UHE Series
Isolated, High Effi ciency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
For full details go to
www.murata-ps.com/rohs
www.murata-ps.com
www.murata-ps.com
email: sales@murata-ps.com
28 Mar 2011 MDC_UHE_12-30W Series.B16 Page 1 of 16
FEATURES
The most IOUT/POUT in this format
Lower priced than bricks
Small 1.6" x 2" x 0.4" plastic package
with standard 2" x 2" pinout
Output confi gurations:
1.2/1.5/1.8/2.5VOUT @ 10 Amps
3.3/5VOUT @ 25 Watts
5/12/15VOUT @ 30 Watts
Five input ranges from 9-75 Volts
Effi ciencies as high as 91.5%
Stable no-load operation
Optional Sense pins for low VOUT
Thermal shutdown, I/O protected
1500 Vdc I/O BASIC Insulation
UL/EN60950-1 certifi ed (2nd Edition);
CE marked for Q48 models
RoHS compliant
The UHE 12-30W Series of high-effi ciency,
isolated DC/DC’s provide output power ranging
from 10 Amps @ 1.2V to 2 Amps @ 15V. Offering
both 2:1 and 4:1 input voltage ranges, UHE’s meet
VIN requirements from 9 to 75 Volts.
Taking full advantage of the synchronous-
rectifi er, forward topology, UHEs boast outstanding
effi ciency (some models exceed 91%) enabling
full-power operation to ambient temperatures as
high as +60°C, without air fl ow. Assembled using
fully automated, SMT-on-pcb techniques, UHEs
provide stable no-load operation, excellent line
(±0.1%) and load (±0.15%) regulation, quick step
response (200μsec), and low output ripple/noise
(50-100mVp-p). Additionally, the UHEs unique
output design eliminates one of the topology’s few
shortcomings–output reverse conduction.
All devices feature full I/O fault protection
including: input overvoltage and undervoltage
shutdown, precise output overvoltage protection
(a rarity on low-voltage outputs), output current
limiting, short-circuit protection, and thermal
shutdown.
All UHE models incorporate a VOUT Trim function
and an On/Off Control pin (positive or negative
polarity). Low-voltage models (1.2V to 5V) offer
optional sense pins facilitating either remote load
regulation or current sharing for true N+1 redun-
dancy. All models are certifi ed to the BASIC insula-
tion requirements of UL/EN60950-1 (2nd Edition),
and 48VIN (75V max.) models carry the CE mark.
Selected models are RoHS compliant (Reduction
of Hazardous Substances).
PRODUCT OVERVIEW
–OUTPUT
(7)
–SENSE
(8)
+INPUT
(1)
–INPUT
(2)
PWM
CONTROLLER
REFERENCE &
ERROR AMP
THERMAL
SHUTDOWN
OPTO
ISOLATION
OPTO
ISOLATION
UVLO & OVLO
COMPARATORS
OVERVOLTAGE
COMPARATOR
ON/OFF
CONTROL
(4)
VOUT TRIM
(9)
+OUTPUT
(6)
+SENSE
(5)
SWITCH
CONTROL
*One phase of two is shown.
c Optional comparator feedback. Contact MPS.
d Sense pins are optional on 1.2-5VOUT models ("R" suffi x).
Typical topology is shown.
Typical units
Figure 1. Simplifi ed Block Diagram
Housed in smaller, 1.6" x 2" x 0.40" (41 x 51 x 10.2mm)
packages carrying the standard 2" x 2" pinout, MPS’s new
UHE Series DC/DC Converters deliver more current/power
(up to 10A/30W) than currently available from either
package size.
UHE Series
Isolated, High Effi ciency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
www.murata-ps.com email: sales@murata-ps.com
28 Mar 2011 MDC_UHE_12-30W Series.B16 Page 2 of 16
PERFORMANCE SPECIFICATIONS AND ORDERING GUIDE ➀
Model Family
(See model numbering
on page 13)
Output Input
Effi ciency Package
(Case/
Pinout)
VOUT
(Volts)
IOUT
(Amps)
R/N (mVp-p)➁ Regulation (Max.) VIN Nom.
(Volts)
Range
(Volts)
IIN ➂
(mA/A)
Typ. Max. Line Load ➃Min. Typ.
