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UQQ Series
Wide Input Range Single Output DC-DC Converters
MDC_UQQ.D06 Page 1 of 18
FEATURES
Standard quarter-brick package/pinout in
through-hole version
Low cost; Low profi le, 0.43" (10.92mm)
9-36V or 18-75V wide range inputs
Output current: 4 to 25 Amps
Output voltages: 3.3, 5, 12, 15 or 24V
Interleaved synchronous-rectifi er topology
Ultra high effi ciency
Outstanding thermal performance
On/off control, trim & sense functions
Fully isolated, up to 2250Vdc (48 VIN)
Output overvoltage protection
Fully I/O protected; Thermal shutdown
Certifi ed to UL/EN/IEC60950-1, 2nd Edition
safety approvals
RoHS hazardous substance compliant
From an 9-36V or 18-75V input, UQQ’s deliver
outputs of 3.3V, 5V,12V,15V, or 24V. They employ
an interleaved, synchronous-rectifi er topology that
exploits 100% of their duty cycle. They simultane-
ously achieve ultra-high effi ciency, tight line/load
regulation, low noise, and quick step response.
A state of the art, single-board, open-frame
design with reduced component count, high
effi ciency, low-on-resistance FET’s, and planar
magnetics embedded in heavy-copper pc boards
all contribute to impressive thermal derating.
The UQQ’s feature set includes high isolation,
input pi fi lters, input undervoltage shutdown, output
overvoltage protection, current limiting, short-circuit
protection and thermal shutdown. The standard
footprint carries on/off control (positive or negative
polarity), output trim (+10/–20%) and output sense
functions.
All UQQ quarter-bricks are designed with full
magnetic and optical isolation up to 2250 Volts DC
(basic insulation).
For applications requiring wide range input, improved electrical and
thermal perfomance consider Murata Power Solutions’ new UQQ
Series “Quarter-Brick” DC-DC Converters. They measure just 1.45
x 2.22 x 0.43 inches (36.8 x 56.4 x 10.92mm) and fi t the industry-
standard footprint.
PRODUCT OVERVIEW
Typical unit
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Figure 1. Connection Diagram
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UQQ Series
Wide Input Range Single Output DC-DC Converters
MDC_UQQ.D06 Page 2 of 18
PERFORMANCE SPECIFICATIONS SUMMARY AND ORDERING GUIDE ➀
Root Model
Output Input
Effi ciency Package
(Case/
Pinout)
VOUT
(V)
IOUT
(A)
Power
(Watts)
R/N (mVp-p) Regulation VIN Nom.
(Volts)
Range
(Volts)
IIN, no load
(mA)
IIN, full load
(A)
Typ. Max. Line Load Min. Typ.
UQQ-3.3/25-Q12P-C 3.3 25 82.5 50 80 ±0.05% ±0.125% 12 9-36 180 7.81 86% 88% C68,P32
UQQ-3.3/25-Q48N-C 3.3 25 82.5 80 125 ±0.05% ±0.2% 48 18-75 80 2.01 86% 88% C68,P32
UQQ-5/17-Q12P-C 5 17 85 40 75 ±0.05% ±0.06% 12 9-36 150 7.83 88.5% 90.5% C68,P32
UQQ-5/20-Q48N-C 5 20 100 100 140 ±0.05% ±0.165% 48 18-75 65 2.47 82.5% 84.5% C68,P32
UQQ-12/8-Q12P-C 12 8 96 40 75 ±0.05% ±0.05% 12 9-36 180 8.99 87% 89% C68,P32
UQQ-12/8-Q48N-C 12 8 96 120 160 ±0.05% ±0.1% 48 18-75 70 2.3 85% 87% C68,P32
UQQ-15/7-Q12P-C 15 7 105 56 100 ±0.05% ±0.1% 12 9-36 250 9.78 88% 89.5% C68,P32
UQQ-24/4-Q12P-C 24 4 96 125 170 ±0.05% ±0.075% 12 10-36 120 8.99 87.7 89% C68,P32
Maximum Rated Output
Quarter-Brick Package
Unipolar Single Output
Nominal Output Voltage
U QQ -/Q12-517 N Lx
Input Voltage Range
Q12 = 9-36V
Q48 = 18-75V
Remote On/Off Control Polarity:
Add "P" for positive polarity
Add "N" for negative polarity
Pin Length Option
Blank = Std. pin length
L1 = 0.110 (2.79mm)*
L2 = 0.145 (3.68mm)*
C
RoHS-6 hazardous substance compliant
(does not claim EU RoHS exemption 7b, lead in solder)
-9
Baseplate (optional):
Blank = no baseplate standard
B = baseplate installed, special order
Baseplate Pin 9 (special order):
Blank = No pin 9, standard
9 = Pin 9 installed, connects to baseplate
Typical at TA = +25°C under nominal line voltage and full-load conditions. All models are
specified with an external 1µF multi-layer ceramic and 10µF capacitors across their output pins
and 100µF external input capacitor.
Ripple/Noise (R/N) measured over a 20MHz bandwidth.
Devices have no minimum-load requirements and will regulate under no-load conditions.
Regulation specifications describe the output voltage deviation as the line voltage or load is
varied from its nominal/midpoint value to either extreme. (Load step = 50%.)
Nominal line voltage, no load/full load condition.
Please refer to the Part Number Structure for additional part numbers and options.
➅ RoHS does not claim EU exemption 7B–lead in solder.
Some model options may require minimum order quantities.
B
Pin 9 Baseplate Connection
The UQQ series may include an optional installed baseplate for extended
thermal management. This baseplate is electrically isolated from the rest of the
converter. Various UQQ models are also available with an additional pin 9 on
special quantity order which electrically connects to the baseplate. Pin 9 is also
isolated from the rest of the converter. Please refer to the mechanical drawings.
Pin 9 offers a positive method of controlling the electrical potential of the base-
plate, independent of the converter. If you do not include pin 9, the baseplate
may also be grounded by the mounting bolts.
The baseplate may be ordered by adding a “B” to the model number tree
and pin 9 will be pre-installed by adding a “9”. The two options are separate.
