LSN-10A D3 Models

LAST TIME BUY: 3/31/2015. CLICK HERE FOR OBSOLESCENCE NOTICE OF 10/31/2014.
LSN-10A D3 Models
www.murata-ps.com
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
Typical Units
Features
■
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:
• ±1% setpoint accuracy
• Efficiencies to 94% @ 10 Amps
• Noise as low as 10mVp-p
• Stable no-load operation
• Trimmable output voltage
■
Remote on/off and sense pins
■
Thermal Shutdown
■
No derating to +71°C, natural convection
■
UL/IEC/EN60950 certified
■
EMC compliant
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 outputs at 10 Amps. LSN D3 SIP’s are designed to take on-board 3.3V
power and convert it, with the highest efficiency in the smallest space,
to any lower voltage required by today’s current-hungry DSP’s, ASIC’s
and CPLD’s.
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" suffix) are only 0.34 inches (8.6mm) high.
The LSN's best-in-class power density is achieved with a fully synchronous,
fixed-frequency (300kHz), buck topology that also delivers: high efficiency (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 shortcircuit protection, an output-voltage trim function, a remote on/off control pin
(pull high to disable), thermal shutdown, and a sense pin. High efficiency enables the
LSN D3's to deliver rated output currents of 10 Amps at ambient temperatures to
+71°C with no air flow (natural convection).
If your low-voltage, high-current requirements have made the use of inefficient
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 certified and EMC compliant. UL, CB,
HALT and EMC reports are available upon request.
+OUTPUT
(1,2,4)
+INPUT
(7,8)
10.5Ω
330µF
44µF
47.1µF
470µF
+SENSE ➀
(3)
COMMON
(5)
COMMON
(6)
CURRENT
SENSE
VOLTAGE
BOOST
VCC
ON/OFF
CONTROL
(11)
Typical topology is shown
PWM
CONTROLLER
REFERENCE &
ERROR AMP
TRIM
(10)
Figure 1. Simplified Schematic
➀ For devices with the sense-pin removed ("B" suffix),
the feedback path is through the +Output pin and not
the +Sense pin.
For full details go to
www.murata-ps.com/rohs
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MDC_LSN10A-D3.D01 Page 1 of 14
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
Performance Specifications and Ordering Guide
Root Model ➄
To Be Discontinued*
LSN-1/10-D3-C
LSN-1.2/10-D3-C
LSN-1.25/10-D3-C
LSN-1.5/10-D3-C
LSN-1.8/10-D3-C
LSN-1.8/10-D3HJHL2-C
LSN-2/10-D3-C
LSN-2.5/10-D3-C
VOUT
(Volts)
1
1.2
1.25
1.5
1.8
1.8
2
2.5
➀
Output
R/N (mVp-p) ➁
Typ.
Max.
10
35
10
35
10
35
10
35
10
35
10
35
10
35
10
35
IOUT
(Amps)
10
10
10
10
10
10
10
10
Regulation (Max.) ➂ VIN Nom.
(Volts)
Line
Load
±0.1%
±0.25%
3.3
±0.1%
±0.25%
3.3
±0.1%
±0.25%
3.3
±0.1%
±0.25%
3.3
±0.1%
±0.25%
3.3
±0.1%
±0.25%
3.3
±0.1%
±0.25%
3.3
±0.1%
±0.25%
3.3
Input
Range
(Volts)
3.0-3.6
3.0-3.6
3.0-3.6
3.0-3.6
3.0-3.6
3.0-3.6
3.0-3.6
3.0-3.6
IIN ➃
(mA/A)
70/3.73
70/4.42
60/4.30
70/5.47
70/6.33
70/6.33
70/6.96
70/8.50
Efficiency
Full Load
Min.
Typ.
83.5%
86.5%
85%
88%
85%
88%
87.5%
90%
89%
91.5%
89%
91.5%
89.5%
92.5%
91%
94%
½ Load
Typ.