UHE-1.2/10000-D12-C 1.2 10 80 120 ±0.1% ±0.36/0.9% 12 9-18 75/1.2 81% 83.5% C32, P51/52
UHE-1.2/10000-D24-C 1.2 10 80 120 ±0.1% ±0.25/0.9% 24 18-36 35/0.6 82.2% 83% C32, P51/52
UHE-1.2/10000-D48-C 1.2 10 80 120 ±0.1% ±0.3/0.625% 48 36-75 35/0.31 81% 83% C32, P51/52
UHE-1.5/10000-D24-C 1.5 10 55 80 ±0.1% ±0.15/0.625% 24 18-36 35/0.73 84% 85.5% C32, P51/52
UHE-1.5/10000-D48-C 1.5 10 55 80 ±0.1% ±0.15/0.625% 48 36-75 35/0.38 82.5% 84% C32, P51/52
UHE-1.8/10000-D24-C 1.8 10 70 90 ±0.1% ±0.15/0.625% 24 18-36 35/0.86 85.5% 87% C32, P51/52
UHE-1.8/10000-D48-C 1.8 10 50 75 ±0.1% ±0.15/0.625% 48 36-75 35/0.44 83.5% 85% C32, P51/52
UHE-2.5/10000-D24-C 2.5 10 50 100 ±0.075% ±0.15/0.5% 24 18-36 35/1.23 87.7% 88.7% C32, P51/52
UHE-2.5/10000-D48-C 2.5 10 65 120 ±0.1% ±0.15/0.5% 48 36-75 35/0.59 87% 88.5% C32, P51/52
UHE-3.3/7500-Q12-C 3.3 7.5 70 90 ±0.25% ±0.2/0.5% 24 9-36 50/1.17 85% 88% C32, P51/52
UHE-3.3/7500-Q48-C 3.3 7.5 90 125 ±0.35% ±0.5% 48 18-75 38/0.57 88% 90% C32, P51/52
UHE-3.3/7500-D48-C 3.3 7.5 80 100 ±0.2% ±0.5% 48 36-75 35/0.6 86.7% 88.7% C32, P51/52
UHE-3.3/7500-D48T-C 3.3 7.5 80 100 ±0.2% ±0.5% 48 36-75 35/0.58 85.5% 88.2% C32, P51
UHE-5/5000-Q12-C 5 5 50 70 ±0.1% ±0.15/0.3% 24 9-36 50/1.2 86% 87.5% C32, P51/52
UHE-5/5000-Q48-C 5 5 60 90 ±0.05% ±0.15/0.3% 48 18-75 38/0.58 87.5% 90% C32, P51/52
UHE-5/6000-Q12-C 5 6 50 70 ±0.1% ±0.3% 24 9-36 50/1.44 86.5% 87% C32, P51/52
UHE-5/6000-D48-C 5 6 80 100 ±0.2% ±0.25/0.5% 48 36-75 45/0.7 87.5% 89% C32, P51/52
UHE-5/6000-D48T-C 5 6 65 100 ±0.2% ±0.5% 48 36-75 45/0.7 87.5% 91% C32, P51
UHE-5/6000-Q48T-C 5 6 55 80 ±0.08% ±0.15% 48 18-75 38/0.69 88.5% 90% C32, P51
UHE-12/2500-Q12-C 12 2.5 125 165 ±0.1% ±0.5% 24 9-36 42/1.43 85.5% 87.5% C32, P51
UHE-12/2500-D12-C 12 2.5 65 100 ±0.2% ±0.3% 12 9-18 90/2.81 87% 89% C32, P51
UHE-12/2500-D24-C 12 2.5 65 100 ±0.2% ±0.3% 24 18-36 55/1.39 88% 90% C32, P51
UHE-12/2500-Q48-C 12 2.5 100 120 ±0.1% ±0.5% 48 18-75 30/0.6 88% 90% C32, P51
UHE-12/2500-D48-C 12 2.5 60 100 ±0.2% ±0.3% 48 36-75 30/0.7 90% 92% C32, P51
UHE-15/2000-D12-C 15 2 70 100 ±0.2% ±0.3% 12 9-18 110/2.81 87% 89% C32, P51
UHE-15/2000-Q12-C 15 2 70 100 ±0.05% ±0.15% 24 9-36 50/1.4 88% 89.5% C32, P51
UHE-15/2000-D24-C 15 2 70 100 ±0.2% ±0.3% 24 18-36 70/1.39 88% 90% C32, P51
UHE-15/2000-Q48-C 15 2 100 150 ±0.1% ±0.5% 48 18-75 45/0.69 88% 90% C32, P51
UHE-15/2000-D48-C 15 2 70 100 ±0.2% ±0.3% 48 36-75 35/0.7 90% 92% C32, P51
Typical at TA = +25°C under nominal line voltage and full-load conditions, unless noted.
Ripple/Noise (R/N) is tested/specifi ed over a 20MHz bandwidth. All models are specifi ed with
an external 0.47µF multi-layer ceramic capacitor installed across their output pins.
Nominal line voltage, no-load/full-load conditions.
Devices have no minimum-load requirements and will regulate under no-load conditions.
Regulation specifi cations describe the output voltage deviation as the line voltage or load
(with/without sense option) is varied from its nominal/midpoint value to either extreme.
UHE Series
Isolated, High Effi ciency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
www.murata-ps.com email: sales@murata-ps.com
28 Mar 2011 MDC_UHE_12-30W Series.B16 Page 3 of 16
PART NUMBER STRUCTURE
Options and Adaptations
Optional Functions and Part Number Suffi xes
The versatile UHE, 12-30W DC/DC converters offer numerous electrical and
mechanical options. Per the Ordering Guide on page 2, the trailing DXX or QXX
(where XX stands for 12, 24 or 48VIN) in each part number pertains to the base
part number. Part-number suffi xes are added after this input identifi cation,
indicating the selection of standard options. The resulting part number is a
"standard product" and is available to any customer desiring that particular
combination of options.
The On/Off Control function on pin 4 employs a positive polarity (on = open
or "high," no suffi x). To request a negative polarity on this pin/function, add an
"N" suffi x to the part number. Standard models have no pins in the pins 5 and
8 positions. For 5-10A models (1.2-5VOUT), ±Sense pin/functions can be added
to these positions (see pinout P52) by adding an "R" suffi x. An "NR" suffi x can
be added for both negative-polarity and sense-pin options. See below.
Suffi x Description
Blank Positive polarity On/Off Control function (pin 4), VOUT trim (pin 9),
no Sense pins, pin length 0.2 inches (5.08 mm).
N Add Negative polarity on the On/Off Control function, VOUT trim (pin 9),
no Sense pins.
R Positive polarity on the On/Off Control function, VOUT trim (pin 9),
±Sense pins in the pin 5 and pin 8 positions (available for low VOUT
models only). Available under special order.
NR Negative polarity on the On/Off Control function, VOUT trim (pin 9),
+/–Sense pins in the pin 5 and pin 8 positions (available for low VOUT
models only). Available under special order.
