Datasheet UEI15 Datasheet (MURATA)

GATE DRIVE

Control

Reference, Trim &

Error Amplifier

+VIN

−VIN

+VOUT

–VOUT

On/Off

Control

TRIM

ISOLATION BARRIER

OPTO

ISOLATION

Typical unit

UEI15 Series

Isolated Wide Input Range 15-Watt DC/DC Converters

Featuring a full 15 Watt or greater output in one square inch of board area, the UEI
series isolated DC/DC converter family offers efficient regulated DC power for printed
circuit board mounting.

FEATURES

nSmall footprint DC/DC converter, ideal for

high current applications

nIndustry standard 0.9" x 1.1" X 0.335"

open frame package and pinout

nWide range input voltages 9-36 and

18-75 Vdc

nDouble lead-free assembly and attachment

for RoHS standards

n2250 Volt Basic Isolation (Q48 models)

n

Up to 15 Watts or greater total output
power with overtemperature shutdown

nHigh efficiency synchronous rectifier

forward topology

nStable no-load operation with no required

external components

nUsable -40 to 85°C temperature range

(with derating)

nDesigned to meet UL 60950-1, CAN/CSA-

C22.2 No. 60950-1, IEC60950-1,
EN60950-1 safety approvals

nExtensive self-protection shut down

features

PRODUCT OVERVIEW

Wide range 4:1 inputs on the 0.9" x 1.1" x 0.335"
converter are either 9 to 36 Volts DC (Q12 models)
or 18 to 75 Volts DC (Q48 models), ideal for battery­powered and telecom equipment. The industry­standard pinout fits larger 1" x 2" converters. Fixed
output voltages from 3.3 VDC to 15 VDC are regu­lated to within ±0.2% or less and may be trimmed
within ±10% of nominal output. Applications
include small instruments, area-limited microcon­trollers, computer-based systems, data communi­cations equipment, remote sensor systems, vehicle
and portable electronics.

Full magnetic and optical isolation includes
Basic protection up to 2250 (Q48 models) Volts DC.
For connection to digital systems, the outputs offer
fast settling to current step loads and tolerance of
higher capacitive loads. Excellent ripple and noise

SIMPLIFIED SCHEMATIC

specifications assure compatibility to circuits
using CPU’s, ASIC’s, programmable logic and
FPGA’s. For systems requiring controlled startup/
shutdown, an external remote On/Off control
may use a switch, transistor or digital logic.

A wealth of self-protection features avoid both
converter and external circuit problems. These
include input undervoltage lockout and overtem­perature shutdown. The outputs current limit using
the “hiccup” autorestart technique and the outputs
may be short-circuited indefinitely. Additional
features include output overvoltage and reverse
conduction elimination.

The high efficiency offers minimal heat buildup
and “no fan” operation.

www.murata-ps.com/rohs

For full details go to

Typical topology is shown.3.3V and 5Vo u t models only.

www.murata-ps.com Technical enquiries email: [e-mail], tel: [phone]

MDC_UEI15W.B12 Page 1 of 12

UEI15 Series

Package – C75

(inches)

(mm)

Case

Pinout

Isolated Wide Input Range 15-Watt DC/DC Converters

PERFORMANCE SPECIFICATIONS AND ORDERING GUIDE

Output Input

R/N (mVp-p) ➁ Regulation (Max.)

Vo u t

Io u t

(A)

Power

(W)

Root Models ➀

UEI15-033-Q12P-C 3.3 4.5 14.85 60 90 ±0.05% ±0.1% 24 9-36 130 0.71 86.5% 89%

UEI15-033-Q48N-C 3.3 5 16.5 60 90 ±0.2% ±0.2% 48 18-75 130 0.4 86.5% 88.8%

UEI15-050-Q12P-C 5 3 15 70 125 ±0.05% ±0.075% 24 9-36 50 0.72 86.3% 87.3%

UEI15-050-Q48N-C 5 3 15 60 95 ±0.05% ±0.06% 48 18-75 130 0.36 84.3% 86.0%

UEI15-120-Q12P-C 12 1.3 15.6 110 150 ±0.05% ±0.05% 24 9-36 130 0.77 82.3% 84.5%

UEI15-120-Q48N-C 12 1.3 15.6 85 120 ±0.075% ±0.05% 48 18-75 15 0.76 83.3% 85%

UEI15-150-Q12P-C 15 1.1 16.5 130 175 ±0.05% ±0.05% 24 9-36 130 0.81 83.5% 85%

UEI15-150-Q48N-C 15 1.1 16.5 80 120 ±0.05% ±0.05% 48 18-75 20 0.4 83.3% 85.3%

➀ Please refer to the part number structure for additional options and complete ordering part

numbers.

➁ All specifications are typical at nominal line voltage and full load, +25 deg.C. unless otherwise

noted. See detailed specifications.