90.5%
91%
91%
92.2%
93.5%
93.5%
94%
95.5%
Package
(Case,
Pinout)
B7/B7x, P59
B7/B7x, P59
B7/B7x, P59
B7/B7x, P59
B7/B7x, P59
B7/B7x, P59
B7/B7x, P59
B7/B7x, P59
*LAST TIME BUY: 3/31/2015. CLICK HERE FOR OBSOLESCENCE NOTICE OF 10/31/2014.
➀ Typical at TA = +25°C under nominal line voltage and full-load conditions, unless otherwise
noted. All models are tested and specified with external 22µF 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.
P A R T
N U M B E R
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 These are not complete model numbers. Please refer to the Part Number Structure for additional options when ordering.
M E C H A N I C A L
S T R U C T U R E
L SN - 1.8 / 10 - D3 B H J - C
Output
Configuration:
L = Unipolar
Low Voltage
RoHS-6 compliant
J Suffix:
Reversed Pin
Vertical Mount
Non-Isolated SIP
Input Voltage Range:
D3 = 3 to 3.6 Volts
(3.3V nominal)
See page 12 for
Part Number Structure
and ordering details.
6 7 8 9 10 11
0.50
(12.7)
0.56
(14.2)
1.000
(25.40)
0.400
(10.16)
4 EQ. SP. @
0.100 (2.54)
ISOLATING
PAD
0.500
(12.70)
5 EQ. SP. @
0.100 (2.54)
RECOMMENDED
COPPER PAD
ON PCB (0.55 SQ. IN.)
LAYOUT PATTERN
TOP VIEW
Case B7
Vertical Mounting
(Standard)
0.36
(9.1)
0.20
(5.1)
0.50
(12.7)
0.16
(4.1)
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)
Case B7A
Horizontal Mounting
0.50
(12.7)
0.45
(11.4)
0.046
(1.2)
0.34
(8.6)
0.17
(4.3)
0.306
(7.8)
Pin Function P59*
1
+Output
2
+Output
3
+Sense *
4
+Output
1.000
(25.40)
2.00
(50.8)
0.360
(9.1)
0.53
(13.5)
0.110
(2.8)
0.05
(1.3)
0.25
(6.4)
0.05
(1.3)
0.500
(12.70)
5 EQ. SP. @
0.100 (2.54)
0.50
(12.7)
0.030 ±0.001 DIA.
(0.762 ±0.025)
1 2 3 4 5
0.030 ±0.001 DIA.
(0.762 ±0.025)
0.400
(10.16)
4 EQ. SP. @
0.100 (2.54)
6 7 8 9 10 11
1 2 3 4 5
0.21
(5.3)
0.05
(1.3)
0.20
(5.1)
LAYOUT PATTERN
TOP VIEW
0.35
(8.9)
2.00
(50.8)
1 2 3 4 5
0.17
(4.3)
B Suffix:
No Remote Sense
(Pin 3 removed)
Maximum Rated Output
Current in Amps
0.34
(8.6)
2.00
(50.8)
H Suffix:
Horizontal Mount
Nominal Output Voltage:
1, 1.2, 1.25, 1.5, 1.8, 2, or 2.5 Volts
S P E C I F I C A T I O N S
Standard model pin
lengths are shown.
I/O Connections
Pin Function P59* Pin Function P59*
5
Common
9
No Pin
6
Common
10
VOUT Trim
7
+Input
11
On/Off Control
8
+Input
1.000
(25.40)
0.05
(1.3)
0.106
(2.7)
0.500
(12.70)
5 EQ. SP. @
0.100 (2.54)
LAYOUT PATTERN
TOP VIEW
0.046
(1.2)
0.36
(9.1)
Case B7B
Reverse Pin
Vertical Mounting
(Tyco/Lineage-compatible)
Dimensions are in inches (mm shown for ref. only).
Third Angle Projection
* Pin 3 (+Sense) removed
for "B" suffix models.
Tolerances (unless otherwise specified):
.XX ± 0.02 (0.5)
.XXX ± 0.010 (0.25)
Angles ± 2˚
Components are shown for reference only.