Alternate pin lengths are available under special order
T Alternate trim confi guration. Special order only.
-C Full RoHS-6 compliance.
-Y RoHS-5 hazardous substance compliance with lead exception. RoHS-5
compliance requires a scheduled quantity order. Not all RoHS-5 “-Y”
models are available. Please contact Product Marketing for further
information.
Adaptations
There are various additional confi gurations available on UHE, 12-30W DC/DCs.
Because designating each of them with a standard part-number suffi x is not
always feasible, such are designated by MPS in assigning a 5-digit “adaptation
code” after the part-number suffi xes. Contact MPS directly if you are interested
in your own set of options/adaptations. Our policy for minimum order quantities
may apply. Consequently, the following products are offered for sale:
UHE-5/6000-D48N-30749
UHE-5/6000-D48N-30749-Y (RoHS-5)
Standard product, 48VIN, 5V/6A output with negative polarity on the On/Off
Control function, modifi ed Trim function (5% trim up = 9.09kΩ, 5% trim down
= 3.83kΩ, compatible with UEP-30750), integrated soft start and with input
OVP and thermal shutdown removed.
RoHS-5 compliance refers to the exclusion of the six hazardous substances
in the RoHS specifi cation with the excepion of lead. MPS’s RoHS-5 products
use all the conforming RoHS materials, however our solders contain lead.
UHE-3.3/7500-D48THL2-Y and
UHE-5/6000-D48THL2-Y (RoHS-5)
Special trim, conformal coating, 3.68mm pin length, positive on/off polarity,
RoHS-5 hazardous substance compliance (with lead).
Maximum Rated Output
Current in mA
High Effi ciency
Output Confi guration:
U = Unipolar
Nominal Output Voltage:
1.2, 1.5, 1.8, 2.5, 3.3, 5, 12 or 15
U HE -/D48-3.3 7500 N
Note: Some model number
combinations may not be available.
Contact Murata Power Solutions.
Input Voltage Range:
D12 = 9-18 Volts
D24 = 18-36 Volts
D48 = 36-75 Volts
Q12 = 9-36 Volts
Q48 = 18-75 Volts
On/Off Polarity
Blank = Positive polarity, standard
N = Negative polarity
R = See Below
NR = See Below
C
RoHS-6 hazardous substance compliant
(Does not claim EU exemption 7b, lead in solder)
-
optional, special order
}
UHE Series
Isolated, High Effi ciency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
www.murata-ps.com email: sales@murata-ps.com
28 Mar 2011 MDC_UHE_12-30W Series.B16 Page 4 of 16
MECHANICAL SPECIFICATIONS
* Pins 5 and 8 are installed for optional R-suffi x versions of 1.2-5VOUT models.
If installed, always connect the sense pins either to a remote load or to their
respective VOUT pin.
See page 3 for complete Part Number structure & ordering details.
6
PLASTIC CASE
0.040 ±0.001 DIA.
(1.016 ±0.025)
0.20 MIN
(5.08)
2.00
(50.8)
0.40
(10.2)
STANDOFF
0.020 (0.5)
1.800
(45.72)
0.10
(2.54)
0.200
(5.1)
0.200
(5.1)
0.20
(5.1)
0.400
(10.16)
0.100
(2.5)
1.60
(40.6)
BOTTOM VIEW
9
5
8
7
1
2
4
3 0.400 (10.16)
2 EQ. SP. @
0.200 (5.08)
0.400
(10.2)
INPUT/OUTPUT CONNECTIONS
Pin Function P51 Function P52
1+Input +Input
2–Input –Input
3No Pin No Pin
4On/Off Control On/Off Control
5No Pin Sense*
6+Output +Output
7–Output –Output
8No Pin –Sense*
9Tr i m Tr i m
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˚
UHE Series
Isolated, High Effi ciency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
www.murata-ps.com email: sales@murata-ps.com
28 Mar 2011 MDC_UHE_12-30W Series.B16 Page 5 of 16
Output
Overvoltage Protection: Magnetic feedback
1.2V Outputs 1.5-2.1 Volts
1.5V Outputs 1.8-2.4 Volts
1.8V Outputs 2.2-2.8 Volts
2.5V Outputs 2.8 to 3.2 Volts
3.3V Outputs 4 to 4.8 Volts
5V Outputs 6.1-7.5 Volts
12V Outputs 12.7-13.5 Volts
15V Outputs 15.8-16.2 Volts
Maximum Capacitive Loading: 10,000μF (1.2-5VOUT)
(Low ESR capacitor) 2,000μF (12-15VOUT)
Dynamic Characteristics
Dynamic Load Response:
(50-100% load step to ±3% VOUT) 200μsec maximum
➇
Start-Up Time: ➇ 8msec typical
V
IN to VOUT and On/Off to VOUT 15msec maximum
UHE-15/2000-Q12 30mS typ., 50mS max.