PART NUMBER STRUCTURE

(V)

UEI15 - Q12- -033

Unipolar Wide Input
15-Watt Series

Nominal Output Voltage
in Tenths of a Volt

➀

Vin

Nom.

Range

(V)

 Minimum output load for UEI15-033-Q12, UEI15-120-Q12 and UEI15-050-Q12 is 10% of

P C

On/Off Control Polarity:

P = Positive
N = Negative

Input Voltage Range

Q12 = 9-36V
Q48 = 18-75V

Iin =

no

load

(V)

(mA)

maximum current.

RoHS-6 Hazardous
Substance Compliance

Efficiency

Iin =

full

load

(A)Typ. Max. Line Load Min. Typ.

Note:

Some model number combinations
may not be available.
Contact Murata Power Solutions.

1.1×0.9×0.335 27.94×22.86×8.51 P22

Technical enquiries email: [e-mail], tel: [phone]www.murata-ps.com

MDC_UEI15W.B12 Page 2 of 12

MECHANICAL SPECIFICATIONS

Top View

1.10 (27.9)
Pin # 1

0.96

(24.4)

0.200
(5.08)

0.300
(7.62)

0.19
(4.8)

Side View

0.36
(9.1)

Ø 0.40±0.002
Ø 0.062±0.002
6x at pins 1-6

Pin with
shoulder

Bottom View End View

0.400 (10.16)

#6

#5

#4

#3

#2

#1

C

L

0.400

(10.16)

0.15
(3.8)

0.800

(20.32)

Pin

Function P22

Pin

Function P22

4

Positive Output

1

Positive Input

5

Trim

2

Negative Input

3

On/Off Control In

6

Negative Output

Third Angle Projection

Dimensions are in inches (mm shown for ref. only).

Components are shown for reference only.

Tolerances (unless otherwise specified):
.XX ± 0.02 (0.5)
.XXX ± 0.010 (0.25)
Angles ± 2˚

Case 75

UEI15 Series

Isolated Wide Input Range 15-Watt DC/DC Converters

INPUT/OUTPUT CONNECTIONS

PHYSICAL CHARACTERISTICS

Pin Material Copper alloy
Pin Diameter 0.04" (1.016mm)
Pin Finish Gold plate
Weight 0.352 oz./10 grams
Electromagnetic Interference FCC part 15, class B, EN55022
Flammability Rating UL 94V-0

Safety (designed to meet)

UL/cUL 60950-1, CAN/CSA­C22.2-60950-1, IEC/EN 60950-1

Technical enquiries email: [e-mail], tel: [phone]www.murata-ps.com

MDC_UEI15W.B12 Page 3 of 12

INPUT CHARACTERISTICS

Model Family

Vin

V

UEI15-033-Q12 24
UEI15-033-Q48 48
UEI15-050-Q12 24
UEI15-050-Q48 48
UEI15-120-Q12 24
UEI15-120-Q48 48
UEI15-150-Q12 24
UEI15-150-Q48 48

Isolated Wide Input Range 15-Watt DC/DC Converters

Start-up

threshold

Under­voltage

V

9.5 8.6

16.7 15.6 130 1.04 2

9.5 8.5 130 1.90 4

16.7 15.6 130 0.96 2

9.5 8.4 130 2.04 4

16.7 15.6 15 1.02 1.5

9.5 8.4 130 2.13 4

16.7 16.2 20 1.06 2

Shut­down

V

Reflected

(back)
Ripple

Current

mA pk-pk

30 0.05 50

Inrush

Transient

A2sec

Input Current

Output Short

Circuit

mA

No

Low

Load

Line

mA

130 1.86

A

Standby

Mode

mA

1

Recom­mended

Fuse

A

4

Inter-

nal
Input
Filter

Type

C

Reverse
Polarity

Protec-

tion

None

- see
notes

UEI15 Series

Remote On/Off Control

On/Off

Current

mA

1

Positive Logic

blank model

suffix

OFF=Gnd pin

or –0.7 to +1.2V

max. ON=open

pin or +5.8 to

+15V max.

Negative Logic

"N" model

OFF=open pin

or +5.8 to +

15V max.

ON=Gnd pin

or –0.7 to

+1.2V max.

suffix

OUTPUT CHARACTERISTICS

Io u t

Model Family

Max.

mA

UEI15-033-Q12
UEI15-033-Q48
UEI15-050-Q12
UEI15-050-Q48
UEI15-120-Q12
UEI15-120-Q48

See

Ordering

Guide

UEI15-150-Q12
UEI15-150-Q48

ISOLATION CHARACTERISTICS

Input to

Model Family

UEI15-033-Q12
UEI15-033-Q48
UEI15-050-Q12
UEI15-050-Q48
UEI15-120-Q12
UEI15-120-Q48
UEI15-150-Q12
UEI15-150-Q48

Output Min.