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MDC_LSN10A-D3.D01 Page 2 of 14
LSN-10A D3 Models
Performance/Functional Specifications
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
Typical @ TA = +25°C under nominal line voltage and full-load conditions unless noted. ➀
Absolute Maximum Ratings
Input
Input Voltage Range
3.0 to 3.6 Volts (3.3V nominal)
Input Current:
Normal Operating Conditions
Inrush Transient
Standby/Off Mode
Output Short-Circuit Condition ➁
Input Voltage:
Continuous or transient
6 Volts
See Ordering Guide
0.02A2sec
3mA
70mA average
On/Off Control (Pin 11)
+VIN
Input Reverse-Polarity Protection
None, install external fuse
Output Overvoltage Protection
None
Input Reflected Ripple Current ➁
50mAp-p
Output Current
Input Filter Type
Capacitive (374µF)
Overvoltage Protection
None
Current limited. Devices can withstand sustained output short circuits without damage.
Reverse-Polarity Protection
None, install external fuse
Storage Temperature
–40 to +125°C
Undervoltage Shutdown
None
Lead Temperature (soldering, 10 sec.)
+300°C
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 Coefficient
±0.02%/°C
Total Accuracy
3% over line/load/temperature
Efficiency 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 final value
Start-Up Time: ➁
VIN to VOUT
On/Off to VOUT
7msec
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 Specifications
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
➀ All models are tested/specified with external 22µF input/output capacitors.These caps 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 11) is designed to be driven with open-collector logic or the application of appropriate voltages (referenced to Common, pins 5 and 6).
➃ Output noise may be further reduced with the installation of additional external output filtering. See I/O Filtering and Noise Reduction.
➄ Calculated using the Telcordia (Bellcore) SR-332 Method 1, Case 3, ground fixed conditions,
TA = +25°C, full load, natural convection, +55°C component temperature.
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 Specifications Table is not implied.
T E C H N I C A L
N O T E S
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
(specifically pin 6).
I/O Filtering and Noise Reduction
All models in the LSN D3 Series are tested and specified 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 applications
with no additional external components.
In particular, the LSN D3'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
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
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
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MDC_LSN10A-D3.D01 Page 3 of 14
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
elements and should be selected for bulk capacitance, low ESR, and appropriate 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 converters 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 efficiency.
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/separation requirements, in compliance with relevant safety-agency specifications (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 specified
absolute maximum ratings and input polarity reversals of longer than "instantaneous" 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 specified input voltage
range (3 Volts) 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 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 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
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
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 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] ≤ 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 specified rating. Therefore:
(VOUT at pins) x (IOUT) ≤ rated output power
The internal 10.5Ω 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
converter pins, if the sense function is not used for remote regulation.
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 mechanical 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.
+INPUT
5kΩ
1.1kΩ
ON/OFF
CONTROL
0.75kΩ
COMMON
Figure 2. Driving the On/Off Control Pin with an Open-Collector Drive Circuit
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.
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MDC_LSN10A-D3.D01 Page 4 of 14
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
+INPUT
+OUTPUT
5kΩ
0.9kΩ
Trim
Down
+INPUT
1.1kΩ
ON/OFF
CONTROL
TRIM
LOAD
Trim
Up
COMMON
0.75kΩ
COMMON
COMMON
Figure 3. Trim Connections Using a Trimpot
Figure 2a. Inverting On/Off Control Pin Signal and Power-Up Sequencing
For a controlled start-up of one or more LSN-D3's, or if several output voltages 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.
Output Overvoltage Protection
LSN D3 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 (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 maximum 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.
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 fixed 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 fixed 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.
The equations below can be used as starting points for selecting specific trimresistor values. Recall, untrimmed devices are guaranteed to be ±1% accurate.
Adjustment beyond the specified ±10% adjustment range is not recommended.
+OUTPUT
Trim
Down
+INPUT
LOAD
TRIM
COMMON
Trim Up
COMMON
Note: Install either a fixed trim-up resistor or a fixed trim-down resistor
depending upon desired output voltage.
