UHE Series
Isolated, High Efficiency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
MDC_UHE_12-30W Series.D05 Page 1 of 16
www.murata-ps.com
www.murata-ps.com/support
For full details go to
www.murata-ps.com/rohs
FEATURES
nThe most IOUT/POUT in this format
nLower priced than bricks
nSmall 1.6" x 2" x 0.4" plastic package
with standard 2" x 2" pinout
nOutput configurations:
1.2/1.5/1.8/2.5VOUT @ 10 Amps
3.3/5VOUT @ 25 Watts
5/12/15VOUT @ 30 Watts
nFive input ranges from 9-75 Volts
nEfficiencies as high as 91.5%
nStable no-load operation
nOptional Sense pins for low VOUT
nThermal shutdown, I/O protected
n1500 Vdc I/O BASIC Insulation
nUL/EN60950-1 certified (2nd Edition);
CE marked for Q48 models
nRoHS compliant
The UHE 12-30W Series of high-efficiency,
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-
rectifier, forward topology, UHEs boast outstanding
efficiency (some models exceed 91%) enabling
full-power operation to ambient temperatures as
high as +60°C, without air flow. 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
logic). 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 certified 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.
Optional comparator feedback. Contact MPS.
Sense pins are optional on 1.2-5VOUT models ("R" suffix).
Typical topology is shown.
Typical units
Figure 1. Simplified 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 Efficiency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
MDC_UHE_12-30W Series.D05 Page 2 of 16
www.murata-ps.com/support
PERFORMANCE SPECIFICATIONS SUMMARY AND ORDERING GUIDE ➀
Model Family
(See model numbering
on page 3)
Output Input
Efficiency 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 55/1.43 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/specified over a 20MHz bandwidth. All models are specified 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 specifications 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-3.3/7500-D48 UHE-3.3/7500-Q12R UHE-5/5000-Q48NR UHE-5/6000-D48-Y-CIS UHE-12/2500-Q48N
UHE-3.3/7500-D48N UHE-3.3/7500-Q12R-C UHE-5/5000-Q48NR-C UHE-5/6000-Q12N UHE-12/2500-Q48N-C
UHE-3.3/7500-D48N-31016 UHE-3.3/7500-Q48 UHE-5/5000-Q48R UHE-5/6000-Q12N-C UHE-12/2500-Q48-Y
UHE-3.3/7500-D48N-C UHE-3.3/7500-Q48N UHE-5/5000-Q48R-C UHE-5/6000-Q48T-C UHE-15/2000-D12
UHE-3.3/7500-D48NR-C UHE-3.3/7500-Q48N-C UHE-5/6000-D48N-30749-Y UHE-12/2500-D12 UHE-15/2000-D12N
UHE-3.3/7500-D48R-C UHE-3.3/7500-Q48NR-C UHE-5/6000-D48N-C UHE-12/2500-D12N UHE-15/2000-D12N-C
UHE-3.3/7500-D48T UHE-3.3/7500-Q48R-C UHE-5/6000-D48NR UHE-12/2500-D12N-C UHE-15/2000-D24
UHE-3.3/7500-D48T-31137-Y UHE-5/5000-Q12 UHE-5/6000-D48NR-C UHE-12/2500-D24 UHE-15/2000-D24N
UHE-3.3/7500-D48T-C UHE-5/5000-Q12N UHE-5/6000-D48R UHE-12/2500-D24N UHE-15/2000-D24N-C
UHE-3.3/7500-D48THL2-C UHE-5/5000-Q12N-C UHE-5/6000-D48R-C UHE-12/2500-D24N-C UHE-15/2000-D48
UHE-3.3/7500-D48THL2-C-HW UHE-5/5000-Q12NR UHE-5/6000-D48T-31136-C UHE-12/2500-D48 UHE-15/2000-D48N
UHE-3.3/7500-D48THL2-Y UHE-5/5000-Q12NR-C UHE-5/6000-D48T-31136-Y UHE-12/2500-D48N UHE-15/2000-D48N-C
UHE-3.3/7500-Q12 UHE-5/5000-Q12R UHE-5/6000-D48T-C UHE-12/2500-D48N-C UHE-15/2000-Q12
UHE-3.3/7500-Q12N UHE-5/5000-Q12R-C UHE-5/6000-D48THL2-C UHE-12/2500-Q12 UHE-15/2000-Q12N
UHE-3.3/7500-Q12N-C UHE-5/5000-Q48 UHE-5/6000-D48THL2-C-HW UHE-12/2500-Q12N UHE-15/2000-Q48
UHE-3.3/7500-Q12NR UHE-5/5000-Q48N UHE-5/6000-D48THL2-Y UHE-12/2500-Q12N-C UHE-15/2000-Q48N
UHE-3.3/7500-Q12NR-C UHE-5/5000-Q48N-C UHE-5/6000-D48-Y UHE-12/2500-Q48 UHE-15/2000-Q48N-C
UHE-5/6000-Q48-C 5 6 55 80 ±0.08% ±0.15% 48 18-75 38/0.69 88.5% 90% C32, P51
To Be Discontinued *
* Last Time Buy date is 3/31/2019. Please click here to view the Discontinuance Notification.