Vdc

2000 10 1000
2250 10 1500
2000 10 1500
2250 10 1000
2000 10 1000
2250 10 1000
2000 10 1500
2250 10 1000

Vo u t
Accuracy
50% Load
% of Vn o m

Isolation

Resistance

Adjustment

Range

% of Vn o m

±1 ±10 ±0.02

Min.

MΩ

Isolation

Capacitance

pF

Temperature

Coefficient

% of Vo u t /ºC

Isolation

Safety
Rating

Basic

insulation

Capacitive Loading Max.

Low ESR <0.02Ω Max,

resistive load

µF

1,000

470

DYNAMIC CHARACTERISTICS

Model Family

UEI15-033-Q12
UEI15-033-Q48
UEI15-050-Q12
UEI15-050-Q48
UEI15-120-Q12
UEI15-120-Q48
UEI15-150-Q12
UEI15-150-Q48

Overvoltage protection

Dynamic Load

(50-75-50% load

V

4.5

3.9

5.9

5.9

14.1
15
18
20

Response

step) µSec

o u t

to 1% V

100

150 340

100

OV

protection

Magnetic
feedback

Start-up Time

in to Vo u t regulated

V

(Max.) mSec

50 50

method

put Range

Voltage Out-

See ordering guide

Remote On/Off to

Vo u t regulated max.)

Ripple/Noise

(20 MHz

8

Line/Load

bandwidth)

Switching
Frequency

Efficiency

Regulation

KHz

350
350
350
375

350
340
380

MISCELLANEOUS CHARACTERISTICS

Operating Temperature Range

Derating

6

6

–40 to +85ºC

6

with derating

See

Curves

Model Family

UEI15-033-Q12

UEI15-033-Q48

UEI15-050-Q12

UEI15-050-Q48

UEI15-120-Q12

UEI15-120-Q48

UEI15-150-Q12

UEI15-150-Q48

Current Limit

Inception 98% of

Vout, after warmup

A

6.0

7.2 3.49 x 10

4.6

4.5

2.0

1.8 135

1.6

1.7

Short

Circuit

Protection

Method

Current

limiting,

hiccup

autorestart

Short

Circuit

Current

A

0.3 Continuous Monotonic

Short Circuit

Duration

(output shorted

to ground)➀

Pre-

biased

setup

Calculated

MTBF
Hours

2 x 10

2 x 10

Remove overload for recovery. Output may be shorted to ground with no damage.

Technical enquiries email: [e-mail], tel: [phone]www.murata-ps.com

Storage

Temperature

Range

ºC

–55 to +125 ºC

Thermal

protection/

shutdown

ºC

115

115

MDC_UEI15W.B12 Page 4 of 12

UEI15 Series

Isolated Wide Input Range 15-Watt DC/DC Converters

ABSOLUTE MAXIMUM RATINGS

Input

Voltage

Input Reverse Polarity Protection

Output Overvoltage, Volts Max.

Output Current, sustained short circuit

Storage Temperature

Lead Temperature ºC Max. (soldering, 10 seconds)

Q12 models

Q48 models

On/Off control,

referred to –V

in

Volts Max. continuous

Volts, transient 100mS

Volts Max. continuous

Volts, transient 100mS

Volts, Min.

Volts, Max.

Range, Min. ºC

Max. ºC

Current-limited, see specs

36

50

75

100

–0.3

15

See fuse section

Vo u t nom. +20%

-55

+125

280

Absolute Maximum Ratings

Absolute maximums 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
is neither implied nor recommended.

SPECIFICATION NOTES

(1) All models are tested and specified with external capacitors listed in the
table below. The external capacitors listed below are ONLY for establishing test
specifications. They are required for our test fixtures and equipment. Your applica­tion may not need them. The converter is stable with no external capacitors but
Murata Power Solutions strongly recommends external caps. All caps are low-ESR
types. Where two or more capacitors are listed, these are connected in parallel. All
caps should mount close to the DC/DC using short leads.

All specifications are typical unless noted. General conditions for Specifica­tions are +25 deg.C, V

in =nominal, Vo u t =nominal, full load. Adequate airflow

must be supplied for extended testing under power.

(2) Input Ripple Current is tested and specified over a 5 Hz to 20 MHz band­width. Input filtering is C
trolytic, L

b u s =12 µH.

Model Input Capacitor Output Capacitor(s)

UEI15-033-Q12 100 µF 1 µF & 10 µF

UEI15-033-Q48 4.7 µF ceramic 1 µF & 10 µF

UEI15-050-Q12 100 µF 1 µF & 10 µF

UEI15-050-Q48 4.7 µF ceramic 1 µF & 10 µF

UEI15-120-Q12 100 µF 1 µF & 10 µF

UEI15-120-Q48 4.7 µF ceramic 1 µF & 10 µF

UEI15-150-Q12 100 µF 1 µF & 10 µF

UEI15-150-Q48 4.7 µF ceramic 1 µF & 10 µF

in =33 µF, 100V tantalum, Cb u s =220 µF, 100V elec-

INPUT/OUTPUT EXTERNAL TEST CAPACITORS

(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. All Derating curves are presented at sea level
altitude. Be aware of reduced power dissipation with increasing density altitude.