Figure 4. Trim Connections Using Fixed Resistors
LSN-1/10-D3 Trim Equations
RT DOWN (kΩ) =
RT UP (kΩ) =
1.62(VO – 0.8)
–1
VO NOM – VO
1.296
–1
VO – VO NOM
LSN-1.2/10-D3, LSN-1.25/10-D3 Trim Equations
RT DOWN (kΩ) =
RT UP (kΩ) =
2.49(VO – 0.8)
VO NOM – VO
1.992
– 2.37
– 2.37
VO – VO NOM
LSN-1.5/10-D3, LSN-1.8/10-D3,
LSN-2/10-D3, LSN-2.5/10-D3 Trim Equations
RT DOWN (kΩ) =
RT UP (kΩ) =
2.37(VO – 0.8)
VO NOM – VO
1.896
VO – VO NOM
– 4.99
– 4.99
Note: Resistor values are in kΩ. Accuracy of adjustment is subject to
tolerances of resistors and factory-adjusted, initial output accuracy.
VO = desired output voltage. VONOM = nominal output voltage.
Output Reverse Conduction
Many DC/DC converters using synchronous rectification 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),
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MDC_LSN10A-D3.D01 Page 5 of 14
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
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 briefly 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.
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-flow
conditions. Similarly, the curves indicate how much air flow 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 I 2 R 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 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.
In all cases below, the DUT's were vertical-mount models, and the direction
of air flow 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 efficiency
curves on the next page, LSN D3 SIP's are more efficient at lower current
levels. Also, I 2 R losses in the output inductor are significantly 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 outputinductor 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 configuration delivers a
16°C to 22°C improvement in ambient operating temperatures.
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MDC_LSN10A-D3.D01 Page 6 of 14
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
Start Up Considerations
Solutions
When power is first applied to the DC/DC converter, operation is different
than when the converter is running and stabilized. There is some risk of start
up difficulties 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:
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 supplies 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 reflected switching
current pulses from the converter.
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 insufficient 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 terminals to below the specified 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 difficulties 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.
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 capacitance.
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 insufficient
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 first in the off setting (for those converters with an
On/Off Control). After the specified 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 fidelity. How low is the resistance of your ground plane? What is the inductance
(and distributed capacitance) of external wiring? Even a detailed mathematical model may not get all aspects of your circuit. Therefore it is difficult to
give cap values which serve all applications. Some experimentation may be
required.
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MDC_LSN10A-D3.D01 Page 7 of 14
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
Typical Performance Curves for LSN D3 SIP Series
LSN-2.5/10-D3
Output Current vs. Ambient Temperature
(Vertical mount, air flow direction from pin 1 to pin 11)
LSN-1/10-D3, LSN-1.2/10-D3, LSN-1.25/10-D3
Output Current vs. Ambient Temperature
