Datasheet UEI30 Datasheet (MURATA)

www.murata-ps.com

Typ

www.murata-ps.com

UEI30 Series

30W Isolated Wide-Range DC/DC Converters

Featuring a full 30 Watt output in 1.8 square inches of board area,
the UEI series isolated DC/DC converter family offers efficient
regulated DC power for printed circuit board mounting.

Typical unit

ical unit

FEATURES



Small footprint DC/DC converter, ideal for high
current applications



0.92" x 1.92" x 0.35" open frame package



Wide range input voltages 9-36 and 18-75Vdc



Double lead-free assembly and attachment
for RoHS standards



Isolation up to 2250 VDC (basic)



Up to 30W total output power with
overtemperature shutdown



High effi ciency synchronous rectifi er forward
topology



Stable no-load operation with no required
external components



–40 to +85°C temperature range with derating



Designed to meet UL60950-1, CSA-C22.2 No.
234, EN60950-1 safety approvals



Extensive self-protection shut down features



RoHS hazardous substance compliant

PRODUCT OVERVIEW

Wide range 4:1 inputs on the 0.92" x 1.92" x 0.35"
converter are either 9 to 36 Volts DC (Q12
models) or 18 to 75 Volts DC (Q48 models), ideal
for battery-powered and telecom equipment.
Fixed output voltages from 3.3 VDC to 15 VDC
are tightly regulated and may be trimmed within
±10% of nominal output. Applications include
small instruments, computer-based systems,
data communications equipment, remote sensor
systems, vehicle and portable electronics.

The UEI 30W Series includes full magnetic and
optical isolation up to 2250 Volts DC (basic insu­lation). For connection to digital systems, the out­puts offer fast settling to current step loads and
tolerance of higher capacitive loads. Excellent
ripple and noise specifi cations assure compatibil­ity to circuits using CPU’s, ASIC’s, programmable
logic and FPGA’s. No minimum load is required.
For systems requiring controlled startup/shut­down, an external switch, transistor or digital

SIMPLIFIED SCHEMATIC

logic may be used to activate the remote On/Off
control. Remote Sense inputs compensate for
resistive line drops at high currents.

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 indefi nitely.
Additional features include output overvoltage
and reverse conduction elimination.

The synchronous rectifi er forward topology
offers high effi ciency for minimal heat buildup
and “no fan” operation. The open frame design
is also available under special quantity order
with an encapsulation shell and thermally­conductive potting compound. This option offers
additional cooling in low-airfl ow, high tempera­ture applications.

For full details go to

www.murata-ps.com/rohs

+V

–V

TRIM

OUT

OUT

+V

IN

–V

IN

On/Off

Control

GATE

DRIVE

ISOLATION

BARRIER

Control

OPTO

ISOLATION

Reference, trim &

Error Amplifier

Typical topology is shown.

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MDC_UEI Series 30W.A01 Page 1 of 11

UEI30 Series

30W Isolated Wide-Range DC/DC Converters

PERFORMANCE SPECIFICATIONS AND ORDERING GUIDE

Output Input

V

OUT

(V)

Root Model

UEI30-033-Q12P-C 3.3 9 29.7

UEI30-033-Q48N-C 3.3 9 29.7 48 18-75 0.92x1.92x0.35 P21

UEI30-050-Q12P-C 5 6 30 24 9-36 0.92x1.92x0.35 P21

UEI30-050-Q48N-C 5 6 30 25 50 ±0.1% ±0.1% 48 18-75 130 0.70 87.9% 89% 0.92x1.92x0.35 P21

UEI30-120-Q12P-C 12 2.5 30

UEI30-120-Q48N-C 12 2.5 30 48 18-75 0.92x1.92x0.35 P21

UEI30-150-Q12P-C 15 2 30 24 9-36 0.92x1.92x0.35 P21

UEI30-150-Q48N-C 15 2 30 48 18-75

c Please refer to the part number structure for additional options and complete ordering part numbers.
d All specifi cations are at nominal line voltage and full load, +25 deg.C. unless otherwise noted. See

detailed specifi cations.

c

Power R/N (mVp-p) Regulation (Max.)