(4) Mean Time Before Failure is calculated using the Telcordia (Belcore) SR­332 Method 1, Case 3, ground fixed conditions, Tpcboard=+25 deg.C, full load,
natural air convection.

(5) The On/Off Control is normally controlled by a switch. But it may also be
driven with external logic or by applying appropriate external voltages which
are referenced to Input Common. The On/Off Control Input should use either an
open collector or open drain transistor.

(6) Output current limiting begins when the output voltage degrades
approximately 2% from the selected setting.

(7) The outputs are not intended to sink appreciable reverse current. This
may damage the outputs.

(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,

0

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) The output overvoltage protection is automatic recovery after fault
removal. The overvoltage may occur either from internal failure or from an
external forcing voltage as in a shared power system.

(12) Output current limit and short circuit protection is non-latching. When
the overcurrent fault is removed, the converter will immediately recover.

(13) Do not exceed maximum power specifications when adjusting the
output trim.

(14) At zero output current, the output may contain low frequency com­ponents which exceed the ripple specification. The output may be operated
indefinitely with no load.

(15) If reverse polarity is accidentally applied to the input, a body diode
will become forward biased and will conduct considerable current. To ensure
reverse input protection with full output load, always connect an external input
fuse in series with the +V

in input. Use approximately twice the full input cur-

rent rating with nominal input voltage.

(16) “Hiccup” operation repeatedly attempts to restart the converter with
a brief, full-current output. If the overcurrent condition still exists, the restart
current will be removed and then tried again. This short current pulse prevents
overheating and damaging the converter. Once the fault is removed, the con­verter immediately recovers normal operation.

CAUTION: This product is not internally fused. To comply with safety
agency certifications and to avoid injury to personnel or equipment, the user
must connect an external fast-blow fuse to the input terminals. See fuse
information.

Technical enquiries email: [e-mail], tel: [phone]www.murata-ps.com

MDC_UEI15W.B12 Page 5 of 12

UEI15 Series

C

IN

V

IN

C

BUS

L

BUS

CIN = 33µF, ESR < 700mΩ @ 100kHz
C

BUS

= 220µF, ESR < 100mΩ @ 100kHz

L

BUS

= 12µH

+INPUT

-INPUT

CURRENT

PROBE

TO

OSCILLOSCOPE

+
–
+
–

Isolated Wide Input Range 15-Watt DC/DC Converters

APPLICATION NOTES

Input Fusing

Certain applications and/or safety agencies may require fuses at the inputs of
power conversion components. Fuses should also be used when there is the
possibility of sustained input voltage reversal which is not current-limited. We
recommend a time delay fuse installed in the ungrounded input supply line
with a value which is approximately twice the maximum line current, calcu­lated at the lowest input voltage.

The installer must observe all relevant safety standards and regulations. For
safety agency approvals, install the converter in compliance with the end-user
safety standard, i.e. IEC/EN/UL 60950-1.

Input Reverse-Polarity Protection

If the input voltage polarity is reversed, an internal diode will become forward
biased and likely draw excessive current from the power source. If this source
is not current-limited or the circuit appropriately fused, it could cause perma­nent damage to the converter.

Input Under-Voltage Shutdown and Start-Up Threshold

Under normal start-up conditions, converters will not begin to regulate properly
until the ramping-up input voltage exceeds and remains at the Start-Up
Threshold Voltage (see Specifications). Once operating, converters will not
turn off until the input voltage drops below the Under-Voltage Shutdown Limit.
Subsequent restart will not occur until the input voltage rises again above the
Start-Up Threshold. This built-in hysteresis prevents any unstable on/off opera­tion at a single input voltage.

Users should be aware however of input sources near the Under-Voltage
Shutdown whose voltage decays as input current is consumed (such as capaci­tor inputs), the converter shuts off and then restarts as the external capacitor
recharges. Such situations could oscillate. To prevent this, make sure the oper­ating input voltage is well above the UV Shutdown voltage AT ALL TIMES.

Start-Up Time

Assuming that the output current is set at the rated maximum, the VIN to VOUT
Start-Up Time (see Specifications) is the time interval between the point when
the ramping input voltage crosses the Start-Up Threshold and the fully loaded
regulated output voltage enters and remains within its specified accuracy band.
Actual measured times will vary with input source impedance, external input
capacitance, input voltage slew rate and final value of the input voltage as it
appears at the converter.

rated current. Similar conditions apply to the On to V

OUT regulated specification

such as external load capacitance and soft start circuitry.

Input Source Impedance

These converters will operate to specifications without external components,
assuming that the source voltage has very low impedance and reasonable in­put voltage regulation. Since real-world voltage sources have finite impedance,
performance is improved by adding external filter components. Sometimes only
a small ceramic capacitor is sufficient. Since it is difficult to totally characterize
all applications, some experimentation may be needed. Note that external input
capacitors must accept high speed switching currents.

