+INPUT

(7,8)

COMMON

(6)

PWM

CONTROLLER

CURRENT

SENSE

REFERENCE &

ERROR AMP

ON/OFF

CONTROL

(11)

TRIM

(10)

+OUTPUT

(1,2,4)

470µF

(330µF)

47.1µF

(100.1µF)

44µF

220µF

10.5

+SENSE

(3)

COMMON

(5)

Single Output

LSN-10A D5 Models

Features

Non-Isolated, 5V

, 1-3.8V

OUT

10 Amp DC/DC's in SIP Packages

Figure 1. Simplifi ed Schematic

DATEL's new LSN D5 Series SIP's (single-in-line packages) are non-isolated

DC/DC converters that accept a 5V input (4.5V to 5.5V input range) and deliver
1V, 1.2V, 1.5V, 1.8V, 2V, 2.5, 3.3 or 3.8V outputs at 10 Amps. LSN D5 SIP's take on-
board 5V 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.

The miniature size of LSN D5's makes them ideal for true point-of-use power pro-

cessing. 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 (to 95%),
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 D5'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.

INNOVATION and EX C ELL E N C E

Industry-standard SIP pinout

Shorter (2.0" vs. 2.5") package length

4.5-5.5V input range

1/1.2/1.5/1.8/2/2.5/3.3/3.8V

OUT

@ 10A

Non-isolated, fully synchronous,
300kHz, buck topology

Outstanding performance:

±1% setpoint accuracy

Effi ciencies to 95% @ 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 certifi ed

EMC compliant

DATEL, Inc., Mansfi eld, MA 02048 (USA) · Tel: (508)339-3000, (800)233-2765 Fax: (508)339-6356 · Email: sales@datel.com · Internet: www.datel.com

For devices with the sense-pin removed ("B" suffi x), the feedback path is
through the +Output pin and not the +Sense pin.

Values in parenthesis for 3.3V models only.

LSN-10A D5 Series

N O N - I S O L A T E D , 1 0 - 3 3 W S I P D C / D C C O N V E R T E R S

Typical at T

= +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.

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.

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.

Nominal line voltage, no-load/full-load conditions.

Performance Specifi cations and Ordering Guide

LSN-1/10-D5 1 10 10 35 ±0.1% ±0.25% 5 4.5-5.5 50/2.43

83% 86%

89% B7/B7x, P59

LSN-1.2/10-D5 1.2 10 10 35 ±0.1% ±0.25% 5 4.5-5.5 50/2.85

85% 88%

91% B7/B7x, P59

LSN-1.5/10-D5 1.5 10 10 35 ±0.1% ±0.25% 5 4.5-5.5 50/3.48

87% 90%

92% B7/B7x, P59

LSN-1.8/10-D5 1.8 10 10 35 ±0.1% ±0.25% 5 4.5-5.5 50/4.09

89% 91.5%

93.5% B7/B7x, P59

LSN-2/10-D5 2 10 10 35 ±0.1% ±0.25% 5 4.5-5.5 50/4.51

89.5% 92.5%

94% B7/B7x, P59

LSN-2.5/10-D5 2.5 10 10 35 ±0.1% ±0.25% 5 4.5-5.5 50/5.50

91% 94%

95.5% B7/B7x, P59

LSN-3.3/10-D5 3.3 10 10 35 ±0.1% ±0.25% 5 4.5-5.5 50/7.25

92% 95%

96% B7/B7x, P59

LSN-3.8/10-D5 3.8 10 10 35 ±0.1% ±0.25% 5 4.5-5.5 50/8.0

92% 95%

96% B7/B7x, P59

Package

OUT

Nom.

Range

(Case,

Model

(Volts) (Amps)

Typ. Max.

Line Load

(Volts) (Volts) (mA/A) Min.

Typ.

Pinout)

Output

Input

R/N (mVp-p)

Regulation

(Max.)

Effi ciency

Full Load

½ Load

1 2 3 4 5

8 9 10 11

2.00

(50.80)

0.030 ±0.001 DIA.

