www.murata-ps.com
www.murata-ps.com/support
For full details go to
www.murata-ps.com/rohs
Figure 1. Bottom View From Pin Side
Optimized for distributed power Regulated Intermediate Bus Architectures (RIBA),
the DRQ DC-DC converter series offer regulated outputs in a quarter brick open
frame package.
SDC_DRQ-11.4/88-L48NB-C.A02 Page 1 of 14
DRQ-11.4/88-L48NB-C
Regulated Quarter-Brick, 986W Isolated DC-DC Converter
FEATURES
Designed for Regulated Intermediate Bus
Architectures (RIBA).
Designed & Tested to Meet the Requirements of
IPC9592, Rev B.
96.3% Ultra-High Efficiency at Full Load.
36V-60V DC Input Range (48V nominal).
Monotonic Startup into Pre-Bias Output
Conditions.
Over-Current & Over-Temperature Protection.
Synchronous Rectifier Topology.
Stable No-Load Operation.
Negative Logic Standard Configuration (Positive
Logic Optional).
Up To +85° Celsius Thermal Performance (With
Derating).
Remote On/Off Enable Control.
Fully Isolated to 1500Vdc.
Extensive Protection Features - UVLO, OVP, OCP,
SCP, OTP.
Full Safety, Emissions and Environmental
Certifications.
Approved to UL 60950-1, CSA-C22.2 No.60950-
1, IEC/EN 60950-1 Safety Approvals.
The DRQ-11.4/88-L48NB-C regulated converter
module deliver a 11.2V output @ Vin = 48Vdc in
a quarter brick open frame package at aston-
ishing efficiency. The fully isolated (1500Vdc)
DRQ-11.4/88-L48NB-C series accept a 36 to 60
Volt DC input voltage range and converts it to a
low Vdc output that drives external point-of-load
(PoL) DC-DC power converters such as Murata
Power Solutions’ tiny Okami series which feature
precise regulation directly at the load. Applications
include datacom and telecom installations, cellular
dataphone repeaters, base stations, instruments
and embedded systems. Wideband output ripple
and noise is typical 100mV, peak-to-peak.
The DRQ’s synchronous-rectifier topology and
fixed frequency operations means excellent effi-
ciencies up to 96.3%.
A wealth of electronic protection features include
input under voltage lockout, over voltage lockout
protection, output current limit, current sharing,
short circuit hiccup, Vout overshoot, and over
temperature shutdown. Available options include
various pin lengths and the baseplate. Assembled
using ISO-certified automated surface-mount
techniques, the DRQ series is designed to meet
all UL and IEC emissions, safety and flammability
certifications.
PRODUCT OVERVIEW
Typical unit
Output (V) Current (A) Nominal Input (V)
11.2 88 48
4 (+Vout)
5 (-Vout)
8 (-Vout)
7 (+Vout)
(-Vin) 3
(Enable) 2
(+Vin) 1
www.murata-ps.com/support
PART NUMBER STRUCTURE
SDC_DRQ-11.4/88-L48NB-C.A02 Page 2 of 14
DRQ-11.4/88-L48NB-C
Regulated Quarter-Brick, 986W Isolated DC-DC Converter
PERFORMANCE SPECIFICATIONS SUMMARY AND ORDERING GUIDE
Root Model [1]
Output Input
Efficiency Dimensions with baseplate
VOUT
(V)
IOUT
(A, max.)
Total Power
(W)
Ripple & Noise
(mVp-p, Max.)
VIN
(V, Nom.)
Range
(V)
IIN, no load
(mA)
IIN, full load
(A) Typ. Case (inches) Case (mm)
DRQ-11.4/88-L48NB-C 11.2 88 986 150 48 36-60 300 21.7 96.3% 2.3 x 1.45 x 0.57 58.42 x 36.83 x 14.5
Notes:
[1] Please refer to the part number structure for additional options and complete ordering part numbers.
[2] All specifications are at nominal line voltage and full load, +25 ºC. unless otherwise noted. See detailed specifications. Output capacitors are 1µF ceramic in parallel with 10µF and
470 µF electrolytic. Input capacitors are 220 µF electrolytic. I/O caps are necessary for our test equipment and may not be needed for your application.
Output Voltage
Voltage in Volts (V)
11.4
Digital Control - Regulated
DR
Q = Quarter-Brick
Q
Input Voltage Range
L48 = 36V-60V
L48
Maximum Rated Output Currrent
Current in Amps (A)
88
N = Negative Logic (Standard Configuration)
P = Positive Logic (Special Order Only)
N
Blank = Standard pin length 0.180 in. (4.6mm)
L1 = 0.110 in. (2.79mm)
L2 = 0.145 in. (3.68mm)
Baseplate (Standard Configuration)
B
Blank = No Load Share (Standard Configuration)
S = Load Sharing Option
S-C
RoHS 6/6 Compliant
--
/L1
Note:
Some model number combinations may not be available. See website or contact your local Murata sales representative.
