+INPUT
(7,8)
COMMON
(6)
PWM
CONTROLLER
CURRENT
SENSE
REFERENCE &
ERROR AMP
VOLTAGE
BOOST
V
CC
ON/OFF
CONTROL
(11) TRIM
(10)
+OUTPUT
(1,2,4)
470μF47.1μF
44μF330μF
10.5Ω
+SENSE
(3)
COMMON
(5)
➀
Features
Figure 1. Simplifi ed Schematic
The miniature size of LSN D3's makes them ideal for true point-of-use power
processing. Vertical-mount packages occupy a mere 0.7 square inches (440 sq.
mm), and they are available in industry-standard and Tyco-compatible pinout.
Horizontal-mount packages ("H" suffi x) are only 0.34 inches (8.6mm) high.
The LSN's best-in-class power density is achieved with a fully synchronous,
fi xed-frequency (300kHz), buck topology that also delivers: high effi ciency (94% for
2.5VOUT models), low noise (10mVp-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 LSN’s feature output overcurrent detection, continuous short-
circuit protection, an output-voltage trim function, a remote on/off control pin
(pull high to disable), thermal shutdown, and a sense pin. High effi ciency enables the
LSN D3's to deliver rated output currents of 10 Amps at ambient temperatures to
+71°C with no air fl ow (natural convection).
If your low-voltage, high-current requirements have made the use of ineffi cient
linear regulators impractical, take a look at one of DATEL’s easy-to-use, low-cost
LSN SIP’s. All devices are UL/IEC/EN60950 certifi ed and EMC compliant. UL, CB,
HALT and EMC reports are available upon request.
■
■
■
■
■
■
■
■
■
■
■
➀ For devices with the sense-pin removed ("B" suffi x),
the feedback path is through the +Output pin and not
the +Sense pin.
Industry-standard SIP pinout
Shorter (2.0" vs. 2.5") package length
3.0-3.6V input range
1/1.2/1.25/1.5/1.8/2/2.5V outputs @ 10A
Non-isolated, fully synchronous,
300kHz, buck topology
Outstanding performance:
x ±1% setpoint accuracy
x Effi ciencies to 94% @ 10 Amps
x Noise as low as 10mVp-p
x Stable no-load operation
x Trimmable output voltage
Remote on/off and sense pins
Thermal Shutdown
No derating to +71°C, natural convection
UL/IEC/EN60950 certifi ed
EMC compliant
Typical topology is shown
Typical Units
DATEL’s new LSN D3 Series SIP’s (single-in-line packages) are
non-isolated DC/DC converters that accept a 3.3V input (3.0V to 3.6V
input range) and deliver 1V, 1.2V, 1.25V, 1.5V, 1.8V, 2V or 2.5V out-
puts at 10 Amps. LSN D3 SIP’s are designed to take on-board 3.3V
power and convert it, with the highest effi ciency in the smallest space,
to any lower voltage required by today’s current-hungry DSP’s, ASIC’s
and CPLD’s.
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
For full details go to
www.murata-ps.com/rohs
www.murata-ps.com
www.murata-ps.com
email: sales@murata-ps.com
16 Dec 2009 MDC_LSN10A-D3.B03 Page 1 of 14
NOT RECOMMENDED
FOR NEW DESIGNS
Third Angle Projection
Dimensions are in inches (mm shown for ref. only).
Components are shown for reference only.
Tolerances (unless otherwise specified):
.XX ± 0.02 (0.5)
.XXX ± 0.010 (0.25)
Angles ± 2˚
C
-
RoHS-6 compliant
➀ Typical at TA = +25°C under nominal line voltage and full-load conditions, unless otherwise
noted. All models are tested and specifi ed with external 22μF input and output capacitors.
These capacitors are necessary to accommodate our test equipment and may not be required
to achieve specifi ed performance in your applications. See I/O Filtering and Noise Reduction.
➁ Ripple/Noise (R/N) is tested/specifi ed over a 20MHz bandwidth and may be reduced with
external fi ltering. 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 specifi cations 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 These are not complete model numbers. Please refer to the Part Number Structure for
additional options when ordering.
Performance Specifi cations and Ordering Guide ➀
LSN-1/10-D3 1 10 10 35 ±0.1% ±0.25% 3.3 3.0-3.6 70/3.73 83.5% 86.5% 90.5% B7/B7x, P59
LSN-1.2/10-D3 1.2 10 10 35 ±0.1% ±0.25% 3.3 3.0-3.6 70/4.42 85% 88% 91% B7/B7x, P59
LSN-1.25/10-D3 1.25 10 10 35 ±0.1% ±0.25% 3.3 3.0-3.6 60/4.30 85% 88% 91% B7/B7x, P59
LSN-1.5/10-D3 1.5 10 10 35 ±0.1% ±0.25% 3.3 3.0-3.6 70/5.47 87.5% 90% 92.2% B7/B7x, P59
LSN-1.8/10-D3 1.8 10 10 35 ±0.1% ±0.25% 3.3 3.0-3.6 70/6.33 89% 91.5% 93.5% B7/B7x, P59
LSN-2/10-D3 2 10 10 35 ±0.1% ±0.25% 3.3 3.0-3.6 70/6.96 89.5% 92.5% 94% B7/B7x, P59
LSN-2.5/10-D3 2.5 10 10 35 ±0.1% ±0.25% 3.3 3.0-3.6 70/8.50 91% 94% 95.5% B7/B7x, P59
Package
VOUT IOUT VIN Nom. Range IIN ➃ (Case,
Root Model ➄ (Volts) (Amps) Typ. Max. Line Load (Volts) (Volts) (mA/A) Min. Typ. Typ. Pinout)
Output Input
R/N (mVp-p) ➁ Regulation (Max.) ➂
Effi ciency
Full Load ½ Load
12345 76891011
2.00
(50.8)
0.030 ±0.001 DIA.
