Murata HPQ-12/25-D48NBHL2-Y Isolated 300-watt quarter brick dc/dc converter Datasheet

HPQ-12/25-D48 Series
www.murata-ps.com
Isolated 300-Watt Quarter Brick DC/DC Converters
PRODUCT OVERVIEW
Typical unit
FEATURES
„
12 Volts DC fixed output up to 25 Amps
„
Industry standard quarter brick 2.3” x 1.45” x
0.44” open frame package
„
Wide range 36 to 75 Vdc input voltages with
2250 Volt Basic isolation
„
Double lead-free assembly and attachment for
RoHS standards
„
Up to 300 Watts total output power
„
High efficiency (94.5%) synchronous rectifier
topology
„
Stable no-load operation with no required external
components
„
Operating temperature range -40 to +85° C.
with no heat sink required
„
Meets UL/EN 60950-1, CSA-C22.2 No. 60950-1,
2nd edition safety approvals
„
Extensive self-protection, current limiting and
shut down features
„
“X” optional version omits trim and sense pins
F1
The HPQ-12/25-D48 series offers high output
current (up to 25 Amps) in an industry standard
“quarter brick” package requiring no heat sink for
most applications. The HPQ-12/25-D48 series delivers fixed 12 Vdc output at 300 Watts for printed
circuit board mounting. Wide range inputs on the
2.3” x 1.45” x 0.44” converter are 36 to 75 Volts
DC (48 Volts nominal), ideal for datacom and telecom
systems. The fixed output voltage is regulated to
within ±2%.
Advanced automated surface mount assembly
and planar magnetics deliver galvanic isolation
rated at 2250 Vdc for basic insulation. To power
digital systems, the outputs offer fast settling to
current steps and tolerance of higher capacitive
loads. Excellent ripple and noise specifications assure compatibility to CPU’s, ASIC’s, programmable
logic and FPGA’s. No minimum load is required. For
systems needing controlled startup/shutdown, an
external remote On/Off control may use either positive or negative polarity. Remote Sense inputs compensate for resistive line drops at high currents.
A wealth of self-protection features avoid problems with both the converter and external circuits.
These include input undervoltage lockout and
overtemperature shutdown using an on-board temperature sensor. Overcurrent protection using the
“hiccup” autorestart technique provides indefinite
short-circuit protection. Additional safety features
include output overvoltage protection and reverse
conduction elimination. The synchronous rectifier topology offers high efficiency for minimal heat buildup
and “no heat sink” operation. The HPQ-12/25-D48
series meets full safety standards to UL/EN/IEC/CSA
60950-1, 2nd edition and RFI/EMI conducted/radiated emission compliance to EN55022, CISPR22 with
external filter.
APPLICATIONS
„
Embedded systems, datacom and telecom
installations
„
Disk farms, data centers and cellular repeater sites
„
Remote sensor systems, dedicated controllers
„
Instrumentation systems, R&D platforms, automated test fixtures
„
Data concentrators, voice forwarding and
speech processing systems
*TPMBUJPO
Barrier
+Vin (3)
+Vout (8)
t4XJUDIJOH
External
DC
Power
Source
On/Off
Control
(2)
Open = On
$MPTFE0GG
1PTJUJWF
polarity)
4FOTF t'JMUFST
Controller
and Power
5SBOTGFS
t$VSSFOU4FOTF
4FOTF Reference and
Error Amplifier
Trim (6)
-Vin (1)
-Vout (4)
Figure 1. Connection Diagram
Typical topology is shown. Murata Power Solutions
recommends an external fuse.
For full details go to
www.murata-ps.com/rohs
* “X” option omits trim and sense pins.
www.murata-ps.com
email: [email protected]
26 Jul 2010
MDC_HPQ-12/25-D48 Series.A02 Page 1 of 12
HPQ-12/25-D48 Series
Isolated 300-Watt Quarter Brick DC/DC Converters
ORDERING GUIDE ➀
Output
Input
R/N (mV
pk-pk)
Regulation (Max.) ➁
IOUT
IIN full
VOUT (Amps, Power
VIN Nom. Range
IIN no
load
Line
Load
(Volts) (Volts) load (mA) (Amps)
Root Model ➀ (Volts) max.) (Watts) Typ. Max.
HPQ-12/25-D48
12
25
300
120
150
±0.125% ±0.25%
48
36-75
150
6.61
Efficiency
Min.
Typ.
Package (C59)
Dimensions
(inches)
Dimensions
(mm)
93.5% 94.5% 1.45x2.3x0.440 max. 36.8x58.4x11.2
➀ Please refer to the part number structure for additional ordering information and options.