(0.762 ±0.025)

0.50

(12.7)

0.34

(8.64)

0.20

(5.08)

0.110

(2.79)

0.046

(1.17)

0.05

(1.27)

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

(4.32)

LAYOUT PATTERN

TOP VIEW

0.34

(8.64)

0.25

(6.35)

M E C H A N I C A L S P E C I F I C A T I O N S

Case B7

Vertical Mounting

(Standard)

0.35

(8.89)

0.21

(5.33)

0.16

(4.06)

0.360

(9.14)

1 2 3 4 5

8 9

ISOLATING

PAD

10 11

2.00

(50.80)

0.030 ±0.001 DIA.

(0.762 ±0.025)

0.50

(12.7)

0.05

(1.27)

0.05

(1.27)

0.50

(12.7)

0.45

(11.43)

0.400

(10.16)

0.56

(14.22)

0.53

(13.46)

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

LAYOUT PATTERN

TOP VIEW

0.36

(9.14)

0.20

(5.08)

0.106

(2.69)

0.046

(1.17)

0.36

(9.14)

0.306

(7.8)

1 2 3 4 5

8 9 10 11

2.00

(50.80)

0.030 ±0.001 DIA.

(0.762 ±0.025)

0.50

(12.7)

0.05

(1.27)

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

(4.32)

Case B7B

Reverse Pin

Vertical Mounting

(Tyco-compatible)

Maximum Rated Output
Current in Amps

P A R T N U M B E R S T R U C T U R E

Non-Isolated SIP

Output
Confi guration:
L = Unipolar

Low Voltage

Nominal Output Voltage:
1, 1.2, 1.5, 1.8, 2, 2.5, 3.3, or 3.8V

Input Voltage Range:
D5 = 4.5 to 5.5 Volts

(5V nominal)

L SN

D5 B

1.8

B Suffi x:
No Remote Sense
(Pin 3 removed)

H Suffi x:
Horizontal Mount

J Suffi x:
Reversed Pin
Vertical Mount

See page 11 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*

+Output

Common

+Output

Common

OUT

Trim

+Sense

+Input

On/Off

Control

+Output

+Input

I/O Connections

LSN-10A D5 Models

N O N - I S O L A T E D , 1 0 - 3 3 W S I P D C / D C C O N V E R T E R S

Input

Input Voltage Range 4.5 to 5.5 Volts (5V nominal)

Input Current:

Normal Operating Conditions See Ordering Guide
Inrush Transient 0.014A

sec

Standby/Off Mode 3mA
Output Short-Circuit Condition

70mA average

Input Refl ected Ripple Current

50mAp-p

Input Filter Type Capacitive (264µF)

Overvoltage Protection None

Reverse-Polarity Protection None

Undervoltage Shutdown None

On/Off Control

On = open (internal pulldown)

Off = +2.8V to +V

(<3mA)

Output

OUT

Accuracy (50% load) ±1% maximum

Minimum Loading

No load

Maximum Capacitive Load 10,000µF (electrolytic)

OUT

Trim Range

±10%

Ripple/Noise (20MHz BW)

See Ordering Guide

Line/Load Regulation See Ordering Guide

Effi ciency

See Ordering Guide

Overcurrent Detection and Short-Circuit Protection:

Current-Limiting Detection Point 17 (12.5-22) Amps
Short-Circuit Detection Point 98% of V

OUT

set

SC Protection Technique Hiccup with auto recovery
Short-Circuit Current 400mA average

Dynamic Characteristics

Transient Response (50% load step) 50µsec to ±2% of fi nal value

Start-Up Time:

to V

OUT

7msec

On/Off to V

OUT

6msec

Switching Frequency 300kHz (+40kHz, 50kHz)

Environmental

MTBF: Bellcore, ground fi xed, T

= +25°C,

full power, natural convection,
+55°C component temperature 2.1 million hours

Operating Temperature: (Ambient)

Without Derating (Natural convection) 40 to +63/71°C (model dependent)
With Derating See Derating Curves

Thermal Shutdown +115°C

Physical

Dimensions See Mechanical Specifi cations

Package Open-frame, single-in-line (SIP)

Pin Dimensions/Material 0.03" (0.76mm) round copper with

tin-lead plate over nickel underplate

Weight 0.3 ounces (8.5g)

Flamability Rating UL94V-0

Performance/Functional Specifi cations

Typical @ T

= +25°C under nominal line voltage and full-load conditions unless 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. 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
fi ltering. See I/O Filtering and Noise Reduction.