IOUT

(A)

(W) Typ. Max. Line Load

Please contact Murata Power

Solutions for further information.

Please contact Murata Power

Solutions for further information.

VIN

Range

Nom.

(V)

e Sense input is not included for 12 Vout and higher models. Sense is optional for 5 Vout and lower.

(V)

24 9-36

24 9-36

Output capacitors are 1 μF ceramic in parallel with 10 μF electrolytic. Input cap is 22 μF, low ESR.
These I/O caps are necessary for our test equipment and may not be needed for your application.

IIN,

no load

IIN, full

load (A)

(mA)

Please contact Murata Power

Solutions for further information.

Please contact Murata Power

Solutions for further information.

Effi ciency

Min. Typ.

Open Frame

Package, C80

Case (inches) Pinout

0.92x1.92x0.35 P21

0.92x1.92x0.35 P21

0.92x1.92x0.35

P21

PART NUMBER STRUCTURE

UEI30 - Q48-050

Nominal Output Voltage

In tenths of a volt

Input Voltage Range:

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

C

-N

RoHS-6 hazardous substancecompliance

Note:

Not all model number combinations are
available. Contact Murata Power Solutions.

On/Off Control Polarity:

P = Positive
N = Negative
Positive “P” polarity is standard for Q12 models and optional special

order for Q48 models. Negative “N” polarity is standard for Q48
models and optional special order for Q12 models.

Soldering Guidelines

Murata Power Solutions recommends the specifi cations below when installing these converters. These specifi cations vary depending on the solder type. Exceeding these specifi ca­tions may cause damage to the product. Be cautious when there is high atmospheric humidity. We strongly recommend a mild pre-bake (100° C. for 30 minutes). Your production

environment may differ; therefore please thoroughly review these guidelines with your process engineers.

Wave Solder Operations for through-hole mounted products (THMT)

For Sn/Ag/Cu based solders: For Sn/Pb based solders:

Maximum Preheat Temperature 115° C. Maximum Preheat Temperature 105° C.

Maximum Pot Temperature 270° C. Maximum Pot Temperature 250° C.

Maximum Solder Dwell Time 7 seconds Maximum Solder Dwell Time 6 seconds

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

MDC_UEI Series 30W.A01 Page 2 of 11

MECHANICAL SPECIFICATIONS

INPUT/OUTPUT CONNECTIONS

Pin Function P21 Pin Function P21

1 + Vin 4 + Vout
2 - Vin 5 - Vout
3 Remote On/Off* 6 Trim

* The Remote On/Off can be provided with either positive (P suffi x) or negative
(N suffi x) polarity.

UEI30 Series

30W Isolated Wide-Range DC/DC Converters

PHYSICAL CHARACTERISTICS

Outline dimensions See mechanical specs

Pin material

Copper alloy with gold plate over nickel

underplate

Pin diameter 0.04" (1.016mm)

Pin Finish Gold plate

Weight 0.53 oz (15g)

Electromagnetic interference

Designed to meet FCC part 15, class B,

EN55022 (may need fi lter)

Flammability Rating UL 94V-0

Safety

Designed to meet IEC/EN/UL/cUL 60950-1,

CSA-C22.2 No. 60950-1

(23.4)

(6.4)

#6

#5

.400

(10.16)
C

L

.400

(10.16)

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

Third Angle Projection

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

Components are shown for reference only.