Please refer to the Ordering Guide. Do not order pin 9 without the baseplate.
Note that “pin 9” converters may be on limited forecast, requiring minimum
order quantities and scheduled deliveries.
Please see page 9 for heatsink information.
PART NUMBER STRUCTURE
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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UQQ Series
Wide Input Range Single Output DC-DC Converters
MDC_UQQ.D06 Page 3 of 18
UQQ-3.3/25-Q12 UQQ-3.3/25-Q48 UQQ-5/17-Q12 UQQ-5/20-Q48 UQQ-12/8-Q12
INPUT
Input Voltage Range See ordering guide
Start-up Threshold 9.0 Volts (18) 17.50 Volts 9.0 Volts (18) 17.5 Volts 9.0 Volts (18)
Undervoltage Shutdown 8.0 Volts 16.75 Volts 8.0 Volts 15.75 Volts (IOUT = ØA) 8.0 Volts
Overvoltage Shutdown 37.5 Volts None 37.5 Volts None 37.5 Volts
Refl ected (back) ripple current (2) 25mAp-p 15mAp-p 75mAp-p 80mAp-p 75mAp-p
Input Current
Full load conditions See ordering guide
Inrush transient 0.1A2sec
Output short circuit 250mA 100mA 100mA 50mA 250mA
No load 150mA 80mA 150mA 65mA 180mA
Low line (VIN = min.) 10.4 Amps 5.18 Amps 10.44 Amps 6.24 Amps 12.12 Amps
Standby mode
(Off, UV, OT shutdown) 30mA 30mA 8mA 30mA 30mA
Internal Input Filter Type LC Pi-type L-C L-C L-C
Reverse Polarity Protection External Fusing
Required (15)
External Fusing
Required (15)
External Fusing
Required (15)
External Fusing
Required (15)
External Fusing
Required (15)
Remote On/Off Control (5)
Positive logic (“P” suffi x) OFF = Ground pin to +0.8V max. ON = open or +3.5-15V max.
Negative logic (“N” suffi x) OFF = open or +5 to +VIN max. ON = Ground pin to +0.8V max. (16)
On/Off Current 1 mA 1 mA 1 mA 1mA 1 mA
OUTPUT
Voltage Output Range See ordering guide
Voltage Output Accuracy
(50% load) ±1% of VNOM
Adjustment Range ±10% of VNOM ±10% of VNOM –20 to +10% of VNOM –20 to +10% of VNOM –20 to +10% of VNOM
Temperature Coeffi cient ±0.02% of
VOUT range/°C
Minimum Loading No minimum load
Remote Sense Compensation +10%
Ripple/noise (20MHz bandwidth)
See ordering guideLine/Load Regulation
Effi ciency
Maximum Capacitive Loading
Low ESR, resistive load
10,000F 4700F 10,000F 10,000F 4700F
Isolation Voltage
Input to Output 2000 VDC min. 2250 VDC min. 2000 VDC min. 2250 VDC min. 2250 VDC min.
Input fo baseplate 1500 VDC min. 1500 VDC min. 1500 VDC min. 1500 VDC min. 1500 VDC min.
Baseplate to output 1500 VDC min. 500 VDC min. 750 VDC min. 1500 VDC min. 750 VDC min.
Isolation resistance 100M100M100M100M100M
Isolation capacitance 1500 pF 1000 pF 1000 pF 1500pF 1000 pF
Isolation safety rating Basic insulation
Current limit inception
(98% of VOUT, after warmup)
30 Amps 29 Amps 20.5 Amps 27 Amps 9.5 Amps
Short Circuit Protection Method Current limiting, hiccup autorestart. Remove overload for recovery.
Short Circuit Current 5 Amps 5 Amps 3 Amps 0.5 Amps 0.5 Amps
Short Circuit Duration Continuous, output shorted to ground (no damage)
Overvoltage Protection
via magnetic feedback
4 Volts 3.96 Volts max. 6 Volts 6 Volts 14.4 Volts
FUNCTIONAL SPECIFICATIONS
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UQQ Series
Wide Input Range Single Output DC-DC Converters
MDC_UQQ.D06 Page 4 of 18
UQQ-12/8-Q48 UQQ-15/7-Q12 UQQ-24/4-Q12
INPUT
Input Voltage Range See ordering guide
Start-up Threshold 17.5 Volts 9.0 Volts (18) 9.0 Volts (18)
Undervoltage Shutdown 16.0 Volts 8.0 Volts 8.0 Volts
Overvoltage Shutdown None 38.5 Volts None
Refl ected (back) ripple current (2) 15mAp-p 50mAp-p 50mAp-p
Input Current
Full load conditions See ordering guide
Inrush transient 0.1A2sec
Output short circuit 100mA 250mA 250mA
No load 70mA 250mA 120mA
Low line (VIN = min.) 5.93A 12.9 Amps 10.73 Amps
Standby mode
(Off, UV, OT shutdown) 30mA 30mA 5mA
Internal Input Filter Type PI-type L-C L-C
Reverse Polarity Protection External Fusing
Required (15)
External Fusing
Required (15)
External Fusing
Required (15)
Remote On/Off Control (5)
Positive logic (“P” suffi x) OFF = Ground pin to +0.8V max. ON = open or +3.5-15V max.
Negative logic (“N” suffi x) OFF = open or +5 to +VIN max. ON = Ground pin to +0.8V max. (16)
On/Off Current 1 mA
OUTPUT
Voltage Output Range See ordering guide
Voltage Output Accuracy
(50% load) ±1.25% of VNOM ±1% of VNOM ±1% of VNOM
Adjustment Range –20 to +10% of VNOM –20 to +10% of VNOM ±10% of VNOM
Temperature Coeffi cient ±0.02% of
VOUT range/°C
Minimum Loading No minimum loading
Remote Sense Compensation +10% of Vout max. +10% of Vout max. +10% of Vout max.
Ripple/noise (20MHz bandwidth)
See ordering guideLine/Load Regulation
Effi ciency
Maximum Capacitive Loading
Low ESR <0.02max., resistive load
2200µF 4700F 1500F max
Isolation Voltage
Input to Output 2250 VDC min. 2000 VDC min. 2000 VDC min.
