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LSN-T/10-D12
Single Adjustable Output, Non-isolated, 12Vin, 10A, SIP, DC/DC Converters
Typical Units
High power density building blocks ideal for on-board
power-distribution schemes in which isolated 12V buses
deliver power to any number of non-isolated, step-down
buck regulators.
PRODUCT OVERVIEW
LSN D12 DC/DC's accept a 12V input (10-14V input
range) and convert it, with the highest efficiency in
the smallest space, to a 0.75 to 5 Volt output fully
rated at 10 Amps. The output is user-adjustable by
trim resistor or adjustment voltage.
LSN D12's are ideal point-of-use/load power
processors. They typically require no external
components. Their vertical-mount packages
occupy a mere 0.7 square inches (4.5 sq. cm),
and reversed pin vertical mount allows mounting
to meet competitor's keep out area. Horizontal-
mount packages ("H" suffix) are only 0.35 inches
(8.89mm) high.
The LSN's best-in-class power density is achieved
with a fully synchronous, fixed-frequency, buck
topology that also delivers: high efficiency (96.5%
for 5V
OUT
models), low noise (35mVp-p typ.), tight
line/load regulation, quick step response (50µsec),
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, thermal shutdown and a
sense pin. High efficiency enables, the LSN D12's to
deliver rated output currents of 10 Amps at ambient
temperatures to +85°C with natural convection.
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, Datel non-
isolated LSN D12 SIP's will save you money.
FEATURES
n
Step-down buck regulators for new distributed
12V power architectures
n
input (10-14V range)
12V
n
0.75-5VOUT @10 Amps
n
Non-isolated, fixed-frequency, synchronous-
rectifier topology
n
Outstanding performance:
•
Efficiencies to 96.5% @ 10 Amps
•
Low noise
•
Stable no-load operation
•
Adjustable output voltage
n
Remote on/off control
n
Sense pin on standard models
n
Thermal shutdown
n
derating to +85°C with 100 lfm
No
n
UL/IEC/EN60950 applied for
n
compliant
EMC
n
up into pre-biased Load
Start
SIMPLIFIED SCHEMATIC
+INPUT
(7,8)
+OUTPUT
(1,2,4)
10Ω
+SENSE
➀
(3)
COMMON
(6)
CURRENT
SENSE
COMMON
(5)
V
CC
ON/OFF
CONTROL
(11)
PWM
CONTROLLER
REFERENCE &
ERROR AMP
V
OUT
TRIM
(10)
For devices with the sense-pin removed ("B" suffix), the feedback path is through the +Output pin and not the +Sense pin.
Typical topology is shown
For full details go to
www.murata-ps.com/rohs
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LSN-T10-D12.E02
Page 1 of 12
LSN-T/10-D12
Single Adjustable Output, Non-isolated, 12Vin, 10A, SIP, DC/DC Converters
PERFORMANCE SPECIFICATIONS AND ORDERING GUIDE
Output
Model
LSN-T/10-D12
LSN-T/10-D12J-Y
Input
Line
±0.06%
±0.06%
±0.06%
Efficiency
I
IN
(mA/A)
80/4.32
80/4.32
80/4.32
V
OUT
(Volts)
0.7525-5.5
0.7525-5.5
I
OUT
(Amps)
10
10
10
R/N (mVp-p)
Regulation (Max.)
Typ.
35
35
35
Max.
55
55
55
Load
±0.2%
±0.2%
±0.2%
V
IN
Nom. Range
(Volts) (Volts)
12
12
12
10-14
10-14
10-14
Full Load
Min.
95.5%
95.5%
95.5%
V
IN
=10V
Typ.
97%
97%
97%
Typ.
96.5%
96.5%
96.5%
Package
(Case/
Pinout)
B5/B5x, P59
B5/B5x, P59
B5/B5x, P59
LSN-T/10-D12J-Y-CIS 0.7525-5.5
Typical at T
A
= +25°C under nominal line voltage, V
OUT
= 5V, and full-load conditions, unless
otherwise 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.
*LAST TIME BUY: 3/31/2017. CLICK HERE FOR DISCONTINUANCE NOTICES.