(0.762 ±0.025)
0.50
(12.7)
0.34
(8.6)
0.20
(5.1)
0.110
(2.8)
0.046
(1.2)
0.05
(1.3)
0.400
(10.16)
4 EQ. SP. @
0.100 (2.54)
0.500
(12.70)
5 EQ. SP. @
0.100 (2.54)
1.000
(25.40)
0.17
(4.3)
LAYOUT PATTERN
TOP VIEW
0.34
(8.6)
0.25
(6.4)
MECHANICAL SPECIFICATIONS
Case B7
Vertical Mounting
(Standard)
0.35
(8.9)
0.21
(5.3)
0.16
(4.1)
0.360
(9.1)
12345 7689
ISOLATING
PA D
10 11
2.00
(50.8)
0.030 ±0.001 DIA.
(0.762 ±0.025)
0.50
(12.7)
0.05
(1.3)
0.05
(1.3)
0.50
(12.7)
0.45
(11.4)
0.400
(10.16)
0.56
(14.2)
0.53
(13.5)
4 EQ. SP. @
0.100 (2.54)
0.500
(12.70)
5 EQ. SP. @
0.100 (2.54)
1.000
(25.40)
LAYOUT PATTERN
TOP VIEW
RECOMMENDED
COPPER PAD
ON PCB (0.55 SQ. IN.)
Case B7A
Horizontal Mounting
Standard model pin
lengths are shown.
LAYOUT PATTERN
TOP VIEW
0.36
(9.1)
0.20
(5.1)
0.106
(2.7)
0.046
(1.2)
0.36
(9.1)
0.306
(7.8)
12345 76891011
2.00
(50.8)
0.030 ±0.001 DIA.
(0.762 ±0.025)
0.50
(12.7)
0.05
(1.3)
0.400
(10.16)
4 EQ. SP. @
0.100 (2.54)
0.500
(12.70)
5 EQ. SP. @
0.100 (2.54)
1.000
(25.40)
0.17
(4.3)
Case B7B
Reverse Pin
Vertical Mounting
(Tyco/Lineage-compatible)
Maximum Rated Output
Current in Amps
PART NUMBER STRUCTURE
Non-Isolated SIP
Output
Confi guration:
L = Unipolar
Low Voltage
Nominal Output Voltage:
1, 1.2, 1.25, 1.5, 1.8, 2, or 2.5 Volts
Input Voltage Range:
D3 = 3 to 3.6 Volts
(3.3V nominal)
L SN 10-/D3 B-1.8
B Suffi x:
No Remote Sense
(Pin 3 removed)
H
H Suffi x:
Horizontal Mount
J
J Suffi x:
Reversed Pin
Vertical Mount
See page 12 for
Part Number Structure
and ordering details.
* Pin 3 (+Sense) removed
for "B" suffi x models.
