output current
Current limit
1
Line and
load regulation
Output voltage
ripple and noise
Output overvoltage
clamping
Temperature coeff.
Admissable
capacitive load
U
i nom
I
o
= 0.5
I
o nom
U
i min
...U
i max
U
i nom
,
T
C
= 25°C
U
i min
...U
i max
I
o
= (0.01...1)
I
o nom
U
i min
...U
i max
I
o
=
I
o nom
(BW = 20 MHz)
u
o
U
o clp
α
Uo
115
∆
U
o
/∆ TC
±0.02
130
115
±0.02
130
%
%/K
µF
ms
mV
C
o ext
t
d
∆
U
o td
≤2500
1
±150
1
≤2000
Dynamic load tran-
U
i nom
sient response time
I
o
= (1...
1
/
4
...1)
I
o nom
Transient output
voltage deviation
±150
Output
Characteristics
U
o nom
Conditions
min
2
×
5V
typ max
5.05
5.07
2
×
12 V
min
11.88
11.84
typ max
2
×
15 V
min
typ max
2
×
24 V
min
typ max
24.25
24.31
Unit
VDC
A
0.6
±1
±3
240
mV
pp
%
U
o1
U
o2
I
o nom
I
CL
∆
U
o U
∆
U
o l
Output voltage
Output current
1
Current limit
1, 2
Line regulation
Load regulation
3
Output voltage
ripple and noise
Output overvoltage
clamping
4
Temperature coeff.
Admissable
capacitive load
2
U
i nom
I
o
= 0.5
I
o nom
U
i min
...
U
i max
U
i nom
,
T
C
= 25°C
U
i min
...
U
i max
I
o nom
U
i nom
I
o
= (0,1...1)
I
o nom
U
i min
...
U
i max
I
o
=
I
o nom
(BW = 20 MHz)
Applies to both
V
o1
and V
o2
∆
U
o
/∆ TC
4.95
4.93
12.12 14.85
12.16 14.80
15.15 23.75
15.20 23.69
2
×
0.7
2.8
±1
±3
80
2
×
0.3
1.2
±1
±3
120
2
×
0.24
1.1
±1
±3
150
2
×
0.15
u
o1/2
U
o clp
α
Uo
115
±0.02
130
115
±0.02
130
115
±0.02
130
115
±0.02
130
%
%/K
C
o ext
t
d
∆
U
o td
1
2
≤2000
1
±150
1
±330
≤300
1
±350
≤200
1
±600
≤100
µF
ms
mV
Dynamic load tran-
U
i nom
sient response time
2
I
o
= (1...
1
/
4
...1)
I
o nom
Transient output
voltage deviation
The current limit is primary side controlled.
Measured with both outputs connected in parallel.
3
Conditions for specified output. Other output loaded with constant current
I
= 0.5
I
o
o nom
.
4
The overvoltage protection device is a zener diode whose breakdown region is typically 120...125% of the nominal output voltage. The
zener diode protects the converter only against internally generated overvoltages.
Edition 2/96 - © Melcher AG
MELCHER
The Power Partners.
6 - 53
6.2
Table 7b: Output data for double output units
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