www.murata-ps.com
CME Series
Isolated 0.75W Single Output Isolated DC-DC Converters
SELECTION GUIDE
Load Regulation
Output Current
Ripple & Noise
Nominal Input
Voltage
Output
Voltage
Input Current
at Rated Load
Isolation
Capacitance
pF
30
30
33
30
35
28
30
22
22
70
70
77
73
73
70
75
76.5
76.5
Efficiency
Order Code
V
V
5
5
12
3.3
5
5
12
5
5
mA
150
150
63
227
150
150
63
150
150
mA
mV p-p
%
Typ. Max. Typ. Max. Min. Typ.
67
67
72
66
68
65
70
74
74
%
MIL. Tel.
kHrs
3400
3400
2200
1230
630
2400
630
2887 47047
2887 47047
FEATURES
Short circuit protection options
UL 60950 recognised
Single Isolated output
1kVDC or 3kVDC option ‘Hi Pot Test’
Wide temperature performance at full
0.75W load -40°C to 85°C
Industry Standard Pinout
3.3V and 5V Inputs
3.3V, 5V & 12V outputs
Pin Compatible with LME, MEE1, MEE3,
NKE, NME, & NML series
CME0505DC
CME0505SC
CME0512SC
CME0303S3C
CME0305S3C
CME0505S3C
CME0512S3C
CME0505SPC
CME0505DPC
5
5
5
3.3
3.3
5
5
5
5
218
10
12
15
25
218
10
12
15
25
195
5
7
20
30
3KVDC isolation options
300
9
12
15
25
300
9
12
15
25
218
9
12
15
25
200
5
7
10
15
Short Circuit Protection Options
195 7.5
9
11
25
195 7.5
9
11
25
INPUT CHARACTERISTICS
Parameter
Voltage range
Input short circuit current
Input reflected ripple
current
Conditions
Continuous operation, 3.3V input types
Continuous operation, 5V input types
Short circuit variants
3.3V input types
5V input types
Short circuit types
Min.
2.97
4.5
Typ.
3.3
5.0
95
1.5
2
3
Max.
3.63
5.5
2
2.5
15
MTTF
1
Units
V
mA
mA p-p
PRODUCT OVERVIEW
The CME series are a cost effective 0.75W DC-DC
converter series, in industry standard packages
with industry standard pinout, Popular input and
output voltages are available as a lower power
alternative to a 1W DC-DC converter. The galvanic
isolation allows the device to be configured to
provide an isolated negative rail in systems where
only positive rails exist. The wide temperature
range guarantees startup from –40°C and full 0.75
watt output at 85°C. For the short circuit protected
parts (PC) protection is continuous and
auto-resetting on removal of the short circuit.
Parameter
2
OUTPUT CHARACTERISTICS
Conditions
Min.
Typ.
Max.
0.75
1.15
1.0
1.2
1.2
Units
W
Rated Power
T
A
=-40°C to 85°C, see derating graphs
Voltage Set Point Accuracy See tolerance envelope
High V
IN
to low V
IN
; Short circuit types
Line regulation
High V
IN
to low V
IN
; All other output types
%/%
ISOLATION CHARACTERISTICS
Parameter
Isolation test voltage
Resistance
Conditions
C Versions Flash tested for 1 second
3C Versions Flash tested for 1 second
Viso= 1000VDC
Min.
1000
3000
Typ.
Max.
Units
VDC
10
GΩ
GENERAL CHARACTERISTICS
Parameter
Switching frequency
Conditions
CME0505XC
Short circuit types
All other types
Min.
Typ.
120
91
135
Max.
