–V
IN
(1)
+V
IN
(3)
OPTO
ISOLATION
PWM
CONTROLLER
REFERENCE &
ERROR AMP
INPUT UNDERVOLTAGE, INPUT
OVERVOLTAGE, AND OUTPUT
OVERVOLTAGE COMPARATORS * Can be ordered with positive (standard) or negative (optional) polarity.
REMOTE
ON/OFF
CONTROL*
(2)
+SENSE
(7)
–SENSE
(5)
+V
OUT
(8)
V
OUT
TRIM
(6)
–V
OUT
(4)
SWITCH
CONTROL
Figure 1. Simplifi ed Schematic
For applications requiring improved electrical and
thermal performance at reduced cost, consider
DATEL’s new UCQ series “quarter brick” DC/DC
power converters. These compact units measure
just 1.45" x 2.3" x 0.4" (36.8 x 60.9 x 10.2 mm)
and fi t the industry-standard footprint.
Available outputs range between 1.2V @ 30 Amps
to 15V @ 6.7 Amps and accept a wide input range.
The UCQ’s interleaved, synchronous-rectifi er
topology offers high effi ciency (up to 93%), tight
line and load regulation, low noise and fast step
response. A single-board optimized open-frame
design contributes to impressive thermal opera-
tion. UCQ’s will operate up to +70°C and 100 LFM
airfl ow with no derating.
The UCQ’s feature full isolation to 2250Vdc
meeting BASIC insulation requirements of
UL/EN/IEC 60950-1. Input fi lters reduce propa-
gated switching noise back to input sources. Also
included is a remote On/Off switch control (with
positive or negative polarity), output trim adjustable
over nominal and output sense functions to reduce
power lead losses. Extensive protection items
avoid damage from out of limit voltages, currents
and temperatures. Protection faults automatically
recover using the hiccup technique. Besides safety
testing to 60950-1, certifi cations for the UCQ in-
clude application for EMC compliance (to EN55022/
CISPR22 with fi lter), qualifi cation testing.
FEATURES

Standard quarter-brick package/pinout

Low cost; Low profi le, 0.4" (10.2mm)

24V or 48V nominal input

Outputs: 1.2V to 15V

Interleaved synchronous-rectifi er topology
• Ultra high effi ciency
• No output reverse conduction

Outstanding thermal performance

On/off control, trim & sense functions

Fully isolated, 2250Vdc (BASIC)
Output overvoltage protection

Fully I/O protected; Thermal shutdown

Designed to meet UL/EN/IEC60950-1
safety approvals
PRODUCT OVERVIEW
Typical topology may vary between units.
Typical units
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For full details go to
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Single Output UCQ Models
Low-Profi le, Quarter Brick, 8.3-40 Amp
Isolated DC/DC Converters
MDC_UCQ Models.B20 Page 1 of 24
Pin length option
Blank = standard pin length 0.180 in. (4.6 mm)
L1 = 0.110 in. (2.79 mm)*
L2 = 0.145 in. (3.68 mm)*
➀ Please refer to the part number structure for additional ordering part numbers and options.
➁ All specifi cations are at nominal line voltage and full load, +25 deg.C unless otherwise noted. See detailed specifi cations. Output capacitors are 1 μF ceramic || 10 μF electrolytic. I/O caps are necessary for
our test equipment and may not be needed for your application.
Outline dimensions: 2.3 × 1.45 × 0.40 inches
58.4 × 36.8 × 10.2 mm
Pinout: P32 (all models)
PERFORMANCE SPECIFICATIONS SUMMARY AND ORDERING GUIDE ➀
Root Models ➀
Output Input
Effi ciency
VOUT
(Volts)
IOUT
(Amps)
Power
(Watts)
R/N (mVp-p) Regulation (Max.) ➁
VIN Nom.
(Volts)
Range
(Volts)
IIN no
load (mA)
IIN full
load
(Amps)Typ. Max. Line Load Min. Typ.
UCQ-1.2/40-D24P-C 1.2 40 48 Please contact Murata Power Solutions for further information.
UCQ-1.2/30-D48N-C 1.2 30 36 50 100 ±0.125% ±0.25% 48 36-75 30 0.90 81% 83%
UCQ-1.5/25-D48N-C 1.5 25 37.5 50 80 ±0.125% ±0.25% 48 36-75 50 0.94 81% 83%
UCQ-1.5/40-D48N-C 1.5 40 60 50 100 ±0.125% ±0.25% 48 36-75 50 1.45 85% 86%
UCQ-1.8/30-D48N-C 1.8 30 54 80 100 ±0.125% ±0.25% 48 36-75 45 1.31 83% 86%
UCQ-1.8/40-D48N-C 1.8 40 72 50 100 ±0.1% ±0.2% 48 36-75 30 1.70 86% 88%
UCQ-2.5/40-D24P-C 2.5 40 100 80 120 ±0.125% ±0.25% 24 18-36 120 4.96 82% 84%
UCQ-2.5/30-D48N-C 2.5 30 75 50 100 ±0.125% ±0.25% 48 36-75 50 1.80 85% 87%
UCQ-3.3/35-D24P-C 3.3 35 115.5 80 120 ±0.25% ±0.25% 24 18-36 130 5.41 87% 89%
UCQ-3.3/20-D48N-C 3.3 20 66 50 80 ±0.125% ±0.25% 48 36-75 50 1.53 88.5% 90%
UCQ-3.3/30-D48N-C 3.3 30 99 50 80 ±0.125% ±0.25% 48 36-75 50 2.3 89.5% 91%
UCQ-3.3/40-D48N-C 3.3 40 132 60 100 ±0.1% ±0.2% 48 36-75 30 3.06 89% 90%
UCQ-5/20-D24P-C 5 20 100 50 60 ±0.125% ±0.25% 24 18-36 160 4.55 88% 91.5%
UCQ-5/20-D48N-C 5 20 100 35 55 ±0.125% ±0.25% 48 36-75 80 2.26 89% 92%
UCQ-5/25-D48N-C 5 25 125 50 100 ±0.125% ±0.25% 48 36-75 30 2.89 88% 90%
UCQ-12/8.3-D48N-C 12 8.3 99.6 100 150 ±0.125% ±0.25% 48 36-75 80 2.28 90% 91%
UCQ-15/6.7-D48N-C 15 6.7 100.5 100 150 ±0.125% ±0.25% 48 36-75 100 2.28 90% 92%
Nominal Output Voltage
3.3
CQ 30-/D48
Input Voltage Range:
D24 = 18-36 Volts (24V nominal)
D48 = 36-75 Volts (48V nominal)
Maximum Rated Output :
Current in Amps
Output
Confi guration:
Unipolar,
single output
-N
U
Quarter-Brick Package
B
Conformal coating (optional)
Blank = no coating, standard
H = coating added, optional special order
-
RoHS Hazardous Materials compliance
C = RoHS-6, standard (does not claim EU RoHS exemption 7B–lead in solder)
Y = RoHS-5 (with lead), optional, special order
C
PART NUMBER STRUCTURE
H
On/Off Control Polarity
P = Positive polarity (standard for D24, optional for D48)
N = Negative polarity (standard for D48, optional for D24)
Baseplate (optional)
Blank = No baseplate, standard
B = Baseplate installed, optional special order
Lx
Note:
Some model number combinations
may not be available. Please contact
Murata Power Solutions.