Switching Frequency 150-350kHz (model dependent)
Environmental
MTBF➈ TBC million hours
Operating Temperature (Ambient): ➉ –40 to +85°C with Derating
(see Derating Curves)
Thermal Shutdown +115°C to +130°C
Storage Temperature –55 to +125°C
Flammability UL 94 V-0
Physical
Dimensions 1.6" x 2" x 0.40" (40.64 x 50.8 x 10.16mm)
Case Material Diallyl Phthalate
Pin Material Gold-plated copper alloy
Weight 1.51 ounces (46.9 grams)
Primary to Secondary Insulation Level Basic
Performance/Functional Specifi cations
Typical @ TA = +25°C under nominal line voltage and full-load conditions, unless noted. ➀ ➁
Input
Input Voltage Range:
D12 Models (start up at 10V max.) 9-18 Volts (12V nominal)
Q12 Models (start up at 10V max.) 9-36 Volts (24V nominal)
D24 Models 18-36 Volts (24V nominal)
Q48 Models 18-75 Volts (48V nominal)
D48 Models 36-75 Volts (48V nominal)
Overvoltage Shutdown:
D12 Models 18.5-23 Volts
Q12/D24 Models 37-42 Volts
D48/Q48 Models Not applicable
Start-Up Threshold: ➁
D12/Q12 Models 9.4-10 Volts
D24/Q48 Models 15.5-18 Volts
D48 Models 33.5-36 Volts
Undervoltage Shutdown: ➁
D12/Q12 Models 7.0-8.8 Volts
D24/Q48 Models 15-17 Volts
D48 Models 32-35.5 Volts
Input Current:
Normal Operating Conditions See Ordering Guide
Standby Mode (Off, OV, UV) 5mA
Input Refl ected Ripple Current ➂ 2.5-10mAp-p
Input Filter Type LC or Pi type
Reverse-Polarity Protection Brief duration, 5A maximum
Remote On/Off Control (Pin 4): ➃
Positive Logic (Standard) On = open, open collector, or to +15V
applied. IIN = 2.6mA max.
Off = pulled low to 0-0.8V. IIN = 2mA max.
Negative Logic ("N" Suffi x Models) On = pulled low to 0-0.8V. IIN = 6mA max.
Off = open, open collector or to +15V
applied. IIN = 1mA max.
Output
VOUT Accuracy (50% load):
Initial ±1.5%
Temperatue Coeffi cient ±0.02% per °C
Extreme(5) ±3%
Minimum Loading for Specifi cation: ➁ No load
Ripple/Noise (20MHz BW) ➀ See Ordering Guide
Line/Load Regulation See Ordering Guide
Effi ciency See Ordering Guide
VOUT Trim Range(6) ±5% minimum (±10% for T models)
Remote Sense Compensation ➁ ±5%
Isolation Voltage:
Input-to-Output 1500Vdc minimum (BASIC)
Isolation Capacitance 650pF
Isolation Resistance 100M:
Current Limit Inception (@98%VOUT): ➆
10 Amp Models 12-15 Amps
7.5 Amp Models 8.2-11.5 Amps
5/6 Amp Models 6.5-8.5 Amps
2.5 Amp Models 2.6-4 Amps
2.0 Amp Models 2.1-3 Amps
Short Circuit Current (Hiccup) 1.5-2.3 Amps
➀ All models are tested and specifi ed with a single, external, 0.47μF, multi-layer ceramic output
capacitor and no external input capacitors, unless otherwise noted. All models will effectively
regulate under no-load conditions (with perhaps a slight increase in output ripple/noise).
➁ See Technical Notes/Performance Curves for additional explanations and details.
➂ Input Ripple Current is tested/specifi ed over a 5-20MHz bandwidth with an external 33μF input
capacitor and a simulated source impedance of 220μF and 12μH. See I/O Filtering, Input Ripple
Current and Output Noise for details.
➃ The On/Off Control is designed to be driven with open-collector (or equivalent) logic or the applica-
tion of appropriate voltages (referenced to –Input (pin 2)). Applying a voltage to the On/Off Control
pin when no input voltage is applied to the converter can cause permanent damage. See Remote
On/Off Control for more details.
➄ Extreme Accuracy refers to the accuracy of either trimmed or untrimmed output voltages over all
normal operating ranges and combinations of input voltage, output load and temperature.
➅ Tie the Output Trim pin (pin 9) to +Output (pin 6) for maximum trim down or to –Output (Output
Return/Common, pin 7) for maximum trim up. See Output Trimming for detailed trim equations.
➆ The Current-Limit-Inception point is the output current level at which the converter's power-limiting
circuitry drops the output voltage 2% from its initial value. See Output Current Limiting and
Short-Circuit Protection for more details.
➇ For Start-Up-Time specifi cations, output settling time is defi ned as the output voltage having
reached ±1% of its fi nal value at maximum load current.
➈ MTBF’s are calculated using TELCORDIA SR-332 Method 1 Case, ground fi xed, +25°C ambient air
and full-load conditions. Contact MPS for demonstrated life-test data.
➉ All models are fully operational and meet all published specifi cations, including "cold start," at –40°C.
Use only as much output fi ltering as needed and no more. Larger caps (especially low-ESR ceramic
types) may slow transient response or degrade dynamic performance. Thoroughly test your system
with all components installed.
UHE Series
Isolated, High Effi ciency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
www.murata-ps.com email: sales@murata-ps.com
28 Mar 2011 MDC_UHE_12-30W Series.B16 Page 6 of 16
5(%$%FFICIENCYVS,OAD #!MBIENT
/UTPUT#URRENT!MPS
%FFICIENCY
6
).
6
6
).
6
6
).
6
5(%$%FFICIENCYVS,OAD #!MBIENT
/UTPUT#URRENT!MPS
%FFICIENCY
6
).
6
6
).
6
6
).
6
5(%$%FFICIENCYVS,OAD #!MBIENT
/UTPUT#URRENT!MPS
%FFICIENCY
6
).
6
6
).
6
6
).
6
5(%$%FFICIENCYVS,OAD #!MBIENT
/UTPUT#URRENT!MPS
%FFICIENCY
6
).
6
6
).
6
6
).
6
/UTPUT#URRENT!MPS
%FFICIENCY
6
).
6
6
).
6
6
).