Pin Function P59* Pin Function P59* Pin Function P59*
1 +Output 5 Common 9 No Pin
2 +Output 6 Common 10 VOUT Tr i m
3 +Sense * 7 +Input 11 On/Off Control
4 +Output 8 +Input
I/O Connections
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
www.murata-ps.com email: sales@murata-ps.com
16 Dec 2009 MDC_LSN10A-D3.B03 Page 2 of 14
Input
Input Voltage Range 3.0 to 3.6 Volts (3.3V nominal)
Input Current:
Normal Operating Conditions See Ordering Guide
Inrush Transient 0.02A2sec
Standby/Off Mode 3mA
Output Short-Circuit Condition ➁ 70mA average
Input Refl ected Ripple Current ➁ 50mAp-p
Input Filter Type Capacitive (374μF)
Overvoltage Protection None
Reverse-Polarity Protection None, install external fuse
Undervoltage Shutdown None
Sense Range 10% of VOUT
On/Off Control ➁ ➂ On = open (internal pulldown)
Off = +2.8V to +VIN (<3mA)
Output
VOUT Accuracy (50% load) ±1% maximum
Minimum Loading ➀ No load
Maximum Capacitive Load 10,000μF (electrolytic)
VOUT Trim Range ➁ ±10%
Ripple/Noise (20MHz BW) ➀ ➁ ➃ See Ordering Guide
Temperature Coeffi cient ±0.02%/°C
Total Accuracy 3% over line/load/temperature
Effi ciency ➁ See Ordering Guide
Overcurrent Detection and Short-Circuit Protection: ➁
Current-Limiting Detection Point 16 (12.5 to 22) Amps
Short-Circuit Detection Point 98% of VOUT set
SC Protection Technique Hiccup with auto recovery
Short-Circuit Current 600mA average
Dynamic Characteristics
Transient Response (50% load step) 100μsec to ±2% of fi nal value
Start-Up Time: ➁
VIN to VOUT 7msec
On/Off to VOUT 6msec
Switching Frequency 300kHz (+40kHz, –50kHz)
Environmental
MTBF ➄ 2.1 million hours
Operating Temperature: (Ambient) ➁ –40 to +85°C with Derating
See Derating Curves
Thermal Shutdown +115°C
Physical
Dimensions See Mechanical Specifi cations
Pin Dimensions/Material 0.03" (0.76mm) round copper alloy with
tin plate over nickel underplate
Weight 0.3 ounces (8.5g)
Flamability Rating UL94V-0
Safety UL/cUL/IEC/EN 60950-1, CSA-C22.2 No. 234
Performance/Functional Specifi cations
Typical @ TA = +25°C under nominal line voltage and full-load conditions unless noted. ➀
TECHNICAL NOTES
Input Voltage:
Continuous or transient 6 Volts
On/Off Control (Pin 11) +VIN
Input Reverse-Polarity Protection None, install external fuse
Output Overvoltage Protection None
Output Current Current limited. Devices can
withstand sustained output short
circuits without damage.
Storage Temperature –40 to +125°C
Lead Temperature (soldering, 10 sec.) +300°C
These are stress ratings. Exposure of devices to greater than any of these conditions may
adversely affect long-term reliability. Proper operation under conditions other than those
listed in the Performance/Functional Specifi cations Table is not implied.
Absolute Maximum Ratings
Return Current Paths
The LSN D3 SIP’s are non-isolated DC/DC converters. Their two Common
pins (pins 5 and 6) are connected to each other internally (see Figure 1). To
the extent possible (with the intent of minimizing ground loops), input return
current should be directed through pin 6 (also referred to as –Input or
Input Return), and output return current should be directed through pin 5
(also referred to as –Output or Output Return). Any on/off control signals
applied to pin 11 (On/Off Control) should be referenced to Common
(specifi cally pin 6).
I/O Filtering and Noise Reduction
All models in the LSN D3 Series are tested and specifi ed with external 22μF
input and output capacitors. These capacitors are necessary to accommodate
our test equipment and may not be required to achieved desired performance
in your application. The LSN D3's are designed with high-quality, high-
performance internal I/O caps, and will operate within spec in most applica-
tions with no additional external components.
In particular, the LSN D3's input capacitors are specifi ed for low ESR
and are fully rated to handle the units' input ripple currents. Similarly, the
internal output capacitors are specifi ed for low ESR and full-range frequency
response. As shown in the Performance Curves, removal of the external
output caps has minimal effect on output noise.
In critical applications, input/output ripple/noise may be further reduced using
fi ltering 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
appropriate 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 impedances can greatly affect system stability. Your specifi c system
confi guration may necessitate additional considerations.
Output ripple/noise (also referred to as periodic and random deviations
or PARD) may be reduced below specifi ed limits with the installation of
additional external output capacitors. Output capacitors function as true fi lter
➀ All models are tested/specifi ed with external 22μF input/output capacitors.These caps
accommodate our test equipment and may not be required to achieve specifi ed 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 11) is designed to be driven with open-collector logic or the appli-
cation of appropriate voltages (referenced to Common, pins 5 and 6).
➃ Output noise may be further reduced with the installation of additional external output
fi ltering. See I/O Filtering and Noise Reduction.
➄ Calculated using the Telcordia (Bellcore) SR-332 Method 1, Case 3, ground fi xed conditions,
T
A = +25°C, full load, natural convection, +55°C component temperature.
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
www.murata-ps.com email: sales@murata-ps.com
16 Dec 2009 MDC_LSN10A-D3.B03 Page 3 of 14
Safety Considerations
LSN D3 SIP'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 speci-
fi cations (usually UL/IEC/EN60950).
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
LSN D3 SIP Series DC/DC's do not incorporate either input overvoltage or
input reverse-polarity protection. Input voltages in excess of the specifi ed
absolute maximum ratings and input polarity reversals of longer than "instan-
taneous" duration can cause permanent damage to these devices.
Start-Up Time
The VIN to VOUT Start-Up Time is the interval between the time at which a
ramping input voltage crosses the lower limit of the specifi ed input voltage
range (3 Volts) and the fully loaded output voltage enters and remains within
its specifi ed accuracy band. Actual measured times will vary with input source
impedance, external input capacitance, and the slew rate and fi nal value of
the input voltage as it appears to the converter.