➁ All specifications are at nominal line voltage and full load, +25 deg.C. unless otherwise noted. See detailed specifications. Output capacitors are 1 μF ceramic || 10 μF electrolytic with no input caps.These
caps are necessary for our test equipment and may not be needed for your application.
PART NUMBER STRUCTURE
HPQ - 12 / 25 - D48 N B
Family
Series:
High Power
Quarter Brick
Nominal Output Voltage
Maximum Rated Output :
Current in Amps
Input Voltage Range:
D48 = 36-75 Volts (48V nominal)
On/Off Control Polarity
N = Negative polarity, standard
P = Positive polarity, optional
H X Lx - C
RoHS Hazardous Materials compliance
C = RoHS-6 (does not claim EU RoHS exemption 7b–lead in solder), standard
Y = RoHS-5 (with lead), optional, special quantity order
Pin length option
Blank = standard pin length 0.180 in. (4.6 mm)
L1 = 0.110 in. (2.79 mm)*
L2 = 0.145 in. (3.68 mm)*
*Special quantity order required
Trim & Sense Pins Option
Blank = Trim and Sense installed, standard
X = Trim and Sense removed
Conformal coating (optional)
Blank = no coating, standard
H = Coating added, optional
Baseplate (optional)
Blank = No baseplate, standard
B = Baseplate installed, optional
Note: Some model combinations may not be
available. Contact Murata Power Solutions for
availability.
Complete Model Number Example: HPQ-12/25-D48NBHXL1-C
Negative On/Off logic, baseplate installed, conformally coated, trim and sense pins removed, 0.110˝ pin length, RoHS-6 compliance
www.murata-ps.com
email: [email protected]
26 Jul 2010
MDC_HPQ-12/25-D48 Series.A02 Page 2 of 12
HPQ-12/25-D48 Series
Isolated 300-Watt Quarter Brick DC/DC Converters
MECHANICAL SPECIFICATIONS (THROUGH-HOLE MOUNT)
TOP VIEW
4 7 .2 4 ± 0 .2 0
1 .8 6 0 ± 0 .0 0 8
4 .2 0
0 .1 6 5
Case C59
1 2 .7
0 .5 0
SIDE VIEW
3 .6 9
0 .1 4 5
0.015 minimum clearance
between standoffs and
highest component
PIN S 1-3, 5-7:
0.040±0. 001(1.016±0. 025)
PIN S 4, 8:
0.062±0. 001(1.575±0. 025)
3
4
5
6
7
8
LABEL
3 6 .8
1 .4 5
1 5 .2 4
0 .6 0 0
1
1 5 .2 4
0 .6 0 0
1 5 .2 4
0 .6 0 0
2
7 .6 2
0 .3 0 0
4
5
6
7
8
1
2
3
1 5 .2 4
0 .6 0 0
5 0 .8 0
2 .0 0 0
5 0 .8 0
2 .0 0 0
7 .6 2
0 .3 0 0
11.2
0.440 Max
PIN S 1-3,5-7:
0. 040±0. 001(1.016±0.025)
PIN S 4,8:
0. 062±0. 001(1.575±0. 025)
M3 THREADED INSERT
4 PLACES SEE NOTE 1&2
5 8 .4
2 .3 0
5 6 .1 3
2 .2 1 0
0.015 minimum clearance
between standoffs and
highest component
2 6 .1 6 ± 0 .2 0
1 .0 3 0 ± 0 .0 0 8
3 6 .8
1 .4 5
3 4 .5 4
1 .3 6 0
LABEL
TOP VIEW
5 8 .4
2 .3 0
OPEN FRAME PIN SIDE VIEW (NO BASEPLATE)
WITH BASEPLATE OPTION, PIN SIDE VIEW
➀ M3 bolts must not exceed 0.138˝ (3.5mm) depth below the baseplate surface.
➁ Applied screw torque must not exceed 5.3 in-lb. (0.6 N-m).
These converters are plug-compatible to competitive units. Other units may use
different pin numbering or alternate outline views. When laying out your PC board,
follow the pin FUNCTION.
The 0.145˝ (L2) pin length is shown. Please refer to the part number structure for
alternate pin lengths.
Dimensions are in inches (mm) shown for ref. only.
Third Angle Projection
I/O Connections (pin side view)
Tolerances (unless otherwise specified):
.XX ± 0.02 (0.5)
.XXX ± 0.010 (0.25)
Angles ± 2˚
Components are shown for reference only.
