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UHP-12/21-D48
Isolated, 21 Amp Half Brick, 48VIN/12VOUT DC/DC Converter
ORDERING GUIDE SUMMARY
Model
VOUT Range
IOUT Range
VIN Range
Ripple/Noise
Efficiency
12V
0-21A
36-75V
125mVp-p
91%
UHP-12/21-D48
INPUT CHARACTERISTICS
Parameter
Typ. @ 25°C, full load
Notes
Voltage Range
36-75 Volts
48V nominal
Current, full power
5.77 Amps
VIN = 48V
Undervoltage Shutdown
33 Volts
Short Circuit Current
20mA
VIN = 48V
Remote On/Off Control
0 to +VIN
Positive or negative logic
OUTPUT CHARACTERISTICS
FEATURES
Parameter
Typ. @ 25°C, full load
Notes
Wide 36-75V input range
Voltage
12 Volts ±10%
Trim range shown
■
12V output @ 21 Amps. max.
Current
0 to 21 Amps
No minimum load
Very high efficiency of 91%
Power Output
255 Watts max.
Maximum baseplate = +110°C @ 255W
■
±1.25%
■
Operates to +110°C baseplate w/derating
Accuracy
Ripple & Noise
125mVp-p
■
Conduction-cooled baseplate, no fans
Line and Load Regulation
±0.05%/±0.25%
■
Industry-standard mounting and pinout
Overcurrent Protection
30 Amps
Overtemperature Protection
+125°C
Efficiency (minimum)
90%
Efficiency (typical)
91%
■
■
Remote sense, trim and On/Off control
■
Isolated to 2250Vdc (Basic insulation)
■
Multiple I/O protection features
■
UL/EN60950 safety approvals, CE mark
■
Start up into pre-biased load
DESCRIPTION
For “distributed architecture” power applications,
DATEL’s UHP-12/21-D48 DC/DC converter offers
a wide input range of 36-75 Volts DC, delivering
up to 21 Amps with 12 Volts DC output. This DC/
DC converter is an ideal precision intermediate
bus power unit with tight regulation and 2250
Volt isolation. It is manufactured on a 2.3" x 2.4"
open-frame package with industry-standard “half
brick” pinout and mounting.
UHP converters use a interleaved forward, fixedfrequency topology with synchronous output rectification to achieve high efficiency. UHP-12/21-D48
can be operated using conduction cooling
attached to a housing wall or system heat sink.
No forced air-flow is needed to +110°C base-
20MHz bandwidth
With hiccup auto-restart
GENERAL SPECIFICATIONS
Parameter
Typ. @ 25°C, full load
Notes
Dynamic Load Response
150μsec
50-75-50% step to ±1.5% of final value
Operating Temperature Range
–40 to +110°C
With baseplate, see derating curve
Operating Temperature Range
–40 to +32°C
Without baseplate
Safety
UL/IEC/EN 60950
And CSA C22.2-No.60950
MECHANICAL CHARACTERISTICS
With baseplate
2.30 x 2.40 x 0.502 inches (58.42 x 60.96 x 12.75 mm)
Without baseplate
2.30 x 2.40 x 0.452 inches (58.42 x 60.96 x 11.48 mm)
plate temperature. Multiple protection features
avoid damage to outside equipment and to the
converter itself. The converter will shut down on
sustained input undervoltage, output overcurrent,
output short circuit and overvoltage and thermal
shutdown. Overload currents less than a short
circuit limit the output current so that operation
is not interrupted. Upon short circuit shutdown,
the converter will automatically attempt to restart
(“hiccup” mode) when the overload is removed.
The overall unit is designed to be as “lead-free”
as practical in construction and attachment
method (no lead added in assembly). Standard
features also include Sense and Trim pins and
On/Off Control.
For full details go to
www.murata-ps.com/rohs
www.murata-ps.com
Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000
UHP-12/21-D48.B02 Page 1 of 12
UHP-12/21-D48
Isolated, 21 Amp Half Brick, 48VIN/12VOUT DC/DC Converter
PERFORMANCE SPECIFICATIONS AND ORDERING GUIDE ➀
Output
Model
UHP-12/21-D48
➀
➁
➂
➃
Input
Load ➂
VIN Nom.