Input fo baseplate 1500 VDC min. 1500 VDC min. 1500 VDC min.
Baseplate to Output 500 VDC min. 1500 VDC min. 1500 VDC min.
Isolation resistance 100M100M100M
Isolation capacitance 1000 pF 1000 pF 1000 pF
Isolation safety rating Basic insulation
Current limit inception
(98% of VOUT, after warmup)
11.5 Amps 9.5 Amps 5.75 Amps
Short Circuit Protection Method Current limiting, hiccup autorestart. Remove overload for recovery
Short Circuit Current 0.1 Amps 0.5 Amps 0.5 Amps
Short Circuit Duration Continuous, output shorted to ground (no damage)
Overvoltage Protection
via magnetic feedback
15 Volts 18 Volts 29 Volts
Absolute Maximum Ratings
Input Voltage 12V models 48V models
Continuous 0 to +36V 0 to +75V
Transient (100msec) +50V +100V
On/Off Control 0V min to +15V max.
Input Reverse Polarity Protection Install external fuse.
Output Overvoltage VOUT +20% max.
Output Current (7)
Current-limited. Devices can
withstand sustained short circuit
without damage.
Storage Temperature –55 to +125°C
Lead Temperature See soldering guidelines
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 or recommended.
FUNCTIONAL SPECIFICATIONS (CONTINUED)
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UQQ Series
Wide Input Range Single Output DC-DC Converters
MDC_UQQ.D06 Page 5 of 18
UQQ-3.3/25-Q12 UQQ-3.3/25-Q48 UQQ-5/17-Q12 UQQ-5/20-Q48 UQQ-12/8-Q12 UQQ-12/8-Q48 UQQ-15/7-Q12 UQQ-24/4-Q12
DYNAMIC CHARACTERISTICS
Dynamic Load Response
(50-75-50% load step)
50sec to ±1%
of fi nal value
100sec to ±1%
of fi nal value
50sec to ±1%
of fi nal value
95sec to ±1%
of fi nal value
50sec to ±1%
of fi nal value
50sec to ±2%
of fi nal value
Start-up Time
VIN to VOUT regulated 10msec 10msec max 10msec 25msec 10msec 20msec 10msec 10msec
Remote On/Off
to VOUT regulated
5msec 5msec max 5msec
Switching frequency 255 ±25kHz 255 ±25kHz 260 ±25kHz 225-265kHz 260 ±25kHz 245 ±20kHz 260 ±25kHz 260 ±25kHz
ENVIRONMENTAL
Calculated MTBF (4) TBC 3,360,928 TBC
Operating Temperature Range
See Derating curves
–40 to +85ºC
with Derating
–40 to +57ºC
with Derating
–40 to +85ºC
with Derating
Operating Temperature Range
with baseplate (3)(14)
–40 to +105ºC –40 to +100ºC –40 to +105°C –40 to +105ºC –40 to +105°C –40 to +100°C –40 to +105°C –40 to +105°C
Storage Temperature Range –55 to +125ºC
Thermal Protection/Shutdown +120ºC, measured at thermistor T1
Relative humidity To +85°C/85% non-condensing
PHYSICAL
Outline dimensions See mechanical specifi cations
Baseplate material Aluminum
Pin material Copper alloy
Pin diameter 0.04/0.062 inches, 1.016/1.524 mm
Weight Without Baseplate = 1 ounce (28 grams), With Baseplate = 2.24 ounces (63.5 grams)
Electromagnetic interference
(conducted, external fi lter
required)
Designed to meet class B, EN55022, CISPR22
Safety Certifi ed to UL/cUL 60950-1, CSA-C22.2 No.60950-1, IEC/EN 60950-1, 2nd Edition
Flammability UL 94V-0
Specifi cation Notes:
(1) All models are tested and specifi ed with 300 lfm airfl ow, external 1 and 10µF paralleled ceramic/
tantalum output capacitors and a 100µF external input capacitor. All capacitors are low ESR
types. These capacitors are necessary to accommodate our test equipment and may not be
required in your applications. All models are stable and regulate within spec under no-load
conditions.
General conditions for Specifi cations are +25°C, VIN = nominal, VOUT = nominal, full load unless
noted.
(2) Input Ripple Current is tested and specifi ed over a 5Hz to 20MHz bandwidth. Input fi ltering is
CIN = 33µF tantalum, CBUS = 220µF electrolytic, LBUS = 12µH.
(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 increas-
ing altitude.
(4) Mean Time Before Failure is calculated using the Telcordia (Belcore) SR-332 Method 1, Case 3,
ground fi xed conditions, TPCBOARD = +25°C, full output load, natural air convection.
(5) The On/Off Control may 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/open drain transistor or logic gate.
(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.
On-board component package temperatures 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) Alternate pin length and/or other output voltages are available under special quantity order.
(12) Overvoltage shutdown on 48V input models can be eliminated under special quantity order. OV
shutdown can be deleted in order to comply with certain telecom reliability requirements. These
requirements attempt continued operation despite signifi cant input overvoltage.
(13) Do not exceed maximum power specifi cations when adjusting the output trim.
(14) Note that the converter may operate up to +105°C with the baseplate installed (+100°C for the
UQQ-3.3/25-Q48). However, thermal self-protection occurs near +120°C. Therefore, +105°C is
recommended to avoid thermal shutdown.
(15) If reverse polarity is accidentally applied to the input, to ensure reverse input protection, 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) For On/Off Control on negative-polarity UQQ-3.3/25-Q48N models, the maximum OFF mode
control voltage is +13.5 Volts. For the ON mode, the range is pin grounded to +1 Volt max.
(17) Always connect the sense pins. If they are not connected to a remote load, connect each sense
pin to its respective output at the converter pins.
(18) Shown at Vin = 10V; after module starts up it operates from 9-36Vdc.