*Special quantity order is required;
no sample quantities available.
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Single Output UCQ Models
Low-Profi le, Quarter Brick, 8.3-40 Amp
Isolated DC/DC Converters
MDC_UCQ Models.B20 Page 2 of 24
UCQ-1.2/30-D48 UCQ-1.5/25-D48 UCQ-1.5/40-D48 UCQ-1.8/30-D48 UCQ-1.8/40-D48
Input
Input voltage range See ordering guide.
Start-up threshold, Volts 34 34 34 34 34
Undervoltage
shutdown, V 33 32 32.5 32.5 32
Overvoltage shutdown none
Refl ected (back) ripple
current, mA pk-pk 10-30, model dependent
Input Current
Full load conditions See ordering guide.
Inrush transient, A2sec 0.05
Output short circuit, mA 50-200, model dependent
Low line (VIN = min.),
Amps 1.23 1.26 1.96 1.74 2.30
Standby mode, mA
(Off, UV, OT shutdown) 1-10, model dependent
Internal input fi lter type Pi-type L-C Pi-type Pi-type Pi-type
Reverse polarity
protection None, install external fuse.
Remote On/Off Control
Positive logic
(P model suffi x)
OFF = Ground pin to +0.8V
ON = Open or +3.5 to +13.5V max
Negative logic
(N model suffi x)
OFF = Open or +3.5 to +13.5V
ON = Ground pin to +0.8V max
Current, mA 1
Output
Voltage output range See ordering guide.
Voltage output accuracy ±1% of VNOM., (50% load)
Adjustment range,
% of VNOM.±10% −20 + 10 ±10% ±10% ±10%
Temperature coeffi cient ±0.02% of VOUT range per °C
Minimum loading No minimum loading.
Remote sense
compensation +10%
Ripple/noise
(20 MHz bandwidth) See ordering guide.
Line/Load regulation See ordering guide.
Effi ciency See ordering guide.
Maximum capacitive
loading, μF low ESR
<0.02Ω max.,
resistive load
1,000 10,000 10,000 4,700 10,000
FUNCTIONAL SPECIFICATIONS
➀ Specs are typical unless noted.
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Single Output UCQ Models
Low-Profi le, Quarter Brick, 8.3-40 Amp
Isolated DC/DC Converters
MDC_UCQ Models.B20 Page 3 of 24
➀ Specs are typical unless noted.
FUNCTIONAL SPECIFICATIONS
UCQ-2.5/40-D24 UCQ-2.5/30-D48 UCQ-3.3/35-D24 UCQ-3.3/20-D48 UCQ-3.3/30-D48
Input
Input voltage range See ordering guide.
Start-up threshold, Volts 16.8 34 17 35 35
Undervoltage
shutdown, V 15 32 15 34 34
Overvoltage shutdown none
Refl ected (back) ripple
current, mA pk-pk 10-30, model dependent
Input Current
Full load conditions See ordering guide.
Inrush transient, A2sec 0.05
Output short circuit, mA 50-200, model dependent
Low line (VIN = min.),
Amps 6.69 2.39 7.21 2.04 3.02
Standby mode, mA
(Off, UV, OT shutdown) 1-10, model dependent
Internal input fi lter type Pi L-C L-C Pi Pi
Reverse polarity
protection None, install external fuse.
Remote On/Off Control
Positive logic
(P model suffi x)
OFF = Ground pin to +0.8V
ON = Open or +3.5 to +13.5V max
Negative logic
(N model suffi x)
OFF = Open or +3.5 to +13.5V
ON = Ground pin to +0.8V max
Current, mA 1
Output
Voltage output range See ordering guide.
Voltage output accuracy ±1% of VNOM., (50% load)
Adjustment range,
% of VNOM.−20 + 10 −20 + 10 ±10% −10 to + 10%
Temperature coeffi cient ±0.02% of VOUT range per °C
Minimum loading No minimum loading.
Remote sense
compensation +10%
Ripple/noise
(20 MHz bandwidth) See ordering guide.
Line/Load regulation See ordering guide.
Effi ciency See ordering guide.
Maximum capacitive
loading, μF low ESR
<0.02Ω max.,
resistive load
10,000 10,000 10,000 10,000 10,000
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Single Output UCQ Models
Low-Profi le, Quarter Brick, 8.3-40 Amp
Isolated DC/DC Converters
MDC_UCQ Models.B20 Page 4 of 24
UCQ-3.3/40-D48 UCQ-5/20-D24 UCQ-5/20-D48 UCQ-5/25-D48 UCQ-12/8.3-D48 UCQ-15/6.7-D48N-C
Input
Input voltage range See ordering guide
Start-up threshold, Volts 33 17 35 35 35 34
Undervoltage
shutdown, V 31.5 16 34 34 34 31.5
Overvoltage shutdown none
Refl ected (back) ripple
current, mA pk-pk 10-30, model dependent. 60 max.
Input Current
Full load conditions See ordering guide.
Inrush transient, A2sec 0.1 0.05 0.03
Output short circuit, mA 1200 50-200, model dependent 120
Low line (VIN = min.),
Amps 4.12 6.04 3.02 3.82 3.04 3.03
Standby mode, mA
(Off, UV, OT shutdown) 1-10, model dependent
Internal input fi lter type Pi L-C L-C L-C L-C Pi
Reverse polarity
protection None, install external fuse.
Remote On/Off Control
Positive logic
(P model suffi x)
OFF = Ground pin to +0.8V
ON = Open or +3.5 to +13.5V max
OFF = Ground pin or to +1V.
ON = Open or +2.5 to +13.5V
Negative logic
(N model suffi x)
OFF = Open or +3.5 to +13.5V
ON = Ground pin to +0.8V max
OFF = Open or +2.5 to +13.5V
ON = Ground pin or to +1V.
Current, mA 1
Output
Voltage output range See ordering guide.
Voltage output accuracy ±1% of VNOM., (50% load)
Adjustment range,
% of VNOM.−10 to + 10%
Temperature coeffi cient ±0.02% of VOUT range per °C.
Minimum loading No minimum loading.
Remote sense
compensation +10%
Ripple/noise
(20 MHz bandwidth) See ordering guide.
Line/Load regulation See ordering guide.
Effi ciency See ordering guide.
