MURATA UWR Technical data
FEATURES
+INPUT
COMMON
V
TRACK
/SEQUENCE
INPUT
PWM
CONTROLLER
CURRENT
SENSE
REFERENCE &
ERROR AMP
VCC
ON/OFF
CONTROL
V
OUT
TRIM
POWER
GOOD
OUTPUT
+OUTPUT
10.57
+SENSE
COMMON
■
Standard (DOSA compatible) SIP package
■
User-selectable outputs: 0.8 to 5Vdc
■
30 Amps maximum output current
■
Double lead free to RoHS standards
■
Selectable phased start-up sequencing,
tracking and pre-bias operation
■
Wide range input voltages 6 to 14Vdc
■
To 150W with overtemperature shutdown
■
Very high efficiency up to 94%
■
Fast settling, high di/dt IOUT slew rate
■
UL 60950-1, CSA-C22.2 No. 60950-1,
EN60950-1 safety approvals
■
Extensive self-protection with short circuit
“hiccup” shutdown
■
Output overvoltage/overcurrent protection
■
Input under and overvoltage shutdown
LSN2-T/30-D12 Series
DOSA-SIP, 30A POL DC/DC Converters
DESCRIPTION
These miniature point-of-load (POL) switching
DC/DCs are an ideal regulation and supply
element for distributed power and intermediate bus architectures. The converter is
fully compatible with the Distributed-power
Open Standards Alliance specification
(www.dosapower.com). LSN2-T/30-D12 can
power CPU’s, programmable logic and mixed
voltage systems with little heat and low noise.
A typical application uses a master isolated
12V DC supply and the LSN2-T/30-D12 converter for local 1.8V and 3.3V DC supplies.
All system isolation resides in the central
48V/12V bus converter supply, leaving lower
cost POL regulation right at the load. Unlike
linear regulators, the LSN2-T/30-D12 can
deliver very high power (up to 150W) in a tiny
area with no heat sinking and no external
components needed. The converter features
quick transient response (to 25µsec) and
very fast current slew rates (to 20A/µsec).
LSN2-T/30-D12 is an open-frame SIP
using advanced surface mount (SMT)
assembly and test techniques. The extraordinary performance is achieved with a fully
synchronous fixed-frequency buck topology
delivering high efficiency, tight line/load
regulation, stable no-load operation and no
output reverse conduction.
Output voltage, selected with an
external programming resistor or DC voltage into the trim pin, means OEM’s can
stock one model for multiple applications.
Also included are protection for out-oflimit voltages, currents and temperature.
Other functions: a remote On/Off control,
optional Power Good output, a phased
start-up sequence and tracking system,
and a load Sense input.
Typical topology is shown.
For full details go to
www.murata-ps.com/rohs
➀
➀ Only one phase of two is shown.
Figure 1. LSN2 -T/30-D12 Series Simplified Schematic
www.murata-ps.com Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000
MDC_LSN2-T/30-D12 Series.B12 Page 1 of 17
LSN2-T/30-D12 Series
DOSA-SIP, 30A POL DC/DC Converters
➀
PERFORMANCE SPECIFICATIONS AND ORDERING GUIDE
Model ➆
LSN2-T/30-D12-C 0.8-5 30 150 25 50 ±0.1% ±0.1% 12 6-14 200/11.1 93% 94% B13, P71
➀ Typical at Ta = +25°C under nominal line voltage and full-load conditions, unless noted. All
models are tested and specified with external 22µF tantalum input and output 0.01//0.1//10µF
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 for Vo u t > 3.63V and may be
reduced with external filtering. See I/O Filtering and Noise Reduction for details.
VOUT
(Volts)
IOUT
(Amps)
Power
(Watts)
PART NUMBER STRUCTURE
Output Input
R/N (mVp-p) ➁ Regulation (max.)
Typ. Max. Line Load
➂
VIN Nom.
(Volts)
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 LSN2-T/30-D12 efficiencies are shown at 5Vo u t .
➅ Input range is 6-14V if Vo u t ≤3.63V. For Vo u t > 3.63V, the input range is 7–14V.
➆ Please refer to the Part Number Structure for additional options when ordering.
Range➅
(Volts)
IIN ➃
(mA/A)
Efficiency
Min. Typ.