www.murata-ps.com/support
SDC_DRQ-11.4/88-L48NB-C.A02 Page 3 of 14
DRQ-11.4/88-L48NB-C
Regulated Quarter-Brick, 986W Isolated DC-DC Converter
FUNCTIONAL SPECIFICATIONS
ABSOLUTE MAXIMUM RATINGS Conditions Minimum Typical/Nominal Maximum Units
Input Voltage, Continuous 36 48 60 Vdc
Input Voltage, Transient 100 mS maximum duration 75 Vdc
Isolation Voltage Input to output 1500 Vdc
On/Off Remote Control Power on, referred to -Vin 0 0.8 Vdc
Output Power 0 986 986 W
Output Current Current-limited, no damage, short-circuit protected 0 88 88 A
Storage Temperature Range Vin = Zero (no power) -40 100 °C
Absolute maximums are stress ratings. Exposure of devices to greater than any of these conditions may adversely affect long-term reliability. Proper operation under conditions other than those
listed in the Performance/Functional Specifications Table is not implied nor recommended.
INPUT
Internal Filter Type Pi
External Input Fuse Recommended 45 A
External Input Capacitance 140 80 μF
Voltage
Operating Voltage Range 36 48 60 Vdc
Start-up Threshold 34 35 36 Vdc
Undervoltage Shutdown 32 33.1 35 Vdc
Voltage Transients 100ms duration 75 Vdc
Current
Full Load Conditions Vin = nominal 21.7 23 A
Low Line Input Current Vin = minimum 28.9 30 A
Short Circuit Input Current 0.03 0.05 A
No Load Input Current Iout = minimum, unit=ON 300 400 mA
Inrush Current 50 % of Iin
Shut-down Mode Input Currrent Off, UV, OT 20 50 mA
Back Ripple Current measured at input pins with 800μF input capacitance 1000 mArms
OUTPUT
Total Output Power 0 986 986 W
Voltage (Without S Option)
Output Voltage 10.95 11.20 11.65 Vdc
Setting Accuracy At 50% load, no trim, all conditions 11.15 11.20 11.25 Vdc
Voltage (With S Option)
Output Voltage 10.75 11.20 11.65 Vdc
Setting Accuracy At 50% load, no trim, all conditions 11.05 11.20 11.45 Vdc
Overvoltage Protection 12.20 13.70 15.20 Vdc
Current
Output Current Range 0 88 88 A
Minimum Load No minimum load
Current Limit Inception 90% of Vnom., cold condition, after warm up 96 105 115 A
Short Circuit
Short Circuit Duration
(Remove Short for Recovery) Output shorted to ground, no damage Continuous
Short Circuit Protection Method Hiccup current limiting Auto recovery
Regulation
Line Regulation Vin = 36-60, Vout = nom., full load ±0.5 %
Load Regulation (No Droop) Iout = min. to max., Vin = nom. ±0.2 %
Ripple and Noise 20MHz BW, Cout = 470µF, approximately 50% ceramic,
50% Oscon or POSCAP, measured at output pins 100 150 mV pk-pk
Pre-Bias Voltage Cout = 470uF, approximately 50% ceramic, 50% Oscon or
POSCAP. Measured at output pins, bandwidth = 20MHz 0 Vdc
Temperature Coefficient (No Droop) At all outputs N/A % of Vnom./°C
Max. Output Capacitance Typically 50% ceramic, 50% Oscon or POSCAP 470 10000 μF
GENERAL and SAFETY
Efficiency Vin = 48V, full load 95.5 96.3 %
Isolation
Input to Output Test Voltage 1500 Vdc
Input to Baseplate Test Voltage 1000 Vdc
Baseplate to Output Test Voltage 1000 Vdc
Safety Rating Functional
www.murata-ps.com/support
SDC_DRQ-11.4/88-L48NB-C.A02 Page 4 of 14
DRQ-11.4/88-L48NB-C
Regulated Quarter-Brick, 986W Isolated DC-DC Converter
FUNCTIONAL SPECIFICATIONS (CONT.)
Notes:
[1] Unless otherwise noted, all specifications apply over the input voltage range, full temperature range, nominal output voltage and full output load. General conditions are near sea
level altitude, heat sink installed and natural convection airflow unless otherwise specified. All models are tested and specified with external parallel 1 µF and 10 µF ceramic and
470 µF electrolytic output capacitors. 220 µF electrolytic external input capacitor is used (see Application Notes). All capacitors are low-ESR types wired close to the converter.
These capacitors are necessary for our test equipment and may not be needed in the user’s application.
[2] Measured at input pin with maximum specified Cin and <500µH inductance between voltage source and Cin.
[3] All models are stable and regulate to specification under no load.
[4] The Remote On/Off Control is referred to -Vin.
[5] Inrush Current is defined as the peak current drawn by the unit when unit is enabled after Vin is present. Iin is defined as the steady-state operating current when unit is operating
under same conditions.
