IMR 15-Family DC-DC Converters <40 W Benign Environment
6 - 84 Edition 2/96 - © Melcher AG
MELCHER
The Power Partners.
6.3
DC-DC Converters IMR 15-Family
Input to output isolation test voltage 500 V DC
Single or dual output
Input voltage range 2:1
Input filter built-in
High efficiency up to 82%
Short-circuit-proof
No derating
2"×2" metal case
Low cost
Table of Contents Page
Type Survey ..............................................................6 - 84
Description ................................................................6 - 84
Safety and Installation Instructions ........................... 6 - 85
Immunity to Environmental Conditions......................6 - 86
Electrical Input and Output Data ...............................6 - 86
Mechanical Data ....................................................... 6 - 88
Type Key and Product Marking.................................6 - 88
Type Survey
Table 1: Type survey
Output Input voltage Nominal input Input to output Type
U
o nom
I
o nom range
U
ivoltage
U
i nom isolation
5 V 3000 mA .. IMR 15-05-2
12 V 1250 mA 12 IMR 15: 9...18 V DC 112 V DC Test voltage: .. IMR 15-12-2
15 V 1000 mA 24 IMR 15: 18...36 V DC 24 V DC 500 V DC min. .. IMR 15-15-2
±12 V ±625 mA 48 IMR 15: 36...72 V DC 48 V DC Resistance: .. IMR 15-1212-2
±15 V ±500 mA 1000 M min. .. IMR 15-1515-2
112 IMR 15: Output current
I
o nom see "Output Data"
Description
The IMR 15 family of DC-DC converters have been devel-
oped for powering commercial type of electronic circuits,
e.g. telephone systems components, industrial controllers
and small appliances. They are suitable for applications
with standard battery voltages. The IMR 15 converters fea-
ture good efficiency and good dynamic response to load
changes and at start-up . The IMR 15 modules are shor t-cir-
cuit-proof.
Vi+
Vo–
Vi–
Vo+
Ref.
Control
Shunt diode,
Filter
COM
Vi+
Vo–
Vi–
Vo+
Ref.
Control
Shunt diode,
Filter
n.c.
Fig. 2:
Dual output converter block diagram
Fig. 1:
Single output converter block diagram
Benign Environment DC-DC Converters <40 W IMR 15-Family
Edition 2/96 - © Melcher AG 6 - 85
MELCHER
The Power Partners.
6.3
Safety and Installation Instructions
Safety
If the output circuit of a DC-DC converter is operator-acces-
sible 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).
In the following section an interpretation is provided of the
IEC 950 safety standard with respect to the safety status of
the output circuit. Ho we ver , it is the sole responsibility of the
installer or user to assure the compliance with the relevant
and applicable safety standards.
If the following table is observed, the output of any DC-DC
converter is considered to be an SELV.
Table 2: Insulation concept for SELV circuits
Nominal Minimum required grade Maximum Minimum required Minimum required grade of Resulting safety
mains of isolation, to be output safety status of the isolation between the input status of the
supply provided by the AC-DC voltage front end output circuit and the output of the DC-DC DC-DC converter
voltage front end, including mains from the converter, provided by output circuit
(AC) supplied battery charger front end the converter
250 V Basic 60 V Earthed SELV circuit 1 Operational SELV circuit 2
72 V Unearthed hazardous Operational Earthed SELV
voltage secondary circuit 3 circuit 1 2
Double or reinforced 60 V SELV circuit Operational SELV circuit 2
72 V Double or reinforced insu- Operational
lated unearthed hazardous
voltage secondary circuit,
supplying an SELV circuit 4
1The earth connection has to be provided by the installer according to the relevant safety standard, e.g. IEC 950.
2The output has to be protected against overvoltages higher than 60 V by external means, e.g. an overvoltage suppressor diode.
3Has 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.
4Has to be insulated from earth by double or reinforced insulation according to the relevant safety standard, based on the maximum in-
put voltage of the DC-DC converter.
Filter recommendations for compliance with
EN 55022, class B
Electromagnetic emission requirements according to EN
55022, class B can be easely achieved by adding an exter-
nal input filter consisting of two additional capacitors and
one current compensated circular double choke.
The filter components should be placed as close as possi-
ble to the input of the converter.
Fig. 4
Input filter arrangement for 48 V DC types
Table 3: Input filter components
Input voltage
C
1
C
2Type
L
1Type
C
iType
12, 24, 40 V DC 2.2 µF 2.2 µF Siemens 2.2 mH Siemens 2.2 µF Siemens
100 V 100 V B 32522 B 82722 100 V B 32522
C1225-K A2202-N1 C1225-K
48 V DC 2.2 µF 1 2.2 µF 1 Siemens 2.2 mH Siemens
100 V 100 V B 32522 B 82722
C1225-K A2202-N1
1Only valid for input voltages up to 60 V DC.
C
1
C
2
L
1IMR 15
Vi+
Vi–
Fig. 3
Input filter arrangement for 12, 24 and 40 V DC types
C
1
C
2
L
1IMR 15
Vi+
Vi–
C
i
IMR 15-Family DC-DC Converters <40 W Benign Environment
6 - 86 Edition 2/96 - © Melcher AG
MELCHER
The Power Partners.
6.3
Connection in Parallel
The outputs of several units can be connected in parallel.
Howev er, the use of a single unit with a higher power rating
is a better choice, because of uneven power distribution
among the outputs connected in parallel. It is recom-
mended to select converters to be connected in parallel
with very small output voltage differences at full load (i.e.
< ±1%). A decoupling diode is not required but recom-
mended.