➄
Package
(Case/
Pinout)
Output Configuration:
L = Unipolar
Low Voltage
Non-Isolated Through-hole
Nominal Output Voltage:
0.8-5 Volts
Maximum Rated Output
Current in Amps
L SN2 -
/
30 G
D12- -T
C
RoHS-6 hazardous
substance compliant
Power Good:
Blank = Omitted (default)
G = Installed (special quantity orders required)
Input Voltage Range:
D12 = 7-14 Volts (12V nominal)
Note:
Some model number combinations may not be available. Contact
Murata Power Solutions.
Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000www.murata-ps.com
MDC_LSN2-T/30-D12 Series.B12 Page 2 of 17
LSN2-T/30-D12 Series
DOSA-SIP, 30A POL DC/DC Converters
Performance/Functional Specifications
Input
(1)
Input Voltage Range See Ordering Guide
Isolation Not isolated. Input and output
Commons are internally connected.
Start-Up Voltage 5.5 Volts
Undervoltage Shutdown 5.2 Volts
Overvoltage Shutdown None
Reflected (Back) Ripple Current
(2)
20mAp-p
Internal Input Filter Type Capacitive
Reverse Polarity Protection See fuse information
Input Current:
Full Load Conditions See Ordering Guide
Inrush Transient 0.4A2sec
Shutdown Mode (Off, UV, OT) 5mA
Output Short Circuit 60mA
No Load, 5VOUT 200mA
Low Line (VIN = VMIN, 5VOUT) 18.8 Amps
Remote On/Off Control:
(5)
Negative Logic (No suffix) ON = 0 to +0.5V max.
OFF = +2V min. to +14V max.
Current 1 mA max.
Output
Voltage Output Range See Ordering Guide
Minimum Loading No minimum load
Accuracy (50% load) ±1.5% of Vnominal
Voltage Adjustment Range
(13)
See Ordering Guide
Overvoltage Protection None
Temperature Coefficient ±0.02% per °C of Vo u t range
Ripple/Noise (20 MHz bandwidth) See Ordering Guide
Line/Load Regulation (See Tech. Notes) See Ordering Guide
(8)
(10)
Efficiency See Ordering Guide
Maximum Capacitive Loading
(15)
Cap-ESR = 0.001 to 0.01W 5,000µF
Cap-ESR > 0.01W 10,000µF
Current Limit Inception 48 Amps (cold star tup)
(98% of VOUT setting) 42 Amps (after warm up)
Short Circuit Mode
Short Circuit Current Output 600mA
Protection Method
(6)
(14)
Hiccup autorecovery on overload removal
Short Circuit Duration Continuous, no damage
(output shorted to ground)
Pre-bias Startup
(16)
Converter will start up if the external
output voltage is less than VNOMINAL
Sequencing
Slew Rate 2V max. per millisecond
Startup delay until sequence start 10 milliseconds
Tracking accuracy, rising input Vout= ±200mV of Sequence In
Tracking accuracy, falling input Vo u t = ±400mV of Sequence In
Remote Sense to Vo u t 0.5V max.
(7)
Power Good Output
(15)
Configuration Positive-true open drain FET with internal
10 Kilohm pullup to +5 Vdc
Operation TRUE (power is okay) = High, approx. 5Vdc
FALSE (power is not ready) = Low, < 1V typ.,
while DC/DC is powered
External sink current 4.5 mA max. (< 1mA is recommended
to retain Vpg < 1V)
FALSE conditions (OR’d) Soft start is active, Tracking is active, output
is greater than ±10% out of regulation,
overcurrent, or overtemperature
Forced Load Share Accuracy 1% of Io u t (5 parallel units)
Dynamic Characteristics
Dynamic Load Response 60µsec to within ±2% of final value
(50-100-50% step, di/dt = 20A/msec)
Start-Up Time 7mS for VOUT = nominal
(VIN on to VOUT regulated or On/Off to VOUT)
Switching Frequency 520 ±50kHz
Environmental
Calculated MTBF
(4)
4, 018, 248 Hours
Operating Temperature Range –40 to +85°C with derating
See Derating Curves
Operating PC Board Temperature –40 to +100°C max.
(12)
Storage Temperature Range –55 to +125°C
Thermal Protection/Shutdown +115°C
Relative Humidity To 85°C/85% RH, non-condensing
Physical
Outline Dimensions See Mechanical Specifications
Weight 0.28 ounces (7.8 grams)
Electromagnetic Interference FCC part 15, class B, EN55022
(conducted and radiated) (may need external filter)
Safety Designed to meet UL/cUL 60950-1,
ABSOLUTE MAXIMUM RATINGS
CSA-C22.2 No.60950-1,
IEC/EN 60950-1
Input Voltage (Continuous or transient) +15 Volts
On/Off Control 0V min. to + Vin max.