Isolation Resistance N/A MΩ
Isolation Capacitance 1000 pF
Safety UL 60950-1, CSA-C22.2 No.60950-1, IEC/EN 609050-1 Yes
Calculated MTBF Per Telcordia SR-332, Issue 3, Method 1, Class 1,
Ground Fixed, Tcase=+25°C 4800 Hours x 103
DYNAMIC CHARACTERISTICS
Switching Frequency 180 KHz
Turn On Time
Vin On to Vout Regulated 20 25 30 mS
Remote On to Vout Regulated 2.5 5 mS
Rise Time 15 mS
Restart Delay 250 mS
Dynamic Load Response Load step = 25% of Rated Power at 1A/uS, 4uF/W of
external capacitance, measured at output pins. 500 µSec
Dynamic Load Peak Deviation Measured at output pin with 470µF output capacitance,
50% Ceramic, 50% Oscon or POSCAP ±350 mV
FEATURES and OPTIONS
Remote On/Off Control (Voltages referenced to -Input, Designed to be drived with an open collector logic)
“N” Suffix:
Negative Logic, ON state ON = ground pin or external voltage -0.1 0.8 Vdc
Negative Logic, OFF state OFF = pin open or external voltage 2.4 20 Vdc
“P” Suffix:
Positive Logic, ON State ON = pin open or external voltage 2.4 20 Vdc
Positive Logic, OFF State OFF = ground pin or external voltage -0.1 0.8 Vdc
MECHANICAL
Outline Dimensions (With Baseplate) 2.3 x 1.45 x 0.57 Inches
58.42 x 36.83 x 14.5 mm
Weight (With Baseplate) 3.14 Ounces
80 Grams
Through Hole Pin Diameter 0.06 & 0.04 Inches
1.524 & 1.016 mm
Through Hole Pin Material Copper alloy
TH Pin Plating Metal and Thickness Nickel subplate 98.4-299 µ-inches
Gold overplate 4.7-19.6 µ-inches
ENVIRONMENTAL
Temperature
Operating Ambient Temperature Range -40 85 °C
Operating Baseplate Temperature No Derating Required -40 120 °C
Storage Temperature Vin = Zero (no power) -40 100 °C
Thermal Protection/Shutdown
(With “B” Suffix) Baseplate temperature measured in the center 130 °C
Electromagnetic Interference Conducted,
EN55022/CISPR22
External filter required;
See emissions performance test. B Class
RoHS Rating RoHS-6
www.murata-ps.com/support
SDC_DRQ-11.4/88-L48NB-C.A02 Page 5 of 14
DRQ-11.4/88-L48NB-C
Regulated Quarter-Brick, 986W Isolated DC-DC Converter
PERFORMANCE DATA
Efficiency and Power dissipation @ +25°C Output Voltage vs. Load Current
Maximum Power Temperature Derating at sea level
(Vin=48V, airflow from Vin- to Vin+, with heatsink on 10X10 inch board)
Maximum Current Temperature Derating at sea level
(Vin=48V, airflow from Vin- to Vin+, with heatsink on 10X10 inch board)
Maximum Power Temperature Derating at sea level
(Vin=48V, airflow from Vin to Vout, with heatsink on 10X10 inch board)
Maximum Current Temperature Derating at sea level
(Vin=48V, airflow from Vin to Vout, with heatsink on 10X10 inch board)
0
10
20
30
40
50
60
70
80
90
100
40 45 50 55 60 65 70 75 80 85
Ambient Temperature in Degrees Celsius
Output Load Current (Amps)
100LFM
200LFM
300LFM
400LFM
500LFM
600LFM
0
200
400
600
800
1000
1200
40 45 50 55 60 65 70 75 80 85
Ambient Temperature in Degrees Celsius
Output Power (W)
100LFM
200LFM
300LFM
400LFM
500LFM
600LFM
0
200
400
600
800
1000
1200
40 45 50 55 60 65 70 75 80 85
Ambient Temperature in Degrees Celsius
Output Power (W)
100LFM
200LFM
300LFM
400LFM
500LFM
600LFM
0
10
20
30
40
50
60
70
80
90
100
40 45 50 55 60 65 70 75 80 85
Ambient Temperature in Degrees Celsius
Output Load Current (Amps)
100LFM
200LFM
300LFM
400LFM
500LFM
600LFM
9
15
21
27
33
39
45
51
57
63
69
75
81
87
93
72
74
76
78
80
82
84
86
88
90
92
94
96
98
100
8 16 24 32 40 48 56 64 72 80
Loss (Watt)
Efficiency (%)
Iout (Amp)
Vin=36V