(Vertical mount, air flow direction from pin 1 to pin 11)
10
8
Output Current (Amps)
Output Current (Amps)
10
Natural Convection
6
100 lfm
4
200 lfm
8
Natural Convection
6
100 lfm
4
200 lfm
2
2
0
–40
0
60
70
80
90
100
0
–40
110
0
60
10
70
80
90
100
110
Ambient Temperature (°C)
Ambient Temperature (°C)
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)
LSM-1/10-D3
Efficiency vs. Line Voltage and Load Current
91
87
Natural Convection
6
Efficiency (%)
Output Current (Amps)
89
8
100 lfm
4
200 lfm
2
85
VIN = 3V
83
VIN = 3.3V
81
VIN = 3.6V
79
0
–40
0
60
70
80
90
100
77
110
Ambient Temperature (°C)
75
1
10
2
3
4
5
6
7
8
9
10
8
9
10
Load Current (Amps)
LSN-1.5/10-D3
Output Current vs. Ambient Temperature
(Vertical mount, air flow direction from pin 1 to pin 11)
LSM-1.2/10-D3
Efficiency vs. Line Voltage and Load Current
Natural Convection
90
6
88
100 lfm
4
Efficiency (%)
Output Current (Amps)
92
8
200 lfm
2
0
–40
0
60
70
80
Ambient Temperature (°C)
90
100
VIN = 3V
86
VIN = 3.3V
84
VIN = 3.6V
110
82
80
1
2
3
4
5
6
7
Load Current (Amps)
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MDC_LSN10A-D3.D01 Page 8 of 14
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
Typical Performance Curves for LSN D3 SIP Series
LSM-1.25/10-D3
Efficiency vs. Line Voltage and Load Current
LSM-2/10-D3
Efficiency vs. Line Voltage and Load Current
92
95
91
94
90
93
Efficiency (%)
Efficiency (%)
89
VIN = 3V
88
87
VIN = 3.3V
86
VIN = 3V
91
VIN = 3.3V
90
VIN = 3.6V
VIN = 3.6V
85
92
89
88
84
83
1
2
3
4
5
6
7
8
9
87
10
1
2
3
Load Current (Amps)
4
5
6
7
8
9
10
8
9
10
Load Current (Amps)
LSM-2.5/10-D3
Efficiency vs. Line Voltage and Load Current
LSM-1.5/10-D3
Efficiency vs. Line Voltage and Load Current
94
97
93
96
92
95
Efficiency (%)
Efficiency (%)
91
90
VIN = 3V
89
VIN = 3.3V
88
93
VIN = 3.3V
VIN = 3.6V
91
86
85
VIN = 3V
92
VIN = 3.6V
87
94
1
2
3
4
5
6
7
8
9
10
Load Current (Amps)
90
1
2
3
4
5
6
7
Load Current (Amps)
LSM-1.8/10-D3
Efficiency vs. Line Voltage and Load Current
95
94
Efficiency (%)
93
92
91
VIN = 3V
90
VIN = 3.3V
89
VIN = 3.6V
88
87
1
2
3
4
5
6
7
8
9
10
Load Current (Amps)
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MDC_LSN10A-D3.D01 Page 9 of 14
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
Typical Performance Curves for LSN D3 SIP Series
Power-Up From VIN
(VIN = 3.3V, VOUT = 2.5V/10A, CIN/COUT = 220µF)
1V/div
5A/div
Input Inrush Current
(VIN = 3.3V, 4300µF as Input Switch )
100µsec/div
2.5msec/div
Power-Up From Enable
(VIN = 3.3V, VOUT = 2.5V/10A, CIN/COUT = 220µF)
1V/div
4mA/div
Input Reflected Ripple Current
(VIN = 3.3V, VOUT = 2.5V/10A, CIN/COUT = 220µF )
2µsec/div
2.5msec/div
Power-Up From Enable
(VIN = 3.3V, VOUT = 2.5V/10A, CIN = 220µF, COUT = 5000µF, OSCON)
1V/div
4mA/div
Input Reflected Ripple Current
(VIN = 3.3V, VOUT = 2.5V/10A, Input Filter = 220µF/12µH/33µF,
COUT = 220µF )
2.5µsec/div
2.5msec/div
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MDC_LSN10A-D3.D01 Page 10 of 14
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
Typical Performance Curves for LSN D3 SIP Series
Dynamic Load Response
(VIN = 3.3V, 100% to 50% Load Step, COUT = 220µF)
20mV/div
10mV/div
Output Ripple/Noise
(VIN = 3.3V, VOUT = 2.5V, Full Load, COUT = 220µF)
1µsec/div
100µsec/div
Dynamic Load Response
(VIN = 3.3V, VOUT = 2.5V, 100% to 0% Load Step, No External COUT)
50mV/div
10mV/div
Output Ripple/Noise
(VIN = 3.3V, VOUT = 2.5V, Full Load, No External Capacitor)
1µsec/div
100µsec/div
Dynamic Load Response
(VIN = 3.3V, VOUT = 2.5V, 0% to 100% Load Step,
COUT = 5000µF OSCON)
50mV/div
10mV/div
Output Ripple/Noise
(VIN = 3.3V, VOUT = 2.5V, No Load, No External Capacitor)
1µsec/div
100µsec/div