The On/Off to VOUT 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 specifi cation defi nes the interval between the time at which the
converter is turned on and the fully loaded output voltage enters and remains
within its specifi ed accuracy band. See Typical Performance Curves.
+INPUT
COMMON
5kΩ
1.1kΩ
0.75kΩ
ON/OFF
CONTROL
elements and should be selected for bulk capacitance, low ESR, and appro-
priate frequency 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.
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 function of
your line voltage and source impedance, as well as your particular load and
layout conditions.
Input Fusing
Most applications and or safety agencies require the installation of fuses at
the inputs of power conversion components. LSN D3 Series DC/DC convert-
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 17 Amps should
be installed within the ungrounded input path to the converter.
As a rule of thumb however, we recommend to use a fast-blow fuse with a
typical value of about twice the maximum input current, calculated at low line
with the converters minimum effi ciency.
On/Off Control and Power-up Sequencing
The On/Off Control pin may be used for remote on/off operation. LSN D3 SIP
Series DC/DC's are designed so they are enabled when the control pin is
left open (internal pull-down to Common) and disabled when the control pin
is pulled high (+2.8V to +VIN), as shown in Figure 2 and 2a.
Dynamic control of the on/off function is best accomplished with a mechani-
cal relay or open-collector/open-drain drive circuit. The drive circuit should
be able to sink appropriate current when activated and withstand appropriate
voltage when deactivated.
Figure 2. Driving the On/Off Control Pin with an Open-Collector Drive Circuit
Remote Sense
LSN D3 SIP Series DC/DC converters offer an output sense function on pin 3.
The sense function enables point-of-use regulation for overcoming moderate
The on/off control function, however, can be externally inverted so that the
converter will be disabled while the input voltage is ramping up and then
"released" once the input has stabilized.
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 DC/
DC converter’s output. The sense line carries very little current and conse-
quently 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 VOUT
and Sense, we recommend installation of a 1000pF capacitor close to the
converter.
The sense function is capable of compensating for voltage drops between
the +Output and +Sense pins that do not exceed 10% of VOUT.
[VOUT(+) – Common] – [Sense(+) – Common] d 10%VOUT
Power derating (output current limiting) is based upon maximum output
current and voltage at the converter's output pins. Use of trim and sense
functions can cause the output voltage to increase, thereby increasing output
power beyond the LSN's specifi ed rating. Therefore:
(VOUT at pins) x (IOUT) d rated output power
The internal 10.5:resistor between +Sense and +Output (see Figure 1)
serves to protect the sense function by limiting the output current fl owing
through the sense line if the main output is disconnected. It also prevents
output voltage runaway if the sense connection is disconnected.
Note: Connect the +Sense pin (pin 3) to +Output (pin 4) at the DC/DC
converter pins, if the sense function is not used for remote regulation.
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
www.murata-ps.com email: sales@murata-ps.com
16 Dec 2009 MDC_LSN10A-D3.B03 Page 4 of 14
Figure 3. Trim Connections Using a Trimpot
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LSN-1/10-D3 Trim Equations
LSN-1.2/10-D3, LSN-1.25/10-D3 Trim Equations
Note: Resistor values are in k:. Accuracy of adjustment is subject to
tolerances of resistors and factory-adjusted, initial output accuracy.
VO = desired output voltage. VONOM = nominal output voltage.
LSN-1.5/10-D3, LSN-1.8/10-D3,
LSN-2/10-D3, LSN-2.5/10-D3 Trim Equations
Figure 4. Trim Connections Using Fixed Resistors
Note: Install either a fi xed trim-up resistor or a fi xed trim-down resistor
depending upon desired output voltage.
Trim
Down
Trim Up
LOAD
+INPUT
COMMON
+OUTPUT
TRIM
COMMON
Output Reverse Conduction
Many DC/DC converters using synchronous rectifi cation suffer from Output
Reverse Conduction. If those devices have a voltage applied across their
output before a voltage is applied to their input (this typically occurs when
another power supply starts before them in a power-sequenced application),
Output Voltage Trimming
Allowable trim ranges for each model in the LSN D3 SIP Series are ±10%.
Trimming is accomplished with either a trimpot or a single fi xed resistor. The
trimpot should be connected between +Output and Common with its wiper
connected to the Trim pin as shown in Figure 3 below.
A trimpot can be used to determine the value of a single fi xed resistor
which can then be connected, as shown in Figure 4, between the Trim pin
and +Output to trim down the output voltage, or between the Trim pin and
Common to trim up the output voltage. Fixed resistors should have absolute
TCR’s less than 100ppm/°C to ensure stability.
Output Overvoltage Protection
LSN D3 SIP Series DC/DC converters do not incorporate output overvolt-
age protection. In the extremely rare situation in which the device’s feedback
loop is broken, the output voltage may run to excessively high levels (VOUT =
VIN). If it is absolutely imperative that you protect your load against any and
all possible overvoltage situations, voltage limiting circuitry must be provided
external to the power converter.