UHE Series
Isolated, High Efficiency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
MDC_UHE_12-30W Series.D05 Page 3 of 16
www.murata-ps.com/support
PART NUMBER STRUCTURE
Options and Adaptations
Optional Functions and Part Number Suffixes
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 suffixes are added after this input identification,
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 logic (on = open or
"high," no suffix). To request a negative logic on this pin/function, add an "N"
suffix 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" suffix. An "NR" suffix can be
added for both negative-logic and sense-pin options. See below.
Suffix Description
Blank Positive logic On/Off Control function (pin 4), Vout trim (pin 9),
no Sense pins, pin length 0.2 inches (5.08 mm).
N Add Negative logic on the On/Off Control function, VOUT trim (pin 9),
no Sense pins.
R Positive logic 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 logic 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 configuration. 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 configurations available on UHE, 12-30W DC/DCs.
Because designating each of them with a standard part-number suffix is not
always feasible, such are designated by MPS in assigning a 5-digit “adaptation
code” after the part-number suffixes. 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 logic on the On/Off Control
function, modified 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 specification 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 logic,
RoHS-5 hazardous substance compliance (with lead).
Maximum Rated Output
Current in mA
High Efficiency
Output Configuration:
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 Logic
Blank = Positive logic, standard
N = Negative logic
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 Efficiency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
MDC_UHE_12-30W Series.D05 Page 4 of 16
www.murata-ps.com/support
MECHANICAL SPECIFICATIONS
* Pins 5 and 8 are installed for optional R-suffix 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 Efficiency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
MDC_UHE_12-30W Series.D05 Page 5 of 16
www.murata-ps.com/support
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
VIN 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 UHE-12/2500-Q12 5,885,546 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 Specifications
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 Reflected Ripple Current ➂2.5-10mAp-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" Suffix 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 Coefficient ±0.02% per °C
Extreme(5) ±3%
Minimum Loading for Specification: ➁No load
Ripple/Noise (20MHz BW) ➀See Ordering Guide
Line/Load Regulation See Ordering Guide
Efficiency 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 100MΩ
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
➀All models are tested and specified 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).
➁See Technical Notes/Performance Curves for additional explanations and details.
➂Input Ripple Current is tested/specified 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.
➃The 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.
➄Extreme 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.
➅Tie 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.
➆The 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.
➇For Start-Up-Time specifications, output settling time is defined as the output voltage having
reached ±1% of its final value at maximum load current.
➈MTBF’s are calculated using TELCORDIA SR-332 Method 1 Case, ground fixed, +25°C ambient air
and full-load conditions. Contact MPS for demonstrated life-test data.
➉All models are fully operational and meet all published specifications, including "cold start," at –40°C.