TOP VIEW

1.92

(48.8)

.92

SIDE VIEW

.25

MOUNTING PLANE

BOTTOM VIEW

1.800

(45.72)

C

L

.900

(22.86)

REF

PIN #1

.35

(8.9)

.040 .002 PIN WITH
.071 .002 SHOULDER

6X AT PINS 1-6

#3

#2

.300 (7.62)

.100 (2.54)

.300 (7.62)

C

#4

L

END VIEW

#1

UEI30 Open Frame

30W

Package C80

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MDC_UEI Series 30W.A01 Page 3 of 11

INPUT CHARACTERISTICS

Under-

Model Family

UEI30-033-Q12P-C
UEI30-033-Q48N-C 17.3 16.0 1.99 6
UEI30-050-Q12P-C
UEI30-050-Q48N-C 17.0 16.2 1.89 6
UEI30-120-Q12P-C
UEI30-120-Q48N-C
UEI30-150-Q12P-C
UEI30-150-Q48N-C

Start-up

threshold

V V mA pk-pk A

voltage

Shut­down

Refl ected

(back)
Ripple

Current

30

2

Input Current

Inrush

Output

Short

Circuit

Low
Line

Tran-

sient

2

sec mA A mA A mA “P” model suffi x “N” model suffi x

0.05 50 1 L-C N/A 1

Standby

Mode

Recom­mended

Fuse

UEI30 Series

30W Isolated Wide-Range DC/DC Converters

Internal

Input
Filter

Type

Reverse

Polarity

Protection

On/Off

Current

Remote On/Off Control

Positive Logic Negative Logic

OFF=Gnd pin or

–0.7 to +1.2V

max. ON=open

pin or +10 to

+15V max.

OFF=open pin

or +10 to +15V

max. ON=Gnd

pin or –0.7 to

+1.2V max.

OUTPUT CHARACTERISTICS

IOUT

Model Family

UEI30-033-Q12P-C
UEI30-033-Q48N-C 9
UEI30-050-Q12P-C
UEI30-050-Q48N-C 6 7.3
UEI30-120-Q12P-C
UEI30-120-Q48N-C
UEI30-150-Q12P-C
UEI30-150-Q48N-C

ABSOLUTE MAXIMUM RATINGS

Input Voltage

On/Off control, referred to –Vin -0.7 V. min to +15V max.
Input Reverse Polarity Protection See fuse section
Output Overvoltage V

Output Current

Overtemperature Protection

Storage Temperature
Lead Temperature See soldering specifi cations

Max.

A % of V

Q12 models

Q48 models

OUT

V

Accuracy

50% Load

Volts, max. continuous 0-36 VDC to rated specifi cations
Volts, transient, 100 mSec
Volts, max. continuous
Volts, transient, 100 mSec 100 VDC, no damage

Adjustment

Range

NOM % of VNOM % of VOUT /ºC µF V

1

±10 ±0.02 2,000 No

Temperature

Coeffi cient

50 VDC, no damage
0-75 VDC to rated specifi cations

Current-limited. Devices can
withstand sustained short circuit
without damage. The outputs are
not intended to accept appreci­able reverse current.

Device includes electronic over­temperature shutdown protection
under normal operation.

-55 to +125° C.

Capacitive Loading Max.

Low ESR <0.02Ω Max,

resistive load

OUT nom. +20% max.

Overvoltage

protection

Hiccup auto-start

after fault removal

5.0

Absolute Maximum Ratings

Absolute maximums are stress ratings. Exposure of devices to
greater than any of these conditions may adversely affect long-term
reliability. Proper operation under conditions other than those listed
in the Performance/Functional Specifi cations Table is not implied nor
recommended.

Maximum Ratings Notes

The UEI-30W series does not include electronic Input Overvoltage
Protection. Therefore it is possible for the input to exceed the con­tinuous ratings listed above and still operate. However, units are not
routinely Production-tested above the continuous ratings. Therefore,
the rated specifi cations do not apply at excessive input voltage and
performance is undetermined.

At some combinations of high ambient temperature, low airfl ow
or high output current, the controller may shut down from overtem­perature if the maximum rated input voltage is exceeded.

The transient specifi cations indicate that sample lots were suc­cessfully tested for 100 mS at the transient stress voltage and were
not damaged. As a practical matter in your application, it is often
diffi cult to determine how long an input overvoltage was applied.
Therefore, do not exceed the continuous voltage rating.

