DATASHEET
DS_V48SR1R825_09262012
FEATURES
High efficiency: 87.0% @ 1.8V/25A
Size: 33.0 x 22.9 x 9.5 mm
(1.30”x0.90”x0.37”)
Industry standard footprint and pinout
Fixed frequency operation
SMD and through-hole versions
Input UVLO and OVP
OTP and output OCP, OVP
Output voltage trim: -20%, +10%
Monotonic startup into normal and
pre-biased loads
2250V isolation and basic insulation
No minimum load required
No negative current during power or enable
on/off
ISO 9001, TL 9000, ISO 14001, QS 9000,
OHSAS18001 certified manufacturing facility
UL/cUL 60950 (US & Canada) recognized,
APPLICATIONS
Optical Transport
Data Networking
Communications
Servers
OPTIONS
SMD pins
Positive remote On/Off
OTP and output OVP, OCP mode
(auto-restart or latch)
Delphi Series V48SR, 1/16th Brick 66W
The Delphi Series V48SR, 1/16th Brick, 48V input, single output,
isolated DC/DC converter, is the latest offering from a world leader in
power systems technology and manufacturing ― Delta Electronics, Inc.
This product family provides up to 66 watts of power or 25A of output
current (1.8V and below) in an industry standard 1/16th brick form factor
(1.30” x 0.90”). The 1.8V output offers one of the highest output currents
available and provides up to 87.0% efficiency at full load. With creative
design technology and optimization of component placement, these
converters possess outstanding electrical and thermal performance, as
well as extremely high reliability under highly stressful operating
conditions. All modules are protected from abnormal input/output
voltage, current, and temperature conditions. For lower power needs with
the 1.5V output, but in a similar small form factor, please check out Delta
S48SP (1.5V/10A) and S48SE (1.5V/5A) series standard DC/DC
modules.
DS_V48SR1R825_09262012
2
TECHNICAL SPECIFICATIONS
(TA=25°C, airflow rate=300 LFM, Vin=48Vdc, nominal Vout unless otherwise noted.)
PARAMETER
NOTES and CONDITIONS
V48SR1R825 (Standard)
Min.
Typ.
Max.
Units
ABSOLUTE MAXIMUM RATINGS
Input Voltage
Continuous
80
Vdc
Transient (100ms)
100ms
100
Vdc
Operating Temperature
Refer to figure 21 for measuring point
-40
127
°C
Storage Temperature
-55
125
°C
Input/Output Isolation Voltage
2250
Vdc
INPUT CHARACTERISTICS
Operating Input Voltage
36
75
Vdc
Input Under-Voltage Lockout
Turn-On Voltage Threshold
32
34
35
Vdc
Turn-Off Voltage Threshold
30
32
33
Vdc
Lockout Hysteresis Voltage
1
2
3
Vdc
Maximum Input Current
100% Load, 36Vin
1.6
A
No-Load Input Current
50
mA
Off Converter Input Current
10
mA
Inrush Current (I2t)
1
A2s
Input Reflected-Ripple Current
P-P thru 12µH inductor, 5Hz to 20MHz
20
mA
Input Voltage Ripple Rejection
120 Hz
60
dB
OUTPUT CHARACTERISTICS
Output Voltage Set Point
Vin=48V, Io=Io.max, Tc=25°C
1.782
1.800
1.818
Vdc
Output Voltage Regulation
Over Load
Io=Io, min to Io, max
±3
±10
mV
Over Line
Vin=36V to 75V
±3
±10
mV
Over Temperature
Tc=-40°C to125°C
±18
mV
Total Output Voltage Range
Over sample load, line and temperature
1.746
1.80
1.854
V
Output Voltage Ripple and Noise
5Hz to 20MHz bandwidth
Peak-to-Peak
Full Load, 1µF ceramic, 10µF tantalum
40
mV
RMS
Full Load, 1µF ceramic, 10µF tantalum
15
30
mV
Operating Output Current Range
0
25
A
Output Over Current Protection
Output Voltage 10% Low
110
140
%
DYNAMIC CHARACTERISTICS
Output Voltage Current Transient
48V, 10µF Tan & 1µF Ceramic load cap, 0.1A/µs
Positive Step Change in Output Current
50% Io.max to 75% Io.max
50
mV
Negative Step Change in Output Current
75% Io.max to 50% Io.max
50
mV
Settling Time (within 1% Vout nominal)
200
us
Turn-On Transient
Start-Up Time, From On/Off Control
30
ms
Start-Up Time, From Input
30
ms
Maximum Output Capacitance
Full load; 5% overshoot of Vout at startup
30000
µF
EFFICIENCY
100% Load
87.0
%
60% Load
87.0
%
ISOLATION CHARACTERISTICS
Input to Output
2250
Vdc
Isolation Resistance
10
MΩ
Isolation Capacitance
1100
pF
FEATURE CHARACTERISTICS
Switching Frequency
420
kHz
ON/OFF Control, Negative Remote On/Off logic
Logic Low (Module On)
Von/off
0.7
V
Logic High (Module Off)
Von/off
2
18
V
ON/OFF Control, Positive Remote On/Off logic
Logic Low (Module Off)
Von/off
0.7
V
Logic High (Module On)
Von/off
2
18
V
ON/OFF Current (for both remote on/off logic)
Ion/off at Von/off=0.0V
1
mA
Leakage Current (for both remote on/off logic)
Logic High, Von/off=15V
50
uA
Output Voltage Trim Range
Pout ≦ max rated power
-20
10
%
Output Voltage Remote Sense Range
Pout ≦ max rated power
10
%
Output Over-Voltage Protection
Over full temp range; % of nominal Vout
130
%
GENERAL SPECIFICATIONS
MTBF
Io=80% of Io, max; Ta=25°C, airflow rate=300FLM
2.0
M hours
Weight
16
grams
Over-Temperature Shutdown
Refer to figure 21 for measuring point
130
°C
DS_V48SR1R825_09262012
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ELECTRICAL CHARACTERISTICS CURVES
Figure 1: Efficiency vs. load current for minimum, nominal, and
maximum input voltage at 25°C
Figure 2: Power dissipation vs. load current for minimum,
nominal, and maximum input voltage at 25°C.