FUNCTIONAL SPECIFICATIONS (CONTINUED)
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TYPICAL PERFORMANCE DATA
UQQ Series
Wide Input Range Single Output DC-DC Converters
MDC_UQQ.D06 Page 6 of 18
64
66
68
70
72
74
76
78
80
82
84
86
88
90
2 4 6 8 10 12 14 16 18 20 22 24 26
UQQ-3.3/25-Q48P
Efficiency vs. Line Voltage and Load Current @ 25ºC
Load Current (Amps)
Efficiency (%)
V
IN
= 72V
V
IN
= 60V
V
IN
= 48V
V
IN
= 36V
V
IN
= 24V
V
IN
= 18V
18
18.5
19
19.5
20
20.5
21
21.5
22
22.5
23
23.5
24
24.5
25
20 25 30 35 40 45 50 55 60 65 70 75 80 85
UQQ-3.3/25-Q12P Maximum Current Temperature Derating
(no baseplate, V
IN
= 12V, air flow is transverse)
Natural Convection
300 lfm
Output Current (Amps)
Ambient Temperature (
°
C)
400 lfm
200 lfm
100 lfm
13
14
15
16
17
18
19
20
21
22
23
24
25
26
20 25 30 35 40 45 50 55 60 65 70 75 80 85 90
Natural Convection
300 LFM
400 LFM
200 LFM
100 LFM
UQQ-3.3/25-Q48 Maximum Current Temperature Derating at sea level
(V
IN
= 48V, with baseplate, transverse air flow)
Output Current (Amps)
Ambient Temperature (
°
C)
20.0
20.5
21.0
21.5
22.0
22.5
23.0
23.5
24.0
24.5
25.0
20 25 30 35 40 45 50 55 60 65 70 75 80 85
Output Current (Amps)
Ambient Temperature (
°
C)
UQQ-3.3/25-Q12PB Maximum Current Temperature Derating
(with baseplate, V
IN
= 12V, air flow is transverse)
200 lfm
300 lfm
100 lfm
Natural Convection
UQQ-3.3/25-Q12
Efficiency vs. Line Voltage and Load Current @ 25°C
Load Current (Amps)
Efficiency (%)
V
IN
= 36V
V
IN
= 30V
V
IN
= 24V
90
88
86
84
82
80
78
76
74 12 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
V
IN
= 18V
V
IN
= 12V
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TYPICAL PERFORMANCE DATA
UQQ Series
Wide Input Range Single Output DC-DC Converters
MDC_UQQ.D06 Page 7 of 18
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IN
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UQQ-5/20-Q48P
Efficiency vs. Line Voltage and Load Current @ 25°C
Load Current (Amps)
Efficiency (%)
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Output Current (Amps)
Ambient Temperature (°C)
–40 25 30 35 40 45 50 55 60 65 70 75 80 85
17
16
15
14
13
12
11
400 lfm
200 lfm
300 lfm
100 lfm
Natural Convection
UQQ-5/17-Q12P Maximum Current Temperature Derating
With baseplate, VIN = 12V (transverse air flow at sea level)
11
12
13
14
15
16
17
18
19
20
20 25 30 35 40 45 50 55 60 65 70 75 80 85 90
400 lfm
200 lfm
300 lfm
100 lfm
Natural Convection
UQQ-5/20-Q48 Maximum Current Temperature Derating at sea level
(VIN = 48V, with baseplate, transverse airflow)
Output Current (Amps)
Ambient Temperature (°C)
Output Current (Amps)
Ambient Temperature (°C)
–40 25 30 35 40 45 50 55 60 65 70 75 80 85
17
16
15
14
13
12
11
400 lfm
200 lfm
300 lfm
100 lfm
Natural Convection
UQQ-5/17-Q12P Maximum Current Temperature Derating
No baseplate, VIN = 12V (transverse air flow at sea level)
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TYPICAL PERFORMANCE DATA
UQQ Series
Wide Input Range Single Output DC-DC Converters
MDC_UQQ.D06 Page 8 of 18
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Output Current (Amps)
Ambient Temperature (
°
C)
–40 25 30 35 40 45 50 55 60 65 70 75 80 85
8.0
7.5
7.0
6.5
6.0
5.5
5.0
4.5
4.0
400 lfm
200 lfm
300 lfm
100 lfm
Natural Convection
UQQ-12/8-Q12P Maximum Current Temperature Derating
With baseplate, V
IN
= 12V (transverse air flow at sea level)
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
20 25 30 35 40 45 50 55 60 65 70 75 80 85 90
UQQ-12/8-Q12P Maximum Current Temperature Derating
(no baseplate, VIN = 12V, air flow is transverse)
Output Current (Amps)
Ambient Temperature (
°
C)
Natural Convection
100 lfm
200 lfm
300 lfm
400 lfm
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TYPICAL PERFORMANCE DATA
UQQ Series
Wide Input Range Single Output DC-DC Converters
MDC_UQQ.D06 Page 9 of 18
74
76
78
80
82
84
86
88
90
92
UQQ-12/8-Q48P
Efficiency vs. Line Voltage and Load Current @ 25°C
Load Current (Amps)
Efficiency (%)
1 2 3 4 5 6 7 8
V
IN
= 75V
V
IN
= 48V
V
IN
= 36V
V
IN
= 18V
4
4.5
5
5.5
6
6.5
7
7.5
8
20 25 30 35 40 45 50 55 60 65 70 75 80 85 90
Output Current (Amps)
Ambient Temperature (
°
C)
UQQ-12/8-Q48P Maximum Current Temperature Derating
(With baseplate, VIN = 48V transverse air flow at sea level)
Natural Convection
100 lfm
200 lfm
300 lfm
400 lfm
4
4.5
5
5.5
6
6.5
7
7.5
8
20 25 30 35 40 45 50 55 60 65 70 75 80 85 90
Output Current (Amps)
Ambient Temperature (
°
C)
UQQ-12/8-Q48P Maximum Current Temperature Derating
(With baseplate, V
IN
= 24V, transverse air flow at sea level)
Natural Convection
100 lfm
200 lfm
300 lfm
400 lfm
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TYPICAL PERFORMANCE DATA
UQQ Series
Wide Input Range Single Output DC-DC Converters
MDC_UQQ.D06 Page 10 of 18
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Ambient Temperature (°C)
–40 25 30 35 40 45 50 55 60 65 70 75 80 85
7
6.5
6
5.5
5
4.5
4
3.5
200 lfm
300 lfm
100 lfm
Natural Convection
400 lfm
UQQ-15/7-Q12P Maximum Current Temperature Derating
With baseplate, VIN = 12V (transverse air flow at sea level)
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TYPICAL PERFORMANCE DATA
UQQ Series
Wide Input Range Single Output DC-DC Converters