6
5(%$%FFICIENCYVS,OAD #!MBIENT
Typical Performance Curves
5(%1%FFICIENCYVS,OAD #!MBIENT
/UTPUT#URRENT!MPS
%FFICIENCY
6
).
6
6
).
6
6
).
6
UHE Series
Isolated, High Effi ciency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
www.murata-ps.com email: sales@murata-ps.com
28 Mar 2011 MDC_UHE_12-30W Series.B16 Page 7 of 16
5(%$%FFICIENCYVS,OAD #!MBIENT
/UTPUT#URRENT!MPS
%FFICIENCY
6
).
6
6
).
6
6
).
6
5(%1%FFICIENCYVS,OAD #!MBIENT
/UTPUT#URRENT!MPS
%FFICIENCY
6
).
6
6
).
6
6
).
6
6
).
6
5(%$%FFICIENCYVS,OAD #!MBIENT
/UTPUT#URRENT!MPS
%FFICIENCY
6
).
6
6
).
6
6
).
6
5(%1%FFICIENCYVS,OAD #!MBIENT
/UTPUT#URRENT!MPS
%FFICIENCY
6
).
6
6
).
6
6
).
6
6
).
6
0.49 0.99 1.49 1.99 2.49 3.00 3.50 4.00 4.50 5.00 5.50 6.00
65
69
73
77
81
85
89
93
UHE-5/6000-Q12 Efficiency vs. Load @ +25°C Ambient
Output Current (Amps)
Efficiency (%)
V
IN
= 9V
V
IN
= 36V
V
IN
= 12V
V
IN
= 24V
5(%1%FFICIENCYVS,OAD #!MBIENT
/UTPUT#URRENT!MPS
%FFICIENCY
6
).
6
6
).
6
6
).
6
Typical Performance Curves
UHE Series
Isolated, High Effi ciency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
www.murata-ps.com email: sales@murata-ps.com
28 Mar 2011 MDC_UHE_12-30W Series.B16 Page 8 of 16
5(%$%FFICIENCYVS,OAD #!MBIENT
/UTPUT#URRENT!MPS
%FFICIENCY
6
).
6
6
).
6
6
).
6
5(%$%FFICIENCYVS,OAD #!MBIENT
/UTPUT#URRENT!MPS
%FFICIENCY
6
).
6
6
).
6
6
).
6
5(%$%FFICIENCYVS,OAD #!MBIENT
/UTPUT#URRENT!MPS
%FFICIENCY
6
).
6
6
).
6
6
).
6
5(%$%FFICIENCYVS,OAD #!MBIENT
/UTPUT#URRENT!MPS
%FFICIENCY
6
).
6
6
).
6
6
).
6
5(%$%FFICIENCYVS,OAD #!MBIENT
/UTPUT#URRENT!MPS
%FFICIENCY
6
).
6
6
).
6
6
).
6
5(%$%FFICIENCYVS,OAD #!MBIENT
/UTPUT#URRENT!MPS
%FFICIENCY
6
).
6
6
).
6
6
).
6
Typical Performance Curves
UHE Series
Isolated, High Effi ciency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
www.murata-ps.com email: sales@murata-ps.com
28 Mar 2011 MDC_UHE_12-30W Series.B16 Page 9 of 16
/UTPUT#IURRENT!MPS
!MBIENT4EMPERATUREo#
n
6).,&-
6).,&-
6).34),,!)2
5(%$4EMPERATURE$ERATING
/UTPUT#IURRENT!MPS
!MBIENT4EMPERATUREo#
n
6).34),,!)2
6).,&-
6).34),,!)2
6).,&-
5(%$4EMPERATURE$ERATING
6).,&-
/UTPUT#IURRENT!MPS
!MBIENT4EMPERATUREo#
n
6).,&-
6).,&-
6).34),,!)2
5(%$AND5(%$4EMPERATURE$ERATING
/UTPUT#IURRENT!MPS
!MBIENT4EMPERATUREo#
n
6).,&-
6).,&-
6).34),,!)2
5(%$AND5(%$4EMPERATURE$ERATING
5(%1%FFICIENCYVS,OAD #!MBIENT
/UTPUT#URRENT!MPS
%FFICIENCY
6
).
6
6
).
6
6
).
6
5(%1%FFICIENCYVS,OAD #!MBIENT
/UTPUT#URRENT!MPS
%FFICIENCY
6
).
6
6
).
6
6
).
6
Typical Performance Curves
UHE Series
Isolated, High Effi ciency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
www.murata-ps.com email: sales@murata-ps.com
28 Mar 2011 MDC_UHE_12-30W Series.B16 Page 10 of 16
/UTPUT0OWER7ATTS
!MBIENT4EMPERATUREo#
n
5(%$4EMPERATURE$ERATING
6).34),,!)2
6).34),,!)2
6).34),,!)2
6).,&-
6).,&-
/UTPUT0OWER7ATTS
!MBIENT4EMPERATUREo#
n
5(%14EMPERATURE$ERATING
6).34),,!)2
6).,&-
6).34),,!)2
6).,&-
6).,&-
6).,&-
Output Power (Watts)
Ambient Temperature (oC)
UHE-3.3/7500-Q48 Maximum Current Temperature Derating
(VIN = 48V, airflow = 300 LFM)
300 LFM
40 50 60 70 80 90 100
0
1
2
3
4
5
6
7
8
Output Power (Watts)
Ambient Temperature (oC)
UHE-5/5000-Q48 Maximum Current Temperature Derating
(VIN = 48V, airflow = 300 LFM)
300 LFM
0
1
2
3
4
5
6
40 50 60 70 80 90 100
/UTPUT0OWER7ATTS
!MBIENT4EMPERATUREo#
n
5(%14EMPERATURE$ERATING
6).34),,!)2
6).,&-
6).34),,!)2
6).,&-
6).,&-
6).,&-
/UTPUT0OWER7ATTS
!MBIENT4EMPERATUREo#
n
5(%$4EMPERATURE$ERATING
.!452!,#/.6%#4)/.
