LME0305SC - power, Murata

LME0305SC
www.murata-ps.com
Isolated 0.25W Single Output DC/DC Converter
SELECTION GUIDE
Order Code
Nominal Input
Voltage
Output
Voltage
Output Current
V
V
3.3
5
LME0305SC
Efficiency
Isolation
Capacitance
mA
%
pF
50
70
25
Package
Style
SIP
INPUT CHARACTERISTICS
Parameter
Conditions
Min.
Typ.
Max.
Units
Voltage range
Continuous operation, 3.3V input types
2.97
3.3
3.63
V
Min.
Typ.
Max.
Units
0.25
W
1.0
3.5
1.2
15
75
%/%
%
mV p-p
Max.
Units
OUTPUT CHARACTERISTICS
Parameter
FEATURES
„
RoHS compliant
„
UL 94V-0 package material
„
No heatsink required
Rated Power1
Voltage Set Point Accuracy
Line regulation
Load Regulation
Ripple and Noise
Conditions
TA=0°C to 70°C
See tolerance envelope
High VIN to low VIN
10% load to rated load
BW=DC to 20MHz
„
Industry standard pinout
ISOLATION CHARACTERISTICS
„
1kVDC isolation
Parameter
Conditions
Min.
Typ.
Isolation test voltage
Resistance
Flash tested for 1 second
Viso= 500V
1000
1
10
Min.
Typ.
„
Internal SMD construction
„
Fully encapsulated with toroidal
magnetics
GENERAL CHARACTERISTICS
„
No external components required
Switching frequency
„
No electrolytic or tantalum capacitors
TEMPERATURE CHARACTERISTICS
DESCRIPTION
The LME0305SC is optimized for low-power
applications and is ideally suited to generating a
negative supply where only a positive rail exists.
Parameter
Conditions
VDC
GΩ
Max.
100
Parameter
Conditions
Min.
Specification
Storage
All output types
0
-50
Typ.
Units
kHz
Max.
Units
70
130
°C
ABSOLUTE MAXIMUM RATINGS
Lead temperature 1.5mm from case for 10 seconds
Input voltage VIN
300°C
5.5V
APPLICATION NOTES
Minimum Load
The minimum load to meet datasheet specification is 10% of the full rated load across the specified input voltage
range. Lower than 10% minimum loading will result in an increase in output voltage, which may rise to typically
double the specified output voltage if the output load falls to less than 5%.
1. See derating graph.
All specifications typical at TA=25°C, nominal input voltage and rated output current unless otherwise specified.
For full details go to
www.murata-ps.com/rohs
www.murata-ps.com
KDC_LME0305SC.A02 Page 1 of 3
LME0305SC
Isolated 0.25W Single Output DC/DC Converter
RoHS COMPLIANCE INFORMATION
The LME0305SC is compatible with RoHS soldering systems with a peak wave solder temperature
of 300°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
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 LME0305SC DC/DC converter is 100% production tested at their stated isolation voltage. This is 1kVDC for 1 second.
A question commonly asked is, “What is the continuous voltage that can be applied across the part in normal operation?”
For a part holding no specific agency approvals, such as the LME0305SC, 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 LME0305SC has a toroidal isolation transformer, with no additional insulation between primary and secondary windings of enameled 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 recognized 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.
PACKAGE SPECIFICATIONS
PIN CONNECTIONS
MECHANICAL DIMENSIONS
0.45
(11.48)
0.236
(6.00)
0.393
(10.0)
LME0305SC
XYYWW
1
2
3
0.181 (4.60)
0.142 (3.60)
Pin
Function
1
2
3
4
-VIN
+VIN
-VOUT
+VOUT
0.022 (0.55)
0.018 (0.45)
4
0.022 (0.55)
0.018 (0.45)
0.074 (1.89)
0.109 (2.77)
0.0118 (0.30)
0.0078 (0.20)
0.049
(1.25)
0.3
(7.62)
All dimensions in inches ±0.01 (mm ±0.25mm). All pins on a 0.1 (2.54) pitch and within ±0.01 (0.25) of true position.
Weight: 1.30g
www.murata-ps.com
KDC_LME0305SC.A02 Page 2 of 3
LME0305SC
Isolated 0.25W Single Output DC/DC Converter
PACKAGE SPECIFICATIONS (continued)
RECOMMENDED FOOTPRINT DETAILS
TUBE OUTLINE DIMENSIONS
9.30 (0.366)
5.00 (0.2)
2.54
(0.1)
Unless otherwise stated all dimensions in inches (mm ±0.5mm).
Tube length: 20.47 (520mm ±2mm).
Tube Quantity : 35
Unless otherwise stated all dimensions in inches (mm ±0.5mm).
TEMPERATURE DERATING GRAPH
TOLERANCE ENVELOPE
+10%
70°C
2
0
-40
Output Voltage
Output Power (W)
3
1
0.50 (0.020)
18.00 (0.709)
2.54
(0.1)
12.43 (0.489)
4 HOLES
0.1 (0.00394)
1.15 (0.0453)
Ø
1.00 (0.0394)
Safe Operating
Area
100
50
0
Ambient Temperature (°C)
150
+1.5%
VNOM
Typical
L
oad Line
+2.5%
-2%
-7.5%
10
75
50
25
Output Load Current (%)
100
The voltage tolerance envelope shows typical load regulation characteristics for this
product series. The tolerance envelope is the maximum output voltage variation due to
changes in output loading.
Murata Power Solutions, Inc.
11 Cabot Boulevard, Mansfield, MA 02048-1151 U.S.A.
ISO 9001 and 14001 REGISTERED
This product is subject to the following operating requirements
and the Life and Safety Critical Application Sales Policy:
Refer to: http://www.murata-ps.com/requirements/
Murata Power Solutions, Inc. makes no representation that the use of its products in the circuits described herein, or the use of other
technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein do not imply
the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifications are subject to change without
notice.
© 2010 Murata Power Solutions, Inc.
www.murata-ps.com/locations
KDC_LME0305SC.A02 Page 3 of 3