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MDC_LSN10A-D3.D01 Page 11 of 14
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
Typical Performance Curves for LSN D3 SIP Series
Input Current with Short Circuit at Output
(VIN = 3.3V, VOUT = Short, IIN = 70mA Average,
IOUT = 400mA Average, CIN/COUT = 220µF, Period = 25msec )
1A/div
100mV/div
Output Hiccup
(VIN = 3.3V, VOUT = Short, IIN = 70mA Average,
IOUT = 400mA Average, CIN/COUT = 220µF)
10msec/div
2.5msec/div
2A/div
Short-Circuit Output Current
(VIN = 3.3V, VOUT = Short, IIN = 70mA Average,
IOUT = 400mA Average, CIN/COUT = 220µF, Period = 25msec)
500µsec/div
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MDC_LSN10A-D3.D01 Page 12 of 14
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
LSN-2/10-D3 Radiated Emissions
EN55022 Class B, 10 Meters
Converter Output = +2Vdc @ +9.98 Amps
E M I C O N D U C T E D / R A D I AT E D E M I S S I O N S
80
70
60
Radiated Emissions (dBµV/M)
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. Conducted/Radiated emissions are tested to the limits of FCC Part 15, Class B
and CISPR 22 (EN 55022), Class B. Correlation to other specifications can
be supplied upon request. The corresponding emissions plots to FCC and
CISPR 22 for model LSN-2/10-D3 appear below.
50
EN 55022 Class B Limit
40
30
20
10
0
Radiated Emissions
LSN-2/10-D3 Conducted Emissions
FCC Part 15 Class B, EN55022 Class B Limit, +3.3Vdc @ 6.7A
Converter Output = +2Vdc @ 10 Amps
–10
–20
1000
100
100
Frequency (MHz)
90
LSN-2/10-D3 Radiated Emissions
FCC Part 15 Class B, 3 Meters
Converter Output = +2Vdc @ 9.98 Amps
70
60
EN55022 Class B Limit
FCC Class B Limit
80
50
70
40
60
30
20
10
0
0.1
Conducted Emissions
1.0
Frequency (MHz)
10.0
Radiated Emissions (dBµV/M)
Conducted Emissions (dBµV/M)
80
FCC Class B Limit
50
40
30
20
10
0
Radiated Emissions
–10
–20
1000
100
Frequency (MHz)
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MDC_LSN10A-D3.D01 Page 13 of 14
LSN-10A D3 Models
Single Output, Non-Isolated, 3.3VIN, 1-2.5VOUT, 10A, DC/DC's in SIP Packages
P A R T
N U M B E R
S T R U C T U R E
}
Options
L SN - 1.8 / 10 - D3 B H J - C
Output
Configuration:
L = Unipolar
Low Voltage
RoHS-6 hazardous
substance compliant
J Suffix:
Reversed Pin, Vertical Mount
H Suffix:
Horizontal Mount
Non-Isolated SIP
Nominal Output Voltage:
1, 1.2, 1.25, 1.5, 1.8, 2, or 2.5 Volts
Maximum Rated Output
Current in Amps
Note:
Some model number combinations may not be
available. Contact Murata Power Solutions
(DATEL).
B Suffix:
No Remote Sense
(Pin 3 removed)
Some options may require a special
quantity order.
Input Voltage Range:
D3 = 3 to 3.6 Volts
(3.3V nominal)
Functional Options
Reversed pin vertical mounting ("J" suffix)
Remote Sense Pin Removed ("B" suffix)
This additional mechanical configuration consists of a low-profile 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."
These devices have their +Sense pin (pin 3) removed, and the feedback
loop is closed through the +VOUT path. The 10.5Ω resistor in Figure 1 is
installed in both standard and "B" models. See the Output Sense Function.
Horizontal Mounting ("H" suffix)
This packaging configuration 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 configuration can significantly 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.
Murata Power Solutions, Inc.
11 Cabot Boulevard, Mansfield, MA 02048-1151 U.S.A.
ISO 9001 and 14001 REGISTERED
Other Options and Modifications
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 modifications.
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.
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. © 2014 Murata Power Solutions, Inc.
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MDC_LSN10A-D3.D01 Page 14 of 14