Typical Performance Curves
UHE Series
Isolated, High Effi ciency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
www.murata-ps.com email: sales@murata-ps.com
28 Mar 2011 MDC_UHE_12-30W Series.B16 Page 11 of 16
/UTPUT0OWER7ATTS
!MBIENT4EMPERATUREo#
n
5(%$4EMPERATURE$ERATING
6).34),,!)2
6).34),,!)2
6).34),,!)2
6).,&-
6).,&-
/UTPUT0OWER7ATTS
!MBIENT4EMPERATUREo#
n
5(%AND5(%!LL-ODELS4EMPERATURE$ERATING
6).34),,!)2
$-ODELS/NLY
6).34),,!)2
6).34),,!)2
6).3TILL!IRFOR1-ODELS/NLY
Typical Performance Curves
UHE Series
Isolated, High Effi ciency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
www.murata-ps.com email: sales@murata-ps.com
28 Mar 2011 MDC_UHE_12-30W Series.B16 Page 12 of 16
TECHNICAL NOTES
Input Voltage:
Continuous:
D12 Models 23 Volts
D24/Q12 Models 42 Volts
D48/Q48 Models 81 Volts
Transient (100msec):
D12 Models 25 Volts
D24/Q12 Models 50 Volts
D48/Q48 Models 100 Volts
On/Off Control (pin 4) Max. Voltages
Referenced to –Input (pin 2)
No Suffi x +15 Volts
"N" Suffi x +7 Volts
Input Reverse-Polarity Protection Current must be <5 Amps. Brief
duration only. Fusing recommended.
Output Current Current limited. Devices can
withstand sustained output short
circuits without damage.
Case Temperature +100°C
Storage Temperature –55 to +125°C
Lead Temperature (soldering, 10 sec.) See soldering specifi cations
These are stress ratings. Exposure of devices to 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.
Absolute Maximum Ratings
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 MPS’s UHE 12-30 Watt DC/DC Converters, you should use
slow-blow type fuses, installed in the ungrounded input supply line, with values
no greater than the following.
Model Fuse Values in Amps
Output/Input D12 Q12 D24 Q48 D48
1.2 VOUT 3 -- 2 -- 1
1.5 VOUT 4 -- 2 -- 1
1.8 VOUT 5 -- 2.5 -- 1
2.5 VOUT 5 -- 2.5 -- 1
3.3 VOUT -- 7.5 - 3 1.5
5 VOUT --5-32
12 VOUT 63352
15 VOUT 63352
All relevant national and international safety standards and regulations must be
observed by the installer. For system safety agency approvals, the converters
must be installed in compliance with the requirements of the end-use safety
standard, e.g. IEC/EN/UL60950-1.
Input Undervoltage Shutdown and Start-Up Threshold
Under normal start-up conditions, devices will not begin to regulate 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
Undervoltage 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 interval of time 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/output
capacitance, and load. The UHE Series implements a soft start circuit that limits
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 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 Overvoltage Shutdown
All D12/Q12 and D24 Models of the UHE DC/DC converters are equipped with
Input Overvoltage Protection. Input voltages exceeding the input overvoltage
shutdown specifi cation listed in the Performance/Functional Specifi cations will
cause the device to shutdown. A built-in hysteresis for all models will not allow
the converter to restart until the input voltage is suffi ciently reduced.
All 48VIN models have this overvoltage shutdown function disabled because
of requirements for withstanding brief input surges to 100V for up to 100μsec
without output voltage interruption.
Please contact MPS to have input overvoltage shutdown for D48/Q48
models enabled.
Input Source Impedance
UHE 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. If the application has a high source impedance, low VIN
models can benefi t of increased external input capacitance.
I/O Filtering, Input Ripple Current, and Output Noise
All models in the UHE 12-30 Watt DC/DC Converters are tested/specifi ed for in-
put 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 capacitors (CIN in Figure 2) serve primarily as energy-storage
elements, minimizing line voltage variations caused by transient IR drops
UHE Series
Isolated, High Effi ciency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
www.murata-ps.com email: sales@murata-ps.com
28 Mar 2011 MDC_UHE_12-30W Series.B16 Page 13 of 16
CINVIN CBUS
LBUS
CIN = 33μF, ESR < 700m7 @ 100kHz
CBUS = 220μF, ESR < 100m7 @ 100kHz
LBUS = 12μH
+INPUT
–INPUT
CURRENT
PROBE
TO
OSCILLOSCOPE
+
–
C1
C1 = 0.47μF CERAMIC
C2 = NA
LOAD 2-3 INCHES (51-76mm) FROM MODULE
C2 R
LOAD
COPPER STRIP
COPPER STRIP
SCOPE
+OUTPUT
–OUTPUT
+SENSE
–SENSE
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. These output caps 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. Our Applications Engineers can recommend potential solutions and
discuss the possibility of our modifying a given device's internal fi ltering to
meet your specifi c requirements. Contact our Applications Engineering Group
for additional details.
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 7) as the
ground/return of the load circuit. You can, however, use the +Output (pin 6) as
ground/return to effectively reverse the output polarity.
Minimum Output Loading Requirements
UHE 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.
