www.murata-ps.com
RBC 17 Series
Quarter Brick, Regulated Bus Converters
Typical unit
Optimized for distributed power Intermediate Bus Architectures (IBA),
the RBC DC/DC bus converter series offer regulated outputs (±1.5%)
in an industry-standard quarter brick open frame package.
PRODUCT OVERVIEW
The present trend in distributed power architec-
tures (DPA) requires both high efficiency and some
regulation of the output voltage to reduce the risk
of under voltage dropout. Earlier unregulated bus
converters were simply ratiometric “DC transform-
ers.” The fully isolated (2250Vdc) RBC series accept
a wide range 36 to 75 Volt DC input (48V nominal)
and convert it to an output of 12Vdc. This output
then drives point-of-load (POL) converters such
as our Okami, LSN, LEN, LSM or LQN series which
feature precise load regulation. Applications include
48V-powered datacom and telecom installations,
base stations, cellular telephone repeaters and
embedded systems. Low overall height of 0.42"
(10.7 mm) fits tight card cages.
The RBC’s synchronous-rectifier topology and fixed
frequency operation means excellent efficiencies.
“No fan” or zero airflow applications may use the
optional base plate for cold surface mounting or
natural-convection heatsinks.
A wealth of electronic protection features include
input undervoltage (UV) lockout, output current limit,
short circuit hiccup, overtemperature shutdown
and output overvoltage. Available options include
positive or negative polarity remote On/Off control
and the baseplate. Assembled using ISO-certified
automated surface-mount techniques, the RBC
series includes all UL and IEC emissions, safety and
flammability certifications.
FEATURES
Up to 210 Watts total output power
To 92% Ultra-high efficiency @ full load
48V Input ( up to 36-75V range)
12V/17A Output for Intermediate Bus
Architectures with POL converters
Synchronous-rectifier topology
225kHz fixed switching frequency
Fully isolated, 2250Vdc (BASIC)
2.3" x 1.45" x 0.42" quarter brick
Stable no-load condition
Thermal shutdown
Fully I/O protected
IEC/EN/UL/cUL60950-1 certification pending
Typical topology is shown.
Figure 1. Simplified Block Diagram
For full details go to
www.murata-ps.com/rohs
www.murata-ps.com
email: sales@murata-ps.com
01 Mar 2010 MDC_RBC.17.A05
Page 1 of 7
RBC 17 Series
Quarter Brick, Regulated Bus Converters
ORDERING GUIDE SUMMARY
Root Model
➀
RBC-12/17-D48N-C
V
OUT
V
12
I
OUT
(Max.)
A
17
R/N (mV pk-pk)
Typ.
50
Max.
75
Regulation
(Max.)
Line
Load
±0.65%
±1.5%
V
IN
(Nom.)
V
48
Range
V
36-75
Iin, no
load
mA
165
Iin, full
load
A
4.52
Efficiency
Min.
92%
Package
Case
C49
Typ.
94%
Pinout
P65
➀
Please refer to the model number structure for complete model numbers
PART NUMBER STRUCTURE
R BC
-
12
/
17
-
D48 N B
-
C
Regulated
Bus Converter
Nominal Output Voltage:
12 Volts
Maximum Rated Output:
Current in Amps
Input Voltage Range:
D48 = 36 to 75 Volts
(48V nominal)
Optional:
On/Off Control
N = negative polarity , standard
P = positive polarity, optional
Optional Baseplate,
special order
Note:
Some model number combinations may not be
available. Contact Murata Power Solutions for
ordering assistance.
RoHS-6 hazardous substance compliant
(does
not claim EU RoHS exemption 7b–lead in solder)
CAUTION – This converter is not internally fused. To avoid danger to persons or
equipment and to retain safety certification, the user must connect an external
fast-blow input fuse as listed in the specifications. Be sure that the PC board
pad area and etch size are adequate to provide enough current so that the fuse
will blow with an overload.
Start-Up Considerations
When power is first applied to the DC/DC converter, there is some risk of start
up difficulties if you do not have both low AC and DC impedance and adequate
regulation of the input source. Make sure that your source supply does not
allow the instantaneous input voltage to go below the minimum voltage at all
times. Even if this voltage depression is very brief, this may interfere with the
on-board controller and possibly cause a failed start.
Use a moderate size capacitor very close to the input terminals. You may need
two parallel capacitors. A larger electrolytic or tantalum cap supplies the surge
current and a smaller parallel low-ESR ceramic cap gives low AC impedance.