OV

loading

Minimum

Magnetic
feedback

method

protection

Ripple/Noise

See ordering guide

8

(20 MHz

bandwidth)

Effi ciency

Line/Load

Regulation

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

MDC_UEI Series 30W.A01 Page 4 of 11

UEI30 Series

30W Isolated Wide-Range DC/DC Converters

ISOLATION CHARACTERISTICS

Model Family

Input to

Output.

Min Min

Isolation

Resistance

Isolation

Capacitance

Insulation Safety

Rating

VDC MΩ pF

UEI30-033-Q12P-C

2000

10

UEI30-033-Q48N-C 2250 10 65 Basic

UEI30-050-Q12P-C 2000

10

UEI30-050-Q48N-C 2250 10 1000 Basic

UEI30-120-Q12P-C 2000 10

UEI30-120-Q48N-C 2250 10

UEI30-150-Q12P-C 2000 10

UEI30-150-Q48N-C 2250 10

MISCELLANEOUS CHARACTERISTICS

Model Family

Output Current
Limit Inception

98% of V

after warmup

A A Hours ºC ºC ºC

OUT,

Output

Short

Circuit

Protection

Method

Output

Short

Circuit

Current

Output Short
Circuit Duration
(output shorted

to ground)

UEI30-033-Q12P-C

UEI30-033-Q48N-C 11.2 TBD

UEI30-050-Q12P-C

UEI30-050-Q48N-C 7.0 0.3 max.

UEI30-120-Q12P-C

UEI30-120-Q48N-C

Current

limiting,

hiccup

auto

restart

Continuous

UEI30-150-Q12P-C 5.3

UEI30-150-Q48N-C 5.8 TBD

DYNAMIC CHARACTERISTICS

Start-up Time

V

IN to VOUT

regulated

(Max.)

Remote On/Off

to VOUT

regulated (Max.)

Model Family

Dynamic Load

Response

(50-75-50%

load step)

sec mSec mSec KHz

UEI30-033-Q12P-C

UEI30-033-Q48N-C

100 to 2% VOUT 50 50 275

180 to 2% 50 50 280

UEI30-050-Q12P-C 275

UEI30-050-Q48N-C 100 to 1% 50 50 275

UEI30-120-Q12P-C 200 to 1% VOUT

UEI30-120-Q48N-C 400 to 1% VOUT 250

UEI30-150-Q12P-C 100 to 1% VOUT 275

UEI30-150-Q48N-C TBD TBD

Output

Pre-biased

setup

Monotonic

(external

OUT < VSET)

V

Calculated

MTBF

(Note 4)

2,000,000

Operating Temperature

Range

–40 to +85ºC;

with Derating

(see Notes)

Storage

temperature

protection/

range

–55 to 125ºC 115

Thermal

shutdown

Switching

Frequency

Relative

Humidity,

non-

condensing

To +85ºC/

85% RH

Specifi cation Notes:

(1) All models are tested and specifi ed with external 1 μF and 10 μF parallel output capacitors and a
22 μF 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 specifi ed performance in your
applications. All models are stable and regulate within spec under no-load conditions.
All specifi cations are typical unless noted. General conditions for Specifi cations are +25 deg.C,
Vin=nominal, Vout=nominal, full load. Adequate airfl ow must be supplied for extended testing under
power.
(2) Input Back Ripple Current is tested and specifi ed over a 5 Hz to 20 MHz bandwidth. Input fi ltering
is Cin=33 μF, 100V, Cbus=220 μF, 100V, Lbus=12 μH.
(3) Note that Maximum Power Derating curves indicate an average current at nominal input voltage.
At higher temperatures and/or lower airfl ow, 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) SR-332 Method 1, Case 3,
ground fi xed conditions, Tpcboard=+25 deg.C, full load, natural air convection.
(5) The On/Off Control is normally selected by a switch or an open collector or open drain transistor.
But it may also be driven with external logic or by applying appropriate external voltages which are
referenced to Input Common and do not exceed the On/Off voltage specifi cations.
(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.
(8) Output noise may be further reduced by adding an external fi lter. Low voltage logic circuits may
have a small voltage margin between logic ZERO and logic ONE, requiring noise suppression. Use only