Pin
1
2
3
4
Function P32
Neg. Vin
Remote On/Off Control
Pos. Vin
Neg. Output
Pin
5
6
7
8
Function P32
Neg. Sense*
Trim*
Pos. Sense*
Pos. Output
* The Sense and Trim pins are removed for the “X” model option.
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email: [email protected]
26 Jul 2010
MDC_HPQ-12/25-D48 Series.A02 Page 3 of 12
HPQ-12/25-D48 Series
Isolated 300-Watt Quarter Brick DC/DC Converters
FUNCTIONAL SPECIFICATIONS
ABSOLUTE MAXIMUM RATINGS
Input Voltage, Continuous
Input Voltage, Transient
Isolation Voltage
Input Reverse Polarity
On/Off Remote Control
Output Power
Conditions ➀
Full power operation
Operating or non-operating,
100 mS max. duration
Input to output tested 100 mS
IEC/EN/UL 60950-1, 2nd edition
None, install external fuse
Power on or off, referred to -Vin
Minimum
Typical/Nominal
36
Maximum
Vdc
100
Vdc
2250
Vdc
15
300
Vdc
Vdc
W
None
0
0
Units
75
Current-limited, no damage,
0
25
A
short-circuit protected
Storage Temperature Range
Vin = Zero (no power)
-55
125
°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 or recommended.
Output Current
INPUT
Operating voltage range
Recommended External Fuse
Start-up threshold
Undervoltage shutdown
Overvoltage protection
Reverse Polarity Protection
Internal Filter Type
Input current
Full Load Conditions
Low Line
Inrush Transient
Output in Short Circuit
No Load
Standby Mode (Off, UV, OT)
Reflected (back) ripple current ➁
Pre-biased startup
Conditions ➀ ➂
36
Fast blow
Rising input voltage
Falling input voltage
Rising input voltage
None, install external fuse
33
31
Vin = nominal
Vin = minimum
Vin = 48V.
Iout = minimum, unit=ON
Measured at input with specified filter
External output voltage < Vset
48
20
34
32
None
None
Pi-type
75
6.61
8.82
0.3
50
150
5
50
Monotonic
6.82
9.09
35
34
100
250
10
70
Vdc
A
Vdc
Vdc
Vdc
Vdc
A
A
A2-Sec.
mA
mA
mA
mA, RMS
GENERAL and SAFETY
Efficiency
Isolation
Isolation Voltage, input to output
Isolation Voltage, input to output
Isolation Voltage, input to baseplate
Isolation Voltage, output to baseplate
Insulation Safety Rating
Isolation Resistance
Isolation Capacitance
Safety (meets the following requirements)
Calculated MTBF
Calculated MTBF
Vin=48V, full load
Vin=45.6V, full load
93.5
93.5
No baseplate
With baseplate
With baseplate
With baseplate
2250
1500
1500
1500
94.5
94.5
%
%
Vdc
Vdc
Vdc
Vdc
basic
10
MΩ
pF
1000
UL-60950-1, CSA-C22.2 No.60950-1,
IEC/EN60950-1, 2nd edition
Per MIL-HDBK-217F, ground benign,
Tambient=+TBD°C
Per Telcordia SR-332, issue 1, class 3, ground
fixed, Tambient=+25°C
Yes
TBD
Hours x 103
1500
Hours x 103
260
KHz
DYNAMIC CHARACTERISTICS
Fixed Switching Frequency
Startup Time
Startup Time
Dynamic Load Response
Dynamic Load di/dt
Dynamic Load Peak Deviation
Power On, to Vout regulation band,
100% resistive load
Remote ON to Vout Regulated
50-75-50% load step to 1% error band
550
same as above
15
mS
±500
15
825
0.1
±750
mS
μSec
A / μSec
mV
1
0.8
13.5
2
Vdc
Vdc
mA
FEATURES and OPTIONS
Remote On/Off Control ➃
“N” suffix:
Negative Logic, ON state
Negative Logic, OFF state
Control Current
ON = pin grounded or external voltage
OFF = pin open or external voltage
open collector/drain
0
3.5
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26 Jul 2010
MDC_HPQ-12/25-D48 Series.A02 Page 4 of 12
HPQ-12/25-D48 Series
Isolated 300-Watt Quarter Brick DC/DC Converters
FUNCTIONAL SPECIFICATIONS (CONT.)
FEATURES and OPTIONS (cont.)