T E C H N I C A L N O T E S

Input Voltage:
Continuous or transient 7 Volts

On/Off Control (Pin 11) +V

Input Reverse-Polarity Protection None

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 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 D5 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 D5 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 D5'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 D5'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

LSN-10A D5 Series

N O N - I S O L A T E D , 1 0 - 3 3 W S I P D C / D C C O N V E R T E R S

+INPUT

COMMON

1.1k

0.75k

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. Our Applications Engineers can recommend potential solu-
tions and discuss the possibility of our modifying a given device's internal fi lter-
ing to meet your specifi c 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. LSN D5 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 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 effi ciency.

Safety Considerations

LSN D5 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 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 D5 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 V

to V

OUT

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 (4.5 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 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 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.

On/Off Control and Power-up Sequencing

The On/Off Control pin may be used for remote on/off operation. LSN D5 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 +V

), 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.

Figure 2. Driving the On/Off Control Pin with an Open-Collector Drive Circuit

Remote Sense

LSN D5 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
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 differ-
ences 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

(+) 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 specifi ed rating. Therefore:

OUT

at pins) x (I

OUT

)

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 D5 Models

N O N - I S O L A T E D , 1 0 - 3 3 W S I P D C / D C C O N V E R T E R S

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

Note: Resistor values are in k

. Accuracy of adjustment is subject to

tolerances of resistors and factory-adjusted, initial output accuracy.

= desired output voltage. V

NOM

= nominal output voltage.

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),

) =

1.296

DOWN

) =

1.62(V

0.8)

1.2

) =

1.992

DOWN

1.2

) =

2.37

2.49(V

0.8)

) =

DOWN

) =

4.99

7.5(V

0.8)

O NOM

) =

1.896

DOWN

O NOM

) =

4.99

2.37(V

0.8)

LSN-1/10-D5

Model

LSN-3.3/10-D5

LSN-1.2/10-D5

LSN-1.5/10-D5
LSN-1.8/10-D5
LSN-2/10-D5
LSN-2.5/10-D5

Trim Equations

Output Voltage Trimming

Allowable trim ranges for each model in the LSN D5 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.

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.

Output Overvoltage Protection

LSN D5 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

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 D5 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% (17 Amps) or
if the output voltage drops to less than 98% of it original value, the LSN D5'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

1.1k

0.75k

ON/OFF
CONTROL

For a controlled start-up of one or more LSN-D5'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.

Figure 3. Trim Connections Using a Trimpot

Trim
Down

Trim

LOAD

+INPUT

COMMON

+OUTPUT

TRIM

COMMON

LSN-10A D5 Series

N O N - I S O L A T E D , 1 0 - 3 3 W S I P D C / D C C O N V E R T E R S

100

110

LSN-1/10-D5
Output Current vs. Ambient Temperature
(Vertical mount, air flow direction from pin 1 to pin 11)

Output Current (Amps)

Ambient Temperature (

°C)

Natural Convection

200 lfm

100 lfm

LSN-1.5/10-D5
Output Current vs. Ambient Temperature
(Vertical mount, air flow direction from pin 1 to pin 11)

Output Current (Amps)

Ambient Temperature (

°C)

Natural Convection

200 lfm

100 lfm

100

110

LSN-1.8/10-D5 & LSN-2/10-D5
Output Current vs. Ambient Temperature
(Vertical mount, air flow direction from pin 1 to pin 11)

Output Current (Amps)

Ambient Temperature (

°C)

Natural Convection

200 lfm

100 lfm

100

110

100

110

LSN-1.2/10-D5
Output Current vs. Ambient Temperature
(Vertical mount, air flow direction from pin 1 to pin 11)

Output Current (Amps)

Ambient Temperature (

°C)

Natural Convection

200 lfm

100 lfm

Typical Performance Curves for LSN D5 SIP Series

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 LSN D5 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 D5 SIP's occur at their output inductor,
whose heat is generated primarily by I

R losses. The above 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 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 D5 SIP's are more effi cient at lower current
levels. Also, I

R losses in the output inductor are signifi cantly less at lower

currents. Consequently, LSN D5 SIP's deliver very impressive temperature
performance if operating at less than full load.