as much output fi ltering as needed to achieve your noise requirements. Excessive output capacitance
can retard transient response or possibly cause instability. Low ESR ceramic capacitors may degrade
dynamic performance. Be sure to thoroughly test your system under full load with all components
installed.
(9) All models are fully operational and meet published specifi cations, including “cold start” at –40°C.
At full power, the package temperature of all on-board components must not exceed +128°C.
(10) Regulation specifi cations 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. 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. After an output overcurrent or short circuit, “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 resumes normal operation.
(13) Do not exceed maximum power specifi cations when adjusting the output trim.
(14) At zero output current, the output may contain low frequency components which exceed the
ripple specifi cation. The output may be operated indefi nitely with no load.
(15) If reverse polarity is accidentally applied to the input, to ensure reverse input protection with full
output load, always connect an external input fuse in series with the +Vin input. Use approximately
twice the full input current rating with nominal input voltage.
CAUTION: This product is not internally fused. To comply with safety agency certifi cations 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: [email protected], tel: [phone]www.murata-ps.com

MDC_UEI Series 30W.A01 Page 5 of 11

UEI30 Series

30W Isolated Wide-Range 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 Specifi cations). 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 Start­Up Time (see Specifi cations) 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 specifi ed accuracy band. Actual measured

times will vary with input source impedance, external input capacitance, input volt­age slew rate and fi nal value of the input voltage as it appears at the converter.

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

OUT regulated

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 specifi ed accuracy
band. The specifi cation assumes that the output is fully loaded at maximum
rated current. Similar conditions apply to the On to V

OUT regulated specifi cation

such as external load capacitance and soft start circuitry.

Input Source Impedance

These converters will operate to specifi cations without external components,
assuming that the source voltage has very low impedance and reasonable
input voltage regulation. Since real-world voltage sources have fi nite imped­ance, performance is improved by adding external fi lter components. Some­times only a small ceramic capacitor is suffi cient. Since it is diffi cult 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 specifi es 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 specifi ed for input refl ected
ripple current and output noise using designated external input/output compo­nents, circuits and layout as shown in the fi gures below. External input capaci-

IN in the fi gure) serve primarily as energy storage elements, minimizing

tors (C
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 fi gure below,

TO

OSCILLOSCOPE

L

+

–

V

IN

+

–

CIN = 33μF, ESR < 700mΩ @ 100kHz
C

BUS

= 220μF, ESR < 100mΩ @ 100kHz

L

BUS

= 12μH

BUS

C

BUS

Figure 2. Measuring Input Ripple Current

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

CURRENT

PROBE

1

+INPUT

C

IN

2

−INPUT

MDC_UEI Series 30W.A01 Page 6 of 11

UEI30 Series

30W Isolated Wide-Range DC/DC Converters

the CBUS and LBUS components simulate a typical DC voltage bus. Your specifi c
system confi guration may require additional considerations. Please note that the
values of C

IN, LBUS and CBUS will vary according to the specifi c converter model.

In critical applications, output ripple and noise (also referred to as periodic
and random deviations or PARD) may be reduced by adding fi lter elements
such as multiple external capacitors. Be sure to calculate component tem­perature rise from refl ected AC current dissipated inside capacitor ESR. In the
fi gure, 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 fi xture.

COPPER STRIP

+OUTPUT

R

C1

−OUTPUT

COPPER STRIP

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

Figure 3 – Measuring Output Ripple and Noise (PARD)

SCOPE

C2

LOAD

Floating Outputs

Since these are isolated DC/DC converters, their outputs are “fl oating” 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 Specifi cations).
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 specifi cations. 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 rectifi er design topology. All models
regulate within specifi cation 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 Specifi cations.