Remote On/Off Control (cont.) ➃
“P” suffix:
Positive Logic, ON state
Positive Logic, OFF state
Control Current
Remote Sense Compliance ➆
Base Plate
Conditions ➀
ON = pin open or external voltage
OFF = ground pin or external voltage
open collector/drain
(Vout - Vsense) Sense pins connected externally
to respective Vout’s
"B" suffix
Minimum
Typical/Nominal
3.5
0
1
Maximum
Units
13.5
0.8
2
V
V
mA
0.5
V
optional
OUTPUT
Total Output Power
Voltage
Setting Accuracy
Output Voltage Range ➆
Overvoltage Protection
Current
Output Current Range
Minimum Load
Current Limit Inception
Short Circuit
Short Circuit Current
Short Circuit Duration
(remove short for recovery)
Short circuit protection method
Hiccup autorestart duty cycle
Regulation ➄
Line Regulation
Load Regulation
Ripple and Noise ➅
Temperature Coefficient
Maximum Capacitive Loading
At 50% load, no trim
User-adjustable
Via magnetic feedback
0.0
300
306
W
11.76
-10
12
12.24
+10
18.0
Vdc
% of Vnom.
Vdc
14.4
0.0
25.0
A
No minimum load
32
39
A
Hiccup technique, autorecovery within 1.25%
of Vout
0.8
1.0
A
Output shorted to ground, no damage
Continuous
Hiccup current limiting
Output shorted to ground
Non-latching
0.25
98% of Vnom., after warmup
Vin=min. to max., Vout=nom., full load
Iout=min. to max., Vin=nom.
5 Hz- 20 MHz BW, Cout=1μF MLCC paralleled
with 10μF tantalum
At all outputs
Full resistive load, low ESR
27
%
±0.125
±0.25
120
150
mV pk-pk
4,700
% of Vout./°C
μF
0.02
0
% of Vout
% of Vout
MECHANICAL (Through Hole Models)
Outline Dimensions (no baseplate)
(Please refer to outline drawing)
Outline Dimensions (with baseplate)
Weight
C59 case
WxLxH
1.45x2.3x0.440 max.
36.8x58.4x11.2
1.45x2.3x0.5
36.8x58.4x12.7
1.51
47
2.4
68
0.04 & 0.062
1.016 & 1.575
Copper alloy
100-299
3.9-19.6
Aluminum
No baseplate
No baseplate
With baseplate
With baseplate
Through Hole Pin Diameter
Through Hole Pin Material
TH Pin Plating Metal and Thickness
Nickel subplate
Gold overplate
Baseplate Material
Inches
mm
Inches
mm
Ounces
Grams
Ounces
Grams
Inches
mm
μ-inches
μ-inches
ENVIRONMENTAL
Operating Ambient Temperature Range
Storage Temperature
Thermal Protection/Shutdown
Electromagnetic Interference
Conducted, EN55022/CISPR22
Radiated, EN55022/CISPR22
Relative humidity, non-condensing
Altitude
Acceleration
Shock
Sinusoidal Vibration
RoHS rating
No derating, full power, 200 LFM, no condensation
Vin = Zero (no power)
Measured at hotspot
External filter is required
-40
-55
105
110
85
125
125
°C
°C
˚C
90
10,000
3048
Class
Class
%RH
feet
meters
g
g
B
B
To +85°C
must derate -1%/1000 feet
Halfsine wave, 3 axes
GR-63-Core, Section 5.4.2
10
-500
-152
50
1
RoHS-6
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email: [email protected]
26 Jul 2010
MDC_HPQ-12/25-D48 Series.A02 Page 5 of 12
HPQ-12/25-D48 Series
Isolated 300-Watt Quarter Brick DC/DC Converters
Notes
➀ 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,
no base plate installed and natural convection airflow unless otherwise specified. All models are
tested and specified with external parallel 1 μF and 10 μF multi-layer ceramic output capacitors.
No 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.
➁ Input (back) ripple current is tested and specified over 5 Hz to 20 MHz bandwidth. Input filtering is
Cin = 33 μF, Cbus = 220μF and Lbus = 4.7 μH.
➂ All models are stable and regulate to specification under no load.
➃ The Remote On/Off Control is referred to -Vin.
➄ Regulation specifications describe the output voltage changes as the line voltage or load current
is varied from its nominal or midpoint value to either extreme. The load step is ±25% of full load
current.
➅ Output Ripple and Noise is measured with Cout = 1μF MLCC paralleled with 10μF tantalum, 20
MHz oscilloscope bandwidth and full resistive load.