MDC_UQQ.D06 Page 11 of 18
Output Current (Amps)
Ambient Temperature (°C)
20 25 30 35 40 45 50 55 60 65 70 75 85
80
4
3.8
3.6
3.4
3.2
3
2.8
2.6
2.4
2.2
2
200 lfm
300 lfm
100 lfm
Natural Convection
400 lfm
UQQ-24/4-Q12P Maximum Current Temperature Derating
No baseplate, VIN = 12V (transverse air flow at sea level)
Output Current (Amps)
Ambient Temperature (°C)
20 25 30 35 40 45 50 55 60 65 70 75 85
80
4
3.8
3.6
3.4
3.2
3
2.8
2.6
2.4
2.2
2
200 lfm
300 lfm
100 lfm
Natural Convection
400 lfm
UQQ-24/4-Q12P Maximum Current Temperature Derating
With baseplate, VIN = 12V (transverse air flow at sea level)
93
92
91
90
89
88
87
86
UQQ-24/4-Q12P
Efficiency vs. Line Voltage and Load Current @ 25°C
Load Current (Amps)
Efficiency (%)
1 2 3 4
V
IN
= 36V
V
IN
= 30V
V
IN
= 24V
V
IN
= 12V
V
IN
= 10V
UQQ-24/4-Q12P
Power Dissipation vs. Load Current @ 25°C
1
Load Current (Amps)
Power Dissipation (Watts)
42 3
2
3
4
5
6
7
8
9
10
11
12
13
14
V
IN
= 36V
V
IN
= 30V
V
IN
= 24V
V
IN
= 12V
V
IN
= 10V
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UQQ Series
Wide Input Range Single Output DC-DC Converters
MDC_UQQ.D06 Page 12 of 18
MECHANICAL SPECIFICATIONS
* The Remote On/Off can be provided with
either positive ("P" suffi x) or negative
("N" suffi x) polarity.
Important! Always connect the sense pins;
see Application Notes.
Standard pin length is shown. Please refer
to the Part Number Structure for alternate
pin lengths.
.43
10.9
REF
25.4
1.00
7.62
.300
7.62
.300
3.81
.150
3.81
.150
.725
REF
18.42
2.000
50.80
.93
REF
23.6
.515
REF
13.08
END VIEW
WITHOUT
BASEPLATE
C
L
C
L
C
L
8
7
6
5
4
1
2
9
Connects to baseplate
And is electrically
isolated from converter
3
Optional pin #9
BOTTOM VIEW
.071±.002 [1.80]
VENTED SHOULDER
ON EACH .040 PIN
OPTIONAL
BASEPLATE
'B' OPTION SIDE VIEW
AT PINS 1-3, 5-7, (9)
1.02±0.05
.040±.0022X .062±.002
AT PINS 4 & 8
1.57±0.05
END VIEW
WITH
BASEPLATE
12.7
.50
4.76
.187
.010
MIN
BOTTOM
CLEARANCE
0.25
C
L
C
L
TOP VIEW
2.22
56.4
1.860
47.24
1.030
26.16
THRU , .10" MAX
PENETRATION
(4 PLS)
4X M3X0.5
1.45
36.8
DOSA-Compatible
Input/Output Connections
Pin Function P32
1+Vin
2 Remote On/Off*
3 –Vin
4 –Vout
5 –Sense
6 Trim
7 +Sense
8 +Vout
9 Baseplate (optional)
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˚
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UQQ Series
Wide Input Range Single Output DC-DC Converters
MDC_UQQ.D06 Page 13 of 18
Removal of Soldered UQQ’s from Printed Circuit Boards
Should removal of the UQQ from its soldered connection be needed, thor-
oughly de-solder the pins using solder wicks or de-soldering tools. At no time
should any prying or leverage be used to remove boards that have not been
properly de-soldered fi rst.
Input Source Impedance
UQQ converters must be driven from a low ac-impedance input 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.
I/O Filtering, Input Ripple Current, and Output Noise
All models in the UQQ Series are tested/specifi ed for input ripple current (also
called input refl ected ripple current) and output noise using the circuits and
layout shown in Figures 2 and 3. External input capacitors (CIN in Figure 2)
serve primarily as energy-storage elements.
Figure 2. Measuring Input Ripple Current
C
IN
V
IN
C
BUS
L
BUS
C
IN
= 33µF, ESR < 700mΩ @ 100kHz
C
BUS
= 220µF, ESR < 100mΩ @ 100kHz
L
BUS
= 12µH
1
3
+VIN
–VIN
CURRENT
PROBE
TO
OSCILLOSCOPE
+
–
TECHNICAL NOTES They 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 imped-
ance as highly inductive source impedance can affect system stability.
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) can be reduced below specifi ed limits using
fi ltering techniques, the simplest of which is the installation of additional
external output capacitors. Output capacitors function as true fi lter ele-
ments and should be selected for bulk capacitance, low ESR, and appropri-
ate 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 be taken into consideration. OS-CONTM organic
semiconductor capacitors (www.sanyo.com) can be especially effective for
further reduction of ripple/noise. 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.
Figure 3. Measuring Output Ripple/Noise (PARD)
C1
C1 = 1µF
C2 = 10µF TANTALUM
LOAD 2-3 INCHES (51-76mm) FROM MODULE
C2 R
LOAD
7
8
4
5
SCOPE
+VOUT
–VOUT
+SENSE
–SENSE
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. Your production environment may dif-
fer; 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
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UQQ Series
Wide Input Range Single Output DC-DC Converters
MDC_UQQ.D06 Page 14 of 18
Start-Up Threshold and Undervoltage Shutdown
Under normal start-up conditions, the UQQ Series will not begin to regulate
properly until the ramping input voltage exceeds the Start-Up Threshold. Once
operating, devices will turn off when the applied voltage drops below the
Undervoltage Shutdown point. Devices will remain off as long as the undervolt-
age condition continues. Units will automatically re-start when the applied
voltage is brought back above the Start-Up Threshold. The hysteresis built into
this function avoids an indeterminate on/off condition at a single input voltage.