Output Overcurrent Detection
Overloading the output of a power converter for an extended period of time
will invariably cause internal component temperatures to exceed their maxi-
mum ratings and eventually lead to component failure. High-current-carrying
components such as inductors, FET's and diodes are at the highest risk. LSN
D3 SIP Series DC/DC converters incorporate an output overcurrent detection
and shutdown function that serves to protect both the power converter and
its load.
If the output current exceeds it maximum rating by typically 60% (16 Amps)
or if the output voltage drops to less than 98% of it original value, the
LSN D3's internal overcurrent-detection circuitry immediately turns off the
converter, which then goes into a "hiccup" mode. While hiccupping, the
converter will continuously attempt to restart itself, go into overcurrent, and
then shut down. Under these conditions, the average output current will be
approximately 400mA, and the average input current will be approximately
70mA. Once the output short is removed, the converter will automatically
restart itself.
Figure 2a. Inverting On/Off Control Pin Signal and Power-Up Sequencing
+INPUT
COMMON
5kΩ
1.1kΩ
0.9kΩ
0.75kΩ
ON/OFF
CONTROL
For a controlled start-up of one or more LSN-D3's, or if several output volt-
ages need to be powered-up in a given sequence, the On/Off Control pin can
be pulled high (external pull-up resistor, converter disabled) and then driven
low with an external open collector device to enable the converter.
The equations below can be used as starting points for selecting specifi c trim-
resistor values. Recall, untrimmed devices are guaranteed to be ±1% accurate.
Adjustment beyond the specifi ed ±10% adjustment range is not recommended.
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
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16 Dec 2009 MDC_LSN10A-D3.B03 Page 5 of 14
Thermal Considerations and Thermal Protection
The typical output-current thermal-derating curves shown above enable
designers to determine how much current they can reliably derive from each
model of the LSN D3 SIP's under known ambient-temperature and air-fl ow
conditions. Similarly, the curves indicate how much air fl ow is required to
reliably deliver a required output current at known temperatures.
The highest temperatures in LSN D3 SIP's occur at their output inductor,
whose heat is generated primarily by I2R losses. The curves below were
developed using thermocouples to monitor the inductor temperature and
varying the load to keep that temperature below +110°C under the assorted
conditions of air fl ow and air temperature. Once the temperature exceeds
+115°C (approx.), the thermal protection will disable the converter. Automatic
restart occurs after the temperature has dropped below +110°C.
In all cases below, the DUT's were vertical-mount models, and the direction
of air fl ow was parallel to the unit in the direction from pin 1 to pin 11.
As you may deduce from the above curves and can observe in the effi ciency
curves on the next page, LSN D3 SIP's are more effi cient at lower current
levels. Also, I2R losses in the output inductor are signifi cantly less at lower
currents. Consequently, LSN D3 SIP's deliver very impressive temperature
performance if operating at less than full load.
Lastly, when LSN D3 SIP's are installed in system boards, they are obviously
subject to numerous factors and tolerances not taken into account above.
If you are attempting to extract the most current out of these units under
demanding temperature conditions, we advise you to monitor the output-
inductor temperature to ensure it remains below +110°C at all times.
Thermal Performance for "H" Models
Enhanced thermal performance can be achieved when LSN D3 SIP's are
mounted horizontally ("H" models) and the output inductor (with its electrically
isolating, thermally conductive pad installed) is thermally coupled to a copper
plane/pad (at least 0.55 square inches in area) on the system board. Your
conditions may vary, however our tests indicate this confi guration delivers a
16°C to 22°C improvement in ambient operating temperatures.
they will either fail to start or self destruct. In both cases, the cause is the
"freewheeling" or "catch" FET biasing itself on and effectively becoming a
short circuit.
LSN D3 SIP DC/DC converters are not damaged from Output Reverse
Conduction. They employ proprietary gate drive circuitry which makes them
immune to applied voltages during the startup sequence. If you are using
an external power source paralleled with the LSN, be aware that during the
start up phase, some low impedance condition or transient current may be
absorbed briefl y into the LSN output terminals before voltage regulation is
fully established. You should insure that paralleled external power sources
are not disrupted by this condition during LSN start up.
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
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16 Dec 2009 MDC_LSN10A-D3.B03 Page 6 of 14
Start Up Considerations
When power is fi rst applied to the DC/DC converter, operation is different
than when the converter is running and stabilized. There is some risk of start
up diffi culties if you do not observe several application features. Lower input
voltage converters may have more problems here since they tend to have
higher input currents. Operation is most critical with any combination of the
following external factors:
1 - Low initial input line voltage and/or poor regulation of the input source.
2 – Full output load current on lower output voltage converters.
3 – Slow slew rate of input voltage.
4 – Longer distance to input voltage source and/or higher external input
source impedance.
5 - Limited or insuffi cient ground plane. External wiring that is too small.
6 – Too small external input capacitance. Too high ESR.
7 – High output capacitance causing a start up charge overcurrent surge.
8 – Output loads with excessive inductive reactance or constant current
characteristics.