Use only as much output filtering 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 Efficiency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
MDC_UHE_12-30W Series.D05 Page 6 of 16
www.murata-ps.com/support
90
85
80
75
70
65
UHE-1.8/10000-D24 Efficiency vs. Load @ +25°C Ambient
Output Current (Amps)
Efficiency (
%
)
1 2 3 4 5 6 7 8 9 10
V
IN
= 36V
V
IN
= 18V
V
IN
= 24V
90
85
80
75
70
65
60
55
UHE-1.8/10000-D48 Efficiency vs. Load @ +25°C Ambient
Output Current (Amps)
Efficiency (
%
)
1 2 3 4 5 6 7 8 9 10
V
IN
= 75V
V
IN
= 36V
V
IN
= 48V
85
80
75
70
65
60
55
UHE-1.5/10000-D48 Efficiency vs. Load @ +25°C Ambient
Output Current (Amps)
Efficiency (
%
)
1 2 3 4 5 6 7 8 9 10
V
IN
= 75V
V
IN
= 36V
V
IN
= 48V
90
85
80
75
70
65
UHE-1.5/10000-D24 Efficiency vs. Load @ +25°C Ambient
Output Current (Amps)
Efficiency (
%
)
1 2 3 4 5 6 7 8 9 10
V
IN
= 36V
V
IN
= 18V
V
IN
= 24V
90
88
86
84
82
80
78
76
Output Current (Amps)
Efficiency (%)
1 2.8 4.6 6.4 8.2 10
V
IN
= 75V
V
IN
= 36V
V
IN
= 48V
UHE-2.5/10000-D48 Efficiency vs. Load @ +25°C Ambient
Typical Performance Curves
95
90
85
80
75
70
65
UHE-3.3/7500-Q12 Efficiency vs. Load @ +25°C Ambient
Output Current (Amps)
Efficiency (%)
0.75 1.5 2.25 3 3.75 4.5 5.25 6 6.75 7.5
V
IN
= 36V
V
IN
= 9V
V
IN
= 24V
UHE Series
Isolated, High Efficiency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
MDC_UHE_12-30W Series.D05 Page 7 of 16
www.murata-ps.com/support
100
90
80
70
60
50
40
UHE-3.3/7500-D48 Efficiency vs. Load @ +25°C Ambient
Output Current (Amps)
Efficiency (
%
)
0.75 1.5 2.25 3 3.75 4.5 5.25 6 6.75 7.5
V
IN
= 75V
V
IN
= 36V
V
IN
= 48V
100
90
80
70
60
50
40
UHE-3.3/7500-Q48 Efficiency vs. Load @ +25°C Ambient
0.75 1.5 2.25 3 3.75 4.5 5.25 6 6.75 7.5
Output Current (Amps)
%
V
IN
= 75V
V
IN
= 36V
V
IN
= 48V
V
IN
= 18V
100
90
80
70
60
50
40
UHE-5/6000-D48 Efficiency vs. Load @ +25°C Ambient
0.6 1.2 1.8 2.4 3 3.6 4.2 4.8 5.4 6
Output Current (Amps)
Efficiency (
%
)
V
IN
= 75V
V
IN
= 36V
V
IN
= 48V
100
90
80
70
60
50
40
UHE-5/5000-Q48 Efficiency vs. Load @ +25°C Ambient
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
Output Current (Amps)
Efficiency (
%
)
V
IN
= 75V
V
IN
= 36V
V
IN
= 48V
V
IN
= 18V
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
95
90
85
80
75
70
65
UHE-5/5000-Q12 Efficiency vs. Load @ +25°C Ambient
Output Current (Amps)
Efficiency (
%
)
0.5 1.0 1.5 2 2.5 3 3.5 4 4.5 5
V
IN
= 36V
V
IN
= 9V
V
IN
= 24V
Typical Performance Curves
UHE Series
Isolated, High Efficiency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
MDC_UHE_12-30W Series.D05 Page 8 of 16
www.murata-ps.com/support
95
90
85
80
75
70
65
UHE-12/2500-D48 Efficiency vs. Load @ +25°C Ambient
Output Current (Amps)
Efficiency (
%
)
0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.25 2.5
V
IN
= 75V
V
IN
= 36V
V
IN
= 48V
95
90
85
80
75
70
65
UHE-15/2000-D24 Efficiency vs. Load @ +25°C Ambient
Output Current (Amps)
Efficiency (
%
)
0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
V
IN
= 36V
V
IN
= 18V
V
IN
= 24V
95
90
85
80
75
70
65
UHE-15/2000-D12 Efficiency vs. Load @ +25
°
C Ambient
Output Current (Amps)
Efficiency (
%
)
0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
V
IN
= 18V
V
IN
= 9V
V
IN
= 12V
95
90
85
80
75
70
65
UHE-15/2000-D48 Efficiency vs. Load @ +25°C Ambient
Output Current (Amps)
Efficiency (
%
)
0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
V