See Performance/Functional Specifi cations table for actual limits.
Start-Up Time
The VIN to VOUT Start-Up Time is the interval between the point at which a ramp-
ing input voltage crosses the Start-Up Threshold voltage and the point at which
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 capacitance, and the slew rate and fi nal value of the input voltage as it
appears to the converter. The On/Off to VOUT start-up time assumes that the
converter is turned off via the Remote On/Off Control with the nominal input
voltage already applied.
On/Off Control
The primary-side, Remote On/Off Control function (pin 2) can be specifi ed to
operate with either positive or negative polarity. Positive-polarity devices ("P"
suffi x) are enabled when pin 2 is left open or is pulled high. Positive-polarity
devices are disabled when pin 2 is pulled low or left open (with respect to
–Input). Negative-polarity devices are off when pin 2 is high and on when pin 2
is pulled low or grounded. See Figure 4.
Dynamic control of the remote on/off function is best accomplished with a
mechanical relay or an open-collector/open-drain drive circuit (optically iso-
lated if appropriate). The drive circuit should be able to sink appropriate current
(see Performance Specifi cations) when activated and withstand appropriate
voltage when deactivated.
Figure 4. Driving the Remote On/Off Control Pin
2
3
1+5V
REF
+ VIN EQUIVALENT CIRCUIT FOR
POSITIVE AND NEGATIVE
LOGIC MODELS
CONTROL
–VIN
O N /O F F
C O N TR O L
COMMON
should not be allowed to exceed 0.5V. Consider using heavier wire if this drop
is excessive.
Sense is connected at the load and corrects for resistive errors only. Be careful
where it is connected. Any long, distributed wiring and/or signifi cant inductance
introduced into the Sense control loop can adversely affect overall system stabil-
ity. If in doubt, test the application, and observe the DC-DC’s output transient
response during step loads. There should be no appreciable ringing or oscilla-
tion. You may also adjust the output trim slightly to compensate for voltage loss
in any external fi lter elements. Do not exceed maximum power ratings.
Current Limiting (Power limit with current mode control)
As power demand increases on the output and enters the specifi ed “limit
inception range” (current in voltage mode and power in current mode) limiting
circuitry activates in the DC-DC converter to limit/restrict the maximum current
or total power available. In voltage mode, current limit can have a “constant or
foldback” characteristic. In current mode, once the current reaches a certain
range the output voltage will start to decrease while the output current con-
tinues to increase, thereby maintaining constant power, until a maximum peak
current is reached and the converter enters a “hiccup” (on off cycling) mode of
operation until the load is reduced below the threshold level, whereupon it will
return to a normal mode of operation. Current limit inception is defi ned as the
point where the output voltage has decreased by a pre-specifi ed percentage
(usually a 2% decrease from nominal).
Short Circuit Condition (Current mode control)
The short circuit condition is an extension of the “Current Limiting” condition.
When the monitored peak current signal reaches a certain range, the PWM
controller’s outputs are shut off thereby turning the converter “off.” This is
followed by an extended time out period. This period can vary depending on
other conditions such as the input voltage level. Following this time out period,
the PWM controller will attempt to re-start the converter by initiating a “normal
start cycle” which includes softstart. If the “fault condition” persists, another
“hiccup” cycle is initiated. This “cycle” can and will continue indefi nitely until
such time as the “fault condition” is removed, at which time the converter will
resume “normal operation.” Operating in the “hiccup” mode during a fault
condition is advantageous in that average input and output power levels are
held low preventing excessive internal increases in temperature.
Thermal Shutdown
UQQ converters are equipped with thermal-shutdown circuitry. If the internal
temperature of the DC-DC converter rises above the designed operating
temperature (See Performance Specifi cations), 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.
Output Overvoltage Protection
The output voltage is monitored for an overvoltage condition via magnetic cou-
pling to the primary side. If the output voltage rises to a fault condition, which
could be damaging to the load circuitry (see Performance Specifi cations), the
sensing circuitry will power down the PWM controller causing the output volt-
age 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 voltages again climb to excessive levels, the overvoltage
circuitry will initiate another shutdown cycle. This on/off cycling is referred to
as “hiccup” mode.
Sense Input
Note: The sense and VOUT lines are internally connected through low-value
resistors. Nevertheless, if sense is not used for remote regulation, the user
must connect + sense to + VOUT and -sense to -VOUT at the converter pins.
Sense is intended to correct small output accuracy errors caused by the
resistive ohmic drop in output wiring as output current increases. This output
drop (the difference between Sense and VOUT when measured at the converter)
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UQQ Series
Wide Input Range Single Output DC-DC Converters
MDC_UQQ.D06 Page 15 of 18
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 the source is not current limited or the circuit appropriately fused, it
could cause permanent damage to the converter.
Pre-Bias Protection
For applications where a pre-bias potential can be present at the output of the
power module it is recommended that either blocking diodes are added in series
with the Vout power lines or, a preferred solution is to use an OR-ing FET control-
ler like the LM5050-1 High-Side & LM5051 Low-Side OR-ing FET Controller from
TI. Starting the module into a pre-bias condition can cause permanent damage
to the module.
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 a sustained, non-current-limited, input-voltage polarity
reversal exists. For MPS UQQ Series DC-DC Converters, fast-blow fuses are
recommended with values no greater than twice the maximum input current.
Trimming Output Voltage
UQQ converters have a trim capability (pin 6) that enables users to adjust the
output voltage from +10% to –20% (refer to the trim equations). Adjustments
to the output voltage can be accomplished with a single fi xed resistor as shown
in Figures 5 and 6. 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.