Lastly, when LSN D5 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 D5 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 D5 SIP DC/DC converters do not suffer from Output Reverse Conduc-
tion. They employ proprietary gate drive circuitry that makes them immune
to applied output voltages.

LSN-10A D5 Models

N O N - I S O L A T E D , 1 0 - 3 3 W S I P D C / D C C O N V E R T E R S

LSN-1.5/10-D5
Efficiency vs. Line Voltage and Load Current

Load Current (Amps)

Efficienc

y (

)

= 4.5V

= 5V

= 5.5V

LSN-1/10-D5
Efficiency vs. Line Voltage and Load Current

Load Current (Amps)

Efficienc

y (

)

= 4.5V

= 5V

= 5.5V

Typical Performance Curves for LSN D5 SIP Series

LSN-1.2/10-D5
Efficiency vs. Line Voltage and Load Current

Load Current (Amps)

Efficienc

y (

)

= 4.5V

= 5V

= 5.5V

LSN-1.8/10-D5
Efficiency vs. Line Voltage and Load Current

Load Current (Amps)

Efficienc

y (

)

= 4.5V

= 5V

= 5.5V

LSN-2/10-D5
Efficiency vs. Line Voltage and Load Current

Load Current (Amps)

Efficienc

y (

)

= 4.5V

= 5V

= 5.5V

LSN-2.5/10-D5 & LSN-3.3/10-D5
Output Current vs. Ambient Temperature
(Vertical mount, air flow direction from pin 1 to pin 11)

Output Current (Amps)

Ambient Temperature (

°C)

100

110

Natural Convection

200 lfm

100 lfm

DATEL 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. The DATEL logo is a registered DATEL, Inc. trademark.

DATEL (UK) LTD. Tadley, England Tel: (01256)-880444
DATEL S.A.R.L. Montigny Le Bretonneux, France Tel: 01-34-60-01-01
DATEL GmbH München, Germany Tel: 89-544334-0
DATEL KK Tokyo, Japan Tel: 3-3779-1031, Osaka Tel: 6-6354-2025

DATEL, Inc. 11 Cabot Boulevard, Mansfi eld, MA 02048-1151
Tel: (508) 339-3000 (800) 233-2765 Fax: (508) 339-6356
Internet: www.datel.com Email: sales@datel.com

ISO 9001 REGISTERED

INNOVATION and EX C ELL E N C E

DS-0516 6/03

LSN-10A D5 Models

N O N - I S O L A T E D , 1 0 - 3 3 W S I P D C / D C C O N V E R T E R S

Maximum Rated Output
Current in Amps

P A R T N U M B E R S T R U C T U R E

Non-Isolated SIP

Output
Confi guration:
L = Unipolar

Low Voltage

Nominal Output Voltage:
1, 1.2, 1.5, 1.8, 2, 2.5, 3.3 or 3.8 Volts

Input Voltage Range:
D5 = 4.5 to 5.5 Volts

(5V nominal)

L SN

D5 B

1.8

B Suffi x:
No Remote Sense
(Pin 3 removed)

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 +V

OUT

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.

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 DATEL directly to discuss these and other possible modifi -
cations.

Examples

LSN-1.8/10-D5

Vertical-mount. Sense function on pin 3. No pin 9.

LSN-1.8/10-D5B Vertical-mount. Pin 3 (+Sense) removed. No pin 9.

LSN-1.8/10-D5H Horizontal-mount. Sense function on pin 3. No pin 9.

LSN-1.8/10-D5BH Horizontal-mount. Pin 3 (+Sense) removed. No pin 9.

LSN-1.8/10-D5J

Reverse pin vertical-mount. Sense function on pin 3.

No pin 9.

H Suffi x:
Horizontal Mount

J Suffi x:
Reversed Pin
Vertical Mount

If you're designing with EMC in mind, please note that all of DATEL's
LSN D5 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 specifi cations
can be supplied upon request. For corresponding emissions plots to FCC
and CISPR 22 for model LSN-5/10-D12 (the highest possible output power
model) and for LSN-2/10-D3 (representing the highest input current models)
see LSN-10A D12 and LSN-10A D3 data sheets for reference. These
respective curves are representative of all LSN models. Contact DATEL's
Applications Engineering Department for more details.

E M I C O N D U C T E D / R A D I A T E D E M I S S I O N S

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ÐÐ»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: LSN-1/10-D5