(Volts)
Range
(Volts)
IIN ➃
(mA/A)
Min.
Typ.
Package
(Case/
Pinout)
±0.15%
48
36-75
195/5.77
90%
91%
C66, P17
Regulation (max.)
R/N (mVp-p) ➁
VOUT
(Volts)
IOUT
(Amps)
Typ.
Max.
Line
12
21
125
175
±0.05%
Efficiency
Typical at TA = +25°C under nominal line voltage and full-load conditions, unless noted.
Ripple/Noise (R/N) is measured over a 20MHz bandwidth and input filter.
Regulation is tested no load to 100% load.
Nominal line voltage, no-load/full-load conditions.
PART NUMBER STRUCTURE
Optional
Functions
UHP - 12 / 21 - D48 N B Lx - C
RoHS-6 compliant *
Unipolar High-Power
Nominal Output Voltage:
12 Volts
On/Off Control Polarity:
P = Positive
N = Negative
Maximum Output Current:
21 Amps
Input Voltage Range:
D48 = 36-75 Volts (48V nominal)
Baseplate:
Blank = not installed
B = Installed
Alternate Pin Length:
Blank = Standard pin length
L1 = 0.110 in. (2.79mm) ±0.010
L2 = 0.145 in. (3.68mm) ±0.010
* Contact Murata Power Solutions (DATEL) for availability
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Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000
UHP-12/21-D48.B02 Page 2 of 12
UHP-12/21-D48
Isolated, 21 Amp Half Brick, 48VIN/12VOUT DC/DC Converter
Performance/Functional Specifications
Dynamic Characteristics
Typical @ TA = +25°C under nominal line voltage, full-load conditions, unless noted.
(1)
Dynamic Load Response (50-75-50%step) 150µsec to ±1.25% of final value
Input
Load Step Peak Deviation
±700mV
Input Voltage Range
See Ordering Guide
Start-Up Time
280msec for VOUT = nominal
Start-Up Threshold
33/35 Volts (min./max.)
Remote On/Off to VOUT Regulated
2msec
Undervoltage Shutdown
32/34 Volts (min./max.)
Switching Frequency
290kHz
Voltage Transients (100msec, no damage)
+100 Volts max.
Overvoltage Shutdown
None (7)
Reflected (Back) Ripple Current (2)
15mAp-p
Input Current:
Full Load Conditions
Inrush Transient
Output Short Circuit
No Load
Low Line (VIN = VMIN)
Standby Mode
(Off, UV, OT, OC shutdown)
See Ordering Guide
0.5A2sec
20mA
195mA
7.65 Amps
8mA
Environmental
Calculated MTBF (4)
945,162 Hours
Operating Temperature Range (Ambient, with unmounted baseplate):
No derating, 400 lfm
–40 to +32°C (9)
With derating
See Derating Curves
Operating Temperature with Baseplate (Mounted to heat sink)
–40 to +110°C max.
(No derating required) (3) (13)
Storage Temperature Range
–55 to +125°C
Thermal Protection/Shutdown (13)
+125°C (hotspot)
Internal Input Filter
Pi-type
Density Altitude
0 to 10,000 feet
Recommended External Fuse
15 Amps slow blow
Relative Humidity
10% to 90%, non-condensing
Reverse Polarity Protection
See fuse information
Remote On/Off Control: (5)
Positive Logic ("P" model suffix)
Negative Logic ("N" model suffix)
ON = open or +3.5V min. to +VIN max.
OFF = –0.5V min. to +0.8V max.
ON = ground pin to +0.8V max.
OFF = +3.5V min. to +VIN max.