➆ The Sense and Trim pins are removed for the “X” model option.
➇ 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 advertisements, product announcements, or website graphics.
We strive to have all technical data in this customer data sheet highly accurate 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.
The pinout (Pxx) and case (Cxx) designations (typically P65 or C59) refer to a generic family of
closely related information. It may not be a single pinout or unique case outline. Please be aware
of small details (such as Sense pins, Power Good pins, etc.) or slightly different dimensions
(baseplates, heat sinks, etc.) which may affect your application and PC board layouts. Study the
Mechanical Outline drawings, Input/Output Connection table and all footnotes very carefully.
Please contact Murata Power Solutions if you have any questions.
TYPICAL PERFORMANCE DATA
Maximum Current Temperature Derating vs. Airflow (Vin=Vnom., airflow direction is
from -Vin to +Vin, with baseplate, at sea level)
40
30
95
35
25
90
30
VIN = 75 V
VIN = 48 V
VIN = 36 V
85
25
80
20
75
15
Power Dissipation
VIN = 48 V
70
65
3
5
7
9
11
Output Current (Amps)
100
Loss (Watts)
Efficiency (%)
Efficiency and Power Dissipation @ +25°C
13
15
17
19
21
23
20
15
10
10
5
5
0
25
100 LFM
200 LFM
300 LFM
400 LFM
30
35
Iout (Amps)
Maximum Current Temperature Derating vs. Airflow (Vin=Vnom., airflow direction is
from Vin to Vout, no baseplate, at sea level)
40
45
50
55
60
65
Ambient Temperature (°C)
70
75
80
85
Power On Startup Delay Output
(Vin = 0 to 48V, Iout = 25A, Cload = 0, Ta = +25°C)
30
Output Current (Amps)
25
20
100 LFM
200 LFM
300 LFM
400 LFM
15
10
5
0
30
35
40
45
50
55
60
65
70
75
80
85
Ambient Temperature (°C)
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26 Jul 2010
MDC_HPQ-12/25-D48 Series.A02 Page 6 of 12
HPQ-12/25-D48 Series
Isolated 300-Watt Quarter Brick DC/DC Converters
TYPICAL PERFORMANCE DATA
Power On Startup Delay Output
(Vin = 0 to 48V, Iout = 0A, Cload = 0, Ta = +25°C)
Output Short Circuit Hiccup
(Vin = Nom., Iout = Imax, Cload = 0, Ta = +25°C)
Max = 81A, Period = 1.180s, Pulse width = 6.4ms
Step Load Transient Response (Vin = 48V, Cload = 1μF ceramic and 10μF tantalum,
Iout = 50-75-50% lmax, Slew = 0.1 mA/μSec., Ta = +25°C)
Output Ripple and Noise (Vin=36V, Iout=0A, Cload=0, Ta=+25˚C., ScopeBW=20MHz)
Output Ripple and Noise (Vin=36V, Iout=25A, Cload=0, Ta=+25˚C., ScopeBW=20MHz)
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26 Jul 2010
MDC_HPQ-12/25-D48 Series.A02 Page 7 of 12
HPQ-12/25-D48 Series
Isolated 300-Watt Quarter Brick DC/DC Converters
TYPICAL PERFORMANCE DATA
Output Ripple and Noise (Vin=48V, Iout=0A, Cload=0, Ta=+25˚C., ScopeBW=20MHz)
Output Ripple and Noise (Vin=48V, Iout=25A, Cload=0, Ta=+25˚C., ScopeBW=20MHz)
Output Ripple and Noise (Vin=75V, Iout=0A, Cload=0, Ta=+25˚C., ScopeBW=20MHz)
Output Ripple and Noise (Vin=75V, Iout=25A, Cload=0, Ta=+25˚C., ScopeBW=20MHz)
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26 Jul 2010
MDC_HPQ-12/25-D48 Series.A02 Page 8 of 12
HPQ-12/25-D48 Series
Isolated 300-Watt Quarter Brick DC/DC Converters
APPLICATION NOTES
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.
The installer must observe all relevant safety standards and regulations. For
safety agency approvals, install the converter in compliance with the end-user
safety standard.
Input Reverse-Polarity Protection
If the input voltage polarity is reversed, an internal diode will become forward
biased and likely draw excessive current from the power source. If this source
is not current-limited or the circuit appropriately fused, it could cause permanent damage to the converter.
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.
Users should be aware however of input sources near the Under-Voltage Shutdown whose voltage decays as input current is consumed (such as capacitor
inputs), the converter shuts off and then restarts as the external capacitor recharges. Such situations could oscillate. To prevent this, make sure the operating
input voltage is well above the UV Shutdown voltage AT ALL TIMES.