Input Reverse Polarity Protection See Fuse section
Output Current (7) Current-limited. Devices can withstand
sustained short circuit without damage.
Storage Temperature –55 to +125°C
Lead Temperature (soldering 10 sec. max.) +280°C
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.
Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000www.murata-ps.com
MDC_LSN2-T/30-D12 Series.B12 Page 3 of 17
Performance/Functional Specification Notes:
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(1) Specifications are typical at +25°C, Vin = nominal (+12V), Vo u t = nominal (+5V), full
load, external caps and natural convection unless otherwise indicated.
All models are tested and specified with external 0.01 || 0.1 || 10µF ceramic/tantalum
output capacitors and a 22µF external input capacitor. All capacitors are low ESR
types. 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.
(2) Input Back Ripple Current is tested and specified over a 5Hz to 20MHz bandwidth.
Input filtering is Cin = 2 x 100µF tantalum, Cb u s = 1000µF electrolytic, Lb u s = 1µH.
(3) Note that Maximum Power Derating curves indicate an average current at nominal
input voltage. At higher temperatures and/or lower airflow, the DC/DC converter will
tolerate brief full current outputs if the total RMS current over time does not exceed the
Derating curve.
(4) Mean Time Before Failure is calculated using the Telcordia (Belcore) SR-332
Method 1, Case 3, ground fixed conditions, TPCBOARD = +25°C, full output load,
natural air convection.
(5) The On/Off Control may be driven with external logic or by applying appropriate exter-
nal voltages which are referenced to –Input Common. The On/Off Control Input should
use either an open collector/open drain transistor or logic gate.
(6) Short circuit shutdown begins when the output voltage degrades approximately 2%
from the selected setting.
(7) If Sense is connected remotely at the load, up to 0.5 Volts difference is allowed between
the Sense and +Vo u t pins to compensate for ohmic voltage drop in the power lines.
A larger voltage drop may cause the converter to exceed maximum power dissipation.
LSN2-T/30-D12 Series
DOSA-SIP, 30A POL DC/DC Converters
(8) Output noise may be further reduced by adding an external filter. See I/O Filtering and
Noise Reduction.
(9) All models are fully operational and meet published specifications, including “cold start”
at –40°C. At full power, the package temperature of all on-board components must not
exceed +128°C.
(10) Regulation specifications describe the deviation as the line input voltage or output load
current is varied from a nominal midpoint value to either extreme.
(11) Other input or output voltage ranges will be reviewed under scheduled quantity special
order.
(12) Maximum PC board temperature is measured with the sensor in the center.
(13) Do not exceed maximum power specifications when adjusting the output trim.
(14) After short circuit shutdown, if the load is partially removed such that the load still
exceeds the overcurrent (OC) detection, the converter will remain in hiccup restart mode.
(15) Static Discharge CAUTION: The Power Good output connects directly to the PWM
controller. Be sure to use proper grounding techniques to avoid damaging the converter.
Power Good is not valid when using Sequence/Tracking.
(16) The maximum output capacitive loads depend on the the Equivalent Series Resistance
(ESR) of theexternal output capacitor. Larger caps will reduce output noise but may
slow transient response or degrade dynamic performance. Use only as much output filtering as needed and no more. Thoroughly test your system under full load, especially
with low-ESR ceramic capacitors.
(17) Do not use Pre-bias startup and sequencing together. See the Technical Notes below.
I/O Filtering and Noise Reduction
All models in the LSN2-T/30-D12 Series are tested and specified with external
0.01 || 0.1 || 10µF ceramic/tantalum output capacitors and a 22µF tantalum
input capacitor. These capacitors are necessary to accommodate our test
equipment and may not be required to achieve desired performance in your
application. The LSN2-T/30-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 LSN2-T/30-D12’s input capacitors are specified for low
ESR and are fully rated to handle the units’ input ripple currents. Similarly, the
internal output capacitors are specified for low ESR and full-range frequency
response.
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/DCs 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.
TECHNICAL NOTES
Figure 2. Measuring Input Ripple Current
Output ripple/noise (also referred to as periodic and random deviations or
PARD) may be reduced below specified limits with the installation of additional
external output capacitors. Output capacitors function as true filter elements
and should be selected for bulk capacitance, low ESR, and appropriate 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.
Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000www.murata-ps.com
MDC_LSN2-T/30-D12 Series.B12 Page 4 of 17
Figure 3. Measuring Output Ripple/Noise (PARD)
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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 Engineering Group for additional details.
Input Fusing
Most applications and or safety agencies require the installation of fuses at the
inputs of power conversion components. The LSN2-T/30-D12 Series 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 twice the maximum input current calculated at low line with the converter’s minimum efficiency should be
installed within the ungrounded input path to the converter.
Safety Considerations
LSN2-T/30-D12 SIPs 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/EN60950-1).
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
LSN2-T/30-D12 SIP Series DC/DCs do not incorporate either input overvoltage
or input reverse-polarity protection. Input voltages in excess of the specified
absolute maximum ratings and input polarity reversals of longer than “instantaneous” duration can cause permanent damage to these devices.
LSN2-T/30-D12 Series
DOSA-SIP, 30A POL DC/DC Converters
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
LSN2-T/30-D12 Series offer an output 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 LSN2-T/30-D12’s specified rating. Therefore:
(VOUT at pins) x (IOUT) ≤ rated output power
The internal 10.5W 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: If the sense function is not used for remote regulation, +Sense
must be tied to +Output at the DC/DC converter pins.
Remote On/Off Control
Normally this input is controlled by the user’s external transistor or relay. With
simple external circuits, it may also be selected by logic outputs. Please note
however that the actual control threshold levels vary somewhat with the PWM
supply and therefore are best suited to “open collector” or “open drain” type
logic. The On/Off control takes effect only when appropriate input power has
been applied and stabilized (approximately 7msec).
The sense function
Start-Up Time
The VIN to VOUT Start-Up Time is the interval between the time at which a ramp-
ing input voltage crosses the lower limit of the specified input voltage range
and the fully loaded output voltage enters and remains within its specified
accuracy band. Actual measured times will vary with input source impedance,
external input capacitance, and the slew rate and final value of the input voltage
as it appears to the converter.
For negative polarity, the default operation leaves this pin open (unconnected)
or LOW. The output will then always be on (enabled) whenever appropriate input
power is applied.
Dynamic control of the On/Off must be capable of sinking or sourcing the
control current (approximately 1mA max.) and not overdrive the input greater
than the +VIN power input. Always wait for the input power to stabilize before
Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000www.murata-ps.com
MDC_LSN2-T/30-D12 Series.B12 Page 5 of 17
LSN2-T/30-D12 Series
+INPUT
+V
CONTROLLER
SMALL
SIGNAL
TRANSISTOR
HI = ON
LO = OFF
SHUTDOWN
SIGNAL
GROUND
COMMON
ON/OFF
CONTROL
DOSA-SIP, 30A POL DC/DC Converters
activating the On/Off control. Be aware that a delay of several milliseconds
occurs (see specifications) between activation of the control and the resulting
change in the output.
Power-up Sequencing
If a controlled start-up of one or more LSN2-T/30-D12 Series DC/DC converters
is required, or if several output voltages need to be powered-up in a given
sequence, the On/Off control pin can be driven with an external open collector
device as per Figure 4.
Figure 4. On/Off Control Using An External Open Collector Driver
Output Overvoltage Protection
LSN2-T/30-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
(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 power converter’s output for an extended 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. LSN2-T/30-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 50% or if the
output voltage drops to less than 98% of it original value, the LSN2-T/30-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.
Once the output short is removed, the converter will automatically restart itself.
Output Reverse Conduction
Many DC/DCs 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), 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.
LSN2-T/30-D12 SIP DC/DC converters do not suffer from Output Reverse
Conduction. They employ proprietary gate drive circuitry that makes them
immune to moderate applied output overvoltages.
Thermal Considerations and Thermal Protection
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 LSN2-T/30-D12 SIPs under known ambient-temperature and airflow conditions. Similarly, the curves indicate how much air flow is required to
reliably deliver a specific output current at known temperatures.
The highest temperatures in LSN2-T/30-D12 SIPs occur at their output
inductor, whose heat is generated primarily by I2R 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.
As you may deduce from the derating curves and observe in the efficiency
curves on the following pages, LSN2-T/30-D12 SIPs maintain virtually constant
efficiency from half to full load, and consequently deliver very impressive
temperature performance even if operating at full load.
Lastly, when LSN2-T/30-D12 SIPs 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
demanding temperature conditions, we advise you to monitor the outputinductor temperature to ensure it remains below +110°C at all times.
Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000www.murata-ps.com
MDC_LSN2-T/30-D12 Series.B12 Page 6 of 17
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