Physical
Output
Total Output Power
255 Watts max.
Voltage Output Range
See Ordering Guide
Outline Dimensions
See Mechanical Specifications
Baseplate Material
Aluminum
Pin Material
Solder-coated brass
Weight
3.3 ounces (94 grams)
Electromagnetic Interference
Conducted and radiated
FCC part 15, class B, EN55022 (external filter may be required)
Safety
UL/cUL 60950 CSA-C22.2 No.234
IEC/EN 60950
Flammability
ULV94-0
Voltage Output Accuracy
±1.25 % of VNOMINAL
Extreme Accuracy
±3 % max. of VNOMINAL (15)
Overvoltage Protection (14)
Method
+14.5 Volts
Magnetic feedback and comparator
Voltage Adjustment Range (12)
±10% of VNOMINAL
Temperature Coefficient
±0.02% of VOUT range per °C
Minimum Loading
No minimum load
Input Voltage
Continuous
Transient (100 msec max.)
Remote Sense Compensation
+5% max.
On/Off Control
–0.3 V min to +VIN max.
Ripple/Noise (20 MHz bandwidth)
See Ordering Guide (8)
Input Reverse Polarity Protection
See Fuse section (11)
Line/Load Regulation
See Ordering Guide and note (10)
Output Overvoltage
VOUT +20% max.
Efficiency
See Ordering Guide
Maximum Capacitive Loading
3300µF (Low ESR <0.02W max.)
Isolation Voltage:
Input to Output
Input to Baseplate
Baseplate to Output
Output Current (7)
Current-limited. Devices can
withstand sustained short circuit
without damage.
2250Vdc min.
1500Vdc min.
750Vdc min.
Storage Temperature
–55 to +125°C
Isolation Resistance
100MW
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, nor recommended.
Isolation Capacitance
2000 pF
Isolation Safety Rating
Basic insulation
Current Limit Inception (98% of VOUT)
30 Amps, cold condition
28 Amps, after warmup
Short Circuit (6)
Protection Method
Short Circuit Current
Short Circuit Duration
(no damage)
Current limiting with hiccup autorestart
1 Amp
Continuous, output shorted to ground
Absolute Maximum Ratings
to +75V
to +100V
Lead Temperature (soldering 10 sec. max.) +280°C
Performance/Functional Specification Notes:
The UHP-12/21-D48 is tested and specified with natural convection airflow, external 1 || 10µF
ceramic/tantalum output capacitors and a 22µF external input capacitor. All capacitors are
low ESR types. These capacitors are necessary to accommodate our test equipment and may
not be required to achieve specified performance in your applications. All models are stable
and regulate within spec under no-load conditions.
General conditions for Specifications are +25°C, VIN = nominal, VOUT = nominal, full load.
(2) Input Ripple Current is tested and specified over a 5Hz to 20MHz bandwidth. Input filtering is
CIN = 33µF tantalum, CBUS = 220µF electrolytic, LBUS = 12µH.
(1)
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UHP-12/21-D48.B02 Page 3 of 12
UHP-12/21-D48
Isolated, 21 Amp Half Brick, 48VIN/12VOUT DC/DC Converter
Performance/Functional Specification Notes:
Note that Maximum Power Derating curves indicate an average current at nominal input voltage.
At higher temperatures and/or lower airflow, the DC/DC converter will tolerate brief full current
outputs if the total RMS current over time does not exceed the Derating curve.
(4) Mean Time Before Failure is calculated using the Telcordia (Belcore) SR-332 Method 1, Case 3,
ground fixed conditions, operating temperature = 55°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 which does not exceed +VIN max.
(6) Short circuit shutdown begins when the output voltage degrades approximately 2% from the
selected setting. Remove overload for recovery.
(7) Input overvoltage shutdown is explicitly not included to improve system reliability in datacom and
telecom applications. These requirements attempt continued operation despite significant input
overvoltage.
(8) Output noise may be further reduced by adding an external filter. See I/O Filtering and Noise
Reduction.
(9) Models are fully operational and meet published specifications, including “cold start” at –40°C.
(10) Regulation specifications describe the deviation as the line input voltage or output load current is
varied from a nominal midpoint value to either extreme.
(11) If the input voltage is reversed, a normally back-biased bulk substrate diode will become forward
biased and draw current. An external fuse is recommended to avoid damage from reverse input
current.
