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UEI Series
50-60W Isolated Wide-Range DC/DC Converters
MDC_UEI Series 50-60W.C10 Page 4 of 14
MISCELLANEOUS CHARACTERISTICS
Model Family
Output Current
Limit Inception
Output
Short
Circuit
Protection
Method
Output
Short
Circuit
Current
Output
Short Circuit
Duration
(output shorted
to ground)
Pre-biased
setup
Calculated
MTBF
Operating Temperature
Range
Storage
temperature
range
Thermal
protection/
shutdown
Relative
Humidity,
non-
condensing
98% of V
OUT,
after warmup
A A Hours ºC ºC ºC
UEI-3.3/15-Q12 20
Current
limiting,
hiccup
auto
restart
0.5 Continuous
Monotonic
(external
V
OUT < VSET)
3,858,079
–40 to +85ºC;
with Derating
(see Notes)
–55 to 125ºC 115
To +85ºC/
85%
UEI-3.3/18-Q48 23
2,000,000
UEI-5/10-Q12 13
UEI-5/12-Q48 15.5
UEI-12/4.2-Q12 6
UEI-12/5-Q48 6.1
UEI-15/3.3-Q12 5.3
UEI-15/4-Q48 5.8
DYNAMIC CHARACTERISTICS
Model Family
Dynamic Load
Response
(50-75-50%
load step)
Start-up Time
Switching
Frequency
V
IN to VOUT
regulated
(Max.)
Remote On/Off
to VOUT
regulated (Max.)
sec mSec mSec KHz
UEI-3.3/15-Q12
100 to 2% V
OUT
50 50
275
UEI-3.3/18-Q48
180 to 2% V
OUT 280
UEI-5/10-Q12 200 to 2% V
OUT
275UEI-5/12-Q48 100 to 2% VOUT
UEI-12/4.2-Q12 200 to 1% VOUT
UEI-12/5-Q48 400 to 1% VOUT 250
UEI-15/3.3-Q12 150 to 1% VOUT 265
UEI-15/4-Q48 150 to 1% V
OUT 255
ISOLATION CHARACTERISTICS
Model Family
Input to
Output.
Isolation
Resistance
Isolation
Capacitance
Isolation Safety
Rating
Min Min
VDC MΩ pF
UEI-3.3/15-Q12 2000 10
1000
Basic
insulation
UEI-3.3/18-Q48 2250 10
UEI-5/10-Q12 2000 10
UEI-5/12-Q48 2250 10
UEI-12/4.2-Q12 2000 10
UEI-12/5-Q48 2250 10
UEI-15/3.3-Q12 2000 10
UEI-15/4-Q48 2250 10
Specifi cation Notes:
(1) All models are tested and specifi ed with external 1||10 μF 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.
(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 overcur-
rent 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.