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 airfl ow 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 airfl ow as long as the average is not exceeded.

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

MPS makes Characterization measurements in a closed cycle wind
tunnel with calibrated airfl ow. We use both thermocouples and an infrared
camera system to observe thermal performance. As a practical matter, it is
quite diffi cult to insert an anemometer to precisely measure airfl ow in most
applications. Sometimes it is possible to estimate the effective airfl ow if you
thoroughly understand the enclosure geometry, entry/exit orifi ce areas and the
fan fl owrate specifi cations. 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.

Output Current Limiting

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

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

MDC_UEI Series 30W.A01 Page 7 of 11

UEI30 Series

30W Isolated Wide-Range DC/DC Converters

current, thereby maintaining a somewhat constant power output. This is com­monly referred to as power limiting.

Current limiting inception is defi ned as the point at which full power falls
below the rated tolerance. See the Performance/Functional Specifi cations. Note
particularly that the output current may briefl y 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 indefi nitely.

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 Specifi cations). In the trim equations and
circuit diagrams that follow, trim adjustments use either a trimpot or a single
fi xed resistor connected between the Trim input and either the +Sense or –Sense
terminals. (On some converters, an external user-supplied precision DC voltage
may also be used for trimming). Trimming resistors should have a low tempera­ture coeffi cient (±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 specifi ed output voltage accuracy.

There are two CAUTIONs 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.

−INPUT

ON/OFF

CONTROL

+OUTPUT

TRIM

5-22

7

TURNS

LOAD

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.

−INPUT

ON/OFF

CONTROL

+INPUT

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

+OUTPUT

TRIM

−OUTPUT

RTRIM DOWN

LOAD

Trim Equations

Trim Up Trim Down

<Connect trim resistor

between Trim and –Sense>

<Connect trim resistor

between Trim and +Sense>

UEI30-033-Q12/-Q48

R

T (:) =

UP

12775

VO – 3.3

– 2050

RT (:) =

DOWN

5110 (Vo - 2.5)

3.3 – V

O

– 2050

UEI30-050-Q12/-Q48

T (:) =

R

UP

12775

VO – 5

– 2050

RT (:) =

DOWN

5110 (Vo - 2.5)

5 – V

O

– 2050

UEI30-120-Q12/-Q48

R

T (:) =

UP

25000

VO – 12

– 5110

RT (:) =

DOWN

10000 (Vo-2.5)

12 – V

O

–5110

UEI30-150-Q12/-Q48

R

T (:) =

UP

25000

VO – 15

– 5110

RT (:) =

DOWN

10000 (Vo-2.5)

15 – V

O

–5110

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.

+INPUT

−OUTPUT

Figure 4 – Trim adjustments using a trimpot

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 Specifi cations). Positive-polarity devices are disabled when the

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

MDC_UEI Series 30W.A01 Page 8 of 11

On/Off is grounded or brought to within a low voltage (see Specifi cations) with
respect to –V

IN.

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

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

DC Max. with respect to –VIN.

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 fi nite time in milliseconds (see
Specifi cations) 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 two CAUTIONs for the On/Off Control:

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 or a relay (which can thereupon be controlled by
logic). The On/Off prefers to be set at approx. +15V (open pin) for the ON state,
assuming positive logic.

UEI30 Series

30W Isolated Wide-Range DC/DC Converters

−INPUT

ON/OFF

CONTROL

+INPUT

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

+OUTPUT

TRIM

−OUTPUT

R TRIM UP

LOAD

+VCC

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

3

ON/OFF

CONTROL

1

-INPUT

Figure 7 – Driving the On/Off Control Pin (suggested circuit)

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

MDC_UEI Series 30W.A01 Page 9 of 11

PERFORMANCE DATA

Effi ciency vs. Line Voltage and Load Current @ 25°C

UEI30-033-Q48

UEI30 Series

30W Isolated Wide-Range DC/DC Converters

Maximum Current Temperature Derating @Sea Level

(V

IN = 24V, airfl ow is from input to output)