(12) Do not exceed maximum power specifications when adjusting the output trim.
(13) Note that the converter may operate up to +110°C with the baseplate installed. However, thermal
self-protection occurs near +125°C on the circuit hotspot. And there is a thermal gradient
between the baseplate and the hotspot. Therefore, +110°C maximum baseplate temperature is
recommended to avoid thermal shutdown.
(14) If the output exceeds the Overvoltage specification, the output will shut down in auto recovery
mode.
(15) Extreme accuracy includes all combinations of temperature coefficient and line/load regulation.
TECHNICAL NOTES
(3)
Input Fusing
Certain applications and/or safety agencies may require the installation of
fuses at the inputs of power conversion components. Fuses should also be
used if the possibility of sustained, non-current-limited, input-voltage polarity
reversals exists. For DATEL UHP Series DC/DC Converters, we recommend the
use of slow-blow type fuses, installed in the ungrounded input supply line,
with values no greater than the following.
Output
Fuse Value
12 VOUT 15 Amp
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, i.e. IEC/EN/UL60950.
Input Undervoltage Shutdown and Start-Up Threshold
Under normal start-up conditions, devices will not begin to regulate properly
until the ramping-up input voltage exceeds the Start-Up Threshold Voltage.
Once operating, devices will not turn off until the input voltage drops below
the 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 90% of VOUT . Actual measured times
will vary with input source impedance, external input capacitance, and the
slew rate and final value of the input voltage as it appears at the converter.
The UHP 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 (released) 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
The UHP Series does not feature input overvoltage shutdown. The converters
do withstand and fully operate during input transients to 100V for 100msec
without interruption; consequently, this function has been disabled.
Input Source Impedance
The input of UHP converters must be driven from a low ac-impedance source.
The DC/DC's performance and stability can be compromised by the use of
highly inductive source impedances. The input circuit shown in Figure 2 is a
practical solution that can be used to minimize the effects of inductance in the
input traces. For optimum performance, components should be mounted as
close as possible to the DC/DC converter.
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UHP-12/21-D48.B02 Page 4 of 12
UHP-12/21-D48
Isolated, 21 Amp Half Brick, 48VIN/12VOUT DC/DC Converter
I/O Filtering, Input Ripple Current, and Output Noise
All models in the UHP Series are tested/specified for input 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 in
conductors from backplane to the DC/DC. Input caps should be selected for
bulk capacitance (at appropriate frequencies), low ESR, and high rms-ripplecurrent ratings. The switching nature of DC/DC converters requires that dc
voltage sources have low ac impedance as highly inductive source impedance can affect system stability. In Figure 2, CBUS and LBUS simulate a typical
dc voltage bus. Your specific system configuration may necessitate additional
considerations.
TO
OSCILLOSCOPE
VIN
CBUS
+OUTPUT
6
COPPER STRIP
5
C1
–OUTPUT
–SENSE
C2
SCOPE
RLOAD
9
8
COPPER STRIP
C1 = 0.1µF CERAMIC
C2 = 10µF TANTALUM
LOAD 2-3 INCHES (51-76mm) FROM MODULE
Figure 3. Measuring Output Ripple/Noise (PARD)
CURRENT
PROBE
4
+INPUT
LBUS
+
+SENSE
Minimum Output Loading Requirements
CIN
–
1
–INPUT
CIN = 33µF, ESR < 700mΩ @ 100kHz
CBUS = 220µF, ESR < 100mΩ @ 100kHz
LBUS = 12µH
Figure 2. Measuring Input Ripple Current
In critical applications, output ripple/noise (also referred to as periodic and
random deviations or PARD) may be reduced below specified limits using
filtering techniques, the simplest of which is the installation of additional
external output capacitors. They 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.
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 as short as possible (i.e. less than ½ inch) and
soldered directly to the fixture.
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 9) as the
ground/return of the load circuit. You can however, use the +Output (pin 5) as
ground/return to effectively reverse the output polarity.