Figure 3: Typical full load input characteristics at room
temperature
DS_V48SR1R825_09262012
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ELECTRICAL CHARACTERISTICS CURVES
For Negative Remote On/Off Logic
Figure 4: Turn-on transient at full rated load current (resistive
load) (5 ms/div). Vin=48V. Top Trace: Vout, 0.5V/div; Bottom
Trace: ON/OFF input, 2V/div
Figure 5: Turn-on transient at zero load current (5 ms/div).
Vin=48V. Top Trace: Vout: 0.5V/div, Bottom Trace: ON/OFF
input, 2V/div
For Positive Remote On/Off Logic
Figure 6: Turn-on transient at full rated load current (resistive
load) (5 ms/div). Vin=48V. Top Trace: Vout, 0.5V/div; Bottom
Trace: ON/OFF input, 2V/div
Figure 7: Turn-on transient at zero load current (5 ms/div).
Vin=48V. Top Trace: Vout, 0.5V/div; Bottom Trace: ON/OFF
input, 2V/div
DS_V48SR1R825_09262012
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ELECTRICAL CHARACTERISTICS CURVES
TBD
Figure 8: Output voltage response to step-change in load
current (75%-50%-75% of Io, max; di/dt = 0.1A/µs). Load cap:
10µF tantalum capacitor and 1µF ceramic capacitor. Top Trace:
Vout (50mV/div,500us/div), Bottom Trace: Iout (10A/div). Scope
measurement should be made using a BNC cable (length
shorter than 20 inches). Position the load between 51 mm to 76
mm (2 inches to 3 inches) from the module
Figure 9: Output voltage response to step-change in load
current (75%-50%-75% of Io, max; di/dt = 2.5A/µs). Load cap:
470µF, 35m
ESR solid electrolytic capacitor and 1µF ceramic
capacitor. Top Trace: Vout (50mV/div, 200us/div), Bottom Trace:
Iout (10A/div). Scope measurement should be made using a
BNC cable (length shorter than 20 inches). Position the load
between 51 mm to 76 mm (2 inches to 3 inches) from the
module
Figure 10: Test set-up diagram showing measurement points
for Input Terminal Ripple Current and Input Reflected Ripple
Current.
Note: Measured input reflected-ripple current with a simulated
source Inductance (LTEST) of 12 μH. Capacitor Cs offset
possible battery impedance. Measure current as shown above
Figure 11: Input Terminal Ripple Current, ic, at full rated output
current and nominal input voltage with 12µH source impedance
and 33µF electrolytic capacitor (200 mA/div, 1us/div)
DS_V48SR1R825_09262012
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ELECTRICAL CHARACTERISTICS CURVES
Figure 12: Input reflected ripple current, is, through a 12µH
source inductor at nominal input voltage and rated load current
(20 mA/div, 1us/div)
Figure 13: Output voltage noise and ripple measurement test
setup
Figure 14: Output voltage ripple at nominal input voltage and
rated load current (Io=25A)(50 mV/div, 1us/div)
Load capacitance: 1µF ceramic capacitor and 10µF tantalum
capacitor. Bandwidth: 20 MHz. Scope measurements should be
made using a BNC cable (length shorter than 20 inches).
Position the load between 51 mm to 76 mm (2 inches to 3
inches) from the module
Figure 15: Output voltage vs. load current showing typical
current limit curves and converter shutdown points
StripCopper
Vo(-)
Vo(+)
10u 1u SCOPE RESISTIVE
LOAD
DS_V48SR1R825_09262012
7
The input source must be insulated from the ac
mains by reinforced or double insulation.
The input terminals of the module are not operator
accessible.
If the metal baseplate is grounded, one Vi pin and
one Vo pin shall also be grounded.
A SELV reliability test is conducted on the system
where the module is used, in combination with the
module, to ensure that under a single fault,
hazardous voltage does not appear at the module’s
output.
