www.murata-ps.com
LSM-10A D12 Models
Single Output Non-Isolated,
12Vin, 0.75-5Vout DC/DC Converters
Typical
Unit
FEATURES
Step-down, wide buck regulators for new
distributed 12V power architectures
input (10.8-13.2V range)
12V
to 5V
OUT
@10A
0.75
Voltage-selectable "T" version
Non-isolated, fixed-frequency,
synchronous-rectifier topology
and reel SMT package
Tape
±1.25% setpoint accuracy
Efficiencies to 96% @ 10 Amps
Stable no-load operation
Remote on/off control
Sense pin and output voltage trim
derating to +65°C with 100 lfm
No
UL/IEC/EN60950-1 certification pending
compliant
EMC
PRODUCT OVERVIEW
LSM Series D12 SMT's (surface-mount packages)
are ideal building blocks for emerging, on-board
power-distribution schemes in which isolated
12V buses deliver power to any number of non-
isolated, step-down buck regulators. LSM D12
DC/DC's accept a 12V input (10.8V to 13.2V input
range) and convert it, with the highest efficiency
in the smallest space, to a 0.75, 1, 1.2, 1.5, 1.8,
2, 2.5, 3.3 or 5 Volt output fully rated at 10 Amps.
LSM D12's are ideal point-of-use/load power
processors. They typically require no external
components. Their surface-mount packages
occupy a mere 1.3" x 0.53" (33.0 x 13.5mm),
and are only 0.34 inches (8.6mm) high.
The LSM's best-in-class power density
is achieved with a fully synchronous, fixed-
frequency, buck topology that also delivers:
high efficiency (96% for 5VOUT models), low
noise (50mVp-p typ.), tight line/load regulation
(±0.1%/±0.25% max.), quick step response
(100μsec), stable no-load operation, and no
output reverse conduction.
The fully functional LSM’s feature output over-
current detection, continuous short-circuit protec-
tion, over-temperature protection, a remote on/off
control pin (pull low to disable), an output-voltage
trim function, and a sense pin. High efficiency
enables the LSM D12's to deliver rated output
currents of 10 Amps at ambient temperatures to
+65°C with 100 lfm air flow.
If your new system boards call for three or
more supply voltages, check out the economics
of on-board 12V distributed power. If you don't
need to pay for multiple isolation barriers, Murata
Power Solutions' non-isolated LSM D12 SMT's
will save you money.
+INPUT
(2)
+OUTPUT
(4)
+SENSE
(6)
COMMON
(3)
CURRENT
SENSE
V
CC
ON/OFF
CONTROL
(1)
PWM
CONTROLLER
REFERENCE &
ERROR AMP
V
OUT
TRIM
(5)
COMMON
(3)
Typical topology is shown
Figure 1. Simplified Schematic
For full details go to
www.murata-ps.com/rohs
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MDC_LSM 10A D12 Models.D02
Page 1 of 18
LSM-10A D12 Models
Single Output Non-Isolated,
12Vin, 0.75-5Vout DC/DC Converters
PERFORMANCE SPECIFICATIONS SUMMARY AND ORDERING GUIDE
➀
Output
V
OUT
(Volts)
0.8
1
1.2
1.5
1.8
2
2.5
3.3
5
0.75-5
I
OUT
(Amps)
10
10
10
10
10
10
10
10
10
10
R/N (mVp-p)
➁
Typ.
45
50
50
50
50
50
50
50
75
50
Max.
60
75
85
75
75
75
75
75
100
75
Regulation (Max.)
➂
Line
±0.1%
±0.1%
±0.2%
±0.1%
±0.1%
±0.1%
±0.1%
±0.1%
±0.3%
±0.1%
Load
±0.375%
±0.25%
±0.65%
±0.25%
±0.25%
±0.25%
±0.25%
±0.7%
±0.95%
±0.25%
V
IN
Nom.
(Volts)
12
12
12
12
12
12
12
12
12
12
Input
Range
(Volts)
10.8-13.2
10.8-13.2
10.8-13.2
10.8-13.2
10.8-13.2
10.8-13.2
10.8-13.2
10.8-13.2
10.8-13.2
10-14
I
IN
➃
(mA/A)
30/0.84
35/1.02
40/1.19
50/1.47
55/1.75
55/1.9
60/2.3
70/3
85/4.5
100/6.5
Efficiency
Full Load
Min.
80.5%
83%
85%
86.5%
88%
89%
90%
92%
93.5%
92%
Typ.
82.5%
85%
87%
88.5%
90%
91%
92.5%
94%
96%
93%
½ Load
Typ.