Vin=48V
Vin=60V
Pd@48V.W
88
10.8
10.9
11
11.1
11.2
11.3
11.4
11.5
0 44 88
Output Voltage (V)
Output Current (A)
Standard Configuration
(No Load Share)
Load Share Option
(S Option)
www.murata-ps.com/support
SDC_DRQ-11.4/88-L48NB-C.A02 Page 6 of 14
DRQ-11.4/88-L48NB-C
Regulated Quarter-Brick, 986W Isolated DC-DC Converter
PERFORMANCE DATA
Maximum Current Temperature Derating at sea level
(Vin=48V, airflow from Vin- to Vin+, with baseplate on 10x10 inch board)
Maximum Current Temperature Derating at sea level
(Vin=48V, airflow from Vin to Vout, with baseplate on 10X10 inch board)
Maximum Power Temperature Derating at sea level
(Vin=48V, airflow from Vin- to Vin+, with baseplate on 10x10 inch board)
Maximum Power Temperature Derating at sea level
(Vin=48V, airflow from Vin to Vout, with baseplate on 10X10 inch board)
0
10
20
30
40
50
60
70
80
90
40 45 50 55 60 65 70 75 80 85
Ambient Temperature in Degrees Celsius
Output Load Current (Amps)
100LFM
200LFM
300LFM
400LFM
500LFM
600LFM
0
100
200
300
400
500
600
700
800
900
1000
40 45 50 55 60 65 70 75 80 85
Ambient Temperature in Degrees Celsius
Output Power (W)
100LFM
200LFM
300LFM
400LFM
500LFM
600LFM
0
10
20
30
40
50
60
70
80
90
40 45 50 55 60 65 70 75 80 85
Ambient Temperature in Degrees Celsius
Output Load Current (Amps)
100LFM
200LFM
300LFM
400LFM
500LFM
600LFM
0
100
200
300
400
500
600
700
800
900
1000
40 45 50 55 60 65 70 75 80 85
Ambient Temperature in Degrees Celsius
Output Power (W)
100LFM
200LFM
300LFM
400LFM
500LFM
600LFM
Output Voltage Ripple @ BW=20MHz
Vin=48V, Iout=0A, Cout=700μF, Ta=+25°C, 2μS/div
Output Voltage Ripple @ BW=20MHz
Vin=48V, Iout=88A, Cout=700μF, Ta=+25°C, 2μS/div
www.murata-ps.com/support
SDC_DRQ-11.4/88-L48NB-C.A02 Page 7 of 14
DRQ-11.4/88-L48NB-C
Regulated Quarter-Brick, 986W Isolated DC-DC Converter
PERFORMANCE DATA
Output Pre-bias Start-up
Vin=48V, Iout=0A, Cload=470μF, Ta =+25°C, 4mS/div
Enable Start-up Delay (CH2: Vout, CH4: On/Off)
Vin=48V, Iout=0A, Cload=10000μF, Ta=+25°C, 2mS/div
Vin Start-up Delay (CH2: Vout, CH1: Vin)
Vin=48V, Iout=0A, Cload=10000μF, Ta=+25°C, 10mS/div
Enable Start-up Delay (CH2: Vout, CH4: On/Off)
Vin=48V, Iout=88A, Cload=10000μF, Ta=+25°C, 2mS/div
Vin Start-up Delay (CH2: Vout, CH1: Vin)
Vin=48V, Iout=88A, Cload=10000μF, Ta=+25°C, 10mS/div
www.murata-ps.com/support
MECHANICAL SPECIFICATIONS (THROUGH-HOLE MOUNT)
47.24
1.860
26.16
1.030
36.8
1.45
58.4
2.30
5.59
0.220
5.33
0.210
M3 TYP 4PL
SIDE VIEW
1.52
0.060
@Pin 4,5,7,8
2.80
0.110
@ Pin 4,5,7,8
1.02
0.040
@Pin 1,2,3
2.31
0.091
@Pin 1,2,3
14.5
0.57
Max
SEE NOTE 4
L
TOP VIEW
SIDE VIEW
1.40
0.055
1.40
0.055
1.40
0.055
1.98
0.078
1.98
0.078
1.98
0.078
1.98
0.078
15.24
0.600
7.62
C
L
0.300
50.80
2.000
C
L
11.43
0.450
19.05
0.750
22.86
0.900
58.9
2.32
37.3
1.47
C
L
25.40
1.000
1
2
5
7
0.25
MTG PLANE
0.010
Min
1
2
3
4
5
7
8
3
4
8
BOTTOM VIEW
50.80
2.000
NOTES:
UNLESS OTHERWISE SPECIFIED
[1] M3 SCREW USED TO BOLT UNIT’S BASEPLATE TO OTHER SURFACES (SUCH AS HEATSINK) MUST NOT EXCEED
0.110’’ (2.8mm) DEPTH BELOW THE SURFACE OF BASEPLATE.
[2] APPLIED TORQUE PER SCREW SHOULD NOT EXCEED 5.3In-Ib (0.6Nm).
[3] ALL DIMENSION ARE IN INCHES (MILIMETER).
[4] STANDARD PIN LENGTH: 0.180Inch.
[5] FOR L2 PIN LENGTH OPTION IN MODEL NAME., USE STANDARD L2 PIN WITH PIN LENGTH TO 0.145Inch.
[6] ALL TOLERANCES: x.xxin, ±0.02in (x.xmm,±0.5mm)
x.xxxin, ±0.01in (x.xxmm, ±0.25mm).
[7] COMPONENTS WILL VARY BETWEEN MODELS.