Standard UQQ’s have a "positive trim" where 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 +10%/–20% 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 overvoltage protection circuitry to
activate (see Performance Specifi cations for overvoltage 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 UQQ’s
specifi ed rating, or cause output voltages to climb into the output overvoltage
region. Therefore:
(VOUT at pins) x (IOUT) rated output power
The Trim pin (pin 6) is a relatively high impedance node that can be susceptible
to noise pickup when connected to long conductors in noisy environments.
LOAD
RTRIM DOWN
+VOUT
+VIN
–VIN
ON/OFF
CONTROL TRIM
+SENSE
–VOUT
–SENSE
LOAD
RTRIM UP
+VOUT
+VIN
–VIN
ON/OFF
CONTROL TRIM
+SENSE
–VOUT
–SENSE
Figure 5. Trim Connections To Increase Output Voltages Using Fixed Resistors
Figure 6. Trim Connections To Decrease Output Voltages Using Fixed Resistors
UP VO – 3.3
RT (k7) =–10.2
13.3(VO – 1.226)
3.3 – VO
RT (k7) =–10.2
16.31
DOWN
UP VO – 5
RT (k7) =–10.2
20.4(VO – 1.226)
5 – VO
RT (k7) =–10.2
25.01
DOWN
UP VO – 12
RT (k7) =–10.2
49.6(VO – 1.226)
12 – VO
RT (k7) =–10.2
60.45
DOWN
UP VO – 15
RT (k7) =–10.2
62.9(VO – 1.226)
15 – VO
RT (k7) =–10.2
76.56
DOWN
UQQ-3.3/25-Q12, UQQ-3.3/25-Q48
UQQ-5/17-Q12, UQQ-5/20-Q48
UQQ-12/8-Q12, UQQ-12/8-Q48
UQQ-15/7-Q12
UP VO – 24
RT (k7) =–10.2
101 × (VO – 1.226)
24 – VO
RT (k7) =–10.2
124.2
DOWN
UQQ-24/4-Q12
Trim Up Trim Down
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UQQ Series
Wide Input Range Single Output DC-DC Converters
MDC_UQQ.D06 Page 16 of 18
Figure 7. Model UQQ Heatsink Assembly Diagram
UQQ Series Aluminum Heatsink
Please note – The UQQ series shares the same heatsink kits as the UVQ
series. Therefore, when ordering these heat sinks, use the model numbers
below which end with the ‘UVQ’ suffi x. The UQQ series converter baseplate
can be attached either to an enclosure wall or a heatsink to remove heat from
internal power dissipation. The discussion below concerns only the heatsink
alternative. The UQQ’s are available with a low-profi le extruded aluminum
heatsink kit, models HS-QB25-UVQ, HS-QB50-UVQ, and HS-QB100-UVQ.
This kit includes the heatsink, thermal mounting pad, screws and mounting
hardware. See the assembly diagram below. Do not overtighten the screws in
the tapped holes in the converter. This kit adds excellent thermal performance
without sacrifi cing too much component height. See the Mechanical Outline
Drawings for assembled dimensions. If the thermal pad is fi rmly attached, no
thermal compound (“thermal grease”) is required.
When assembling these kits onto the converter, include ALL kit hardware to
assure adequate mechanical capture and proper clearances. Thread relief is
0.090" (2.3mm).
Thermal Performance
The HS-QB25-UVQ heatsink has a thermal resistance of 12 degrees Celsius
per Watt of internal heat dissipation with “natural convection” airfl ow (no
fans or other mechanical airfl ow) at sea level altitude. This thermal resistance
assumes that the heatsink is fi rmly attached using the supplied thermal pad
and that there is no nearby wall or enclosure surface to inhibit the airfl ow. The
thermal pad adds a negligible series resistance of approximately 0.5°C/Watt so
that the total assembled resistance is 12.5°C/Watt.
Be aware that we need to handle only the internal heat dissipation, not the full
power output of the converter. This internal heat dissipation is related to the
effi ciency as follows:
Power Dissipation [Pd] = Power In – Power Out [1]
Power Out / Power In = Effi ciency [in %] / 100 [2]
Power Dissipation [Pd] = Power In x (1 –Effi ciency%/100) [3]
Power Dissipation [Pd] = Power Out x (1 / (Effi ciency%/100) - 1) [4]
Effi ciency of course varies with input voltage and the total output power. Please
refer to the Performance Curves.
Since many applications do include fans, here is an approximate equation to
calculate the net thermal resistance:
R [at airfl ow] = R [natural convection] / (1 + (Airfl ow in LFM) x
[Airfl ow Constant]) [5]
Where,
R [at airfl ow] is the net thermal resistance (in °C/W) with the amount of
airfl ow available and,
R [natural convection] is the still air total path thermal resistance or in this
case 12.5°C/Watt and,
“Airfl ow in LFM” is the net air movement fl ow rate immediately at the converter.
This equation simplifi es an otherwise complex aerodynamic model but is a
useful starting point. The “Airfl ow Constant” is dependent on the fan and enclo-
sure geometry. For example, if 200 LFM of airfl ow reduces the effective natural
convection thermal resistance by one half, the airfl ow constant would be
0.005. There is no practical way to publish a “one size fi ts all” airfl ow constant
because of variations in airfl ow direction, heatsink orientation, adjacent walls,
enclosure geometry, etc. Each application must be determined empirically and
the equation is primarily a way to help understand the cooling arithmetic.
This equation basically says that small amounts of forced airfl ow are quite
effective removing the heat. But very high airfl ows give diminishing returns.
Conversely, no forced airfl ow causes considerable heat buildup. At zero airfl ow,
cooling occurs only because of natural convection over the heatsink. Natural
convection is often well below 50 LFM, not much of a breeze.
While these equations are useful as a conceptual aid, most users fi nd it very
diffi cult to measure actual airfl ow rates at the converter. Even if you know
the velocity specifi cations of the fan, this does not usually relate directly to
the enclosure geometry. Be sure to use a considerable safety margin doing
thermal analysis. If in doubt, measure the actual heat sink temperature with
a calibrated thermocouple, RTD or thermistor. Safe operation should keep the
heat sink below 100°C.