IN
= 75V
V
IN
= 36V
V
IN
= 48V
95
90
85
80
75
70
65
UHE-12/2500-D24 Efficiency vs. Load @ +25°C Ambient
Output Current (Amps)
Efficiency (
%
)
0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.25 2.5
V
IN
= 36V
V
IN
= 18V
V
IN
= 24V
95
90
85
80
75
70
65
UHE-12/2500-D12 Efficiency vs. Load @ +25
°
C Ambient
Output Current (Amps)
Efficiency (
%
)
0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.25 2.5
V
IN
= 18V
V
IN
= 9V
V
IN
= 12V
Typical Performance Curves
UHE Series
Isolated, High Efficiency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
MDC_UHE_12-30W Series.D05 Page 9 of 16
www.murata-ps.com/support
Output Ciurrent (Amps)
Ambient Temperature (°C)
10
9
8
7
6
5
4
3
2
1
0
–40 0 40 45 50 55 60 65 70 75 80 85 90 95 100
24VIN, 150LFM
24VIN, 300LFM
24VIN, STILL AIR
UHE-1.8/10000-D24 Temperature Derating
Output Ciurrent (Amps)
Ambient Temperature (°C)
10
9
8
7
6
5
4
3
2
1
0
–40 0 40 45 50 55 60 65 70 75 80 85 90 95 100
48VIN, STILL AIR
75VIN, 150LFM
75VIN, STILL AIR
48VIN, 150LFM
UHE-1.8/10000-D48 Temperature Derating
48VIN, 300LFM
Output Ciurrent (Amps)
Ambient Temperature (°C)
10
9
8
7
6
5
4
3
2
1
0
–40 0 40 45 50 55 60 65 70 75 80 85 90 95 100
48VIN, 150LFM
48VIN, 300LFM
48VIN, STILL AIR
UHE-1.2/10000-D48 and UHE-1.5/10000-D48 Temperature Derating
Output Ciurrent (Amps)
Ambient Temperature (°C)
10
9
8
7
6
5
4
3
2
1
0
–40 0 40 45 50 55 60 65 70 75 80 85 90 95 100
24VIN, 150LFM
24VIN, 300LFM
24VIN, STILL AIR
UHE-1.2/10000-D24 and UHE-1.5/10000-D24 Temperature Derating
95
90
85
80
75
70
65
UHE-12-2500-Q48 Efficiency vs. Load @ +25°C Ambient
Output Current (Amps)
Efficiency (%)
0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.25 2.5
V
IN
= 75V
V
IN
= 18V
V
IN
= 48V
95
90
85
80
75
70
65
UHE-15-2000-Q48 Efficiency vs. Load @ +25°C Ambient
Output Current (Amps)
Efficiency (
%
)
0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
V
IN
= 75V
V
IN
= 18V
V
IN
= 48V
Typical Performance Curves
UHE Series
Isolated, High Efficiency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
MDC_UHE_12-30W Series.D05 Page 10 of 16
www.murata-ps.com/support
Output Power (Watts)
Ambient Temperature (°C)
30
25
20
15
10
5
0
–40 0 40 45 50 55 60 65 70 75 80 85 90 95 100
UHE-3.3/7500-D48 Temperature Derating
48VIN, STILL AIR
36VIN, STILL AIR
75VIN, STILL AIR
75VIN, 150LFM
75VIN, 300LFM
Output Power (Watts)
Ambient Temperature (°C)
25
20
15
10
5
0
–40 0 40 45 50 55 60 65 70 75 80 85 90 95 100
UHE-5/5000-Q12 Temperature Derating
24VIN, STILL AIR
36VIN, 150LFM
36VIN, STILL AIR
24VIN, 150LFM
24VIN, 300LFM
36VIN, 300LFM
Output Power (Watts)
Ambient Temperature (°C)
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 (°C)
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
Output Power (Watts)
Ambient Temperature (°C)
25
20
15
10
5
0
–40 0 40 45 50 55 60 65 70 75 80 85 90 95 100
UHE-3.3/7500-Q12 Temperature Derating
24VIN, STILL AIR
36VIN, 150LFM
36VIN, STILL AIR
24VIN, 150LFM
24VIN, 300LFM
36VIN, 300LFM
Output Power (Watts)
Ambient Temperature (°C)
30
25
20
15
10
5
0
–40 0 40 45 50 55 60 65 70 75 80 85 90 95 100
UHE-2.5/10000-D48 Temperature Derating
NATURAL CONVECTION
Typical Performance Curves
UHE Series
Isolated, High Efficiency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
MDC_UHE_12-30W Series.D05 Page 11 of 16
www.murata-ps.com/support
Output Power (Watts)
Ambient Temperature (°C)
30
25
20
15
10
5
0