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UHP 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
The UHP converters are equipped with thermal-shutdown circuitry. If environmental conditions cause the temperature of the DC/DC converter to rise
above the designed operating temperature, a precision temperature sensor
will power down the unit. When the internal temperature decreases below the
threshold of the temperature sensor, the unit will self start. See Performance/
Functional Specifications.
Output Overvoltage Protection
The UHP output voltage is monitored for an overvoltage condition using a
comparator. The signal is optically 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 voltage to
decrease. Following a time-out period the PWM will restart, causing the output
voltage to ramp to its appropriate value. If the fault condition persists, and the
output voltage again climbs to excessive levels, the overvoltage circuitry will
initiate another shutdown cycle. This on/off cycling is referred to as "hiccup"
mode.
Current Limiting
As soon as the output current increases to approximately 120% of 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 defined as
the point at which the full-power output voltage falls below the specified tolerance. See Performance/Functional Specifications. If the load current, being
drawn from the converter, is significant enough, the unit will go into a short
circuit condition as described below.
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UHP-12/21-D48.B02 Page 5 of 12
UHP-12/21-D48
Isolated, 21 Amp Half Brick, 48VIN/12VOUT DC/DC Converter
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 voltage to begin ramping to their
appropriate value. If the short-circuit condition persists, another shutdown
cycle will be initiated. This on/off cycling is referred to as "hiccup" mode. The
hiccup cycling reduces the average output current, thereby preventing internal
temperatures from rising to excessive levels. The UHP Series is capable of
enduring an indefinite short circuit output condition.
Features and Options
Remote Sense
Note: The Sense and VOUT lines are internally connected through resistors
(=<10Ω). 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.
UHP Series converters employ 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, which are capacitively
coupled to their respective output lines, are used by the feedback control-loop
to regulate the output. As such, they are not low impedance points and must
be treated with care in layouts and cabling. Sense lines on a pcb should be
run adjacent to dc signals, preferably ground. In cables and discrete wiring
applications, twisted pair or other techniques should be implemented.
UHP 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
(=<10% VOUT for 3.3V models)
1
–INPUT
+OUTPUT
+SENSE
3
6
IOUT
(VOUT at pins) x (IOUT ) =< rated output power
On/Off Control Function
The input-side remote On/Off Control is an external input signal available in
either positive (“P” suffix) or negative polarity (“N” suffix). Normally this input
is controlled by an external transistor or relay. However, with simple external
circuits, it may also be selected by logic outputs.
For the positive polarity, the default operation is to leave this pin open (unconnected). This results in the converter always on whenever appropriate input
power is applied. Negative polarity models require the On/Off input to be
grounded to the –INPUT terminal or brought low to turn the converter on.
Both models include an internal pullup source on this pin. For positive polarity,
grounding the input will turn it off (zero output) and raising the input above
approximately +3.5 Volts or an open pin will turn it on (or driving a control
transistor into cutoff).
For negative polarity, ground the input to –INPUT to turn on the converter. An
open pin (or if the input is raised above +3.5 Volts) turns it off. For both polarities, do not raise the On/Off Control above +VIN relative to the –INPUT terminal.
All control inputs must be referred to the –INPUT terminal.
Dynamic control of the On/Off Control should be capable of sinking the appropriate current (less than 1mA) and not overdrive the input above +VIN. Do not
apply external voltage to the On/Off Control when no input power is present.
Always wait for input power to stabilize before activating the On/Off Control.
Be aware that several milliseconds (see specifications) are required between
activation of the control and when output power is stabilized and in regulation.
Special Note: Although a small internal protective diode is included in series
with the On/Off, do not directly use the 48V +INPUT line as an external pullup
source for the external On/Off control. The On/Off input must be held to +VIN
maximum.