Because of the switching nature of DC/DC converters, the input of these
converters must be driven from a source with both low AC impedance and
adequate DC input regulation. Performance will degrade with increasing input
inductance. Excessive input inductance may inhibit operation. The DC input
regulation specifies that the input voltage, once operating, must never degrade
below the Shut-Down Threshold under all load conditions. Be sure to use
adequate trace sizes and mount components close to the converter.

I/O Filtering, Input Ripple Current and Output Noise

All models in this converter series are tested and specified for input reflected
ripple current and output noise using designated external input/output compo­nents, circuits and layout as shown in the figures below. External input capaci­tors (Cin in the figure) serve primarily as energy storage elements, minimizing
line voltage variations caused by transient IR drops in the input conductors.
Users should select input capacitors for bulk capacitance (at appropriate
frequencies), low ESR and high RMS ripple current ratings. In the figure below,
the Cbus and Lbus components simulate a typical DC voltage bus. Your specific
system configuration may require additional considerations. Please note that the
values of Cin, Lbus and Cbus will vary according to the specific converter model.

In critical applications, output ripple and noise (also referred to as periodic and
random deviations or PARD) may be reduced by adding filter elements such as
multiple external capacitors. Be sure to calculate component temperature rise from
reflected AC current dissipated inside capacitor ESR. Our Application Engineers can
recommend potential solutions.

These converters include a soft start circuit to moderate the duty cycle of its

PWM controller at power up, thereby limiting the input inrush current.

The On/Off Remote Control interval from On command to V
assumes that the converter already has its input voltage stabilized above the
Start-Up Threshold before the On command. The interval is measured from the
On command until the output enters and remains within its specified accuracy
band. The specification assumes that the output is fully loaded at maximum

OUT regulated

Figure 2. Measuring Input Ripple Current

Technical enquiries email: [e-mail], tel: [phone]www.murata-ps.com

MDC_UEI15W.B12 Page 6 of 12

UEI15 Series

C1

C1 = 0.1µF CERAMIC
C2 = 10µF TANTALUM
LOAD 2-3 INCHES (51-76mm) FROM MODULE

C2

R

LOAD

COPPER STRIP

COPPER STRIP

SCOPE

Isolated Wide Input Range 15-Watt DC/DC Converters

In figure 3, the two copper strips simulate real-world printed circuit imped­ances between the power supply and its load. In order to minimize circuit errors
and standardize tests between units, scope measurements should be made using
BNC connectors or the probe ground should not exceed one half inch and soldered
directly to the fixture.

Figure 3 – Measuring Output Ripple and Noise (PARD)

Floating Outputs

Since these are isolated DC/DC converters, their outputs are “floating” with
respect to their input. The essential feature of such isolation is ideal ZERO
CURRENT FLOW between input and output. Real-world converters however do
exhibit tiny leakage currents between input and output (see Specifications).
These leakages consist of both an AC stray capacitance coupling component
and a DC leakage resistance. When using the isolation feature, do not allow
the isolation voltage to exceed specifications. Otherwise the converter may
be damaged. Designers will normally use the negative output (-Output) as
the ground return of the load circuit. You can however use the positive output
(+Output) as the ground return to effectively reverse the output polarity.

Minimum Output Loading Requirements

These converters employ a synchronous rectifier design topology. All models
regulate within specification and are stable under no load to full load condi­tions. Operation under no load might however slightly increase output ripple
and noise.

Thermal Shutdown

To prevent many over temperature problems and damage, these converters
include thermal shutdown circuitry. If environmental conditions cause the
temperature of the DC/DC’s to rise above the Operating Temperature Range
up to the shutdown temperature, an on-board electronic temperature sensor
will power down the unit. When the temperature decreases below the turn-on
threshold, the converter will automatically restart. There is a small amount of
hysteresis to prevent rapid on/off cycling. The temperature sensor is typically
located adjacent to the switching controller, approximately in the center of the
unit. See the Performance and Functional Specifications.

CAUTION: If you operate too close to the thermal limits, the converter may
shut down suddenly without warning. Be sure to thoroughly test your applica­tion to avoid unplanned thermal shutdown.

Temperature Derating Curves

The graphs in the next section illustrate typical operation under a variety of
conditions. The Derating curves show the maximum continuous ambient air
temperature and decreasing maximum output current which is acceptable
under increasing forced airflow measured in Linear Feet per Minute (“LFM”).
Note that these are AVERAGE measurements. The converter will accept brief
increases in temperature and/or current or reduced airflow as long as the aver­age is not exceeded.

Note that the temperatures are of the ambient airflow, not the converter
itself which is obviously running at higher temperature than the outside air.
Also note that very low flow rates (below about 25 LFM) are similar to “natural
convection”, that is, not using fan-forced airflow.