Connection in Series
The outputs of one or more units can be connected in se-
ries. No suppressor diodes are required. Melcher, however
recommends to protect each individual output with a Zener
diode or preferably a suppressor diode, to avoid reverse
polarity that may occur if the output voltages do not rise si-
multaneously.
Immunity to Environmental Conditions
Thermal Considerations
Table 4: Temperature specification
Characteristics Conditions min max Unit
T
AAmbient temperature
U
i nom –10 50 °C
T
CCase temperature
I
o = 0...
I
o nom –10 80
T
SStorage temperature Not operational 25 100
Table 5: MTBF
Values at specified Ground Benign Ground Fixed Ground Mobile Unit
Case Temperature 40°C40°C50°C
MTBF according to MIL-HDBK-217F, N2 2'932'000 695'900 261'800 h
Electrical Input and Output Data
General condition:
– T
A = 25°C unless otherwise specified.
Table 6a: Input data
Input 12 IMR 15 24 IMR 15
Characteristics Conditions min typ max min typ max Unit
U
iInput voltage range
T
A min...
T
A max
, I
o = 0...
I
o nom 9181836V DC
U
i nom Nominal input voltage 12 24
I
i 0 No load input current
U
i nom,
I
o = 0 35 26 mA
I
i L Input current limitation
U
i nom, full load 1.25
P
i nom 1.25
P
i nom W
response
U
i rev Reverse input voltage
U
i = negative or shunt diode shunt diode
protection reverse polarity use external fuse use external fuse
Table 6b: Input data
Input 48 IMR 15
Characteristics Conditions min typ max Unit
U
iInput voltage range
T
A min...
T
A max,
I
o = 0...
I
o nom 36 72 V DC
U
i nom Nominal input voltage 48
I
i 0 No load input current
U
i nom,
I
o = 0 26 mA
I
i L Input current limitation
U
i nom, full load 1.25
P
i nom W
response
U
i rev Reverse input voltage
U
i = negative or shunt diode
protection reverse polarity use external fuse
Benign Environment DC-DC Converters <40 W IMR 15-Family
Edition 2/96 - © Melcher AG 6 - 87
MELCHER
The Power Partners.
6.3
Table 7a: Output data
Output .. IMR 15-05 .. IMR 15-12 .. IMR 15-15
Characteristics Conditions min typ max min typ max min typ max Unit
U
o nom Nominal output voltage
U
i nom,
I
o nom 4.90 5.10 11.76 12.24 14.70 15.30 V
I
o nom Nominal output current:
– 12 IMR 15 types
U
i min...
U
i max 2000 834 667 mA
– other types 3000 1250 1000
u
oOutput voltage noise
U
i nom 100 240 300 mVpp
(BW = 20 MHz)
I
o = 0.2
I
o nom
U
o U Static line regulation
U
i min...
U
i max ±1±1±1%
I
o nom
U
o I Static load regulation
U
i nom
,
±2±2±2
I
o = 0
I
o nom
t
rTransient recovery time
I
o =10.5
I
o nom 500 500 500 µs
αuo Temperature coefficient
U
i nom
, I
o nom ±0.02 ±0.02 ±0.02 %/K
f
sSwitching frequency 200 200 200 kHz
Efficiency
η
– 12 IMR 15 types
U
i nom,
I
o nom 63 65 65 %
– other types 70 76 78
Table 7b: Output data
Output .. IMR 15-1212 .. IMR 15-1515
Characteristics Conditions min typ max min typ max Unit
U
o nom Nominal output voltage
U
i nom,
I
o nom ±11.76 ±12.24 ±14.70 ±15.30 V
I
o nom Nominal output current:
– 12 IMR 15 types
U
i min...
U
i max ±417 ±334 mA
– other types ±625 ±500
I
o min Minimum output current 0.2
I
o nom 0.2
I
o nom
each output
u
oOutput voltage noise
U
i nom, 240 300 mVpp
(BW = 20 MHz)
I
o = 0.2
I
o nom
U
o U Static line regulation
U
i min...
U
i max,±1±1%
I
o nom
U
o I Static load regulation
U
i nom
,
±5±5
I
o = 0.2
I
o nom
t
rTransient recovery time
I
o =1 0.5
I
o nom 500 500 µs
αuo Temperature coefficient
U
i nom
, I
o nom ±0.02 ±0.02 %/K
f
sSwitching frequency 200 200 kHz
Efficiency
η
– 12 IMR 15 types
U
i nom,
I
o nom 73 75 %
– other types 80 80
IMR 15-Family DC-DC Converters <40 W Benign Environment
6 - 88 Edition 2/96 - © Melcher AG
MELCHER
The Power Partners.
6.3
12
ø 1
12min. 5
ø 1
50.8
20.32
15.24
15.24
Vo+
Bottom view
50.8
5.08
22.86
10.2 10.2
Vi– Vi+
NC
(COM)
Vo–
min. 5
Fig. 5
Case 2"
×
2"
Weight: 70 g
Mechanical Data
Dimensions in mm. Tolerances ±0.3 mm unless otherwise specified. European
Projection
Type Key and Product Marking
Type Key 24 IMR 15 - 12 12 -2
Nominal input voltage in volt ................................... 12...48
Blank ..................................................................................
Family.......................................................................... IMR
Nominal output power in watt......................................... 15
Nominal output voltage for output 1 in volt................ 5...15
Nominal output voltage for output 2 in volt.............. 12...15
Operational ambient temperature range ......................... -2
Product Marking
Main face: Melcher name, data code on separate label, type of converter, input voltage range and pin assignment.