If the input voltage is already at the low limit before power is applied, the start
up surge current may instantaneously reduce the voltage at the input termi-
nals to below the specifi ed minimum voltage. Even if this voltage depression
is very brief, this may interfere with the on-board controller and possibly
cause a failed start. Or the converter may start but the input current load will
now drive the input voltage below its running low limit and the converter will
shut down.
If you measure the input voltage before start up with a Digital Voltmeter
(DVM), the voltage may appear to be adequate. Limited external capacitance
and/or too high a source impedance may cause a short downward spike at
power up, causing an instantaneous voltage drop. Use an oscilloscope not a
DVM to observe this spike. The converter’s soft-start controller is sensitive to
input voltage. What matters here is the actual voltage at the input terminals
at all times.
Symptoms of start-up diffi culties may include failed started, output oscillation
or brief start up then overcurrent shutdown. Since the input voltage is never
absolutely constant, the converter may start up at some times and not at
others.
Solutions
To improve start up, review the conditions above. One of the better solutions
is to place a moderate size capacitor very close to the input terminals. You
may need two parallel capacitors. A larger electrolytic or tantalum cap sup-
plies the surge current and a smaller parallel low-ESR ceramic cap gives low
AC impedance. Too large an electrolytic capacitor may have higher internal
impedance (ESR) and/or lower the start up slew rate enough to upset the
DC/DC’s controller. Make sure the capacitors can tolerate refl ected switching
current pulses from the converter.
The capacitors will not help if the input source has poor regulation. A
converter which starts successfully at 3.3 Volts will turn off if the input voltage
decays to below the input voltage theshold, regardless of external capaci-
tance.
Increase the input start up voltage if possible to raise the downward voltage
spike. Also, make sure that the input voltage ramps up in a reasonably short
time (less than a few milliseconds). If possible, move the input source closer
to the converter to reduce ohmic losses in the input wiring. Remember that
the input current is carried both by the wiring and the ground plane return.
Make sure the ground plane uses adequate thickness copper. Run additional
bus wire if necessary.
Any added output capacitor should use just enough capacitance (and no
more) to reduce output noise at the load and to avoid marginal threshold
noise problems with external logic. An output cap will also “decouple”
inductive reactance in the load. Certain kinds of electronic loads include
“constant current” characteristics which destabilize the output with insuffi cient
capacitance. If the wiring to the eventual load is long, consider placing this
decoupling cap at the load. Use the Remote Sense input to avoid ohmic
voltage drop errors.
An elegant solution to start up problems is to apply the input voltage with the
Remote On/Off control fi rst in the off setting (for those converters with an
On/Off Control). After the specifi ed start-up delay (usually under 20 mSec),
turn on the converter. The controller will have already been stabilized. The
short delay will not be noticed in most applications. Be aware of applications
which need “power management” (phased start up).
Finally, it is challenging to model some application circuits with absolute fi del-
ity. How low is the resistance of your ground plane? What is the inductance
(and distributed capacitance) of external wiring? Even a detailed mathemati-
cal model may not get all aspects of your circuit. Therefore it is diffi cult to
give cap values which serve all applications. Some experimentation may be
required.
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
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16 Dec 2009 MDC_LSN10A-D3.B03 Page 7 of 14
n       
,3.$,3.$,3.$
/UTPUT#URRENTVS!MBIENT4EMPERATURE
6ERTICALMOUNTAIRFLOWDIRECTIONFROMPINTOPIN
/UTPUT#URRENT!MPS
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
.ATURAL#ONVECTION
LFM
LFM
LSN-1.8/10-D3 & LSN-2/10-D3
Output Current vs. Ambient Temperature
(Vertical mount, air flow direction from pin 1 to pin 11)
Output Current (Amps)
Ambient Temperature (°C)
10
8
6
4
2
0
Natural Convection
200 lfm
100 lfm
–40 0 60 70 80 90 100 110
LSN-2.5/10-D3
Output Current vs. Ambient Temperature
(Vertical mount, air flow direction from pin 1 to pin 11)
Output Current (Amps)
Ambient Temperature (°C)
10
8
6
4
2
0
–40 0 60 70 80 90 100 110
Natural Convection
200 lfm
100 lfm
LSN-1.5/10-D3
Output Current vs. Ambient Temperature
(Vertical mount, air flow direction from pin 1 to pin 11)
Output Current (Amps)
Ambient Temperature (°C)