Maximum capacitive
loading, μF low ESR
<0.02Ω max.,
resistive load
10,000 10,000 10,000 10,000 1,000 1000
➀ Specs are typical unless noted.
FUNCTIONAL SPECIFICATIONS
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Single Output UCQ Models
Low-Profi le, Quarter Brick, 8.3-40 Amp
Isolated DC/DC Converters
MDC_UCQ Models.B20 Page 5 of 24
UCQ-1.2/30-D48 UCQ-1.5/25-D48 UCQ-1.5/40-D48 UCQ-1.8/30-D48 UCQ-1.8/40-D48
Isolation Voltage
Input to Output,
Volts min. 2250
Input to baseplate,
Volts min. 1500
Baseplate to output,
Volts min. 1500
Isolation resistance, MΩ 10-100, model dependent
Isolation capacitance, pF 1000
Isolation safety rating Basic insulation
Miscellaneous
Current limit inception
(98% of VOUT, after
warmup), Amps
35 35 49 35 49
Short circuit protection
method Current limiting, hiccup autorestart. Remove overload for recovery.
Short circuit current,
Amps 5
Short circuit duration Continuous, output shorted to ground. No damage.
Overvoltage protection,
Volts (via magnetic
feedback)
1.8 1.8 1.95 2.7 V max 2.2
Dynamic characteristics
Dynamic load response
(50-75-50% load step)
200 μSec to ±1%
of fi nal value
200 μSec to ±1%
of fi nal value
50 μSec to ±1% of
fi nal value
100 μSec to ±1%
of fi nal value
50 μSec to ±1% of
fi nal value
Start-up time
VIN to VOUT regulated,
mSec 10 max.
Remote On/Off to VOUT
regulated, mSec 10 max.
Switching frequency, KHz 350 ± 20 440 ± 40 400 ± 40 400 380 ±40
Environmental
Calculated MTBF 2M hours 2.1M hours 2.2M hours 2M hours 2.1M hours
Operating temperature
range, °C
See Derating curves.
−40 to +85, with derating
Operating case
temperature, °C
(no derating)
−40 to +120, model dependent
Storage temperature
range, °C −55 to +125
Thermal protection/
shutdown, °C 110-125, model dependent
Relative humidity To +85°C/85%, non-condensing
FUNCTIONAL SPECIFICATIONS
➀ Specs are typical unless noted.
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Single Output UCQ Models
Low-Profi le, Quarter Brick, 8.3-40 Amp
Isolated DC/DC Converters
MDC_UCQ Models.B20 Page 6 of 24
UCQ-2.5/40-D24 UCQ-2.5/30-D48 UCQ-3.3/35-D24 UCQ-3.3/20-D48 UCQ-3.3/30-D48
Isolation Voltage
Input to Output,
Volts min. 2250
Input to baseplate,
Volts min. 1500
Baseplate to output,
Volts min. 1500
Isolation resistance, MΩ 10-100, model dependent
Isolation capacitance, pF 1000
Isolation safety rating Basic insulation
Miscellaneous
Current limit inception
(98% of VOUT, after
warmup), Amps
46 37 41 24 35
Short circuit protection
method Current limiting, hiccup autorestart. Remove overload for recovery.
Short circuit current,
Amps 5125
Short circuit duration Continuous, output shorted to ground. No damage.
Overvoltage protection,
Volts (via magnetic
feedback)
2.95 2.95 4 4.6 4
Dynamic characteristics
Dynamic load response
(50-75-50% load step)
200 μSec to ±1%
of fi nal value
200 μSec to ±1%
of fi nal value
200 μSec to ±1%
of fi nal value
200 μSec to ±1.5%
of fi nal value
200 μSec to ±1%
of fi nal value
Start-up time
VIN to VOUT regulated,
mSec 10 max.
Remote On/Off to VOUT
regulated, mSec 10 max.
Switching frequency, KHz 480 480 ± 30 350 ± 10 330 ± 40 330 ± 40
Environmental
Calculated MTBF 2.1M hours 2.2M hours 1.7M hours 1.8M hours 1.7M hours
Operating temperature
range, °C
See Derating curves.
−40 to +85, with derating
Operating case
temperature, °C
(no derating)
−40 to +120, model dependent
Storage temperature
range, °C −55 to +125
Thermal protection/
shutdown, °C 110-125, model dependent
Relative humidity To +85°C/85%, non-condensing
FUNCTIONAL SPECIFICATIONS
➀ Specs are typical unless noted.
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Single Output UCQ Models
Low-Profi le, Quarter Brick, 8.3-40 Amp
Isolated DC/DC Converters
MDC_UCQ Models.B20 Page 7 of 24
UCQ-3.3/40-D48 UCQ-5/20-D24 UCQ-5/20-D48 UCQ-5/25-D48 UCQ-12/8.3-D48 UCQ-15/6.7-D48N-C
Isolation Voltage
Input to Output,
Volts min. 2250
Input to baseplate,
Volts min. 1500
Baseplate to output,
Volts min. 1500
Isolation resistance, MΩ 10-100, model dependent
Isolation capacitance, pF 1000
Isolation safety rating Basic insulation
Miscellaneous
Current limit inception
(98% of VOUT, after
warmup), Amps
49 26 22 27 10 9
Short circuit protection
method Current limiting, hiccup autorestart. Remove overload for recovery.
Short circuit current,
Amps 15 5 5 5 TBD 2
Short circuit duration Continuous, output shorted to ground. No damage.
Overvoltage protection,
Volts (via magnetic
feedback)
4.25 6.25 TBD 6.2 14.4 18
Dynamic characteristics
Dynamic load response
(50-75-50% load step)
50 μSec to ±1% of
fi nal value
200 μSec to ±1%
of fi nal value
200 μSec to ±1%
of fi nal value
200 μSec to ±1%
of fi nal value
200 μSec to ±1%
of fi nal value 150 μSec to ±2% of fi nal value
Start-up time
VIN to VOUT regulated,
mSec 5 4 10 max. 10 max. 10 max. 10 max.
Remote On/Off to VOUT
regulated, mSec 5 4 10 max. 10 max. 10 max. 10 max.
Switching frequency, KHz 360 ± 20 400 ± 24 315 ± 30 315 ± 30 330 ± 40 300 ± 30 KHz
Environmental
Calculated MTBF 2.2M hours 2.2M hours TBD 1.7M hours 1.8M hours TBD
Operating temperature
range, °C.
See Derating curves.
−40 to +85, with derating
Operating case
temperature, °C
(no derating)
−40 to +120, model dependent −40 to +110
Storage temperature
range, °C −55 to +125
Thermal protection/
shutdown, °C 110-125, model dependent
Relative humidity To +85°C/85%, non-condensing
FUNCTIONAL SPECIFICATIONS
➀ Specs are typical unless noted.