MPS makes Characterization measurements in a closed cycle wind tunnel
with calibrated airflow. We use both thermocouples and an infrared camera
system to observe thermal performance. As a practical matter, it is quite diffi­cult to insert an anemometer to precisely measure airflow in most applications.
Sometimes it is possible to estimate the effective airflow if you thoroughly un­derstand the enclosure geometry, entry/exit orifice areas and the fan flowrate
specifications. If in doubt, contact MPS to discuss placement and measurement
techniques of suggested temperature sensors.

CAUTION: If you routinely or accidentally exceed these Derating guidelines,
the converter may have an unplanned Over Temperature shut down. Also, these
graphs are all collected at slightly above Sea Level altitude. Be sure to reduce
the derating for higher density altitude.

Output Overvoltage Protection

This converter monitors its output voltage for an over-voltage condition using
an on-board electronic comparator. The signal is optically coupled to the pri­mary side PWM controller. If the output exceeds OVP limits, the sensing circuit
will power down the unit, and the output voltage will decrease. After a time-out
period, the PWM will automatically attempt to restart, causing the output volt­age to ramp up to its rated value. It is not necessary to power down and reset
the converter for the this automatic OVP-recovery restart.

If the fault condition persists and the output voltage climbs to excessive levels,
the OVP circuitry will initiate another shutdown cycle. This on/off cycling is referred
to as “hiccup” mode. It safely tests full current rated output voltage without damag­ing the converter.

Output Fusing

The converter is extensively protected against current, voltage and temperature
extremes. However your output application circuit may need additional protec­tion. In the extremely unlikely event of output circuit failure, excessive voltage
could be applied to your circuit. Consider using an appropriate fuse in series
with the output.

Technical enquiries email: [e-mail], tel: [phone]www.murata-ps.com

MDC_UEI15W.B12 Page 7 of 12

Output Current Limiting

LOAD

7

5-22

TURNS

+OUTPUT

TRIM

−OUTPUT

−INPUT

ON/OFF

CONTROL

+INPUT

+OUTPUT

TRIM

ON/OFF

CONTROL

+INPUT

LOAD

R TRIM UP

−OUTPUT

−INPUT

LOAD

RTRIM DOWN

+OUTPUT

TRIM

ON/OFF

CONTROL

+INPUT

−OUTPUT

−INPUT

As soon as the output current increases to approximately 125% to 150% of
its maximum rated value, the DC/DC converter will enter a current-limiting
mode. The output voltage will decrease proportionally with increases in output
current, thereby maintaining a somewhat constant power output. This is com­monly referred to as power limiting.

Current limiting inception is defined as the point at which full power falls
below the rated tolerance. See the Performance/Functional Specifications. Note
particularly that the output current may briefly rise above its rated value. This
enhances reliability and continued operation of your application. If the output
current is too high, the converter will enter the short circuit condition.

Output Short Circuit Condition

When a converter is in current-limit mode, the output voltage will drop as
the output current demand increases. If the output voltage drops too low, the
magnetically coupled voltage used to develop primary side voltages will also
drop, thereby shutting down the PWM controller. Following a time-out period,
the PWM will restart, causing the output voltage to begin ramping up to its ap­propriate value. If the short-circuit condition persists, another shutdown cycle
will initiate. This on/off cycling is called “hiccup mode”. The hiccup cycling
reduces the average output current, thereby preventing excessive internal
temperatures. A short circuit can be tolerated indefinitely.

UEI15 Series

Isolated Wide Input Range 15-Watt DC/DC Converters

Figure 4 – Trim adjustments using a trimpot

Trimming the Output Voltage

The Trim input to the converter allows the user to adjust the output voltage
over the rated trim range (please refer to the Specifications). In the trim equa­tions and circuit diagrams that follow, trim adjustments use either a trimpot or
a single fixed resistor connected between the Trim input and either the positive
or negative output terminals. (On some converters, an external user-supplied
precision DC voltage may also be used for trimming). Trimming resistors should
have a low temperature coefficient (±100 ppm/deg.C or less) and be mounted
close to the converter. Keep leads short. If the trim function is not used, leave
the trim unconnected. With no trim, the converter will exhibit its specified
output voltage accuracy.

There are two CAUTION’s to be aware for the Trim input:

CAUTION: To avoid unplanned power down cycles, do not exceed EITHER the
maximum output voltage OR the maximum output power when setting the trim.
Be particularly careful with a trimpot. If the output voltage is excessive, the
OVP circuit may inadvertantly shut down the converter. If the maximum power
is exceeded, the converter may enter current limiting. If the power is exceeded
for an extended period, the converter may overheat and encounter overtem­perature shut down.

CAUTION: Be careful of external electrical noise. The Trim input is a senstive
input to the converter’s feedback control loop. Excessive electrical noise may
cause instability or oscillation. Keep external connections short to the Trim
input. Use shielding if needed. Also consider adding a small value ceramic
capacitor between the Trim and –V

OUT to bypass RF and electrical noise.