Remember that the input current is carried both by the wiring and the ground
plane return. Make sure the ground plane uses adequate thickness copper. Run
additional bus wire if necessary.
www.murata-ps.com
email: sales@murata-ps.com
01 Mar 2010 MDC_RBC.17.A05
Page 2 of 7
RBC 17 Series
Quarter Brick, Regulated Bus Converters
MECHANICAL SPECIFICATIONS
2.30
(58.4)
A
A
B
1.45
(36.8)
B
1.860
(47.24)
1.030
(26.16)
TOP VIEW
M3 x 0.5-6H THREAD
X .15 DP TYP (4 PLS)
0.14
(3.5)
ALUMINUM
BASEPLATE
OPTION
0.50
(12.7) WITH
BASEPLATE
SIDE VIEW
Ø.040 ±.002 (1.02 ± 0.05)
3X AT PINS 1-3
Ø .060 ±.002 (1.52±0.05)
2X AT PINS 4-5
0.42
(10.7) WITHOUT
BASEPLATE
SEATING PLANE
0.012
(0.31)
SEATING PLANE CLEARANCE
TO HIGHEST COMPONENT
0.19 (4.8)
PIN LENGTH ABOVE SEATING PLANE
B
1
0.600
(15.24)
4
1.45
(36.8)
REF
5
0.300
(7.62)
2
3
BOTTOM VIEW
2.000
(50.8)
A
Dimensions are in inches (mm) shown for ref. only.
Third Angle Projection
INPUT/OUTPUT CONNECTIONS
Pin
Function P65
1
2
3
4
5
-Input
Remote On/Off
+Input
-Output
+Output
Tolerances (unless otherwise specified):
.XX ± 0.02 (0.5)
.XXX ± 0.010 (0.25)
Angles ± 2˚
Components are shown for reference only.
www.murata-ps.com
email: sales@murata-ps.com
01 Mar 2010 MDC_RBC.17.A05
Page 3 of 7
RBC 17 Series
Quarter Brick, Regulated Bus Converters
Performance/Functional Specifications
Typical at T
A
= +25°C under nominal input voltage and full-load conditions unless noted.
Refer to required airflow and Derating curves for thermal specifications. [1]
Electronic Thermal Shutdown
Operating Temperature Range
(With Derating)
Storage Temperature Range
Flammability
Relative Humidity
Safety Compliance
Electromagnetic Interference
conducted or radiated
Pin Material
Weight
+125°C min.
-40ºC to +85ºC, See Derating curves
–55 to +125°C
UL94V-0
To 85% / +85°C
UL60950-1, CSA-C22.2 No.60950-1,
IEC/EN60950-1
EN55022/CISPR22
(may require external filters)
Input
Input Voltage Range
Recommended External Fuse
Start-up Threshold
Undervoltage shutdown
Overvoltage shutdown
Input Current, nominal
Input Current, V
IN
= V
MIN
Input Current, shut-down mode
Inrush Transient
Reflected Ripple Current [2]
Internal Filter Type
Reverse Polarity Protection
Remote On/Off Control [5]
Positive Logic
Negative Logic
Current
Total Output Power [3]
Setpoint Accuracy (50% load)
Extreme Accuracy [14]
Output Current [7]
Minimum Load
Ripple and Noise (20MHz bandwidth)
Line and Load Regulation [10]
Efficiency
Isolation Voltage (Input/output)
(Input to baseplate)
(Baseplate to output)
Isolation Resistance
Isolation Capacitance
Isolation Safety Rating
Current Limit Inception (98% of V
OUT
)
Short Circuit Current [6]
36-75 Volts
20 Amp fast blow
35V
33.5V
None [note 12]
See ording guide
6.00A
6.5mA max.
0.05A
2
-seconds
15mAp-p
L-C
None (see note 11), install external fuse
On = Open or +3.5 to +13.5 V.
Off = Gnd. Pin or 0 to +1V.
On = Gnd. Pin or 0 to +1V.
Off = Pin open or +3.5V to +13.5V.
2mA max.
Physical
Copper alloy with gold plate over nickel underplate
1 ounce (28.4 grams)
Absolute Maximum Ratings
Input Voltage:
Continuous
Transient (100msec max.)
Input Reverse-Polarity Protection
Output Current
75 Volts
100 Volts
None, see notes. Install external fuse.
Current limited. Devices can
withstand an indefinite output short
circuit without damage.
–55 to +125°C
+280°C
Output
210W max.
±3% of V
NOMINAL
11.4V min. to 12.6V max.
See ordering guide
No minimum load
See ordering guide
See ordering guide
See ordering guide
2250Vdc min.
1500Vdc min.
1500Vdc min.
100MΩ
1500pF
Basic
27.5A, after warm up
5 Amps
(hiccup autorestart – remove short for
recovery)
15Vdc max. via magnetic feedback
10,000μF, low ESR 0.02 Ohms
±0.02% per °C
(4)
(5)
(1)
Storage Temperature
Lead Temperature (soldering, 10 sec.)
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.
All models are tested and specified with external 1 || 10uF ceramic/tantalum output capacitors and external
22uF 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)
(3)
Input Ripple Current is tested and specified over a 5 Hz to 20 MHz bandwidth. Input filtering is CIN = 33μF/100V
tantalum, CBUS = 220μF/100V electrolytic, LBUS = 12μH.
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. All Derating curves are presented at sea level altitude. Be
aware of reduced power dissipation with increasing density altitude.