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Single Output UCQ Models
Low-Profi le, Quarter Brick, 8.3-40 Amp
Isolated DC/DC Converters
MDC_UCQ Models.B20 Page 8 of 24
UCQ-1.2/30-D48 UCQ-1.5/25-D48 UCQ-1.5/40-D48 UCQ-1.8/30-D48 UCQ-1.8/40-D48
Physical
Outline dimensions See mechanical specs.
Pin material Copper alloy
Pin diameter 0.040/0.062 inches (1.016/1.575 mm)
Pin fi nish Nickel underplate with gold overplate
Weight, ounces 0.9 1.06 0.9 0.9 1.23
Weight, grams 25 30 25 25 35
Electromagnetic
interference Designed to meet EN55022/CISPR22 (External fi lter required)
Safety Designed to meet UL 60950-1, CSA C22.2 No.60950-1, IEC/EN 60950-1
UCQ-3.3/40-D48 UCQ-5/20-D24 UCQ-5/20-D48 UCQ-5/25-D48 UCQ-12/8.3-D48 UCQ-15/6.7-D48N-C
Physical
Outline dimensions See mechanical specs.
Pin material Copper alloy
Pin diameter 0.040/0.062 inches (1.016/1.575 mm)
Pin fi nish Nickel underplate with gold overplate
Weight, ounces 1.25 1.06 1.06 1.06 1.13 1.034
Weight, grams 35.5 30 30 30 32 29.3
Electromagnetic
interference Designed to meet EN55022/CISPR22 (External fi lter required)
Safety Designed to meet UL 60950-1, CSA C22.2 No.60950-1, IEC/EN 60950-1
UCQ-2.5/40-D24 UCQ-2.5/30-D48 UCQ-3.3/35-D24 UCQ-3.3/20-D48 UCQ-3.3/30-D48
Physical
Outline dimensions See mechanical specs.
Pin material Copper alloy
Pin diameter 0.040/0.062 inches (1.016/1.575 mm)
Pin fi nish Nickel underplate with gold overplate
Weight, ounces 1.06 1.06 1.06 0.7 1.06
Weight, grams 30 30 30 20 30
Electromagnetic
interference Designed to meet EN55022/CISPR22 (External fi lter required)
Safety Designed to meet UL 60950-1, CSA C22.2 No.60950-1, IEC/EN 60950-1
FUNCTIONAL SPECIFICATIONS
➀ Specs are typical unless noted.
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Single Output UCQ Models
Low-Profi le, Quarter Brick, 8.3-40 Amp
Isolated DC/DC Converters
MDC_UCQ Models.B20 Page 9 of 24
Specifi cation Notes
(1) All models are tested and specifi ed 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 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 and VOUT = nominal, full load. Adequate airfl ow must be supplied for extended testing under power.
(2) Input Ripple Current is tested and specifi ed over a 5 Hz to 20 MHz bandwidth. Input fi ltering 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 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 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 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 fi lter. See I/O Filtering and Noise Reduction.
(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) Output accuracy is dependent on user-supplied trim resistors. To achieve high accuracy, use ±1% or better tolerance metal-fi lm 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 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) 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 Specifi cation. Since these product adaptations largely share a common
parts list and similar specifi cations 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 polarity, no baseplate, conformal coat-
ing 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 polarity, 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 Specifi cations Table is not implied, nor recommended.
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Single Output UCQ Models
Low-Profi le, Quarter Brick, 8.3-40 Amp
Isolated DC/DC Converters
MDC_UCQ Models.B20 Page 10 of 24
TYPICAL PERFORMANCE CURVES
4 6 8 10 14 16 18 2012 24 26 28 3022
72
74
70
78
76
82
80
84
88
86
90
VIN = 48V
VIN = 75V
Efficiency (%)
Load Current (Amps)
VIN = 36V
UCQ-1.8/30-D48 Efficiency vs Line Voltage and Load Current @25˚ C
VIN = 48V
VIN = 75V
Efficiency (%)
Load Current (Amps)
VIN = 36V
40
50
55
65
75
60
70
85
80
90
45
63 9 12 15 18 21 24 27 75 30
95
UCQ-1.2/30-D48 Efficiency vs Line Voltage and Load Current @25˚ C
Efficiency (%)
Load Current (Amps)
3114567 910 12813 2114 15 16 17 19 20 22 2423 2518
60
62
64
66
68
70
72
74
76
78
80
82
84
86
88
90
UCQ-1.5/25-D48 Efficiency vs Line Voltage and Load Current @25˚ C
VIN = 48V
VIN = 75V
VIN = 36V
Output Current (Amps)
Ambient Temperature (°C)
400 LFM
200 LFM
300 LFM
100 LFM
30
0
10
15
25
35
20
30
5
35 40 45 50 55 60 65 70 75 80
UCQ-1.2/30-D48 Maximum Current Temperature Derating
No baseplate, VIN = 48V (at sea level), longitudinal airflow
Output Current (Amps)
Ambient Temperature (°C)
400 LFM
200 LFM
300 LFM
100 LFM
30
0
10
15
25
20
30
5
35 40 45 50 55 60 65 70 75 80
UCQ-1.5/25-D48 Maximum Current Temperature Derating
No baseplate, VIN = 48V (at sea level), longitudinal airflow
Output Current (Amps)
Ambient Temperature (°C)
400 LFM
200 LFM
300 LFM
100 LFM
Natural convection
30
22
24
18
20
28
26
32
30
35 40 45 50 55 60 65 70 75 8
0
UCQ-1.8/30-D48 Maximum Current Temperature Derating
No baseplate, VIN = 48V (at sea level), longitudinal airflow
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Single Output UCQ Models
Low-Profi le, Quarter Brick, 8.3-40 Amp
Isolated DC/DC Converters
MDC_UCQ Models.B20 Page 11 of 24
TYPICAL PERFORMANCE CURVES