Start-Up Delay
Assuming that the output current is set at the rated maximum, the Vin to Vout StartUp Delay (see Specifications) is the time interval between the point when the rising
input voltage crosses the Start-Up Threshold and the fully loaded regulated output
voltage enters and remains within its specified regulation band. Actual measured
times will vary with input source impedance, external input capacitance, 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 the
PWM controller at power up, thereby limiting the input inrush current.
The On/Off Remote Control interval from inception to VOUT regulated 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 regulation band.
The specification assumes that the output is fully loaded at maximum rated
current.
Input Source Impedance
These converters will operate to specifications without external components,
assuming that the source voltage has very low impedance and reasonable input voltage regulation. Since real-world voltage sources have finite impedance,
performance is improved by adding external filter components. Sometimes only
a small ceramic capacitor is sufficient. Since it is difficult to totally characterize
all applications, some experimentation may be needed. Note that external input
capacitors must accept high speed switching currents.
Because of the switching nature of DC/DC converters, the input of these
converters must be driven from a source with both low AC impedance and
adequate DC input regulation. Performance will degrade with increasing input
inductance. Excessive input inductance may inhibit operation. The DC input
regulation specifies that the input voltage, once operating, must never degrade
below the Shut-Down Threshold under all load conditions. Be sure to use
adequate trace sizes and mount components close to the converter.
I/O Filtering, 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 components, circuits and layout as shown in the figures below. External input capacitors (CIN in the figure) serve primarily as energy storage elements, minimizing
line voltage variations caused by transient IR drops in the input conductors.
Users should select input capacitors for bulk capacitance (at appropriate
frequencies), low ESR and high RMS ripple current ratings. In the figure below,
the CBUS and LBUS components simulate a typical DC voltage bus. Your specific
TO
OSCILLOSCOPE
VIN
+
–
+
–
CURRENT
PROBE
1
+INPUT
LBUS
CBUS
CIN
2
−INPUT
CIN = 33μF, ESR < 200mΩ @ 100kHz
CBUS = 220μF, 100V
LBUS = 4.7μH
Figure 2. Measuring Input Ripple Current
system configuration may require additional considerations. Please note that the
values of CIN, LBUS and CBUS may vary according to the specific converter model.
In critical applications, output ripple and noise (also referred to as periodic and
random deviations or PARD) may be reduced by adding filter elements such
as multiple external capacitors. Be sure to calculate component temperature
rise from reflected AC current dissipated inside capacitor ESR. In figure 3, the
two copper strips simulate real-world printed circuit impedances between the
power supply and its load. In order to minimize circuit errors and standardize
tests between units, scope measurements should be made using BNC connectors or the probe ground should not exceed one half 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. The essential feature of such isolation is ideal ZERO
CURRENT FLOW between input and output. Real-world converters however do
exhibit tiny leakage currents between input and output (see Specifications).
These leakages consist of both an AC stray capacitance coupling component
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MDC_HPQ-12/25-D48 Series.A02 Page 9 of 12
HPQ-12/25-D48 Series
Isolated 300-Watt Quarter Brick DC/DC Converters
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.
COPPER STRIP
+OUTPUT
C1
C2
SCOPE
RLOAD
−OUTPUT
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 Overvoltage Protection (OVP)
This converter monitors its output voltage for an over-voltage condition using
an on-board electronic comparator. The signal is optically coupled to the primary side PWM controller. If the output exceeds OVP limits, the sensing circuit
will power down the unit, and the output voltage will decrease. After a time-out
period, the PWM will automatically attempt to restart, causing the output voltage to ramp up to its rated value. It is not necessary to power down and reset
the converter for this automatic OVP-recovery restart.
COPPER STRIP
C1 = 0.1μF CERAMIC
C2 = 10μF LOW ES
LOAD 2-3 INCHES (51-76mm) FROM MODULE
Figure 3. Measuring Output Ripple and Noise (PARD)
and a DC leakage resistance. When using the isolation feature, do not allow
the isolation voltage to exceed specifications. Otherwise the converter may
be damaged. Designers will normally use the negative output (-Output) as
the ground return of the load circuit. You can however use the positive output
(+Output) as the ground return to effectively reverse the output polarity.
Minimum Output Loading Requirements
These converters employ a synchronous rectifier design topology. 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.
If the fault condition persists and the output voltage climbs to excessive levels,
the OVP circuitry will initiate another shutdown cycle. This on/off cycling is
referred to as “hiccup” mode.