Mean Time Before Failure is calculated using the Telcordia (Belcore) SR-332 Method 1, Case 3, ground fixed
conditions, TPCBOARD = +25°C, full output load, natural air convection.
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 +13.5V.
Short circuit shutdown begins when the output voltage degrades approximately 2% from the selected setting.
The outputs are not intended to sink appreciable reverse current.
Output noise may be further reduced by adding an external filter. See I/O Filtering and Noise Reduction.
All models are fully operational and meet published specifications, including “cold start” at –40°C.
Short Circuit Duration (+V
OUT
grounded) Continuous, no damage
Overvoltage Protection
Max. Capacitive Loading (resistive load)
Temperature Coefficient
Dynamic Load Response
(to within 3% of V
OUT
)
Start Up Time
(V
IN
to V
OUT
regulated)
(Remote On to Vout regulated)
Fixed Switching Frequency
Calculated MTBF [4]
Operating Case Temperature [13]
(6)
(7)
(8)
(9)
Dynamic Characteristics
75μsec, 50-75-50% load step
(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 reverse polarity is accidentally applied to the input, a body diode will become forward biased and will accept
considerable current. To ensure reverse input protection with full output load, always connect an external input
fuse in series with the +VIN input. Use approximately twice the full input current rating with nominal input
voltage.
(12) Input overvoltage shutdown on 48V input models is normally deleted in order to comply with certain telecom
reliability requirements. These requirements attempt continued operation despite significant input overvoltage.
(13) Note that the converter may operate up to +110°C PCB temperature with the baseplate installed. However,
thermal self-protection occurs near +125°C and there is a temperature gradient from high power components.
Therefore, +100°C baseplate temperature is recommended to avoid thermal shutdown.
(14) “Extreme accuracy” refers to all combinations of line and load regulation, output current, initial setpoint
accuracy and temperature coefficient.
60msec
60msec
225 ±25kHz
Environmental
TBD
+110°C max.
www.murata-ps.com
email: sales@murata-ps.com
01 Mar 2010 MDC_RBC.17.A05
Page 4 of 7
RBC 17 Series
Quarter Brick, Regulated Bus Converters
Performance/Functional Specifications
I/O Filtering and Noise Reduction
The RBC is tested and specified with external output capacitors. These
capacitors are necessary to accommodate our test equipment and may not
be required to achieve desired performance in your application. The RBC is
designed with high-quality, high-performance
internal
I/O caps, and will oper-
ate within spec in most applications with
no additional external components.
In particular, the RBC input capacitors are specified for low ESR and are fully
rated to handle the units' input ripple currents. Similarly, the internal output
capacitors are specified for low ESR and full-range frequency response.
In critical applications, input/output ripple/noise may be further reduced using
filtering techniques, the simplest being the installation of external I/O caps.
External input capacitors serve primarily as energy-storage devices. They
minimize high-frequency variations in input voltage (usually caused by IR
drops in conductors leading to the DC/DC) as the switching converter draws
pulses of current. Input capacitors should be selected for bulk capacitance
(at appropriate frequencies), low ESR, and high rms-ripple-current ratings.
The switching nature of modern DC/DC's requires that the dc input voltage
source have low ac impedance at the frequencies of interest. Highly inductive
source impedances can greatly affect system stability. Your specific system
configuration may necessitate additional considerations.
Input Fusing
Most applications and or safety agencies require the installation of fuses at
the inputs of power conversion components. The RBC Series may have an
optional input fuse. Therefore, if input fusing is mandatory, either a normal-
blow or a fast-blow fuse with a value no greater than twice the maximum
input current should be installed within the ungrounded input path to the
converter.
Input Overvoltage and Reverse-Polarity Protection
The RBC does not incorporate input reverse-polarity protection. Input voltages
in excess of the specified absolute maximum ratings and input polarity rever-
sals of longer than "instantaneous" duration can cause permanent damage to
these devices.
Start-Up Time
The V
IN
to V
OUT
Start-Up Time is the interval between the time at which a rising
input voltage crosses the lower limit of the specified input voltage range
and the fully loaded output voltage enters and remains within its specified
regulation band. Actual measured times will vary with input source imped-
ance, external input capacitance, and the slew rate and final value of the input
voltage as it appears to the converter.
The On/Off to V
OUT
Start-Up Time assumes the converter is turned off via the
On/Off Control with the nominal input voltage already applied to the converter.
The specification defines the interval between the time at which the converter
is turned on and the fully loaded output voltage enters and remains within its
specified regulation band.
Thermal Considerations and Thermal Protection
The typical output-current thermal-derating curves shown below enable
designers to determine how much current they can reliably derive from each
model of the RBC under known ambient-temperature and air-flow conditions.
Similarly, the curves indicate how much air flow is required to reliably deliver
a specific output current at known temperatures.
Figure 2. Measuring Input Ripple Current
www.murata-ps.com
email: sales@murata-ps.com
01 Mar 2010 MDC_RBC.17.A05
Page 5 of 7
京公网安备 11010802033920号
EEWORLD