4 8 12 16 20 24 28 32 36 40
0
2
4
6
8
10
12
14
16
18
20
22
40
45
50
55
60
65
70
75
80
85
90
95
UCQ-1.8/40-D48 Efficiency and Power Dissipation @25˚ C
Load Current (Amps)
Efficiency (%)
Power Dissipation (watts)
V
IN
= 36V
V
IN
= 75V
V
IN
= 48V
Power Dissipation
V
IN
= 48V
30 35 40 45 50 55 60 65 70 75 80 85
0
5
10
15
20
25
30
35
40
45
UCQ-1.8/40-D48 Maximum Current Temperature Derating at Sea Level
(VIN = 48V, no baseplate, airflow is from Vin to Vout)
Output Current (Amps)
Ambient Temperature (°C)
400 LFM
200 LFM
300 LFM
100 LFM
Natural Convection
V
IN
= 48V
V
IN
= 75V
V
IN
= 36V
UCQ-2.5/30-D48 Efficiency vs Line Voltage and Load Current @25˚ C
Efficiency (%)
40
50
55
65
75
60
70
85
80
90
45
95
Load Current (Amps)
631 9 12 15 18 21 24 27 30
369
70
75
85
95
80
90
65
60
55
50
12 15 18 21 24 27 30 33 36 39 40
V
IN
= 24V
V
IN
= 35V
Efficiency (%)
Load Current (Amps)
V
IN
= 18V
UCQ-2.5/40-D24 Efficiency vs Line Voltage and Load Current @25˚ C
Output Current (Amps)
Ambient Temperature (°C)
400 LFM
200 LFM
300 LFM
100 LFM
0
10
15
25
35
20
30
5
3530 40 45 50 55 60 65 70 75 80
UCQ-2.5/30-D48 Maximum Current Temperature Derating
No baseplate, V
IN
= 24V (at sea level)
Output Current (Amps)
Ambient Temperature (°C)
400 LFM
200 LFM
300 LFM
100 LFM
30
0
10
15
25
35
20
30
5
35 40 45 50 55 60 65 70 75 80
UCQ-2.5/40-D24 Maximum Current Temperature Derating
No baseplate, VIN = 24V (at sea level)
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Single Output UCQ Models
Low-Profi le, Quarter Brick, 8.3-40 Amp
Isolated DC/DC Converters
MDC_UCQ Models.B20 Page 12 of 24
TYPICAL PERFORMANCE CURVES
10
12
14
16
18
20
30 35 40 45 50 55 60 65 70 75 80 85
UCQ-3.3/20-D48 Maximum Current Temperature Derating at Sea Level
(VIN = 48V, longitudinal airflow, no baseplate)
Output Current (Amps)
Ambient Temperature (°C)
400 LFM
200 LFM
300 LFM
100 LFM
30 35 40 45 50 55 60 65 70 75 80 85
16
18
20
22
24
26
28
30
UCQ-3.3/30-D48 Maximum Current Temperature Derating at Sea Level
(VIN = 48V, no baseplate, airflow is from Vin to Vout)
Ambient Temperature (°C)
Output Current (Amps)
400 LFM
200 LFM
300 LFM
100 LFM
65
70
75
80
85
90
95
2 5 8 11141720
0
3
6
9
12
15
18
UCQ-3.3/20-D48 Efficiency vs Line Voltage and Load Current @25°C
Load Current (Amps)
Efficiency (%)
Power Dissipation (watts)
V
IN
= 75V
V
IN
= 36V
V
IN
= 48V
Power Dissipation
V
IN
= 48V
3 6 9 12151821242730
0
3
6
9
12
15
70
75
80
85
90
95
Load Current (Amps)
UCQ-3.3/30-D48 Efficiency vs Line Voltage and Load Current @25°C
Efficiency (%)
V
IN
= 75V
V
IN
= 36V
V
IN
= 48V
Power Dissipation (watts)
Power Dissipation
V
IN
= 48V
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Single Output UCQ Models
Low-Profi le, Quarter Brick, 8.3-40 Amp
Isolated DC/DC Converters
MDC_UCQ Models.B20 Page 13 of 24
TYPICAL PERFORMANCE CURVES
30 35 40 45 50 55 60 65 70 75 80 85
0
5
10
15
20
25
30
35
40
UCQ-3.3/35-D24 Maximum Current Temperature Derating at Sea Level
(VIN = 24V, with baseplate, airflow is from -Vin to +Vin)
Output Current (Amps)
Ambient Temperature (°C)
400 LFM
200 LFM
300 LFM
100 LFM
Natural Convection
Efficiency (%)
Load Current (Amps)
70
74
76
80
84
78
82
88
86
90
72
92
UCQ-3.3/35-D24 Efficiency vs Line Voltage and Load Current @25˚ C
V
IN
= 18V
V
IN
= 24V
V
IN
= 36V
537911171915 21 23 25 27 29 353331
30 35 40 45 50 55 60 65 70 75 80 85
0
5
10
15
20
25
30
35
40
UCQ-3.3/35-D24 Maximum Current Temperature Derating at Sea Level
(VIN = 24V, no baseplate, airflow is from -Vin to +Vin)
Output Current (Amps)
Ambient Temperature (°C)
400 LFM
200 LFM
300 LFM
100 LFM
Natural Convection
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Single Output UCQ Models
Low-Profi le, Quarter Brick, 8.3-40 Amp
Isolated DC/DC Converters
MDC_UCQ Models.B20 Page 14 of 24
TYPICAL PERFORMANCE CURVES
30 35 40 45 50 55 60 65 70 75 80 85
0
10
20
30
40
50
UCQ-3.3/40-D48 Maximum Current Temperature Derating at Sea Level
(VIN = 48V, with baseplate, transverse airflow)
400 LFM
200 LFM
300 LFM
100 LFM
Natural Convection
Output Current (Amps)
Ambient Temperature (°C)
4 8 12 16 20 24 28 32 36 40
0
2
4
6
8
10
12
14
16
18
20
22
40
45
50
55
60
65
70
75
80
85
90
95
UCQ-3.3/40-D48 Efficiency and Power Dissipation @25˚ C
Load Current (Amps)
Efficiency (%)
Power Dissipation (watts)
V
IN
= 36V
V
IN
= 75V
V
IN
= 48V
Power Dissipation
V
IN
= 48V
30 35 40 45 50 55 60 65 70 75 80 85
0
10
20
30
40
50
UCQ-3.3/40-D48 Maximum Current Temperature Derating at Sea Level
(VIN = 48V, no baseplate, transverse airflow)
400 LFM
200 LFM
300 LFM
100 LFM
Natural Convection
Output Current (Amps)
Ambient Temperature (°C)
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Single Output UCQ Models
Low-Profi le, Quarter Brick, 8.3-40 Amp
Isolated DC/DC Converters
MDC_UCQ Models.B20 Page 15 of 24
TYPICAL PERFORMANCE CURVES
0
2
4
6
8
10
12
14
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
60
64
68
72
76
80
84
88
92
96
UCQ-5/20-D24 Efficiency and Power Dissipation @25°C
Load Current (Amps)
Efficiency (%)
Power Dissipation (watts)
V
IN
= 36V
V
IN
= 18V
V
IN
= 24V
Power Dissipation
V
IN
= 24V