–40 0 40 45 50 55 60 65 70 75 80 85 90 95 100
UHE-5/6000-D48 Temperature Derating
48VIN, STILL AIR
36VIN, STILL AIR
75VIN, STILL AIR
75VIN, 150LFM
75VIN, 300LFM
Output Power (Watts)
Ambient Temperature (°C)
30
25
20
15
10
5
0
–40 0 40 45 50 55 60 65 70 75 80 85 90 95 100
UHE-12/2500 and UHE-15/2000 (All Models) Temperature Derating
48VIN, STILL AIR
(D48 Models Only)
12VIN, STILL AIR
24VIN, STILL AIR
(48VIN, Still Air for Q48 Models Only)
Typical Performance Curves
UHE Series
Isolated, High Efficiency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
MDC_UHE_12-30W Series.D05 Page 12 of 16
www.murata-ps.com/support
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 Suffix +15 Volts
"N" Suffix +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 specifications
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 Specifications 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 - 3 2
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 specified 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
specification defines the interval between the point at which the converter is
turned on and the fully loaded output voltage enters and remains within its
specified 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 insignificant.
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 specification listed in the Performance/Functional Specifications 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 sufficiently 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 benefit 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/specified for in-
put reflected ripple current and output noise using the specified external input/
output components/circuits and layout as shown in the following two figures.
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 Efficiency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
MDC_UHE_12-30W Series.D05 Page 13 of 16
www.murata-ps.com/support
C
IN
V
IN
C
BUS
L
BUS
C
IN
= 33µF, ESR < 700mΩ @ 100kHz
C
BUS
= 220µF, ESR < 100mΩ @ 100kHz
L
BUS
= 12µH
+INPUT
–INPUT
CURRENT
PROBE
TO
OSCILLOSCOPE
+
–
C1
C1 = 0.47µF
C2 = NA
LOAD 2-3 INCHES (51-76mm) FROM MODULE
C2 R
LOAD
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 specified limits using filter-
ing techniques, the simplest of which is the installation of additional external
output capacitors. These output caps function as true filter 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 filtering to
meet your specific requirements. Contact our Applications Engineering Group
for additional details.
Minimum Output Loading Requirements
UHE converters employ a synchronous-rectifier 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 Specifications.
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 (Power limit with current mode control)
As power demand increases on the output and enters the specified “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 defined as the
point where the output voltage has decreased by a pre-specified 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 indefinitely 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.
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 specific system configuration may necessitate additional
considerations.
Floating Outputs
Since these are isolated DC/DC converters, their outputs are "floating" 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.