MATERIAL:
Dia 0.040 PINS: COPPER ALLOY
FINISH: (ALL PINS)
GOLD (5μ”MIN) OVER NICKEL (100μ”MIN)
SDC_DRQ-11.4/88-L48NB-C.A02 Page 8 of 14
DRQ-11.4/88-L48NB-C
Regulated Quarter-Brick, 986W Isolated DC-DC Converter
Third Angle Projection
Dimensions are in inches (mm shown for ref. only).
Components are shown for reference only
and may vary between units.
Tolerances (unless otherwise specified):
.XX ± 0.02 (0.5)
.XXX ± 0.010 (0.25)
Angles ± 2˚
INPUT/OUTPUT CONNECTIONS
PIN FUNCTION PIN FUNCTION
1 Vin(+) 5 Vout(-)
2 Enable
3 Vin(-) 7 Vout(+)
4 Vout(+) 8 Vout(-)
Please refer to the part number structure
for alternate pin lengths.
RECOMMEND PCB FOOTPRINT
www.murata-ps.com/support
SDC_DRQ-11.4/88-L48NB-C.A02 Page 9 of 14
DRQ-11.4/88-L48NB-C
Regulated Quarter-Brick, 986W Isolated DC-DC Converter
SHIPPING TRAYS AND BOXES, THROUGH-HOLE MOUNT
SHIPPING TRAY DIMENSIONS
DRQ modules are supplied in a 15-piece (5 x 3) shipping tray. The tray is an anti-static closed-cell polyethylene foam. Dimensions are shown below.
2.0
2.40
3.025
R0.25
9.92
0.571.45
1.825
9.92
0.38
0.38
0.25
0.39 TYP 30PL
0.25 CHAMFER TYP 4PL
0.570
0.970
SECTION A-A
SCALE 1 : 3
A
A
NOTES:
1: LOW DENSITY CLOSED CELL POLYETHYLENE STATIC DISSIPATIVE FOAM:10
2: SURFACE RESISTIVITY:10 OHMS PER SQUARE
MAXIMUM DENSITY: 1.8 PCF
3: COMPRESSION SET: VERTICAL DIRECTION <20%
4: COMPRESSION DEFLECTION: ASTM D 3575 SUFFIX D @ 10%
VERTICAL 5PSI
EXTRUDED 7PSI
HORIZONTAL 3PSI
5: COMPRESSION DEFLECTION : ASTM D 3575 SUFFIX D @ 25%
VERTICAL 7PSI
EXTRUDED 8PSI
HORIZONTAL 5PSI
6: COMPRESSION DEFLECTION:ASTM D 3575 SUFFIX D @ 50%
VERTICAL 13PSI
EXTRUDED 15PSI
HORIZONTAL 12PSI
TENSILE STRENGTH: 35PSI AVERAGE
CARTON ACCOMMODATES 2 TRAYS YIELDING
30 CONVERTERS PER CARTON
INPUT END OF CONVERTERS
(ALL 0.040" PINS)
OUTPUT END OF CONVERTERS
( 0.062" PINS WITH OR WITHOUT
ADDITIONAL 0.040" PINS)
1/4" HOLE ONE CORNER
OF FORM TRAY ADDED TO
VISUALLY CONTROL
CONVERTER ORIENTATIONS
2.75
REF
10.50
REF
11.25
REF
SHIPPING BOX
10"x10"x2.50"
SHIPPING TRAY x2
1/4 BRICK, 3x5 CAVITIES
SHIPPING TRAY BASE (PAD)
75" THICK
LABEL
1.0"x1.5", PAPER
LABEL
2.0"x4.0", PAPER
LABEL
PRE-PRINTED ESD ATTENTION
ESD TAPE
3/4" WIDE
EACH STATIC DISSIPATIVE POLYETHYLENE FOAM TRAY ACCOMMODATES
15 CONVERTERS IN A 3x5 ARRAY
Third Angle Projection
Dimensions are in inches (mm shown for ref. only).
Components are shown for reference only
and may vary between units.
Tolerances (unless otherwise specified):
.XX ± 0.02 (0.5)
.XXX ± 0.010 (0.25)
Angles ± 1˚
www.murata-ps.com/support
Load Sharing
Load sharing occurs when two or more DRQ-11.4/88-L48NB-C s are con-
nected in parallel at both the input and output terminals to supply greater
output current than one unit alone or to offer system redundancy for moderate
loads. If one converter fails, the other converter(s) will carry the load until the
system is repaired.
The DRQ-11.4/88-L48NB-C ’s design allows load sharing using the “droop”
method, also called the “direct connect” technique. Simply put, at light loads,
the converter with slightly higher output voltage will carry more of the output
current. Since the DRQ-11.4/88-L48NB-C ’s synchronous rectifier design
will not accept appreciable reverse output current, starting at zero load, the
DRQ-11.4/88-L48NB-C with the higher output voltage will carry more of the
full load until the voltage at the output drops to that of the lower DRQ-11.4/88-
L48NB-C ’s.
Load Sharing Guidelines
If you wish to operate two or more DRQ-11.4/88-L48NB-C ’s in load sharing,
use these guidelines:
[1] Operate both converters connected in parallel to the same 50V input
power source. This simplifies the design and makes more balanced power
sharing. Using two different 50V input supplies must be carefully analyzed to
avoid overloading one of the converters and is not recommended.