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.
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.
Nominal line voltage, no-load/full-load conditions.
is not a complete model number. Please see the Part Number Structure when ordering.
This
PART NUMBER STRUCTURE
MECHANICAL SPECIFICATIONS - VERTICAL MOUNTING
L SN
-
T
/
10
-
D12 N H J
-
C
Output
Configuration:
L
= Unipolar
Low Voltage
Non-Isolated SIP
Nominal Output Voltage:
T = 0.75 - 5.25
Maximum Rated Output
Current in Amps
RoHS-6 Compliant
J Suffix:
Reversed Pin
Vertical Mount
H Suffix:
Horizontal Mount
N Suffix:
On/Off Polarity:
Blank = Positive logic
N = Negative logic
Case B5 - Vertical Mounting
(Standard)
2.00
(50.80)
0.17
(4.32)
0.34
(8.64)
0.20
(5.08)
0.55
(13.97)
1 2 3 4 5
6 7 8 9 10 11
0.030 ±0.001 DIA.
(0.762 ±0.025)
0.400
(10.16)
4 EQ. SP. @
0.100 (2.54)
1.000
(25.40)
0.500
(12.70)
5 EQ. SP. @
0.100 (2.54)
0.05
(1.27)
0.110
(2.79)
0.046
(1.17)
Note:
Input Voltage Range:
Not all model number combinations
D12
= 10-14 Volts
are available. Contact Murata Power
(12V nominal)
Solutions.
LAYOUT PATTERN
TOP VIEW
0.25
(6.35)
0.34
(8.64)
MECHANICAL SPECIFICATIONS - HORIZONTAL MOUNTING
Case B5B - Reverse Pin Vertical Mounting
(Tyco-compatible package)
2.00
(50.80)
0.36
(9.14)
0.20
(5.08)
Case B5A - Horizontal Mounting
2.00
(50.80)
0.05
(1.27)
1 2 3 4 5
6 7 8 9 10 11
0.35
(8.89)
0.21
(5.33)
0.55
(13.97)
ISOLATING
PAD
0.17
(4.32)
1 2 3 4 5
6 7 8 9 10 11
0.55
(13.97)
0.030 ±0.001 DIA.
(0.762 ±0.025)
0.400
(10.16)
4 EQ. SP. @
0.100 (2.54)
0.56
(14.22)
1.000
(25.40)
0.500
(12.70)
5 EQ. SP. @
0.100 (2.54)
0.05
(1.27)
0.360
(9.14)
0.16
(4.06)
0.030 ±0.001 DIA.
(0.762 ±0.025)
0.400
(10.16)
4 EQ. SP. @
0.100 (2.54)
1.000
(25.40)
0.500
(12.70)
5 EQ. SP. @
0.100 (2.54)
0.05
(1.27)
0.046
(1.17)
0.106
(2.69)
0.53
(13.46)
0.306
(7.8)
LAYOUT PATTERN
TOP VIEW
0.36
(9.14)
All dimension in Inches (mm)
0.50
(12.7)
LAYOUT PATTERN
TOP VIEW
0.55
(13.97)
RECOMMENDED
COPPER PAD
ON PCB (0.55 SQ. IN.)
All dimension in Inches (mm)
Pin
1
2
3
4
Function P59
+Output
+Output
+Sense
+Output
I/O Connections
Pin
Function P59
5
Common
6
Common
7
+Input
8
+Input
Pin
9
10
11
Function P59
No Pin
V
OUT
Trim
On/Off Control
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LSN-T10-D12.E02
Page 2 of 12
LSN-T/10-D12
Single Adjustable Output, Non-isolated, 12Vin, 10A, SIP, DC/DC Converters
Performance/Functional Specifications
Input
Input Voltage Range
Input Current:
Normal Operating Conditions
Inrush Transient
Standby/Off Mode
Output Short-Circuit Condition
Input Reflected Ripple Current
Input Filter Type
Overvoltage Protection
Reverse-Polarity Protection
Start-up Voltage
Undervoltage Shutdown
On/Off Control
Positive Polarity (no suffix)
Negative Polarity
On/Off Current
10-14 Volts (12V nominal)
See Ordering Guide
0.02A
2
sec
5mA
60mA average
30mAp-p
Capacitive
None
None
9.2 Volts
8 Volts
On = Pin open to +V
IN
max.
