Datasheet
Specification Notes
(1) All models are tested and specified with external 1||10 µF ceramic/tantalum output capacitors no 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. All specifications are typical unless
noted. General conditions for Specifications are +25 deg.C, Vin and 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, 100V tantalum, Cbus = 220 µF, 100V 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 altitude.
(4) Mean Time Before Failure is calculated using the Telcordia (Belcore) SR-332 Method 1, Case 3, ground fixed conditions, Tpcboard = +25 deg.C, full output load, natural air convection.
(5) The On/Off Control is normally controlled by a switch or 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.
(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.
(9) All models are fully operational and meet published specifications, including “cold start” at –40 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) Output accuracy is dependent on user-supplied trim resistors. To achieve high accuracy, use ±1% or better tolerance metal-film resistors mounted close to the converter.
(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) Input Fusing: To ensure reverse input protection with full output load, always connect an external input fast-blow fuse in series with the +Vin input. Use approximately twice the full input current rating with
nominal input voltage.
(16) “Hiccup” overcurrent 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.
(17) Normally, the Sense lines are connected at the remote load to compensate for IR voltage drops in the power wiring and to improve dynamic response. If Sense is not used, each Sense pin should be con-
nected at the converter to its respective Vout pin.
Product Adaptations
Murata Power Solutions offers several variations of our core product family.
These products are available under scheduled quantity orders and may also
include separate manufacturing documentation from a mutually agreeable
Product Specification. Since these product adaptations largely share a common
parts list and similar specifications and test methods with their root products,
they are provided at excellent costs and delivery. Please contact Murata Power
Solutions for details.
As of this date, the following products are available:
UCQ-1.2/30-D48NHL2-Y
UCQ-1.8/30-D48NHL2-Y
UCQ-1.8/40-D48NHL2-Y
UCQ-2.5/30-D48NHL2-Y
UCQ-2.5/40-D48NHL2-Y
UCQ-5/20-D48NHL2-Y
UCQ-12/8.3-D48NHL2-Y
These models are all negative On/Off logic, no baseplate, conformal coating
added, 3.68mm pin length, and RoHS-5 hazardous substance compliance (with
lead).
UCQ-3.3/30-D48NBHL2-Y
UCQ-3.3/40-D48NBHL2-Y
These models are all negative On/Off logic, baseplate installed, conformal
coating added, 3.68mm pin length, and RoHS-5 hazardous substance compli-
ance (with lead).
Absolute Maximum Ratings
Input Voltage 24V Models 48V Models
Continuous 0 to +36 Volts 0 to +75 Volts
Transient (100msec) +50 Volts +100 Volts
On/Off Control 0V min. to +13.5V max.
Input Reverse Polarity Protection See Fuse section
Output Current Current-limited. Devices can withstand
sustained short circuit without damage.
Operating Temperature –40 to +100°C (with derating)
Storage Temperature –55 to +125°C
These 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 Specifications Table is not implied, nor recommended.
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Single Output UCQ Models
Low-Profile, Quarter Brick, 8.3-40 Amp
Isolated DC-DC Converters
MDC_UCQ Models.E02 Page 10 of 24