Make sure the single 50V input source can supply the total current needed
by all the parallel-connected DRQ-11.4/88-L48NB-C ’s. (Actually, it is pos-
sible to rate the full system at more than the current capacity of a single
DRQ-11.4/88-L48NB-C . However, you now lose the redundancy protection
feature.)
[2] Use conservative loading. Do not assume for example that two parallel
DRQ-11.4/88-L48NB-C ’s can always supply “times two” amounts of output
current. Allow for limits in input voltage and other factors.
If one DRQ-11.4/88-L48NB-C overloads while in load share, it will protect
itself by entering the overcurrent mode. If the whole system is running close
to maximum output current, the remaining good DRQ-11.4/88-L48NB-C will
soon also enter overcurrent mode. These two events probably will not happen
together, possibly leaving the system operating in degraded mode for awhile.
The solution here is conservative design to avoid getting close to the load
limits.
TECHNICAL NOTES [3] Make the input wiring lengths and wire gauges identical on both inputs
and outputs. If in doubt, make some precision measurements under full load.
But if you attempt to measure the current in one of the converters using a
series shunt, remember that the current meter itself may introduce enough
finite resistance to affect the readings. (Hint: Use a non-contacting “clamp-on”
Hall effect DC current meter with zero IR loss.)
[4] If you add the optional input filters, use identical components with the
same layout.
[5] Operate both converters in the same temperature and airflow environ-
ment. Under load sharing, small differences in cooling can amplify into load
imbalances.
[6] Avoid operation near the low input voltage limit of the converter. Another
subtle factor here is the external source impedance of the input supply. A
source with higher source impedance at full load may make the net input
voltage seen by the converter close to its minimum input voltage. Be sure to
account for the decrease in effective input voltage under load.
For battery sources, this means that the batteries should be freshly charged
and that the AC trickle charger is in good working order. Note that older batter-
ies increase their internal cell impedance even if their no-load output voltage
appears acceptable. Remember that what counts here is the voltage seen at
the DRQ-11.4/88-L48NB-C input connections with full current.
[7] As with any system design, thoroughly test the DRQ-11.4/88-L48NB-C ’s
connected in load sharing before committing the design to a real application.
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.
Use a moderate size capacitor very close to the input terminals. You may
need two or more parallel capacitors. A larger electrolytic or ceramic cap sup-
plies 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.
On/Off Control
The input-side, remote On/Off Control function (pin 2) can be ordered to oper-
ate with either logic type:
Negative (“N” suffix): Negative-logic devices are off when pin 2 is left open
(or pulled high, applying +3.5V to +20V), and on when pin 2 is pulled low (0 to
0.8V) with respect to –Input as shown in Figure 3.
SDC_DRQ-11.4/88-L48NB-C.A02 Page 10 of 14
DRQ-11.4/88-L48NB-C
Regulated Quarter-Brick, 986W Isolated DC-DC Converter
+48V
POWER
SOURCE
+Vout
OPTIONAL INPUT FILTERS
RBQ 1
RBQ 2
VIN
VIN VOUT
VOUT
ILOAD
RLOAD
Figure 2. Load Sharing Block Diagram
DRQ1
DRQ2
www.murata-ps.com/support
SDC_DRQ-11.4/88-L48NB-C.A02 Page 11 of 14
DRQ-11.4/88-L48NB-C
Regulated Quarter-Brick, 986W Isolated DC-DC Converter
Dynamic control of the remote on/off function is best accomplished with
a mechanical relay or an open-collector/open-drain drive circuit (optically
isolated if appropriate). The drive circuit should be able to sink appropriate cur-
rent (see Performance Specifications) when activated and withstand appropri-
ate voltage when deactivated. Applying an external voltage to pin 2 when no
input power is applied to the converter can cause permanent damage to the
converter.
Input Fusing
Certain applications and/or safety agencies may require fuses at the inputs of
power conversion components. Fuses should also be used when there is the
possibility of sustained input voltage reversal which is not current-limited. For
greatest safety, we recommend a fast blow fuse installed in the ungrounded
input supply line.
Input Under-Voltage Shutdown and Start-Up Threshold
Under normal start-up conditions, converters will not begin to regulate properly
until the rising input voltage exceeds and remains at the Start-Up Threshold
Voltage (see Specifications). Once operating, converters will not turn off until
the input voltage drops below the Under-Voltage Shutdown Limit. Subsequent
restart will not occur until the input voltage rises again above the Start-Up
Threshold. This built-in hysteresis prevents any unstable on/off operation at a
single input voltage.
Start-Up Time
Assuming that the output current is set at the rated maximum, the Vin to Vout
Start-Up Time (see Specifications) is the time interval between the point when
the rising 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 capaci-
tance, input voltage slew rate and final value of the input voltage as it appears
at the converter.
These converters include a soft start circuit to moderate the duty cycle of its
PWM controller at power up, thereby limiting the input inrush current.