Output Fusing
The converter is extensively protected against current, voltage and temperature
extremes. However, your application circuit may need additional protection. In the
extremely unlikely event of output circuit failure, excessive voltage could be applied
to your circuit. Consider using an appropriate external protection.
Thermal Shutdown
To protect against thermal over-stress, 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 application to avoid unplanned thermal shutdown.
Output Current Limiting
As soon as the output current increases to approximately its overcurrent limit,
the DC/DC converter will enter a current-limiting mode. The output voltage will
decrease proportionally with increases in output current, thereby maintaining a
somewhat constant power output. This is commonly referred to as power limiting.
Temperature Derating Curves
The graphs in the next section 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 temperature
and/or current or reduced airflow as long as the average is not exceeded.
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, the
magnetically coupled voltage used to develop PWM bias voltage will also drop,
thereby shutting down the PWM controller. 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 on/off cycling is called “hiccup mode.” The hiccup cycling reduces the
average output current, thereby preventing excessive internal temperatures.
Note that the temperatures are of the ambient airflow, not the converter itself
which is obviously running at higher temperature than the outside air. Also note
that “natural convection” is defined as very low flow rates which are not using
fan-forced airflow. Depending on the application, “natural convection” is usually about 30-65 LFM but is not equal to still air (0 LFM).
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,
Current limiting inception is defined as the point at which full power falls below
the rated tolerance. See the Performance/Functional Specifications. Note
particularly that the output current may briefly rise above its rated value. This
enhances reliability and continued operation of your application. If the output
current is too high, the converter will enter the short circuit condition.
Trimming the Output Voltage (See Specification Note 7)
The Trim input to the converter allows the user to adjust the output voltage over
the rated trim range (please refer to the Specifications). In the trim equations
and circuit diagrams that follow, trim adjustments use a single fixed resistor
connected between the Trim input and either Vout pin. Trimming resistors should
have a low temperature coefficient (±100 ppm/deg.C or less) and be mounted
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MDC_HPQ-12/25-D48 Series.A02 Page 10 of 12
HPQ-12/25-D48 Series
Isolated 300-Watt Quarter Brick DC/DC Converters
close to the converter. Keep leads short. If the trim function is not used, leave
the trim unconnected. With no trim, the converter will exhibit its specified output
voltage accuracy.
+OUTPUT
-INPUT
+SENSE
There are two CAUTIONs to observe for the Trim input:
CAUTION: To avoid unplanned power down cycles, do not exceed EITHER the
maximum output voltage OR the maximum output power when setting the trim.
If the output voltage is excessive, the OVP circuit may inadvertantly shut down
the converter. If the maximum power is exceeded, the converter may enter
current limiting. If the power is exceeded for an extended period, the converter
may overheat and encounter overtemperature shut down.
ON/OFF
CONTROL
Trim Equations
Vout -Vnominal
Vnominal
Figure 5. Trim adjustments to Decrease Output Voltage using a Fixed Resistor
Positive: Models equipped with Positive Logic are enabled when the On/Off
pin is left open or is pulled high to +15VDC with respect to –VIN. An internal
bias current causes the open pin to rise to +VIN. Positive-polarity devices are
disabled when the On/Off is grounded or brought to within a low voltage (see
Specifications) with respect to –VIN.
1
-2
Δ
Vnominal -Vout
Vnominal
Radj_down (in kΩ) =
where Δ =
-OUTPUT
Remote On/Off Control
On the input side, a remote On/Off Control can be specified with either positive
or negative logic as follows:
Radj_up (in kΩ) = Vnominal x (1+Δ) - 1 - 2
1.225 x Δ
Δ
where Δ =
LOAD
R TRIM DOWN
-SENSE
+INPUT
CAUTION: Be careful of external electrical noise. The Trim input is a senstive
input to the converter’s feedback control loop. Excessive electrical noise may
cause instability or oscillation. Keep external connections short to the Trim
input. Use shielding if needed.
TRIM
Where Vo = Desired output voltage. Adjustment accuracy is subject to resistor
tolerances and factory-adjusted output accuracy. Mount trim resistor close
to converter. Use short leads. Note that “Δ” is given as a small fraction, not a
percentage.
+OUTPUT
-INPUT
+SENSE
Negative: Models with negative polarity are on (enabled) when the On/Off is
grounded or brought to within a low voltage (see Specifications) with respect to
–VIN. The device is off (disabled) when the On/Off is left open or is pulled high
to +15VDC Max. with respect to –VIN.