Units
kHz
ABSOLUTE MAXIMUM RATINGS
Lead temperature 1.5mm from case for 10 seconds
Input voltage V
IN
, 3.3V input
Input voltage V
IN
, 5V input
260°C
5.5V
7V
For full details go to
www.murata-ps.com/rohs
1. Calculated using MIL-HDBK-217 FN2 and Telcordia SR-332 calculation model with nominal input voltage at full load.
2. See derating curve.
All specifications typical at T
A
=25°C, nominal input voltage and rated output current unless otherwise specified.
www.murata-ps.com/support
KDC_CME.B02
Page 1 of 11
CME Series
Isolated 0.75W Single Output Isolated DC-DC Converters
TECHNICAL NOTES
ISOLATION VOLTAGE
‘Hi Pot Test’, ‘Flash Tested’, ‘Withstand Voltage’, ‘Proof Voltage’, ‘Dielectric Withstand Voltage’ & ‘Isolation Test Voltage’ are all terms that relate to the same thing, a test voltage,
applied for a specified time, across a component designed to provide electrical isolation, to verify the integrity of that isolation.
Murata Power Solutions CME series of DC-DC converters are all 100% production tested at their stated isolation voltage. This is 1kVDC for 1 second for C versions and 3kVDC for 1
second for 3C versions.
A question commonly asked is, “What is the continuous voltage that can be applied across the part in normal operation?”
The CME has been recognised by Underwriters Laboratory for functional insulation, both input and output should normally be maintained within SELV limits i.e. less than 42.4V
peak, or 60VDC. The isolation test voltage represents a measure of immunity to transient voltages and the part should never be used as an element of a safety isolation system.
The part could be expected to function correctly with several hundred volts offset applied continuously across the isolation barrier; but then the circuitry on both sides of the barrier
must be regarded as operating at an unsafe voltage and further isolation/insulation systems must form a barrier between these circuits and any user-accessible circuitry according
to safety standard requirements.
REPEATED HIGH-VOLTAGE ISOLATION TESTING
It is well known that repeated high-voltage isolation testing of a barrier component can actually degrade isolation capability, to a lesser or greater degree depending on materials,
construction and environment. The CME series has toroidal isolation transformers, with no additional insulation between primary and secondary windings of enamelled wire. While
parts can be expected to withstand several times the stated test voltage, the isolation capability does depend on the wire insulation. Any material, including this enamel (typically
polyurethane) is susceptible to eventual chemical degradation when subject to very high applied voltages thus implying that the number of tests should be strictly limited. We
therefore strongly advise against repeated high voltage isolation testing, but if it is absolutely required, that the voltage be reduced by 20% from specified test voltage.
This consideration equally applies to agency recognised parts rated for better than functional isolation where the wire enamel insulation is always supplemented by a further
insulation system of physical spacing or barriers.
SAFETY APPROVAL
The CME series has been recognised by Underwriters Laboratory (UL) to UL 60950 for functional insulation in a maximum ambient temperature of 85ºC and/or case temperature
limit of 100ºC for CMExxxxxC, 130ºC for CMExxxxS3C. Case temperature measured on the face opposite the pins.
The CME series of converters are not internally fused so to meet the requirements of UL 60950 an anti-surge input line fuse should always be used with ratings as defined below.
CME03xxS3C: 0.9A
CME05xxxxC: 0.5A
All fuses should be UL recognised and rated to 125V.
File number E151252 applies.
RoHS COMPLIANCE INFORMATION
This series is compatible with RoHS soldering systems with a peak wave solder temperature of 260°C for 10 seconds. The pin termination finish
on the SIP package type is Tin Plate, Hot Dipped over Matte Tin with Nickel Preplate. The DIP types are Matte Tin over Nickel Preplate. Both
types in this series are backward compatible with Sn/Pb soldering systems.
For further information, please visit www.murata-ps.com/rohs
TEMPERATURE DERATING GRAPHS
0303, 0305 & Short Circuit types.
All other types.
Output Power (W)
0.75
85°C
Output Power (W)
0.75
85°C
Safe Operating Area
0
-40
Safe Operating Area
120°C
0
-40
100
50
0
Ambient Temperature (°C)
150
100
50
0
Ambient Temperature (°C)
150
www.murata-ps.com/support
KDC_CME.B02
Page 3 of 11
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