30 35 40 45 50 55 60 65 70 75 80 85
0
2
4
6
8
10
12
14
16
18
20
22
UCQ-5/20-D24 Maximum Current Temperature Derating at Sea Level
(VIN = 24V, no baseplate, airflow is from -Vin to +Vin)
Output Current (Amps)
Ambient Temperature (°C)
400 LFM
200 LFM
300 LFM
100 LFM
30 35 40 45 50 55 60 65 70 75 80 85
0
5
10
15
20
25
UCQ-5/20-D24 Maximum Current Temperature Derating at Sea Level
(VIN = 24V, with baseplate, airflow is from -Vin to +Vin)
Output Current (Amps)
Ambient Temperature (°C)
400 LFM
200 LFM
300 LFM
100 LFM
95
90
85
80
75
70
UCQ-5/20-D48
Efficiency vs Line Voltage and Load Current @25°C
4 6 8 10 12 14 16 18 20
Load Current (Amps)
Efficiency (%)
V
IN
= 75V
V
IN
= 36V
V
IN
= 50V
30 35 40 45 50 55 60 65 70 75 80 85
0
2
4
6
8
10
12
14
16
18
20
22
UCQ-5/20-D48 Maximum Current Temperature Derating at Sea Level
(VIN = 48V, no baseplate, airflow is from -Vin to +Vin)
Output Current (Amps)
Ambient Temperature (°C)
400 LFM
200 LFM
300 LFM
100 LFM
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Single Output UCQ Models
Low-Profi le, Quarter Brick, 8.3-40 Amp
Isolated DC/DC Converters
MDC_UCQ Models.B20 Page 16 of 24
TYPICAL PERFORMANCE CURVES
50
55
60
65
70
75
80
85
90
95
0
2
4
6
8
10
12
14
16
18
3 5 7 9 11 13 15 17 19 21 23 25
UCQ-5/25-D48 Efficiency and Power Dissipation @25˚ C
Load Current (Amps)
Efficiency (%)
Power Dissipation (watts)
V
IN
= 36V
V
IN
= 75V
V
IN
= 48V
Power Dissipation
V
IN
= 48V
30 35 40 45 50 55 60 65 70 75 80 85
0
5
10
15
20
25
30
UCQ-5/25-D48 Maximum Current Temperature Derating at Sea Level
(V
IN
= 48V, no baseplate, airflow is from Vin to Vout)
400 LFM
200 LFM
300 LFM
100 LFM
Output Current (Amps)
Ambient Temperature (°C)
50
55
60
65
70
75
80
85
90
95
100
0.8 1.6 2.4 3.2 4 4.8 5.6 6.4 7.2 8.3
0
2
4
6
8
10
12
14
16
18
20
UCQ-12/8.3-D48 Efficiency and Power Dissipation @25˚ C
Load Current (Amps)
Efficiency (%)
Power Dissipation (watts)
V
IN
= 36V
V
IN
= 75V
V
IN
= 48V
Power Dissipation
V
IN
= 48V
30 35 40 45 50 55 60 65 70 75 80 85
0
1
2
3
4
5
6
7
8
9
UCQ-12/8.3-D48 Maximum Current Temperature Derating at Sea Level
(VIN = 48V, no baseplate, airflow is from Vin to Vout)
400 LFM
200 LFM
300 LFM
100 LFM
Output Current (Amps)
Ambient Temperature (°C)
4
5
6
7
8
9
10
30 35 40 45 50 55 60 65 70 75 80 85
UCQ-12/8.3-D48 Maximum Current Temperature Derating at Sea Level
(V
IN
= 48V, with baseplate, longitudinal airflow)
400 LFM
200 LFM
300 LFM
100 LFM
Output Current (Amps)
Ambient Temperature (°C)
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MDC_UCQ Models.B20 Page 17 of 24
TYPICAL PERFORMANCE CURVES
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
1.2 1.7 2.2 2.7 3.2 3.7 4.2 4.7 5.2 5.7 6.2 6.7
50
55
60
65
70
75
80
85
90
95
100
UCQ-15/6.7-D48 Efficiency and Power Dissipation @Ta = 25˚ C
Load Current (Amps)
Efficiency (%)
Loss (watts)
V
IN
= 36V
V
IN
= 75V
V
IN
= 48V
Power Dissipation
V
IN
= 48V
30 35 40 45 50 55 60 65 70 75 80 85
3.5
4.5
5.5
6.5
UCQ-15/6.7-D48 Maximum Current Temperature Derating at Sea Level
(V
IN
= 48V, no baseplate, airflow is from Vin to Vout)
400 LFM
200 LFM
300 LFM
100 LFM
Output Current (Amps)
Ambient Temperature (°C)
30 35 40 45 50 55 60 65 70 75 80 85
3.5
4.5
5.5
6.5
UCQ-15/6.7-D48 Maximum Current Temperature Derating at Sea Level
(V
IN
= 48V, with baseplate, airflow is from Vin to Vout)
100 LFM
Output Current (Amps)
Ambient Temperature (°C)
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TYPICAL PERFORMANCE CURVES
5#1$/UTPUT4RANSIENT2ESPONSE
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6).6)/54!RESISTIVEOUTPUTCAPS§&CERAMIC\\§&TANTALUM
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5#1$/UTPUT4RANSIENT2ESPONSE
6).6RESISTIVELOADSTEPTO
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Single Output UCQ Models
Low-Profi le, Quarter Brick, 8.3-40 Amp
Isolated DC/DC Converters
MDC_UCQ Models.B20 Page 19 of 24
0.300
(7.6)
1.45 (36.8)
0.600 (15.24)
4 EQ. SP.
0.600
(15.2)
2.00 (50.8) A
B
B
B
A
2.30 (58.4)
0.015 minimum
clearance between
standoffs and
highest component
0.40
(10.2)
0.18
(4.6)
BOTTOM VIEW
PINS 1-3, 5-7:
0.040Ø ±0.002 (1.016 ±0.05)
PINS 4, 8:
0.062Ø ±0.002 (1.575 ±0.05)
1
2
3 8
7
6
5
4
Case C67
UCQ with Optional Baseplate
DOSA-Compatible I/O Connections
Pin Function P32 Pin Function P32
1 −Input* 5 −Sense
2 Remote On/Off 6 Output Trim
3 +Input* 7 +Sense
4 −Output 8 +Output
MECHANICAL SPECIFICATIONS
Component locations may vary between units.
Standard pin length is shown. Please refer to the Part
Number Structure for special order pin lengths.
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˚
1.03 (26.2)
A
B
1.45 (36.8) B
A
2.30 (58.4)
1.860 (47.2)
#M3 THD. X 0.15 DEEP
TYPICAL 4 PL.
SCREW LENGTH MUST
NOT GO THROUGH BASEPLATE
0.50
(12.7)
0.18
(4.6)
PINS 1-3, 5-7:
0.040Ø ±0.002 (1.016 ±0.05)
PINS 4, 8:
0.062Ø ±0.002 (1.575 ±0.05)
* These converters are pin-for-pin/plug-compatible to competitive
units. Other units may use different pin numbering or alternate
outline views. When laying out your PC board, follow the pin
FUNCTION. DOSA designates Pin 1 as +Input and Pin 3 as -Input.