10
8
6
4
2
0
Natural Convection
200 lfm
100 lfm
–40 0 60 70 80 90 100 110
Typical Performance Curves for LSN D3 SIP Series
123 45678910
91
89
87
85
83
81
79
77
75
LSM-1/10-D3
Efficiency vs. Line Voltage and Load Current
Load Current
(
Am
p
s
)
Efficiency (%)
V
IN
= 3V
V
IN
= 3.3V
V
IN
= 3.6V
123 45678910
92
90
88
86
84
82
80
LSM-1.2/10-D3
Efficiency vs. Line Voltage and Load Current
Load Current
(
Am
p
s
)
Efficiency (%)
V
IN
= 3V
V
IN
= 3.3V
V
IN
= 3.6V
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
www.murata-ps.com email: sales@murata-ps.com
16 Dec 2009 MDC_LSN10A-D3.B03 Page 8 of 14
94
93
92
91
90
89
88
87
86
85
LSM-1.5/10-D3
Efficiency vs. Line Voltage and Load Current
123 45678910
Load Current (Amps)
Efficiency (%)
V
IN
= 3V
V
IN
= 3.3V
V
IN
= 3.6V
Typical Performance Curves for LSN D3 SIP Series
97
96
95
94
93
92
91
90
LSM-2.5/10-D3
Efficiency vs. Line Voltage and Load Current
123 45678910
Load Current (Amps)
Efficiency (%)
V
IN
= 3V
V
IN
= 3.3V
V
IN
= 3.6V
123 45678910
95
94
93
92
91
90
89
88
87
LSM-1.8/10-D3
Efficiency vs. Line Voltage and Load Current
Load Current
(
Am
p
s
)
Efficiency (%)
V
IN
= 3V
V
IN
= 3.3V
V
IN
= 3.6V
123 45678910
95
94
93
92
91
90
89
88
87
LSM-2/10-D3
Efficiency vs. Line Voltage and Load Current
Load Current (Amps)
Efficiency (%)
V
IN
= 3V
V
IN
= 3.3V
V
IN
= 3.6V
1 2 3 4 5 6 7 8 9 10
92
91
90
89
88
87
86
85
84
83
LSM-1.25/10-D3
Efficiency vs. Line Voltage and Load Current
Load Current (Amps)
Efficiency (%)
V
IN
= 3V
V
IN
= 3.3V
V
IN
= 3.6V
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
www.murata-ps.com email: sales@murata-ps.com
16 Dec 2009 MDC_LSN10A-D3.B03 Page 9 of 14
Typical Performance Curves for LSN D3 SIP Series
Input Inrush Current
(VIN = 3.3V, 4300μF as Input Switch )
100μsec/div
5A/div
Power-Up From Enable
(VIN = 3.3V, VOUT = 2.5V/10A, CIN/COUT = 220μF)
2.5msec/div
1V/div
Power-Up From Enable
(VIN = 3.3V, VOUT = 2.5V/10A, CIN = 220μF, COUT = 5000μF, OSCON)
2.5msec/div
1V/div
Input Reflected Ripple Current
(VIN = 3.3V, VOUT = 2.5V/10A, CIN/COUT = 220μF )
2μsec/div
4mA/div
Input Reflected Ripple Current
(V
IN
= 3.3V, V
OUT
= 2.5V/10A, Input Filter = 220μF/12μH/33μF,
C
OUT =
220μF )
2.5μsec/div
4mA/div
Power-Up From VIN
(VIN = 3.3V, VOUT = 2.5V/10A, CIN/COUT = 220μF)
2.5msec/div
1V/div
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
www.murata-ps.com email: sales@murata-ps.com
16 Dec 2009 MDC_LSN10A-D3.B03 Page 10 of 14
Typical Performance Curves for LSN D3 SIP Series
Output Ripple/Noise
(VIN = 3.3V, VOUT = 2.5V, No Load, No External Capacitor)
1μsec/div
10mV/div
Output Ripple/Noise
(VIN = 3.3V, VOUT = 2.5V, Full Load, COUT = 220μF)
1μsec/div
10mV/div
Output Ripple/Noise
(VIN = 3.3V, VOUT = 2.5V, Full Load, No External Capacitor)
1μsec/div
10mV/div
Dynamic Load Response
(VIN = 3.3V, VOUT = 2.5V, 100% to 0% Load Step, No External COUT)
100μsec/div
50mV/div
Dynamic Load Response
(VIN = 3.3V, 100% to 50% Load Step, COUT = 220μF)
100μsec/div
20mV/div
Dynamic Load Response
(VIN = 3.3V, VOUT = 2.5V, 0% to 100% Load Step,
COUT = 5000μF OSCON)
100μsec/div
50mV/div
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
www.murata-ps.com email: sales@murata-ps.com
16 Dec 2009 MDC_LSN10A-D3.B03 Page 11 of 14
Typical Performance Curves for LSN D3 SIP Series
Short-Circuit Output Current
(VIN = 3.3V, VOUT = Short, IIN = 70mA Average,
IOUT = 400mA Average, CIN/COUT = 220μF, Period = 25msec)
500μsec/div
2A/div
Output Hiccup
(VIN = 3.3V, VOUT = Short, IIN = 70mA Average,
IOUT = 400mA Average, CIN/COUT = 220μF)
10msec/div
100mV/div
Input Current with Short Circuit at Output
(VIN = 3.3V, VOUT = Short, IIN = 70mA Average,
IOUT = 400mA Average, CIN/COUT = 220μF, Period = 25msec )
2.5msec/div
1A/div
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
www.murata-ps.com email: sales@murata-ps.com
16 Dec 2009 MDC_LSN10A-D3.B03 Page 12 of 14
LSN-2/10-D3 Radiated Emissions
EN55022 Class B, 10 Meters
Converter Output = +2Vdc @ +9.98 Amps
80
70
60
50
40
30
20
10
0
–10
–20
Frequency (MHz)
100 1000
Radiated Emissions
EN 55022 Class B Limit
Radiated Emissions (dBμV/M)
80
70
60
50
40
30
20
10
0
–10
–20
Frequency (MHz)
100 1000
FCC Class B Limit
LSN-2/10-D3 Radiated Emissions
FCC Part 15 Class B, 3 Meters
Converter Output = +2Vdc @ 9.98 Amps
Radiated Emissions (dBμV/M)
Radiated Emissions
If you’re designing with EMC in mind, please note that all of DATEL’s LSN
D3 DC/DC Converters have been characterized for conducted and radiated
emissions in our EMI/EMC laboratory. Testing is conducted in an EMCO
5305 GTEM test cell utilizing EMCO automated EMC test software. Con-
ducted/Radiated emissions are tested to the limits of FCC Part 15, Class B
and CISPR 22 (EN 55022), Class B. Correlation to other specifi cations can
be supplied upon request. The corresponding emissions plots to FCC and
CISPR 22 for model LSN-2/10-D3 appear below.