Sense Current
ON/OFF
CONTROL
TRIM
–SENSE
4
Contact and PCB resistance
losses due to IR drops
5
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 conveter's specified rating, or cause output voltages to climb into the
output overvoltage region. Therefore, the designer must ensure:
7
8
LOAD
Sense Return
IOUT Return
+INPUT
–OUTPUT
9
Contact and PCB resistance
losses due to IR drops
Figure 4. Remote Sense Circuit Configuration
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UHP-12/21-D48.B02 Page 6 of 12
UHP-12/21-D48
Isolated, 21 Amp Half Brick, 48VIN/12VOUT DC/DC Converter
4
+INPUT
EQUIVALENT CIRCUIT FOR
POSITIVE AND NEGATIVE
LOGIC MODELS
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Figure 6. Trim Connections Using A Trim Pot
Figure 5. Driving the On/Off Control Pin
1
+OUTPUT
–INPUT
Trimming Output Voltage
+SENSE
UHP converters have a trim capability (pin 7) that allows users to adjust the
output voltage within the specified range. Adjustments to the output voltages
can be accomplished via a trim pot (Figure 7) 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.
TRIM
3
4
6
7
LOAD
RTRIM UP
ON/OFF
CONTROL
–SENSE
+INPUT
–OUTPUT
8
9
Figure 7. Trim Connections To Increase Output Voltages
Using Fixed Resistors
A single resistor connected from the Trim (pin 7) to the +Sense (pin 6), will
increase the output voltage (Figure 7). A resistor connected from the Trim (pin
9) to the –Sense (pin 8), will decrease the output voltage (Figure 8).
Trim adjustments greater than the specified range can have an adverse affect
on the converter's performance and are not recommended. Excessive voltage
differences between VOUT and Sense, in conjunction with trim 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:
5
1
+OUTPUT
–INPUT
+SENSE
TRIM
3
4
6
7
LOAD
RTRIM DOWN
ON/OFF
CONTROL
+INPUT
5
–SENSE
–OUTPUT
8
9
(VOUT at pins) x (IOUT ) =< rated output power
Figure 8. Trim Connections To Decrease Output Voltages
Using Fixed Resistors
Trim Equations
RTUP (kW) =
VO(100 + D%)
100 + 2 x D%
–
1.225 x D%
D%
RTDOWN (kW) =
100
–2
D%
where D% is the desired change of the output voltage in percent relative to VNOMINAL. Or,
±D% =
www.murata-ps.com
VOUT – VNOM
x 100
VNOM
Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000
UHP-12/21-D48.B02 Page 7 of 12
UHP-12/21-D48
Isolated, 21 Amp Half Brick, 48VIN/12VOUT DC/DC Converter
Vertical Wind Tunnel
,Ê/À>˜Ã«>Ài˜Ì
œ«ÌˆV>Ê܈˜`œÜ
1˜ˆÌÊ՘`iÀ
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i>̈˜}Ê
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λÊLiœÜÊ11/
DATEL employs a custom-designed enclosed 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 can watch thermal characteristics of the Unit
Under Test (UUT) with both dynamic loads and static steadystate conditions. A special optical port is used which is transparent to infrared wavelengths. The computer files from the IR
camera can be studied for later analysis.
Both pinned 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 both adjustable airflow, adjustable ambient heat
and adjustable Input/Output currents and voltages mean that a
very wide range of measurement conditions can be studied.
Whereas some competitors use only thermocouples or RTDs for
heat dissipation studies, IR cameras offer superior advantages:
“Lˆi˜ÌÊ
Ìi“«iÀ>ÌÕÀi
Ãi˜ÃœÀ
1.Thermocouples obviously measure only one point each. Adding
more points is a burden to supply more low-level TC electronics.
The investigator has to guess which components to measure
and where to measure. In contrast, the IR camera measures ALL
points simultaneously on the UUT. More important, TC wires can
conduct away a significant amount of heat, giving false readings
of peak temperatures. Many wires mean more lost heat and is not
representative of real-world applications.
ˆÀvœÜ
Vœˆ“>̜À
Figure 9. Vertical Wind Tunnel
Securely attaching the TC wires with thermal compound is time-consuming
and not totally repeatable unit to unit.
2. The IR camera shows areas which were not previously suspected of
overheating. While the usual method is to concentrate on high power inductors and semiconductors, the IR camera has unwittingly caught overheating
capacitors and other small components.