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UQQ Series
Wide Input Range Single Output DC-DC Converters
MDC_UQQ.D06 Page 17 of 18
Calculating Maximum Power Dissipation
To determine the maximum amount of internal power dissipation, fi nd the
ambient temperature inside the enclosure and the airfl ow (in Linear Feet per
Minute – LFM) at the converter. Determine the expected heat dissipation using
the Effi ciency curves and the converter Input Voltage. You should also compen-
sate for lower atmospheric pressure if your application altitude is considerably
above sea level.
The general proceedure is to compute the expected temperature rise of the
heatsink. If the heatsink exceeds +100°C. either increase the airfl ow and/or
reduce the power output. Start with this equation:
Internal Heat Dissipation [Pd in Watts] = (Ts – Ta)/R [at airfl ow] [6]
where “Ta” is the enclosure ambient air temperature and,
where “Ts” is the heatsink temperature and,
where “R [at airfl ow]” is a specifi c heat transfer thermal resistance (in
degrees Celsius per Watt) for a particular heat sink at a set airfl ow rate. We
have already estimated R [at airfl ow] in the equations above.
Note particularly that Ta is the air temperature inside the enclosure at the
heatsink, not the outside air temperature. Most enclosures have higher
internal temperatures, especially if the converter is “downwind” from other
heat-producing circuits. Note also that this “Pd” term is only the internal heat
dissipated inside the converter and not the total power output of the converter.
We can rearrange this equation to give an estimated temperature rise of the
heatsink as follows:
Ts = (Pd x R [at airfl ow]) + Ta [7]
These model numbers are correct for the UQQ series.
Heat Sink Example
Assume an effi ciency of 92% and power output of 100 Watts. Using equation
[4], Pd is about 8.7 Watts at an input voltage of 48 Volts. Using +30°C ambient
temperature inside the enclosure, we wish to limit the heat sink temperature to
+90°C maximum baseplate temperature to stay well away from thermal shut-
down. The +90°C. fi gure also allows some margin in case the ambient climbs
above +30°C or the input voltage varies, giving us less than 92% effi ciency.
The heat sink and airfl ow combination must have the following characteristics:
8.7 W = (90-30) / R[airfl ow] or,
R[airfl ow] = 60/8.7 = 6.9°C/W
Since the ambient thermal resistance of the heatsink and pad is 12.5°C/W, we
need additional forced cooling to get us down to 6.9°C/W. Using a hypothetical
airfl ow constant of 0.005, we can rearrange equation [5] as follows:
(Required Airfl ow, LFM) x (Airfl ow Constant) = R[Nat.Convection] /
R[at airfl ow] –1, or,
(Required Airfl ow, LFM) x (Airfl ow Constant) = 12.5/6.9 –1 = 0.81
and, rearranging again,
(Required Airfl ow, LFM) = 0.81/0.005 = 162 LFM
162 LFM is the minumum airfl ow to keep the heatsink below +90°C. Increase
the airfl ow to several hundred LFM to reduce the heatsink temperature further
and improve life and reliability.
Heatsink Kit *
Model Number
Still Air (Natural convection)
thermal resistance
Heatsink height
(see drawing)
HS-QB25-UVQ 12°C/Watt 0.25" (6.35mm)
HS-QB50-UVQ 10.6°C/Watt 0.50" (12.7mm)
HS-QB100-UVQ 8°C/Watt 1.00" (25.4mm)
* Kit includes heatsink, thermal pad and mounting hardware. These are
non-RoHS models. For RoHS-6 versions, add “-C” to the model number
(e.g., HS-QB25-UVQ-C).
0.10
(2.54)
*
* UQQ SERIES HEATSINKS ARE AVAILABLE IN 3 HEIGHTS:
0.25 (6.35), 0.50 (12.70) AND 1.00 (25.4)
1.45
(36.83)
2.28
(57.91)
MATERIAL: BLACK ANODIZED ALUMINUM
1.03
(26.16)
1.860
(47.24)
0.140 DIA. (3.56) (4 PLACES)
Dimensions in inches (mm)
Figure 8. Optional Heatsink
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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. © 2019 Murata Power Solutions, Inc.
Murata Power Solutions, Inc.
129 Flanders Road, Westborough, MA 01581 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/
UQQ Series
Wide Input Range Single Output DC-DC Converters
MDC_UQQ.D06 Page 18 of 18
Figure 9. Vertical Wind Tunnel
IR Video
Camera
IR Transparent
optical window Variable
speed fan
Heating
element
Ambient
temperature
sensor
Airflow
collimator
Precision
low-rate
anemometer
3” below UUT
Unit under
test (UUT)
Vertical Wind Tunnel
Murata Power Solutions employs a computer controlled custom-
designed closed loop vertical wind tunnel, infrared video camera
system, and test instrumentation for accurate airfl ow and heat dis-
sipation analysis of power products. The system includes a precision
low fl ow-rate anemometer, variable speed fan, power supply input
and load controls, temperature gauges, and adjustable heating ele-
ment.
The IR camera monitors the thermal performance of the Unit Under
Test (UUT) under static steady-state conditions. A special optical port
is used which is transparent to infrared wavelengths.
Both through-hole and surface mount converters are soldered down
to a 10" x 10" host carrier board for realistic heat absorption and
spreading. Both longitudinal and transverse airfl ow studies are pos-
sible by rotation of this carrier board since there are often signifi cant
differences in the heat dissipation in the two airfl ow directions. The
combination of adjustable airfl ow, adjustable ambient heat, and
adjustable Input/Output currents and voltages mean that a very wide
range of measurement conditions can be studied.
The collimator reduces the amount of turbulence adjacent to the UUT
by minimizing airfl ow turbulence. Such turbulence infl uences the
effective heat transfer characteristics and gives false readings. Excess
turbulence removes more heat from some surfaces and less heat
from others, possibly causing uneven overheating.
Both sides of the UUT are studied since there are different thermal
gradients on each side. The adjustable heating element and fan, built-in
temperature gauges, and no-contact IR camera mean that power supplies
are tested in real-world conditions.