Figure 5 – Trim adjustments to decrease Output Voltage using a Fixed Resistor

Figure 6 – Trim adjustments to increase Output Voltage using a Fixed Resistor

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MDC_UEI15W.B12 Page 8 of 12

UEI15 Series

VO – 5

– 2050

12775

– 2050

5 – V

O

5110 (Vo - 2.5)

V

O – 12

– 5110

25000

– 5110

12 – V

O

10000 (Vo-2.5)

UEI15-050-Q12, Q48

UEI15-120-Q12, Q48

VO – 3.3

– 2050

12775

R

T

DOWN

() =RTUP () =

R

T

UP

() =

R

T

UP

() =

R

T

UP

() =

R

T

DOWN

() =

R

T

DOWN

() =

R

T

DOWN

() =

– 2050

3.3 – V

O

5110 (Vo - 2.5)

UEI15-033-Q12, Q48

VO – 15

– 5110

25000

– 5110

15 – V

O

10000 (Vo-2.5)

UEI15-150-Q12, Q48

Trim Up

<Connect trim

resistor between

Trim and −V

OUT>

Trim Down

<Connect trim
resistor between
Trim and +V

OUT>

ON/OFF

CONTROL

-INPUT

ON/OFF

CONTROL

-INPUT

Isolated Wide Input Range 15-Watt DC/DC Converters

Trim Equations

Where Vo = Desired output voltage. Adjustment accuracy is subject to resis­tor tolerances and factory-adjusted output accuracy. Mount trim resistor close
to converter. Use short leads.

Remote On/Off Control

On the input side, a remote On/Off Control can be ordered with either polarity.

Positive: Standard models are enabled when the On/Off pin is left open or
is pulled high to +V
open pin to rise to +V

IN with respect to –VIN. An internal bias current causes the

IN. Some models will also turn on at lower intermediate

voltages (see Specifications). Positive-polarity devices are disabled when the
On/Off is grounded or brought to within a low voltage (see Specifications) with

IN.

respect to –V

Negative: Optional negative-polarity devices are on (enabled) when the On/
Off is grounded or brought to within a low voltage (see Specifications) with
respect to –V
pulled high to +15V

IN. The device is off (disabled) when the On/Off is left open or is

d c max. with respect to –VIN.

Figure 8 – Driving the Negative Polarity On/Off Control Pin

Dynamic control of the On/Off function should be able to sink appropriate
signal current when brought low and withstand appropriate voltage when
brought high. Be aware too that there is a finite time in milliseconds (see
Specifications) between the time of On/Off Control activation and stable,
regulated output. This time will vary slightly with output load type and current
and input conditions.

There are three CAUTION’s for the On/Off Control:

CAUTION: To retain full output circuit isolation, control the On/Off from the in­put side ONLY. If you must control it from circuits in the output, use some form
of optoisolation to the On/Off Control. This latter condition is unlikely because
the device controlling the On/Off would have to remain powered on and not be
powered from the converter.

CAUTION: While it is possible to control the On/Off with external logic if you
carefully observe the voltage levels, the preferred circuit is either an open
drain/open collector transistor, a switch or a relay (which can thereupon be
controlled by logic). The On/Off prefers to be set at +V

IN (open pin) for the

ON state, assuming positive logic.

CAUTION: Do not apply voltages to the On/Off pin when there is no input
power voltage. Otherwise the converter may be permanently damaged.

Figure 7 – Driving the Positive Polarity On/Off Control Pin

Special Note for Low Noise Circuits

In order to achieve their extraordinary high efficiency and low heat dissipa­tion, DC/DC converters by necessity have small residual switching noise
in their outputs. Generally this switching noise is at hundreds of kilohertz
therefore it can be extensively filtered. For circuits which are sensitive to this
kind of noise, multipole L-C passive filters are an effective solution. Be sure
to size the inductors to stay well below magnetic saturation and temperature
rise at the maximum operating current. Please refer to MPS’s FLT series
passive filters.

Technical enquiries email: [e-mail], tel: [phone]www.murata-ps.com

MDC_UEI15W.B12 Page 9 of 12

PERFORMANCE DATA

3.50

3.70

3.90

4.10

4.30

4.50

4.70

4.90

5.10

20 25 30 35 40 45 50 55 60 65 70 75 80 85 90

Ambient Temperature

(°C)

Output Current (Amps)

Natural Convection

100 LFM
200 LFM
300 LFM

3.80

4.00

4.20

4.40

4.60

4.80

5.00

5.20

20 25 30 35 40 45 50 55 60 65 70 75 80 85 90

Ambient temperaturea

(°C)

Output Current (Amps)

Natural Convection

100 LFM
200 LFM
300 LFM
400 LFM

50

55

60

65

70

75

80

85

90

0 0.5 1 1.5 2 2.5 3 3.5 4

Load Current (Amps)