85%
86%
88%
89.5%
90.5%
91.5%
92%
93.5%
95.5%
--
Package
(Case,
Pinout)
C45, P63
C45, P63
C45, P63
C45, P63
C45, P63
C45, P63
C45, P63
C45, P63
C45, P63
C45, P63
Models
LSM-0.8/10-D12
LSM-1/10-D12
LSM-1.2/10-D12
LSM-1.5/10-D12
LSM-1.8/10-D12
LSM-2/10-D12
LSM-2.5/10-D12
LSM-3.3/10-D12
LSM-5/10-D12
LSM-T/10-D12
➀
Typical at T
A
= +25°C under nominal line voltage and full-load conditions, unless noted. All
models are tested and specified with external 22µF tantalum input and output capacitors. These
capacitors are necessary to accommodate our test equipment and may not be required to
achieve specified performance in your applications. See I/O Filtering and Noise Reduction.
➁
Ripple/Noise (R/N) is tested/specified over a 20MHz bandwidth and may be reduced with
external filtering. See I/O Filtering and Noise Reduction for details.
➂
These devices have no minimum-load requirements and will regulate under no-load conditions.
Regulation specifications describe the output-voltage deviation as the line voltage or load is
varied from its nominal/midpoint value to either extreme.
➃
Nominal line voltage, no-load/full-load conditions.
➄
LSM-T/10-D12 specifications are given at V
OUT
= 5V, full load.
PART NUMBER STRUCTURE
L SM
-
1.8
/
10
-
D12
-
C
Output
Configuration:
L
= Unipolar
Low Voltage
Non-Isolated SMT
Nominal Output Voltage:
0.8, 1, 1.2, 1.5, 1.8, 2, 2.5, 3.3, 5
Volts or "T" voltage selectable
RoHS-6 compliant*
Input Voltage:
D12
= 12V nominal
Maximum Rated Output
Current in Amps
* Contact Murata Power Solutions
for availability.
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MDC_LSM 10A D12 Models.D02
Page 2 of 18
LSM-10A D12 Models
Single Output Non-Isolated,
12Vin, 0.75-5Vout DC/DC Converters
MECHANICAL SPECIFICATIONS
1.36
(34.54)
0.55
(13.97)
I/O Connections
Pin
Function P63
1
On/Off Control
2
+Input
3
Common
4
+Output
5
V
OUT
Trim
6
+Sense
0.010
(0.254)
0.570 (14.48)
3 EQ. SP. @
0.190 (4.83)
0.60
(15.24)
0.310
(7.87)
0.375
(9.53)
0.052
(1.32)
3
4
5
6
1
0.062
(1.57)
2
0.112 TYP.
(2.84)
0.049
(1.24)
0.047
(1.19)
0.052
(1.32)
CAUTION
PRESS TO REMOVE
THE HEAT SHIELD
AFTER THE SOLDER
PROCESS
BOTTOM VIEW
LSM WITH REMOVEABLE HEAT SHIELD
FOR HIGH TEMPERATURE SOLDER
(
)
Case C45
CAUTION
PRESS TO REMOVE
THE HEAT SHIELD
AFTER THE SOLDER
PROCESS
NOTCH IN SHELL
INDICATES PIN ONE
Refer to the last page for
Tape and Reel information.
DIMENSIONS ARE IN INCHES (MM)
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MDC_LSM 10A D12 Models.D02
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LSM-10A D12 Models
Performance/Functional Specifications
Input
Typical @ T
A
= +25°C under nominal line voltage and full-load conditions unless noted.
➀
Single Output Non-Isolated,
12Vin, 0.75-5Vout DC/DC Converters
➃
Output noise may be further reduced with the installation of additional external output filtering.
See I/O Filtering and Noise Reduction.
➄
MTBF’s are calculated using Telcordia SR-332(Bellcore), ground fixed, T
A
= +25°C, full power,
natural convection, +67°C pcb temperature.
➅
Input Ripple Current is tested/specified over a 5-20MHz bandwidth with an external 33µF input
capacitor and a simulated source impedance of 220µF and 12µH. See I/O Filtering, Input
Ripple Current and Output Noise for details.
➆
On/Off Control for LSM-T/10-D12 only: Positive Logic: On = pin open or to +4V max.,
Off = pin grounded or 0 to +0.4V max. Shutdown current is 3µA sink.
➇
The Output Voltage Range for the LSM-T/10-D12 is +0.75V to +5V, user selectable.