100

90

80

70

60

50

Efficien cy (%)

40

30

20

1234567890

Vin = 75 V

Vin = 48 V

Vin = 24 V

Vin = 18 V

9.1

9

8.9

8.8

8.7

Output Current (Amps)

8.6

8.5
20 25 30 35 40 45 50 55 60 65 70 75 80 85 90

Ambient Temperature (ºC)

Natural convection

100 LFM
200 LFM

Load Current (Amps)

UEI30-033-Q48

Maximum Current Temperature Derating @Sea Level

(V

IN = 48V, airfl ow is from input to output)

9.1

9

8.9

8.8

8.7

Output Current (Amps)

8.6

8.5
20 25 30 35 40 45 50 55 60 65 70 75 80 85 90

Ambient Temperature (ºC)

Natural convection

100 LFM
200 LFM

Effi ciency vs. Line Voltage and Load Current @ 25°C

100

90

80

70

60

50

Efficiency (%)

40

30

20

0

1.00

Vin = 75 V

Vin = 48 V

Vin = 24 V

Vin = 18 V

2.00

0

3.0

4.00

UEI30-050-Q12

5.00

6.00

Maximum Current Temperature Derating @Sea Level

IN = 36V, longitudinal airfl ow)

(V

6.1

6.0

5.9

5.8

5.7

Output Current (Amps)

5.6

5.5

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

Natural convection

100 LFM
200 LFM
300 LFM

Ambient Temperature (ºC)

Load Current (Amps)

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

MDC_UEI Series 30W.A01 Page 10 of 11

PERFORMANCE DATA

UEI30 Series

30W Isolated Wide-Range DC/DC Converters

UEI30-050-Q48

Effi ciency vs. Line Voltage and Load Current @ 25°C Maximum Current Temperature Derating @Sea Level

100

90

80

70

60

Efficien cy (%)

50

40

30

20

0

1.00

2.00

Load Current (Amps)

Vin = 75 V

Vin = 48 V

Vin = 24 V

Vin = 18 V

3.0

0

4.00

5.00

Maximum Current Temperature Derating @Sea Level

(VIN = 24V, transverse airfl ow)

6.1

6.0

5.9

5.8

5.7

Output Current (Amps)

5.6

5.5
20 25 30 35 40 45 50 55 60 65 70 75 80 85 90

Ambient Temperature (ºC)

Natural convection

6.1

6.0

5.9

5.8

5.7

Output Current (Amps)

5.6

5.5
20 25 30 35 40 45 50 55 60 65 70 75 80 85 90

6.00

UEI30-050-Q48

6.1

6.0

5.9

5.8

5.7

Output Current (Amps)

5.6

5.5
20 25 30 35 40 45 50 55 60 65 70 75 80 85 90

(VIN = 18V, transverse airfl ow)

Natural convection

100 LFM
200 LFM
300 LFM

Ambient Temperature (ºC)

Maximum Current Temperature Derating @Sea Level

(VIN = 48V, transverse airfl ow)

Natural convection

100 LFM

Ambient Temperature (ºC)

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

www.murata-ps.com email: [email protected] ISO 9001 and 14001 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. Specifi cations are subject to change without
notice. © 2008 Murata Power Solutions, Inc.

02/20/09

USA: Mansfi eld (MA), Tel: [phone], email: [email protected]

Canada: Toronto, Tel: [phone], email: [email protected]

UK: Milton Keynes, Tel: [phone], email: [email protected]

France: Montigny Le Bretonneux, Tel: [phone], email: [email protected]

Germany: München, Tel: [phone], email: [email protected]

Japan: Tokyo, Tel: [phone], email: [email protected]

Osaka, Tel: [phone], email: [email protected]

China: Shanghai, Tel: [phone], email: [email protected]

Guangzhou, Tel: [phone], email: [email protected]

Singapore: Parkway Centre, Tel: [phone], email: [email protected]

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

MDC_UEI Series 30W.A01 Page 11 of 11