Off = Zero (ground) to +0.8V max.
On = Pin open or grounded to +0.3V
Off = +2.5V to +V
IN
max.
0.5 mA maximum
51 Watts
±2%
No minimum load
2,000µF (ESR < 0.02 Ohms)
10,000µF (ESR > 0.02 Ohms)
+0.7525 to +5.5 Volts (no load)
See Ordering Guide
3% max. over line/load/temperature
See Ordering Guide
Converter will start up if the external output
voltage is less than Vsetpoint
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.
All models are tested and specified with external 22µF tantalum input and 10 || 1µF 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.
See Technical Notes and Performance Curves for details.
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).
Output noise may be further reduced with the installation of additional external output
filtering. See I/O Filtering and Noise Reduction.
MTBF’s are calculated using Telcordia SR-332(Bellcore), ground fixed, T
A
= +25°C, full
power, natural convection.
Do not exceed maximum rated output power when adjusting the output voltage.
Typical @ T
A
= +25°C under nominal line voltage, V
OUT
=5V, and full-load conditions unless noted.
Absolute Maximum Ratings
Input Voltage:
Continuous or transient
On/Off Control
(Pin 11)
Input Reverse-Polarity Protection
Output Overvoltage Protection
Output Current
14 Volts
+V
IN
None
None
Current limited. Devices can
withstand sustained output short
circuits without damage.
–40 to +125°C
+280°C
Storage Temperature
Lead Temperature
(soldering, 10 sec.)
Output
Maximum Output Power
V
OUT
Accuracy
(50% load)
Minimum Loading
Maximum Capacitive Load
V
OUT
Trim Range
Ripple/Noise
(20MHz BW)
Extreme Accuracy
Efficiency
Pre-Bias Startup
Overcurrent Detection and Short-Circuit Protection:
Current-Limit Inception
Cold Condition
21 Amps
Short-Circuit Detection Point
98% of V
O U T
set
SC Protection Technique
Hiccup with auto recovery
Short-Circuit Current
400mA average
Dynamic Characteristics
Transient Response
(50-100-50% load) 50µsec to ±2% of final value
Start-Up Time:
V
IN
to V
OUT
and On/Off to V
OUT
Switching Frequency:
8msec
250 ±30 KHz
TBC
Environmental
Calculated MTBF
Operating Temperature:
(Ambient)
Without Derating (Natural convection) –40 to +85°C
With Derating
See Derating Curves
Storage Temperature
Thermal Shutdown
-40 to +125°C
+115°C
See Mechanical Specifications
0.03" (0.76mm) dia. round copper with
tin plate over nickel underplate.
Length: 0.17” (4.32mm)
0.3 ounces (8.5g)
UL94V-0
Physical
Dimensions
Pin Dimensions/Material
Weight
Flamability Rating
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LSN-T10-D12.E02
Page 3 of 12
LSN-T/10-D12
Single Adjustable Output, Non-isolated, 12Vin, 10A, SIP, DC/DC Converters
TECHNICAL NOTES
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
LSN D12 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-
fications (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 D12 SIP Series DC/DC's 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 ram-
ping 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.
Installing the Converter
These converters may be installed into either commercial pin sockets on
0.1" centers (similar to those used with through-hole integrated circuits)
or inserted into plated-through holes on the host printed circuit board. Pin
sockets obviously facilitate repair and replacement whereas PCB mounting
is mechanically and electrically more secure. Soldered-down PCB installation
also conducts more heat away from the converter. Consider increasing the
copper etch area near the output pins.