➈
LSM-T/10-D12 Overcurrent and Short-circuit specs:
Current limit
25 Amps
Short Circuit Current 600mA
Absolute Maximum Ratings
Input Voltage Range
Input Current:
Normal Operating Conditions
Inrush Transient
Standby/Off Mode
Output Short-Circuit Condition
Input Reflected Ripple Current
➁ ➅
Input Filter Type
Overvoltage Protection
Reverse-Polarity Protection
Undervoltage Shutdown
On/Off Control
➁ ➂ ➆
See Ordering Guide
See Ordering Guide
0.08A
2
sec
1.5mA
12-40mA average (model dependent)
40mAp-p
Capacitive
None
None
None (except 8V LSM-T/10-D12)
On = open (internal pull-up to +V
IN
)
Off = 0 to +0.4V (1mA max.)
Output
±1.25% max. (±2% "T" version, 50% load)
No load
1000µF (low ESR, OSCON)
±10% (0.8V not trimmable)
See Ordering Guide
Total Accuracy
3% over line/load/temperature
Efficiency
See Ordering Guide
Overcurrent Detection and Short-Circuit Protection:
➈
Current-Limiting Detection Point
17 Amps
Short-Circuit Detection Point
98% of V
OUT
set
SC Protection Technique
Hiccup with auto recovery
Short-Circuit Current
120-400mA average (model dependent)
Dynamic Characteristics
V
OUT
Accuracy
(50% load)
Minimum Loading
➀
Maximum Capacitive Load
V
OUT
Trim Range
➇
Ripple/Noise
(20MHz BW)
➀ ➁ ➃
Input Voltage:
Continuous or transient
On/Off Control
(Pin 1)
Input Reverse-Polarity Protection
Output Overvoltage Protection
Output Current
15 Volts
+V
IN
(+4V for "T" version)
None
None
Current limited. Devices can
withstand sustained output short
circuits without damage.
–40 to +125°C
See Reflow Solder Profile
Storage Temperature
Lead Temperature
These are stress ratings. Exposure of devices to any of these conditions may adversely
affect long-term reliability. Proper operation under conditions other than those listed in the
Performance/Functional Specifications Table is not implied.
Transient Response
(50% load step)
Start-Up Time:
➁
V
IN
to V
OUT
and On/Off to V
OUT
Switching Frequency:
0.8V, 1V/1.2V Models
1.5V/1.8V, 2V Models
2.5V, 3.3V, 5V Models
LSM-T/10-D12
115µsec to ±2% of final value
75msec for V
OUT
= 1V and 0.8V
50msec for V
OUT
= 1.2V to 5V
105/120kHz ±10%
160/177kHz ±10%
195kHz ±10%
230kHz ±30kHz
TECHNICAL NOTES
Environmental
Calculated MTBF
➄
2.3-1.8 million hours (1V
OUT
to 5V
OUT
)
Operating Temperature:
(Ambient)
➁
Without Derating (100 lfm)
–40 to +48/64°C (model dependent)
With Derating
See Derating Curves
Thermal Shutdown
+115°C (110 to 125°C)
Physical
I/O Filtering and Noise Reduction
All models in the LSM D12 Series are tested and specified with external 22μF
tantalum input and output capacitors. These capacitors are necessary to
accommodate our test equipment and may not be required to achieve desired
performance in your application. The LSM D12's are designed with high-qual-
ity, high-performance
internal
I/O caps, and will operate within spec in most
applications with
no additional external components.
In particular, the LSM D12's input capacitors are specified for low ESR and
are fully rated to handle the units' input ripple currents. Similarly, the internal
output capacitors are specified for low ESR and full-range frequency response.
As shown in the Performance Curves, removal of the external 22μF tantalum
output caps has minimal effect on output noise.
In critical applications, input/output ripple/noise may be further reduced using
filtering techniques, the simplest being the installation of external I/O caps.
External input capacitors serve primarily as energy-storage devices. They
minimize high-frequency variations in input voltage (usually caused by IR drops
in conductors leading to the DC/DC) as the switching converter draws pulses of
current. Input capacitors should be selected for bulk capacitance (at appropri-
ate frequencies), low ESR, and high rms-ripple-current ratings. The switching
nature of modern DC/DC's requires that the dc input voltage source have low
ac impedance at the frequencies of interest. Highly inductive source imped-
ances can greatly affect system stability. Your specific system configuration
may necessitate additional considerations.
Dimensions
1.3" x 0.53" x 0.34" (33.02 x 13.46 x 8.64 mm)
Pin Dimensions/Material
0.112" x 0.062" (2.84 x 1.57mm) rectangular
copper with gold plate over nickel underplate
Weight
0.28 ounces (7.8g)
Flamability Rating
EMI
Safety
UL94V-0
Conducted and radiated FCC part 15,
EN55022 (may require external filter)
UL/cUL/IEC/EN 60950-1, CSA-C22.2 No. 234
➀
All models are tested and specified with external 22µF tantalum input and output capacitors.