Dynamic control of the On/Off function should be able to sink the specified
signal current when brought low and withstand specified voltage when brought
high. Be aware too that there is a finite time in milliseconds (see Specifications)
between the time of On/Off Control activation and stable, regulated output. This
time will vary slightly with output load type and current and input conditions.
There are two CAUTIONs for the On/Off Control:
ON/OFF
CONTROL
TRIM
LOAD
R TRIM UP
-SENSE
+INPUT
-OUTPUT
CAUTION: While it is possible to control the On/Off with external logic if you
carefully observe the voltage levels, the preferred circuit is either an open
drain/open collector transistor or a relay (which can thereupon be controlled by
logic). The On/Off prefers to be set at approx. +15V (open pin) for the ON state,
assuming positive logic.
CAUTION: Do not apply voltages to the On/Off pin when there is no input power
voltage. Otherwise the converter may be permanently damaged.
Figure 4. Trim adjustments to Increase Output Voltage using a Fixed Resistor
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HPQ-12/25-D48 Series
Isolated 300-Watt Quarter Brick DC/DC Converters
Remote Sense Input (See Specification Note 7)
Sense inputs compensate for output voltage inaccuracy delivered at the load.
This is done by correcting voltage drops along the output wiring such as moderate IR drops and the current carrying capacity of PC board etch. Sense inputs
also improve the stability of the converter and load system by optimizing the
control loop phase margin.
Note: The Sense input and power Vout lines are internally connected through
low value resistors to their respective polarities so that the converter can
operate without external connection to the Sense. Nevertheless, if the Sense
function is not used for remote regulation, the user should connect +Sense to
+Vout and –Sense to –Vout at the converter pins.
On/Off Enable Control Ground Bounce Protection
To improve reliability, if you use a small signal transistor or other external
circuit to select the Remote On/Off control, make sure to return the LO side
directly to the –Vin power input on the DC/DC converter. To avoid ground
bounce errors, do not connect the On/Off return to a distant ground plane or
current-carrying bus. If necessary, run a separate small return wire directly to
the –Vin terminal. There is very little current (typically 1-5 mA) on the On/Off
control however, large current changes on a return ground plane or ground bus
can accidentally trigger the converter on or off. If possible, mount the On/Off
transistor or other control circuit adjacent to the converter.
The remote Sense lines carry very little current. They are also capacitively
coupled to the output lines and therefore are in the feedback control loop to
regulate and stabilize the output. As such, they are not low impedance inputs
and must be treated with care in PC board layouts. Sense lines on the PCB
should run adjacent to DC signals, preferably Ground. In cables and discrete
wiring, use twisted pair, shielded tubing or similar techniques
+VCC
Please observe Sense inputs tolerance to avoid improper operation:
ON/OFF
CONTROL
[Vout(+) –Vout(-)] – [ Sense(+) – Sense(-)] ≤ 10% of Vout
-INPUT
Contact and PCB resistance
losses due to IR drops
-INPUT
+OUTPUT
I OUT
+SENSE
Figure 7. Driving the On/Off Control Pin (suggested circuit)
Sense Current
ON/OFF
CONTROL
TRIM
LOAD
Sense Return
-SENSE
DC/DC Converter
I OUT Return
+INPUT
-OUTPUT
+ Vin
Preferred location
of On/Off control
adjacent to -Vin
terminal
Contact and PCB resistance
losses due to IR drops
On/Off Enable
Figure 6. Remote Sense Circuit Configuration
Output overvoltage protection is monitored at the output voltage pin, not the
Sense pin. Therefore excessive voltage differences between Vout and Sense
together with trim adjustment of the output can cause the overvoltage protection circuit to activate and shut down the output.
Power derating of the converter is based on the combination of maximum output current and the highest output voltage. Therefore the designer must insure:
(Vout at pins) x (Iout) ≤ (Max. rated output power)
Murata Power Solutions, Inc.
11 Cabot Boulevard, Mansfield, MA 02048-1151 U.S.A.
ISO 9001 and 14001 REGISTERED
On/Off
Control
Transistor
-Vin return
Ground plane or power return bus
Do not connect
control transistor
through remote
power bus
Install separate
return wire for
On/Off control
with remote
transistor
Figure 8. On/Off Enable Control Ground Bounce Protection
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.
© 2010 Murata Power Solutions, Inc.
www.murata-ps.com/locations
26 Jul 2010
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MDC_HPQ-12/25-D48 Series.A02 Page 12 of 12
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