3. To compensate for the slightly greater accuracy of TCs or RTDs, DATEL
sometimes uses BOTH the IR camera and TCs to compare readings.
4. The IR camera is excellent at showing heat flow. It has identified higher
temperature ground planes which need area and/or thickness increase. It
has also pointed out overheating components “downwind” from hot spots,
depending on airflow direction.
The airflow collimator mixes the heat from the heating element to make
uniform temperature distribution. The collimator also reduces the amount of
turbulence adjacent to the UUT by restoring laminar airflow. Such turbulence
can change the effective heat transfer characteristics and give false readings.
Excess turbulence removes more heat from some surfaces and less heat from
others, possibly causing uneven overheating.
Figure 10. Thermal Image, Bottom View
(VIN = 48V, TA = +25°C, IOUT = 14.1 Amps, natural convection, unmounted)
www.murata-ps.com
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.
Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000
UHP-12/21-D48.B02 Page 8 of 12
UHP-12/21-D48
Isolated, 21 Amp Half Brick, 48VIN/12VOUT DC/DC Converter
Typical Performance Curves
TYPICAL PERFORMANCE CURVES
/UTPUT2IPPLEAND.OISE0!2$
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6).6DIV
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MSECDIV
/UTPUT#URRENT,IMITHICCUP
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6).6#/54§&\\§&,OAD3TEP
6/54M6DIV
6).6—#
6/546DIV
)/54!DIV
)/54!DIV
§SECDIV
§SECDIV
www.murata-ps.com
Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000
UHP-12/21-D48.B02 Page 9 of 12
UHP-12/21-D48
Isolated, 21 Amp Half Brick, 48VIN/12VOUT DC/DC Converter
Typical Performance Curves
TYPICAL PERFORMANCE CURVES
5(0$%FFICIENCYVS,INE6OLTAGEAND,OAD#URRENT —#
5(0$0OWER$ISSIPATIONVS,INE6OLTAGEAND,OAD#URRENT
6).6
%FFICIENCY
0OWER$ISSIPATION7ATTS
6).6
6).6
6).6
6).6
6).6
6).6
6).6
,OAD#URRENT!MPS
UHP-12/21-D48 Maximum Output Current Temperature Derating
6).67ITHBASEPLATE!IRFLOWDIRECTIONFROMINTPUTPINSTOOUTPUTPINS
UHP-12/21-D48 Maximum Output Current Temperature Derating
6).6.OBASEPLATE!IRFLOWDIRECTIONFROMINTPUTPINSTOOUTPUTPINS
The baseplate is not attached to a heatsink or thermal surface.
Full power is available if the baseplate does not exceed +100°C.
LFM
LFM
LFM
Output Current (Amps)
Output Current (Amps)
,OAD#URRENT!MPS
LFM
LFM
LFM
LFM
LFM
.ATURALCONVECTION
n
Ambient Temperature (°C)
Ambient Temperature (°C)
5(0$."ODE0LOT!NALYSIS —#
6).6)/54!4!—##/54§&\\§&\\§&
5(0$."ODE0LOT!NALYSIS —#
6).6)/54!4!—##/54§&\\§&
0HASE
0HASE
'AIND"
0HASE
0HASE—
'AIND"
0HASE—
n
'AIN
'AIN
'AIN
n
n
&REQUENCYK(Z
n
n
&REQUENCYK(Z
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Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000
UHP-12/21-D48.B02 Page 10 of 12
UHP-12/21-D48
Isolated, 21 Amp Half Brick, 48VIN/12VOUT DC/DC Converter
MECHANICAL SPECIFICATIONS
Case C66
2.30
(58.42)
A
B
B
1.900
(48.26)
A
I/O CONNECTIONS
BASEPLATE
2.40
2.000
(60.96) (50.8)
#M3 x 0.50
THREAD THROUGH
0.53 MAX.
(13.46)
Pin
Function P17
1
–Input
2
Case
3
On/Off Control
4
+Input
5
+Output
6
+Sense
7
Trim
8
–Sense
9
–Output
0.49 (12.45)
Without Baseplate
B
PINS 5 & 9:
0.080 ±0.001 (2.03 ±0.025)