Figure 2. Measuring Input Ripple Current
Figure 3. Measuring Output Ripple/Noise (PARD)
UHE Series
Isolated, High Efficiency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
MDC_UHE_12-30W Series.D05 Page 14 of 16
www.murata-ps.com/support
Features and Options
On/Off Control
The input-side, remote On/Off Control function (pin 4) can be ordered to operate
with either logic type:
Standard models are equipped with Positive-logic (no part-number suffix) and
these devices are enabled when pin 4 is left open (or is pulled high, applying to
+15V with respect to –Input, pin 2) as per Figure 4. Positive-logic devices are
disabled when pin 4 is pulled low (0 to 0.8V with respect to –Input).
Optional Negative-logic devices ("N" suffix) 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 fixed resistor
as shown in Figures 7 and 8. A single fixed 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 floating.
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
configuration. 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
configuration.
Soldering Guidelines
Murata Power Solutions recommends the specifications below when installing these
converters. These specifications vary depending on the solder type. Exceeding these
specifications 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
1+INPUT
13V CIRCUIT
5V CIRCUIT
–INPUT
ON/OFF
CONTROL
Figure 4. Driving the Positive Logic On/Off Control Pin
4
2
1+INPUT +VCC
–INPUT
ON/OFF
CONTROL
Figure 5. Driving the Negative Logic On/Off Control Pin
LOAD
+OUTPUT
–INPUT
+INPUT
ON/OFF
CONTROL TRIM
+SENSE
–OUTPUT
–SENSE
7
8
2
1
9
6
5
420kΩ
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 Efficiency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
MDC_UHE_12-30W Series.D05 Page 15 of 16
www.murata-ps.com/support
–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 (kΩ) =R1 (kΩ) = –3.169
0.459(VO – 0.7096)
1.5 – VO
1.2 – VO
–7.596
0.9647
VO – 1.8
R2 (kΩ) =R1 (kΩ) = –7.596
1.027(VO – 0.9352)
1.8 – VO
–7.503
2.142
VO – 2.5
R2 (kΩ) =
R1 (kΩ) = –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 (kΩ) =R1 (kΩ) = –34.8
10(VO – 2.5)
12 – VO
UHE-15/2000-D12, -D24, -D48
–38.3
37.875
VO – 15
R2 (kΩ) =R1 (kΩ) = –38.3
13.3(VO – 2.5)
15 – VO
–34.8
37.875
VO – 15
R2 (kΩ) =R1 (kΩ) = –34.8
13.3(VO – 2.5)
15 – VO
–22.42
5.65
VO – 3.3
R2 (kΩ) =R1 (kΩ) = –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 (kΩ) =R1 (kΩ) = –15.52
2.15(VO – 2.592)
5 – VO
VO – 1.2
R1 (kΩ) = R2 (kΩ) =
–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 (kΩ) = 1.55/2y
where y = (VO – 3.3)/3.3
R1 (kΩ) = (2.54/y – 4.08)/2
where y = (3.3 – VO)/3.3
R1 (kΩ) = 1.25/y – 2.69
where y = (5 – VO)/5
R2 (kΩ) = 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 Configuration
Trim adjustments greater than the specified ±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 Specifications 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 specified 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 10Ω 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 (–)] ≤ 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 Specifications
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 specified rating or cause output voltages to climb into the output
overvoltage region. Therefore, the designer must ensure:
(VOUT at pins) × (IOUT) ≤ rated output power
Trim Equations
UHE Series
Isolated, High Efficiency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
MDC_UHE_12-30W Series.D05 Page 16 of 16
www.murata-ps.com/support
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. Specifications are subject to change
without notice. © 2018 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/
Figure 10. 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
airflow and heat dissipation analysis of power products.
The system includes a precision low flow-rate anemometer,
variable speed fan, power supply input and load controls,
temperature gauges, and adjustable heating element.
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 host carrier board for realistic heat
absorption and spreading. Both longitudinal and transverse
airflow studies are possible by rotation of this carrier board
since there are often significant differences in the heat
dissipation in the two airflow directions. The combination of
adjustable airflow, 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 airflow turbulence. Such turbu-
lence influences 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.