The On/Off Remote Control interval from On command to Vout (final ±5%)
assumes that the converter already has its input voltage stabilized above the
Start-Up Threshold before the On command. The interval is measured from the
On command until the output enters and remains within its specified accuracy
band. The specification assumes that the output is fully loaded at maximum
rated current. Similar conditions apply to the On to Vout regulated specification
such as external load capacitance and soft start circuitry.
Recommended Input Filtering
The user must assure that the input source has low AC impedance to provide
dynamic stability and that the input supply has little or no inductive content,
including long distributed wiring to a remote power supply. The converter will
operate with no additional external capacitance if these conditions are met.
For best performance, we recommend installing a low-ESR capacitor
immediately adjacent to the converter’s input terminals. The capacitor should
be a ceramic type such as the Murata GRM32 series or a polymer type. Make
sure that the input terminals do not go below the undervoltage shutdown volt-
age at all times. More input bulk capacitance may be added in parallel (either
electrolytic or tantalum) if needed.
Recommended Output Filtering
The converter will achieve its rated output ripple and noise with no additional
external capacitor. However, the user may install more external output capaci-
tance to reduce the ripple even further or for improved dynamic response.
Again, use low-ESR ceramic (Murata GRM32 series) or polymer capacitors.
Mount these close to the converter. Measure the output ripple under your load
conditions.
Use only as much capacitance as required to achieve your ripple and noise
objectives. Excessive capacitance can make step load recovery sluggish or
possibly introduce instability. Do not exceed the maximum rated output capaci-
tance listed in the specifications.
Figure 3. Driving the Negative Logic On/Off Control Pin
ON/OFF
CONTROL
–VIN
+VIN +VCC
Fuse
RLOAD
–VIN
+VIN
–VIN
+VIN
–VO
+VO
Figure 4. Input Fusing
www.murata-ps.com/support
SDC_DRQ-11.4/88-L48NB-C.A02 Page 12 of 14
DRQ-11.4/88-L48NB-C
Regulated Quarter-Brick, 986W Isolated DC-DC Converter
Input Ripple Current and Output Noise
All models in this converter series are tested and specified for input reflected
ripple current and output noise using designated external input/output com-
ponents, circuits and layout as shown in the figures below. The Cbus and Lbus
components simulate a typical DC voltage bus.
Minimum Output Loading Requirements
All models regulate within specification and are stable under no load to full
load conditions. Operation under no load might however slightly increase
output ripple and noise.
Thermal Shutdown
To prevent many over temperature problems and damage, these converters
include thermal shutdown circuitry. If environmental conditions cause the
temperature of the DC/DC’s to rise above the Operating Temperature Range
up to the shutdown temperature, an on-board electronic temperature sensor
will power down the unit. When the temperature decreases below the turn-on
threshold, the converter will automatically restart. There is a small amount of
hysteresis to prevent rapid on/off cycling.
CAUTION: If you operate too close to the thermal limits, the converter may
shut down suddenly without warning. Be sure to thoroughly test your applica-
tion to avoid unplanned thermal shutdown.
Temperature Derating Curves
The graphs in this data sheet illustrate typical operation under a variety of
conditions. The Derating curves show the maximum continuous ambient air
temperature and decreasing maximum output current which is acceptable
under increasing forced airflow measured in Linear Feet per Minute (“LFM”).
Note that these are AVERAGE measurements. The converter will accept brief
increases in current or reduced airflow as long as the average is not exceeded.
Note that the temperatures are of the ambient airflow, not the converter
itself which is obviously running at higher temperature than the outside air.
Murata Power Solutions makes Characterization measurements in a closed
cycle wind tunnel with calibrated airflow. We use both thermocouples and an
infrared camera system to observe thermal performance. As a practical matter,
it is quite difficult to insert an anemometer to precisely measure airflow in
most applications. Sometimes it is possible to estimate the effective airflow if
you thoroughly understand the enclosure geometry, entry/exit orifice areas and
the fan flowrate specifications.
CAUTION: If you exceed these Derating guidelines, the converter may have
an unplanned Over Temperature shut down. Also, these graphs are all collected
near Sea Level altitude. Be sure to reduce the derating for higher altitude.
Output Fusing
The converter is extensively protected against current, voltage and temperature
extremes. However your output application circuit may need additional protec-
tion. In the extremely unlikely event of output circuit failure, excessive voltage
could be applied to your circuit. Consider using an appropriate fuse in series
with the output.
Output Current Limiting
Current limiting inception is defined as the point at which full power falls below
the rated tolerance. See the Performance/Functional Specifications. Note par-
ticularly that the output current may briefly rise above its rated value in normal
operation as long as the average output power is not exceeded. This enhances
reliability and continued operation of your application. If the output current is
too high, the converter will enter the short circuit condition.
Output 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 (approxi-
mately 97% of nominal output voltage for most models), the PWM controller
will shut down. Following a time-out period, the PWM will restart, causing
the output voltage to begin rising to its appropriate value. If the short-circuit
condition persists, another shutdown cycle will initiate. This rapid on/off cycling
is called “hiccup mode.” The hiccup cycling reduces the average output cur-
rent, thereby preventing excessive internal temperatures and/or component
damage.