Efficiency (%)

Vin = 24 V

Vin = 36 V

Vin = 9 V

Vin = 18 V

Load Current (Amps)

0.5

1

1.5

2

2.5

0 0.5 1 1.5 2 2.5 3 3.5 4

Loss (Watts)

Vin = 24 V

Vin = 36 V

Vin = 9.5 V

Vin = 18 V

Load Current (Amps)

Efficiency (%)

10

20

30

40

50

60

70

80

90

100

0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.25 2.5 2.75 3

Vin = 24 V

Vin = 36 V

Vin = 9 V

Vin = 18 V

Efficiency vs. Line Voltage and Load Current @ 25°C Power Dissipation vs. Load Current @ 25°C

UEI15 Series

Isolated Wide Input Range 15-Watt DC/DC Converters

UEI15-033-Q12

UEI15-033-Q48

Maximum Current Temperature Derating @sea level

in = 24V, airflow from input to output)

(V

Maximum Current Temperature Derating @sea level

(Vin = 48V, airflow from input to output)

UEI15-050-Q12

Efficiency vs. Line Voltage and Load Current @ 25°C Power Dissipation vs. Load Current @ 25°C

Technical enquiries email: [e-mail], tel: [phone]www.murata-ps.com

MDC_UEI15W.B12 Page 10 of 12

PERFORMANCE DATA

Load Current (Amps)

Efficiency (%)

60

65

70

75

80

85

90

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3

Vin = 24 V

Vin = 36 V

Vin = 9 V

Vin = 18 V

20 25 3 0 3 5 40 45 5 0 5 5 60 65 7 0 7 5 80 85 9 0

0.50

0.60

0.70

0.80

0.90

1.00

1.10

1.20

1.30

Ambient Temperature (°C)

Output Current (Amps)

Natural Convection

100 LFM
200 LFM
300 LFM
400 LFM

Load Current (Amps)

Efficiency (%)

74

76

78

80

82

84

86

88

90

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1

Vin = 24 V

Vin = 36 V

Vin = 9 V

Ambient Temperature (°C)

Output Current (Amps)

0.80

0.85

0.90

0.95

1.00

1.05

1.10

1.15

20 25 30 35 40 45 50 55 60 65 70 75 80 85 90

Natural Convection

Load Current (Amps)

Efficiency (%)

0.2 0.3 0.4 0.5 0.6 0.7 0. 8 0.9 1 1.1 1.2

70

72

74

76

78

80

82

84

86

88

90

Vin = 48 V

Vin = 75 V

Vin = 18 V

Vin = 24 V

Ambient Temperature (°C)

0.8

0.9

1

1.1

1.2

1.3

20 25 30 35 40 45 50 55 60 65 70 75 80 85 90

Outpu t Current (Amps)

Natural Convection

100 LFM
200 LFM

Efficiency vs. Line Voltage and Load Current @ 25°C

UEI15 Series

Isolated Wide Input Range 15-Watt DC/DC Converters

UEI15-120-Q12

Maximum Current Temperature Derating @Sea Level

(Vin = 36V, airflow is from pin 2 to pin 1)

Efficiency vs. Line Voltage and Load Current @ 25°C

Efficiency vs. Line Voltage and Load Current @ 25°C

UEI15-120-Q48

UEI15-150-Q12

Maximum Current Temperature Derating @Sea Level

(V

in = 75V, airflow is from pin 2 to pin 1)

Maximum Current Temperature Derating @Sea Level

in = 24V, airflow is from input to output)

(V

Technical enquiries email: [e-mail], tel: [phone]www.murata-ps.com

MDC_UEI15W.B12 Page 11 of 12

UEI15 Series

Isolated Wide Input Range 15-Watt DC/DC Converters

Murata Power Solutions, Inc.
11 Cabot Boulevard, Mansfield, MA 02048-1151 U.S.A.
Tel: [phone] [phone] Fax: [phone]

www.murata-ps.com email: [e-mail] ISO 9001 REGISTERED

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. © 2008 Murata Power Solutions, Inc.

07/25/08

USA: Mansfield (MA), Tel: [phone], email: [e-mail]

Canada: Toronto, Tel: [phone], email: [e-mail]

UK: Milton Keynes, Tel: [phone], email: [e-mail]

France: Montigny Le Bretonneux, Tel: [phone], email: [e-mail]

Germany: München, Tel: [phone], email: [e-mail]

Japan: Tokyo, Tel: [phone], email: [e-mail]

Osaka, Tel: [phone], email: [e-mail]
Website: www.murata-ps.jp

China: Shanghai, Tel: [phone], email: [e-mail]

Guangzhou, Tel: [phone], email: [e-mail]

Technical enquiries email: [e-mail], tel: [phone]www.murata-ps.com

MDC_UEI15W.B12 Page 12 of 12