B
0.15 MIN.
(3.81)
0.24Ø (6.1) Brass Standoff
TYP. 4 PL
PINS 1-4, 6-8:
0.040Ø ±0.001
(1.016 ±0.025)
9
1
8
2
1.40
(35.56)
7
6
3
5
4
0.30
(7.62)
1.900
(48.26)
0.60
(15.24)
A
BOTTOM VIEW
DIMENSIONS ARE IN INCHES (MM)
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Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000
UHP-12/21-D48.B02 Page 11 of 12
UHP-12/21-D48
Isolated, 21 Amp Half Brick, 48VIN/12VOUT DC/DC Converter
UHP Converter Series Mounting
The UHP series include a multilayer planar-magnetic Printed Circuit Board
(PCB), high-current Input/Output pins, four removable brass mounting standoffs
and an optional machined aluminum baseplate. See Mechanical Specifications.
A user’s installation will normally have a host PCB to solder to the converter’s
I/O pins. To avoid placing the full mechanical mounting load on the I/O pins,
we recommend that the user’s PCB also includes bolts through the PCB to
assemble to the standoffs. Note the #M3 metric threading of the standoffs.
Avoid excessive torque assembling the bolts to the standoffs. Use lock washers or locking compound to avoid loosening of the mounting bolts.
The standoffs include machined shoulders so that mechanical force is not
placed against the converter’s power components. To avoid long-term oxidation of the host PCB, be sure to accommodate the relatively high temperatures
of the power components adjacent to the user’s host PCB. Normally, a planar
grounded area of copper etch on the PCB surface will be sufficient to spread
the heat, reduce electrical noise and avoid hotspots. A relief dimension on the
standoffs floats the power components 0.02 inches minimum from the user’s
host PCB.
The baseplate is in thermal contact with the power components and practically all the converter’s internal heat dissipation is conducted away via the
baseplate. Users typically have two choices to remove this thermal load—
either an extruded aluminum finned heat sink or a thermal mounting surface
such as a chassis wall. The heatsink depends on ambient temperature, airflow
and total power extracted from the converter, depending on the input voltage
and converter efficiency. Do not attempt to conduct all baseplate heat solely
through the standoffs. Use either a thermal pad or thermal mounting compound (“thermal grease”) when attaching the baseplate to its mounting surface. Keep baseplate temperature below +110°C. Study the Derating Curve.
For chassis wall mounting, the user must consider the tolerance buildup—the
host PCB, mounting standoffs, thermal pad and placement of the chassis wall.
Measure carefully to avoid unwanted mechanical stresses.
USA:
Tucson (Az), Tel: (800) 547 2537, email: sales@murata-ps.com
Canada: Toronto, Tel: (866) 740 1232, email: toronto@murata-ps.com
Murata Power Solutions, Inc.
11 Cabot Boulevard, Mansfield, MA 02048-1151 U.S.A.
Tel: (508) 339-3000 (800) 233-2765 Fax: (508) 339-6356
UK:
Milton Keynes, Tel: +44 (0)1908 615232, email: mk@murata-ps.com
France:
Montigny Le Bretonneux, Tel: +33 (0)1 34 60 01 01, email: france@murata-ps.com
Germany: München, Tel: +49 (0)89-544334-0, email: munich@murata-ps.com
www.murata-ps.com email: sales@murata-ps.com ISO 9001 REGISTERED
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. © 2008 Murata Power Solutions, Inc.
Japan:
Tokyo, Tel: 3-3779-1031, email: sales_tokyo@murata-ps.com
Osaka, Tel: 6-6354-2025, email: sales_osaka@murata-ps.com
Website: www.murata-ps.jp
China:
Shanghai, Tel: +86 215 027 3678, email: shanghai@murata-ps.com
Guangzhou, Tel: +86 208 221 8066, email: guangzhou@murata-ps.com
03/21/08
www.murata-ps.com
Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000
UHP-12/21-D48.B02 Page 12 of 12