Do not use excessive force when installing these converters. If you are not in-
serting the converter into pin sockets, make sure the holes on the host printed
circuit board are of adequate size and spaced properly. You may bend the pins
slightly to line them up with the PCB holes. Using two needle nose pliers, se-
curely hold the base of the pin with one plier (where it enters the converter’s
PCB or the lead frame) and apply a very small bend with the other plier part
way down the pin length. The two-plier method avoids excessive force on the
converter’s PCB. If pins are bent too far or too great an insertion force is used
during installation, this may cause hidden damage on the converter, possibly
voiding the warranty.
Remote Sense
LSN D12 SIP Series DC/DC converters offer an output sense function on pin 3.
Return Current Paths
The LSN D12 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
(specifically pin 6).
I/O Filtering and Noise Reduction
All models in the LSN D12 Series are tested and specified with external 22µF
tantalum input and 10 || 1µF output capacitors. These capacitors are neces-
sary to accommodate our test equipment and may not be required to achieve
desired performance in your application. The LSN D12's are designed with
high-quality, high-performance internal I/O caps, and will operate within spec
in most applications with no additional external components.
In particular, the LSN D12's input capacitors are specified for low ESR and are
fully rated to handle the units' input ripple currents. Similarly, the internal out-
put capacitors are specified for low ESR and full-range frequency response.
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 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 specific system
configuration may necessitate additional considerations.
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.
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. 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. LSN D12 Series DC/DC convert-
ers are not internally fused. Therefore, if input fusing is mandatory, either
a normal-blow or a slow-blow fuse with a value no greater than 15 Amps
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LSN-T10-D12.E02
Page 4 of 12
LSN-T/10-D12
Single Adjustable Output, Non-isolated, 12Vin, 10A, SIP, DC/DC Converters
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
DC/DC 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.
The sense function is capable of compensating for voltage drops between the
+Output and +Sense pins that do not exceed 10% of V
OUT
.
[V
OUT
(+) – Common] – [Sense(+) – Common]
≤
10%V
OUT
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 specified rating. Therefore:
(V
OUT
at pins) x (I
OUT
)
≤
rated output power
The internal 10Ω resistor between +Sense and +Output (see Figure 1) serves
to protect the sense function by limiting the output current flowing 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 con-
verter pins, if the sense function is not used for remote regulation.
On/Off Control
The On/Off Control pin may be used for remote on/off operation. LSN-T/10-D12
SIP is 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, as
shown in Figure 2 and 2a.
+INPUT
LSN D12 SIP Series DC/DC converters do not incorporate output overvoltage
protection. In the extremely rare situation in which the device’s feedback loop
is broken, the output voltage may run to excessively high levels (V
OUT
= V
IN
). If
it is absolutely imperative that you protect your load against any and all possi-
ble 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
D12 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 70% or if the
output voltage drops to less than 98% of it's original value, the LSN D12'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. Once the output short is removed, the converter will automatically
restart itself.
Thermal Performance
The typical output-current thermal-derating curves shown below enable
designers to determine how much current they can reliably derive from each
model of the LSN D12 SIP's under known ambient-temperature and air-flow
conditions. Similarly, the curves indicate how much air flow is required to reli-
ably deliver a specific output current at known temperatures.
The highest temperatures in LSN D12 SIP's occur at their output inductor,
whose heat is generated primarily by I
2
R losses. The derating curves 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 flow 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.
Lastly, when LSN D12 SIP's are installed in system boards, they are obviously
subject to numerous factors and tolerances not taken into account here. If you
are attempting to extract the most current out of these units under demand-
ing temperature conditions, we advise you to monitor the output-inductor
temperature to ensure it remains below +110°C at all times.
30.1kΩ
ON/OFF
CONTROL
30.1kΩ
9.09kΩ
Small
Signal
Transistor
or FET
C
SS
20kΩ
COMMON
Thermal Performance for "H" Models
Enhanced thermal performance can be achieved when LSN D12 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 configuration delivers a
16°C to 22°C improvement in ambient operating temperatures.
Figure 2. Driving the On/Off Control Pin with an Open-Collector Drive Circuit
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.The on/off control function, however, can be exter-
nally inverted so that the converter will be disabled while the input voltage is
ramping up and then "released" once the input has stabilized.
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LSN-T10-D12.E02
Page 5 of 12
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