Thermal Shutdown
These UHE converters are equipped with thermal-shutdown circuitry. If envi-
ronmental conditions cause the internal 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 Overvoltage Protection
UHE output voltages are monitored for an overvoltage condition via magnetic
feedback. The signal is coupled to the primary side and if the output voltage
rises to a level which could be damaging to the load, the sensing circuitry will
power down the PWM controller causing the output voltages to decrease. Fol-
lowing a time-out period the PWM will restart, causing the output voltages to
ramp to their appropriate values. 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.
Contact MPS for an optional output overvoltage monitor circuit using a
comparator which is optically coupled to the primary side thus allowing tighter
and more precise control.
Current Limiting
As soon as the output current increases to 10% to 50% above its rated value,
the DC/DC converter will go into a current-limiting mode. In this condition, 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 specifi ed under “Performance.”
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
magnetically 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 voltages to begin ramping to their
appropriate values. 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 UHE is capable of enduring
an indefi nite short circuit output condition.
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 imped-
ance 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 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.
Figure 2. Measuring Input Ripple Current
Figure 3. Measuring Output Ripple/Noise (PARD)
UHE Series
Isolated, High Effi ciency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
www.murata-ps.com email: sales@murata-ps.com
28 Mar 2011 MDC_UHE_12-30W Series.B16 Page 14 of 16
Features and Options
On/Off Control
The input-side, remote On/Off Control function (pin 4) can be ordered to operate
with either polarity:
Standard models are equipped with Positive-polarity (no part-number suffi x)
and these devices are enabled when pin 4 is left open (or is pulled high, ap-
plying to +15V with respect to –Input, pin 2) as per Figure 4. Positive-polarity
devices are disabled when pin 4 is pulled low (0 to 0.8V with respect to –Input).
Optional Negative-polarity devices ("N" suffi x) are off when pin 4 is left
open (or pulled high, applying +3.5V to +15V), and on when pin 4 is pulled low
(0 to 0.8V) with respect to –VIN as shown in Figure 5.
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 Specs) when activated and withstand appropriate voltage
when deactivated. Applying an external voltage to pin 4 when no input power is
applied to the converter can cause permanent damage to the converter.
Trimming Output Voltage
UHE converters have a trim capability (pin 9) that allows users to adjust the
output voltages ±5% of VOUT (±10% for T models). Adjustments to the output
voltages can be accomplished via a trim pot (Figure 6) or a single fi xed resistor
as shown in Figures 7 and 8. A single fi xed resistor can increase or decrease
the output voltage depending on its connection. The resistor should be located
close to the converter and have a TCR less than 100ppm/°C to minimize
sensitivity to changes in temperature. If the trim function is not used, leave the
trim pin fl oating.
A single resistor connected from the Trim (pin 9) to the +Output (pin 6), or
+Sense where applicable, will decrease the output voltage for all models with
the exception of the 1.2V models, which will increase the output voltage in this
confi guration. A resistor connected from the Trim (pin 9) to the –Output (pin 7),
or –Sense where applicable, will increase the output voltage for all models with
the exception of the 1.2V models, which will decrease the output voltage in this
confi guration.
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. Be cautious when there is high atmo-
spheric humidity. 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:
Maximum Preheat Temperature 115° C.
Maximum Pot Temperature 270° C.
Maximum Solder Dwell Time 7 seconds
For Sn/Pb based solders:
Maximum Preheat Temperature 105° C.
Maximum Pot Temperature 250° C.
Maximum Solder Dwell Time 6 seconds
4
2
13V CIRCUIT
5V CIRCUIT
–INPUT
ON/OFF
CONTROL
+ Vcc
Figure 4. Driving the Positive Polarity On/Off Control Pin
4
2–INPUT
ON/OFF
CONTROL
+ Vcc
Figure 5. Driving the Negative Polarity On/Off Control Pin
LOAD
+OUTPUT
–INPUT
+INPUT
ON/OFF
CONTROL TRIM
+SENSE
–OUTPUT
–SENSE
7
8
2
1
9
6
5
420k7
5-22
TURNS
Figure 6. Trim Connections Using A Trimpot
LOAD
R1
+OUTPUT
–INPUT
+INPUT
ON/OFF
CONTROL TRIM
+SENSE
–OUTPUT
–SENSE
7
8
2
1
9
6
5
4
Figure 7. Trim Connections To Decrease Output Voltages Using a Fixed Resistor
(for all models except 1.2V models which will increase VOUT)
LOAD
R2
+OUTPUT
–INPUT
+INPUT
ON/OFF
CONTROL TRIM
+SENSE
–OUTPUT
–SENSE
7
8
2
1
9
6
5
4
Figure 8. Trim Connections To Increase Output Voltages
(for all models except 1.2V models which will decrease VOUT)
UHE Series
Isolated, High Effi ciency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
www.murata-ps.com email: sales@murata-ps.com
28 Mar 2011 MDC_UHE_12-30W Series.B16 Page 15 of 16
– 3.169
0.3232
UHE-1.5/10000-D12, -D24, -D48
UHE-1.8/10000-D12, -D24, -D48
