ULE Series
Isolated, High Density, Eighth-Brick
1.25–30 Amp, DC/DC Converters
PERFORMANCE SPECIFICATION NOTES
1. All models are tested and specified with external 1||10 μF ceramic/tantalum 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 specified performance in your applications. All models
are stable and regulate within spec under no-load conditions. General conditions
for Specifications are +25 deg.C, VIN=nominal, VOUT=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 CIN=33 μF tantalum, CBUS=220 μF electrolytic, LBUS=12 μH.
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) SR-332 Method 1,
Case 3, ground fixed conditions, Tpcboard=+25ºC, full output 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.
9. All models are fully operational and meet published specifications, including “cold
start” at –40ºC.
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. Alternate pin length and/or other output voltages are available under special quantity
order.
12. Electronic overvoltage shutdown is not included on 48V input models to comply
with certain telecom reliability requirements. These requirements attempt continued
operation despite input overvoltage. The converter is rated only to the maximum
input voltage.
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 +VIN input. Use approximately twice the full input current rating with nominal
input voltage.
16. Output current limit is non-latching. When the overcurrent fault is removed, the
converter will immediately recover.
17. The Sense inputs are not included on 12V, 24V & 48V input models.
18. ULE-12/4.2-D24 minimum load is 0.42 Amps (10%) for rated specifications.
19. ULE-5/12-D24 IOUT=8A max. if VIN=19-20V.
6. Short circuit shutdown 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 filter. See I/O Filtering
and Noise Reduction.
20. ULE-12/4.2-D48 has no surface mount option.
21. Full load conditions, see ordering guide.
PHYSICAL CHARACTERISTICS AND SAFETY
Outline dimensions
See mechanical specs (below)
Copper alloy
Pin material
Pin diameter
Pin finish
0.04/0.062" (1.016/1.524mm)
Nickel underplate with gold overplate
1 ounce (28 grams)
Weight
Electromagnetic interference (conducted and radiated)
(external filter required)
Safety
Designed to meet FCC part 15, class B, EN55022
Designed to meet UL/cUL 60950-1, CSA-C22.2 No. 60950-1, IEC/EN 60950-1
www.murata-ps.com
Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000
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