EMI CONDUCTED/RADIATED EMISSIONS
100
90
80
70
60
50
40
30
20
10
0
Frequency (MHz)
0.1 1.0 10.0
LSN-2/10-D3 Conducted Emissions
FCC Part 15 Class B, EN55022 Class B Limit, +3.3Vdc @ 6.7A
Converter Output = +2Vdc @ 10 Amps
Conducted Emissions (dBμV/M)
Conducted Emissions
FCC Class B Limit
EN55022 Class B Limit
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
www.murata-ps.com email: sales@murata-ps.com
16 Dec 2009 MDC_LSN10A-D3.B03 Page 13 of 14
Maximum Rated Output
Current in Amps
PART NUMBER STRUCTURE
Non-Isolated SIP
Output
Confi guration:
L = Unipolar
Low Voltage
Nominal Output Voltage:
1, 1.2, 1.25, 1.5, 1.8, 2, or 2.5 Volts
Input Voltage Range:
D3 = 3 to 3.6 Volts
(3.3V nominal)
L SN 10-/D3 B-1.8
B Suffi x:
No Remote Sense
(Pin 3 removed)
H
Functional Options
Remote Sense Pin Removed ("B" suffi x)
These devices have their +Sense pin (pin 3) removed, and the feedback
loop is closed through the +VOUT path. The 10.5: resistor in Figure 1 is
installed in both standard and "B" models. See the Output Sense Function.
Horizontal Mounting ("H" suffi x)
This packaging confi guration reduces above-board height to 0.35" (8.89mm)
including the "pad." For "H" models, a thermally conductive, electrically
insulating "pad" is factory installed on the output inductor. The pad material is
Bergquist Sil Pad 400. The pad size is 0.4 x 0.5 x 0.009 inches (10.16 x 12.7
x 0.23mm). This confi guration can signifi cantly improve thermal performance.
See Thermal Derating for details.
Sense Pins
Note: If the sense pin is installed, it must be connected to either a remote
load or to +output at the converter pins. Do not leave sense unconnected.
H Suffi x:
Horizontal Mount
J
J Suffi x:
Reversed Pin, Vertical Mount
Some options may require a special
quantity order.
Options
C
-
RoHS-6 hazardous
substance compliant
Reversed pin vertical mounting ("J" suffi x)
This additional mechanical confi guration consists of a low-profi le pin header
attached to the reverse side of the converter. It allows the LSN series to be
mechanically compatible with Tyco's "keep out area."
Other Options and Modifi cations
Other options include a positive polarity (pull low to disable) on the On/Off
Control. Contact Murata Power Solutions (DATEL) directly to discuss these
and other possible modifi cations.
Examples
LSN-1.8/10-D3 Vertical-mount. Sense function on pin 3. No pin 9.
LSN-1.8/10-D3B Vertical-mount. Pin 3 (+Sense) removed. No pin 9.
LSN-1.8/10-D3H Horizontal-mount. Sense function on pin 3. No pin 9.
LSN-1.8/10-D3BH Horizontal-mount. Pin 3 (+Sense) removed. No pin 9.
LSN-1.8/10-D3J Reverse pin vertical-mount. Sense function on pin 3.
No pin 9.
LSN-1.8/10-D3HJHL2-C Reverse pin vertical mount, conformal
coating added, special pin length, RoHS-6 hazardous
substance compliance.
}
Note:
Some model number combinations may not be
available. Contact Murata Power Solutions
(DATEL).
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
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. Specifi cations are subject to change without
notice. © 2009 Murata Power Solutions, Inc.
www.murata-ps.com/locations email: sales@murata-ps.com
Murata Power Solutions, Inc.
11 Cabot Boulevard, Mansfi eld, MA 02048-1151 U.S.A.
ISO 9001 and 14001 REGISTERED
16 Dec 2009 MDC_LSN10A-D3.B03 Page 14 of 14