UHE-2.5/10000-D12, -D24, -D48
UHE-3.3/7500-Q12, -Q24, -D48
VO – 1.5
R2 (k7) =R1 (k7) = – 3.169
0.459(VO – 0.7096)
1.5 – VO
1.2 – VO
– 7.596
0.9647
VO – 1.8
R2 (k7) =R1 (k7) = – 7.596
1.027(VO – 0.9352)
1.8 – VO
– 7.503
2.142
VO – 2.5
R2 (k7) =
R1 (k7) = – 7.503
2.226(VO – 0.9625)
2.5 – VO
UHE-12/2500-D12, -D24, -D48, -Q12, -Q48
– 34.8
29.5
VO – 12
R2 (k7) =R1 (k7) = – 34.8
10(VO – 2.5)
12 – VO
UHE-15/2000-D12, -D24, -D48
– 38.3
37.875
VO – 15
R2 (k7) =R1 (k7) = – 38.3
13.3(VO – 2.5)
15 – VO
– 34.8
37.875
VO – 15
R2 (k7) =R1 (k7) = – 34.8
13.3(VO – 2.5)
15 – VO
– 22.42
5.65
VO – 3.3
R2 (k7) =R1 (k7) = – 22.42
3.21(VO – 1.759)
3.3 – VO
UHE-5/5000-Q12, -Q48, UHE-5/6000-D48, -Q48
– 15.52
5.58
VO – 5
R2 (k7) =R1 (k7) = – 15.52
2.15(VO – 2.592)
5 – VO
VO – 1.2
R1 (k7) = R2 (k7) =
– 1.413
0.4432(VO – 0.397) – 1.413
0.397
UHE-1.2/10000-D12, -D24, -D48
Trim Up
Trim Up
Trim Down
Trim Down
UHE-3.3/7500-D48T (Quantity order only)
UHE-5/6000-Q48T, -D48T (Quantity order only)
UHE-15/2000-Q12, -Q48
R2 (k) = 1.55/2y
where y = (VO – 3.3)/3.3
R1 (k) = (2.54/y – 4.08)/2
where y = (3.3 – VO)/3.3
R1 (k) = 1.25/y – 2.69
where y = (5 – VO)/5
R2 (k) = 1.25/y
where y = (VO – 5)/5
LOAD
+OUTPUT
–INPUT
Sense Current
Contact and PCB resistance
losses due to IR drops
Contact and PCB resistance
losses due to IR drops
Sense Return
+INPUT
ON/OFF
CONTROL TRIM
+SENSE
–OUTPUT
–SENSE
7
8
2
1
9
5
IOUT Return
IOUT
6
4
Figure 9. Remote Sense Circuit Confi guration
Trim adjustments greater than the specifi ed ±5% 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 adjustment of the
output voltage, can cause the overvoltage protection circuitry to activate (see
Performance Specifi cations for overvoltage limits). Power derating is based on
maximum output current and voltage at the converter’s output pins. Use of 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 overvoltage region. Therefore:
(VOUT at pins) x (IOUT) < = rated output power
Note: Resistor values are in kΩ. Adjustment accuracy is subject to resistor
tolerances and factory-adjusted output accuracy. VO = desired output voltage.
Remote Sense (Optional on 1.2-5VOUT models)
Note: The Sense and VOUT lines are internally connected through 10: resis-
tors. 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.
UHE series converters have a sense feature to provide point of use regulation,
thereby overcoming moderate IR drops in pcb conductors or cabling. The remote
sense lines carry very little current and therefore require minimal cross-sectional-
area conductors. The sense lines are used by the feedback control-loop to regu-
late 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. In cables and discrete wiring applications, twisted
pair or other techniques should be implemented.
UHE series converters will compensate for drops between the output voltage
at the DC/DC and the sense voltage at the DC/DC provided that:
[VOUT(+) –VOUT(–)] –[Sense(+) –Sense (–)]
d
5% VOUT
Output overvoltage protection is monitored at the output voltage 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
overvoltage protection circuitry to activate (see Performance Specifi cations
for overvoltage limits). Power derating is based on maximum output current
and voltage at the converter’s output pins. Use of trim and sense functions can
cause output voltages to increase thereby increasing output power beyond
the UHE’s specifi ed rating or cause output voltages to climb into the output
overvoltage region. Therefore, the designer must ensure:
(VOUT at pins) × (IOUT)
d
rated output power
Trim Equations
UHE Series
Isolated, High Effi ciency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
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. © 2011 Murata Power Solutions, Inc.
www.murata-ps.com/locations email: sales@murata-ps.com
Murata Power Solutions, Inc.
11 Cabot Boulevard, Mansfi eld, MA 02048-1151 U.S.A.
ISO 9001 and 14001 REGISTERED
28 Mar 2011 MDC_UHE_12-30W Series.B16 Page 16 of 16
,Ê6`iÊ
>iÀ>
,Ê/À>ë>ÀiÌ
«ÌV>ÊÜ`Ü 6>À>Li
ëii`Êv>
i>Ì}Ê
iiiÌ
LiÌÊ
Ìi«iÀ>ÌÕÀi
ÃiÃÀ
ÀvÜ
V>ÌÀ
*ÀiVÃ
ÜÀ>Ìi
>iiÌiÀ
λÊLiÜÊ11/
1ÌÊÕ`iÀ
ÌiÃÌÊ11/®
Vertical Wind Tunnel
Murata Power Solutions employs a custom-designed enclosed
vertical wind tunnel, infrared video camera system and test
instrumentation for accurate airfl ow and heat dissipation
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
element.
The IR camera can watch thermal characteristics of the Unit
Under Test (UUT) with both dynamic loads and static steady-
state conditions. A special optical port is used which is transpar-
ent to infrared wavelengths. The computer fi les from the IR
camera can be studied for later analysis.
Both through-hole and surface mount converters are soldered
down to a host carrier board for realistic heat absorption and
spreading. Both longitudinal and transverse airfl ow studies are
possible 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 both 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 airfl ow collimator mixes the heat from the heating ele-
ment to make uniform temperature distribution. The collimator
also reduces the amount of turbulence adjacent to the UUT by
restoring laminar airfl ow. Such turbulence can change the effec-
tive heat transfer characteristics and give 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.
Figure 10. Vertical Wind Tunnel