These capacitors are necessary to accommodate our test equipment and may not be required
to achieve specified performance in your applications. All models are stable and regulate within
spec under no-load conditions.
➁
See Technical Notes and Performance Curves for details.
➂
The On/Off Control (pin 1) is designed to be driven with open-collector logic or the application
of appropriate voltages (referenced to Common, pin 3). Applying a voltage to On/Off Control when
no input voltage is applied to the converter may cause permanent damage.
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MDC_LSM 10A D12 Models.D02
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MDC_LSM10AD12_A01 Page 4 of 14
LSM-10A D12 Models
Single Output Non-Isolated,
12Vin, 0.75-5Vout DC/DC Converters
ers are not internally fused. Therefore, if input fusing is mandatory, either a
normal-blow or a fast-blow fuse with a value no greater than 20 Amps should
be installed within the ungrounded input path to the converter.
As a rule of thumb however, we recommend to use a normal-blow or
slow-blow fuse with a typical value of about twice the maximum input current,
calculated at low line with the converters minimum efficiency.
Safety Considerations
LSM D12 SMT's are non-isolated DC/DC converters. In general, all DC/DC's
must be installed, including considerations for I/O voltages and spacing/sepa-
ration requirements, in compliance with relevant safety-agency specifications
(usually UL/IEC/EN60950-1).
Figure 2. Measuring Input Ripple Current
Output ripple/noise (also referred to as periodic and random deviations or
PARD) may be reduced below specified limits with the installation of additional
external output capacitors. Output capacitors function as true filter elements
and should be selected for bulk capacitance, low ESR, and appropriate fre-
quency response. Any scope measurements of PARD should be made directly
at the DC/DC output pins with scope probe ground less than 0.5" in length.
In particular, for a non-isolated converter's output voltage to meet SELV
(safety extra low voltage) requirements, its input must be SELV compliant. If the
output needs to be ELV (extra low voltage), the input must be ELV.
Input Overvoltage and Reverse-Polarity Protection
LSM D12 SMT Series DC/DCs do not incorporate either input overvoltage or
input reverse-polarity protection. Input voltages in excess of the specified
absolute maximum ratings and input polarity reversals of longer than "instan-
taneous" duration can cause permanent damage to these devices.
Start-Up Time
The V
IN
to V
OUT
Start-Up Time is the interval between the time at which a ramp-
ing input voltage crosses the lower limit of the specified input voltage range
and the fully loaded output voltage enters and remains within its specified
accuracy band. Actual measured times will vary with input source impedance,
external input capacitance, and the slew rate and final value of the input volt-
age as it appears to the converter.
The On/Off to V
OUT
Start-Up Time assumes the converter is turned off via the
On/Off Control with the nominal input voltage already applied to the converter.
The specification defines the interval between the time at which the converter
is turned on and the fully loaded output voltage enters and remains within its
specified accuracy band. See Typical Performance Curves.
Remote Sense
LSM D12 SMT Series DC/DC converters offer an output sense function on pin 6.
The sense function enables point-of-use regulation for overcoming moderate
IR drops in conductors and/or cabling. Since these are non-isolated devices
whose inputs and outputs usually share the same ground plane, sense is
provided only for the +Output.
The remote sense line is part of the feedback control loop regulating the
converter’s output. The sense line carries very little current and consequently
requires a minimal cross-sectional-area conductor. As such, it is not a low-
impedance point and must be treated with care in layout and cabling. Sense
lines should be run adjacent to signals (preferably ground), and in cable and/or
discrete-wiring applications, twisted-pair or similar techniques should be used.
To prevent high frequency voltage differences between V
OUT
and Sense, we
recommend installation of a 1000pF capacitor close to the converter.
+SENSE
+OUTPUT
6
4
COPPER STRIP
C1
C2
SCOPE
R
LOAD
COMMON
3
COPPER STRIP
C1 = NA
C2 = 22µF TANTALUM
LOAD 2-3 INCHES (51-76mm) FROM MODULE
Figure 3. Measuring Output Ripple/Noise (PARD)
All external capacitors should have appropriate voltage ratings and be
located as close to the converters as possible. Temperature variations for all
relevant parameters should be taken into consideration.
The most effective combination of external I/O capacitors will be a func-
tion of your line voltage and source impedance, as well as your particular load
and layout conditions. Our Applications Engineers can recommend potential
solutions and discuss the possibility of our modifying a given device’s internal
filtering to meet your specific requirements. Contact our Applications Engineer-
ing Group for additional details.
Input Fusing
Most applications and or safety agencies require the installation of fuses at
the inputs of power conversion components. LSM D12 Series DC/DC convert-
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MDC_LSM 10A D12 Models.D02
Page 5 of 18
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