The “hiccup” system differs from older latching short circuit systems
because you do not have to power down the converter to make it restart. The
system will automatically restore operation as soon as the short circuit condi-
tion is removed.
C
IN
V
IN
L
BUS
C
IN
= 300µF, ESR < 700mΩ @ 100kHz
L
BUS
= <500µH
+VIN
-VIN
CURRENT
PROBE
TO
OSCILLOSCOPE
+
–
+
–
Figure 5. Measuring Input Ripple Current
C1
C1 = 1µF
C2 = 10µF
LOAD 2-3 INCHES (51-76mm) FROM MODULE
C2 R
LOAD
SCOPE
+VOUT
-VOUT
Figure 6. Measuring Output Ripple and Noise (PARD)
www.murata-ps.com/support
SDC_DRQ-11.4/88-L48NB-C.A02 Page 13 of 14
DRQ-11.4/88-L48NB-C
Regulated Quarter-Brick, 986W Isolated DC-DC Converter
Output Capacitive Load
These converters do not require external capacitance added to achieve rated
specifications. Users should only consider adding capacitance to reduce
switching noise and/or to handle spike current load steps. Install only enough
capacitance to achieve noise objectives. Excess external capacitance may
cause degraded transient response and possible oscillation or instability.
NOTICE—Please use only this customer data sheet as product documentation
when laying out your printed circuit boards and applying this product into your
application. Do NOT use other materials as official documentation such as adver-
tisements, product announcements, or website graphics.
We strive to have all technical data in this customer data sheet highly accu-
rate and complete. This customer data sheet is revision-controlled and dated.
The latest customer data sheet revision is normally on our website (www
.murata-ps.com) for products which are fully released to Manufacturing. Please
be especially careful using any data sheets labeled “Preliminary” since data
may change without notice.
Emissions Performance, Model DRQ-11.4/88-L48NB-C
Murata Power Solutions measures its products for radio frequency emissions
against the EN 55022 and CISPR 22 standards. Passive resistance loads are
employed and the output is set to the maximum voltage. If you set up your
own emissions testing, make sure the output load is rated at continuous power
while doing the tests.
The recommended external input and output capacitors (if required) are
included. Please refer to the fundamental switching frequency. All of this
information is listed in the Product Specifications. An external discrete filter is
installed and the circuit diagram is shown below.
[1] Conducted Emissions Parts List
[2] Conducted Emissions Test Equipment Used
Hewlett Packard HP8594L Spectrum Analyzer – S/N 3827A00153
2Line V-networks LS1-15V 50Ω/50Uh Line Impedance Stabilization Network
[3] Conducted Emissions Test Results
[4] Layout Recommendations
Most applications can use the filtering which is already installed inside the
converter or with the addition of the recommended external capacitors. For
greater emissions suppression, consider additional filter components and/or
shielding. Emissions performance will depend on the user’s PC board layout,
the chassis shielding environment and choice of external components. Please
refer to Application Note GEAN-02 for further discussion.
Since many factors affect both the amplitude and spectra of emissions, we
recommend using an engineer who is experienced at emissions suppression.
Reference Part Number Description Vendor
C1, C2, C3, C4, C5 GRM32ER72A105KA01L SMD CERAMIC-100V-
1000nF-X7R-1210 Murata
C6 GRM319R72A104KA01D SMD CERAMIC100V-100nF-
±10%-X7R-1206 Murata
L1, L2 7448263505 COMMON MODE-500uH-
±30%-35A Würth
C8, C9, C10, C11 GRM55DR72J224KW01L SMD CERAMIC630V-0.22uF-
±10%-X7R-2220 Murata
C7 UHE2A221MHD Aluminum100V-220Uf-
±10%-long lead Nichicon
C12 NA
LOAD
C2 L1
C6 C7 DC/DC C12
+ +
VCC
RTN
-48V
GND
GND
C3C1 L2
C5C4
C8 C9 C10 C11
Figure 7. Conducted Emissions Test Circuit
Graph 1. Conducted emissions performance, Positive Line,
CISPR 22, Class B, full load
Graph 2. Conducted emissions performance, Negative Line,
CISPR 22, Class B, full load
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 Rd, Westborough, MA 01581 USA
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/
SDC_DRQ-11.4/88-L48NB-C.A02 Page 14 of 14
DRQ-11.4/88-L48NB-C
Regulated Quarter-Brick, 986W Isolated DC-DC Converter
Soldering Guidelines
Murata Power Solutions recommends the specifications below when installing these converters. These specifications vary depending on the solder type. Exceeding these specifica-
tions may cause damage to the product. 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: For Sn/Pb based solders:
Maximum Preheat Temperature 115° C. Maximum Preheat Temperature 105° C.
Maximum Pot Temperature 270° C. Maximum Pot Temperature 250° C.
Maximum Solder Dwell Time 7 seconds Maximum Solder Dwell Time 6 seconds
Figure 8. Vertical Wind Tunnel
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 10" x 10" host carrier board for realistic
heat absorption and spreading. Both longitudinal and trans-
verse 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.