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I/O Filtering, Input Ripple Current, and Output Noise
All models in the UCQ Series are tested/specifi ed for input refl ected ripple
current and output noise using the specifi ed external input/output components/
circuits and layout as shown in the following two fi gures. External input capaci-
tors (CIN in Figure 2) serve primarily as energy-storage elements, minimiz-
ing line voltage variations caused by transient IR drops in conductors from
backplane to the DC/DC. Input caps should be selected for bulk capacitance
(at appropriate frequencies), low ESR, and high rms-ripple-current ratings. The
switching nature of DC/DC converters requires that dc voltage sources have
low ac impedance as highly inductive source impedance can affect system sta-
bility. In Figure 2, CBUS and LBUS simulate a typical dc voltage bus. Your specifi c
system confi guration may necessitate additional considerations.
In critical applications, output ripple/noise (also referred to as periodic and
random deviations or PARD) may be reduced below specifi ed limits using fi lter-
ing techniques, the simplest of which is the installation of additional external
output capacitors. They function as true fi lter elements and should be selected
for bulk capacitance, low ESR and appropriate frequency response.
All external capacitors should have appropriate voltage ratings and be
located as close to the converter as possible. Temperature variations for all
relevant parameters should also be taken carefully into consideration. The most
effective combination of external I/O capacitors will be a function of line voltage
and source impedance, as well as particular load and layout conditions.
Input Fusing
Certain applications and/or safety agencies may require the installation of
fuses at the inputs of power conversion components. Fuses should also be
used if the possibility of sustained, non-current-limited, input-voltage polarity
reversals exists. For DATEL UCQ series DC/DC converters, we recommend the
use of a fast blow fuse, installed in the ungrounded input supply line with a
typical value about twice the maximum input current, calculated at low line
with the converter’s minimum effi ciency.
All relevant national and international safety standards and regulations must
be observed by the installer. For system safety agency approvals, the convert-
ers must be installed in compliance with the requirements of the end- use
safety standard, i.e. IEC/EN/UL60950-1.
Input Reverse-Polarity Protection
If the input voltage polarity is accidentally 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, devices will not begin to regulate properly
until the ramping-up input voltage exceeds the Start-Up Threshold Voltage.
Once operating, devices will not turn off until the input voltage drops below the
Under-Voltage Shutdown limit. Subsequent re-start will not occur until the input
is brought back up to the Start-Up Threshold. This built in hysteresis prevents
any unstable on/off situations from occurring at a single input voltage.
Start-Up Time
The VIN to VOUT Start-Up Time is the time interval between the point at which
the ramping input voltage crosses the Start-Up Threshold and the fully loaded
output voltage enters and remains within its specifi ed accuracy band. Actual
measured times will vary with input source impedance, external input capaci-
tance, and the slew rate and fi nal value of the input voltage as it appears at the
converter. The UCQ Series implements a soft start circuit to limit the duty cycle
of its PWM controller at power up, thereby limiting the input inrush current.
The On/Off Control to VOUT start-up time assumes the converter has its
nominal input voltage applied but is turned off via the On/Off Control pin. The
specifi cation defi nes the interval between the point at which the converter is
turned on (released) and the fully loaded output voltage enters and remains
within its specifi ed accuracy band. Similar to the VIN to VOUT start-up, the On/Off
Control to VOUT start-up time is also governed by the internal soft start circuitry
and external load capacitance. The difference in start up time from VIN to VOUT
and from On/Off Control to VOUT is therefore insignifi cant.
Input Source Impedance
The input of UCQ converters must be driven from a low ac-impedance source.
The DC/DC’s performance and stability can be compromised by the use of
highly inductive source impedances. The input circuit shown in Figure 2 is a
practical solution that can be used to minimize the effects of inductance in the
input traces. For optimum performance, components should be mounted close
to the DC/DC converter.
In Figure 3, the two copper strips simulate real-world PCB impedances
between the power supply and its load. In order to minimize measurement
errors, scope measurements should be made using BNC connectors, or the
probe ground should be less than ½ inch and soldered directly to the fi xture.
Floating Outputs
Since these are isolated DC/DC converters, their outputs are “fl oating” with
respect to their input. Designers will normally use the –Output (pin 4) as the
ground/return of the load circuit. You can however, use the +Output (pin 8) as
ground/return to effectively reverse the output polarity.
Minimum Output Loading Requirements
UCQ converters employ a synchronous-rectifi er design topology and all models
regulate within spec and are stable under no-load to full load conditions.
Operation under no-load conditions however might slightly increase the output
ripple and noise.
Figure 2. Measuring Input Ripple Current
C
IN
V
IN
C
BUS
L
BUS
C
IN
= 33μF, ESR < 700m: @ 100kHz
C
BUS
= 220μF, ESR < 100mW @ 100kHz
L
BUS
= 12μH
3
1
+INPUT
–INPUT
CURRENT
PROBE
TO
OSCILLOSCOPE
+
–
TECHNICAL NOTES
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Single Output UCQ Models
Low-Profi le, Quarter Brick, 8.3-40 Amp
Isolated DC/DC Converters
MDC_UCQ Models.B20 Page 21 of 24
Remote Sense
Note: The Sense and VOUT lines are internally connected through low-value
resistors. Nevertheless, if the sense function is not used for remote regulation
the user should connect the +Sense to +VOUT and –Sense to –VOUT at the DC/
DC converter pins. UCQ series converters employ a sense feature to provide
point of use regulation, thereby overcoming moderate IR drops in PCB conduc-
tors or cabling. The remote sense lines carry very little current and therefore
require minimal cross-sectional-area conductors. The sense lines, which are
capacitively coupled to their respective output lines, are used by the feedback
control-loop to regulate the output. As such, they are not low impedance points
and must be treated with care in layouts and cabling. Sense lines on a PCB
should be run adjacent to dc signals, preferably ground.
[VOUT(+)-VOUT(–)] – [Sense(+)-Sense(–)] d 10%VOUT
In cables and discrete wiring applications, twisted pair or other techniques
should be used. Output over-voltage protection is monitored at the output volt-
age pin, not the Sense pin. Therefore, excessive voltage differences between
VOUT and Sense in conjunction with trim adjustment of the output voltage can
cause the over-voltage protection circuitry to activate (see Performance Speci-
fi cations for over-voltage limits). Power derating is based on maximum output
current and voltage at the converter’s output pins. Use of trim and sense func-
tions can cause output voltages to increase, thereby increasing output power
beyond the converter’s specifi ed rating, or cause output voltages to climb into
the output over-voltage region. Therefore, the designer must ensure:
(VOUT at pins) x (IOUT) d rated output power
The UCQ converters are equipped with thermal-shutdown circuitry. If environ-
mental conditions cause the temperature of the DC/DC converter to rise above
the designed operating temperature, a precision temperature sensor will power
down the unit. When the internal temperature decreases below the threshold
of the temperature sensor, the unit will self start. See Performance/Functional
Specifi cations.
Output Over-Voltage Protection
The UCQ output voltage is monitored for an over-voltage condition using a com-
parator. The signal is optically coupled to the primary side and if the output volt-
age rises to a level which could be damaging to the load, the sensing circuitry
will power down the PWM controller causing the output voltage to decrease.
Following a time-out period the PWM will restart, causing the output voltage
to ramp to its appropriate value. If the fault condition persists, and the output
voltage again climbs to excessive levels, the over-voltage circuitry will initiate
another shutdown cycle. This on/off cycling is referred to as “hiccup” mode.
Current Limiting
As soon as the output current increases to approximately 130% of its rated
value, the DC/DC converter will go into a current-limiting mode. In this condi-
tion, the output voltage will decrease proportionately with increases in output
current, thereby maintaining somewhat constant power dissipation. This is
commonly referred to as power limiting. Current limit inception is defi ned
as the point at which the full-power output voltage falls below the specifi ed
tolerance. See Performance/Functional Specifi cations. If the load current, being
drawn from the converter, is signifi cant enough, the unit will go into a short
circuit condition as described below.
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 mag-
netically 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 to their appropri-
ate value. If the short-circuit condition persists, another shutdown cycle will be
initiated. This on/off cycling is referred to as “hiccup” mode. The hiccup cycling
reduces the average output current, thereby preventing internal temperatures
from rising to excessive levels. The UCQ Series is capable of enduring an
indefi nite short circuit output condition.
Thermal Shutdown
Trimming Output Voltage
UCQ converters have a trim capability (pin 6) that enables users to adjust the
output voltage (refer to the trim equations and trim graphs that follow). Adjust-
ments to the output voltage can be accomplished via a trim pot (Figure 5) or
a single fi xed resistor as shown in Figures 6 and 7. A single fi xed resistor can
increase or decrease the output voltage depending on its connection. Resistors
should be located close to the converter and have TCR’s less than 100ppm/°C
to minimize sensitivity to changes in temperature. If the trim function is not
used, leave the trim pin open.
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Figure 4. Remote Sense Circuit Confi guration
C1
C1 = 1μF CERAMIC
C2 = 10μF TANTALUM
LOAD 2-3 INCHES (51-76mm) FROM MODULE
C2 RLOAD
7
8
COPPER STRIP
4
5COPPER STRIP
SCOPE
+OUTPUT
–OUTPUT
+SENSE
–SENSE
Figure 3. Measuring Output Ripple/Noise (PARD)
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Single Output UCQ Models
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Isolated DC/DC Converters
MDC_UCQ Models.B20 Page 22 of 24
A single resistor connected from the Trim pin (pin 6) to the +Sense (pin 7)
will increase the output voltage. A resistor connected from the Trim Pin (pin 6)
to the –Sense (pin 5) will decrease the output voltage.
Trim adjustments greater than the specifi ed range can have an adverse
affect on the converter’s performance and are not recommended. Excessive
voltage differences between VOUT and Sense, in conjunction with trim adjust-
ment of the output voltage, can cause the over-voltage protection circuitry to
activate (see Performance Specifi cations for over-voltage limits). Temperature/
power derating is based on maximum output current and voltage at the
converter’s output pins. Use of the trim and sense functions can cause output
voltages to increase, thereby increasing output power beyond the converter’s
specifi ed rating, or cause output voltages to climb into the output over-voltage
region. Therefore:
(VOUT at pins) x (IOUT) t rated output power
The Trim pin (pin 6) is a relatively high impedance node that can be suscep-
tible to noise pickup when connected to long conductors in noisy environments.
Where,
' = | (VNOM − VOUT) / VNOM |
VNOM is the nominal, untrimmed output voltage.
VOUT is the desired new output voltage.
Do not exceed the specified trim range or maximum power ratings
when adjusting trim. Use 1% precision resistors mounted close
to the converter on short leads.
Trim Equations
(For all models except the UCQ-1.2/40-D24 and -1.2/30-D48)
Trim Down
Connect trim resistor between
trim pin and −Sense
'
5.11
RTrimDn (k Ω) = − 10.22
Trim Up
Connect trim resistor between
trim pin and +Sense
1.225 × '
5.11 × VNOM × (1+')
RTrimUp (k Ω) = − 10.22
'
− 5.11
q
(For the UCQ-1.2/40-D24 and -1.2/30-D48)
Trim Down
Connect trim resistor between
trim pin and −Sense
2' − 2
5.11
RTrimDn (k Ω) =
Trim Up
Connect trim resistor between
trim pin and +Sense
1.225 × '
5.11 × VNOM × (1+')
RTrimUp (k Ω) =
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Figure 7. Trim Connections To Decrease Output Voltages Using Fixed Resistors
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Figure 6. Trim Connections To Increase Output Voltages Using Fixed Resistors
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Figure 5. Trim Connections Using A Trimpot
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Single Output UCQ Models
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Isolated DC/DC Converters
MDC_UCQ Models.B20 Page 23 of 24
Dynamic control of the remote on/off function is best accomplished with a
mechanical relay or an open-collector/open-drain drive circuit (optically isolated
if appropriate). The drive circuit should be able to sink appropriate current (see
Performance Specifi cations) when activated and withstand appropriate voltage
when deactivated. Applying an external voltage to pin 2 when no input power is
applied to the converter can cause permanent damage to the converter.
2
1
+Vcc
13V CIRCUIT
5V CIRCUIT
–I N P U T
O N /O F F
C O N TR O L
3
+INPUT
Figure 8. Driving the Negative Polarity On/Off Control Pin
(simplifi ed circuit)
2
1 –I N P U T
+VCC
O N /O F F
C O N TR O L
3
+INPUT
Figure 9. Driving the Negative Polarity On/Off Control Pin
(simplifi ed circuit)
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 ca-
tions may cause damage to the product. 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
On/Off Control
The input-side, remote On/Off Control function (pin 2) can be ordered to operate
with either polarity:
Positive (no suffi x) polarity models are enabled when pin 2 is left open (or
is pulled high, applying +3.5V to +13.5V with respect to –Input, pin 1) as per
Figure 8. Positive-polarity devices are disabled when pin 2 is pulled low (0 to
0.8V with respect to –Input).
Negative (“N” suffi x) polarity devices are off when pin 2 is left open (or
pulled high, applying +3.5V to +13.5V), and on when pin 2 is pulled low (0 to
1V) with respect to –Input as shown in Figure 9.
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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. © 2012 Murata Power Solutions, Inc.
Murata Power Solutions, Inc.
11 Cabot Boulevard, Mansfi eld, MA 02048-1151 U.S.A.
ISO 9001 and 14001 REGISTERED
This product is subject to the following operating requirements
and the Life and Safety Critical Application Sales Policy:
Refer to: http://www.murata-ps.com/requirements/
Single Output UCQ Models
Low-Profi le, Quarter Brick, 8.3-40 Amp
Isolated DC/DC Converters
MDC_UCQ Models.B20 Page 24 of 24