When installed into a Class II equipment (without
grounding), spacing consideration should be given to
the end-use installation, as the spacing between the
module and mounting surface have not been evaluated.
The power module has extra-low voltage (ELV) outputs
when all inputs are ELV.
This power module is not internally fused. To achieve
optimum safety and system protection, an input line fuse
is highly recommended. The safety agencies require a
normal-blow fuse with 5A maximum rating to be installed
in the ungrounded lead. A lower rated fuse can be used
based on the maximum inrush transient energy and
maximum input current.
Soldering and Cleaning Considerations
Post solder cleaning is usually the final board assembly
process before the board or system undergoes electrical
testing. Inadequate cleaning and/or drying may lower the
reliability of a power module and severely affect the
finished circuit board assembly test. Adequate cleaning
and/or drying is especially important for un-encapsulated
and/or open frame type power modules. For assistance
on appropriate soldering and cleaning procedures,
please contact Delta’s technical support team.
DESIGN CONSIDERATIONS
Input Source Impedance
The impedance of the input source connecting to the
DC/DC power modules will interact with the modules and
affect the stability. A low ac-impedance input source is
recommended. If the source inductance is more than a
few μH, we advise adding a 10 to 100 μF electrolytic
capacitor (ESR < 0.7 Ω at 100 kHz) mounted close to the
input of the module to improve the stability.
Layout and EMC Considerations
Delta’s DC/DC power modules are designed to operate in
a wide variety of systems and applications. For design
assistance with EMC compliance and related PWB layout
issues, please contact Delta’s technical support team. An
external input filter module is available for easier EMC
compliance design. Application notes to assist
designers in addressing these issues are pending
release.
Safety Considerations
The power module must be installed in compliance with
the spacing and separation requirements of the
end-user’s safety agency standard, i.e., UL60950,
CAN/CSA-C22.2 No. 60950-00 and EN60950: 2000 and
IEC60950-1999, if the system in which the power module
is to be used must meet safety agency requirements.
Basic insulation based on 75 Vdc input is provided
between the input and output of the module for the
purpose of applying insulation requirements when the
input to this DC-to-DC converter is identified as TNV-2 or
SELV. An additional evaluation is needed if the source
is other than TNV-2 or SELV.
When the input source is SELV circuit, the power module
meets SELV (safety extra-low voltage) requirements. If the
input source is a hazardous voltage which is greater than
60 Vdc and less than or equal to 75 Vdc, for the module’s
output to meet SELV requirements, all of the following
must be met:
DS_V48SR1R825_09262012
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FEATURES DESCRIPTIONS
Over-Current Protection
The modules include an internal output over-current
protection circuit, which will endure current limiting for an
unlimited duration during output overload. If the output
current exceeds the OCP set point, the modules will
automatically shut down, and enter hiccup mode or latch
mode, which is optional.
For hiccup mode, the module will try to restart after
shutdown. If the over current condition still exists, the
module will shut down again. This restart trial will continue
until the overload condition is corrected.
For latch mode, the module will latch off once it shutdown.
The latch is reset by either cycling the input power or by
toggling the on/off signal for one second.
Over-Voltage Protection
The modules include an internal output over-voltage
protection circuit, which monitors the voltage on the
output terminals. If this voltage exceeds the over-voltage
set point, the module will shut down, and enter in hiccup
mode or latch mode, which is optional.
For hiccup mode, the module will try to restart after
shutdown. If the over voltage condition still exists, the
module will shut down again. This restart trial will continue
until the overload condition is corrected.
For latch mode, the module will latch off once it shutdown.
The latch is reset by either cycling the input power or by
toggling the on/off signal for one second.
Over-Temperature Protection
The over-temperature protection consists of circuitry that
provides protection from thermal damage. If the
temperature exceeds the over-temperature threshold the
module will shut down, and enter in hiccup mode or latch
mode, which is optional.
For hiccup mode, the module will try to restart after
shutdown. If the over temperature condition still exists,
the module will shut down again. This restart trial will
continue until the overload condition is corrected.
For latch mode, the module will latch off once it shutdown.
The latch is reset by either cycling the input power or by
toggling the on/off signal for one second.
Remote On/Off
The remote on/off feature on the module can be either
negative or positive logic. Negative logic turns the module
on during a logic low and off during a logic high. Positive
logic turns the modules on during a logic high and off
during a logic low.
Remote on/off can be controlled by an external switch
between the on/off terminal and the Vi(-) terminal. The
switch can be an open collector or open drain.
For negative logic if the remote on/off feature is not used,
please short the on/off pin to Vi(-). For positive logic if the
remote on/off feature is not used, please leave the on/off
pin floating.
Vo(+)Vi(+)
Vo(-)
Sense(-)
Sense(+)
Vi(-)
ON/OFF
Figure 16: Remote on/off implementation
Remote Sense
Remote sense compensates for voltage drops on the
output by sensing the actual output voltage at the point
of load. The voltage between the remote sense pins and
the output terminals must not exceed the output voltage
sense range given here:
[Vo(+) – Vo(–)] – [SENSE(+) – SENSE(–)] ≤ 10% × Vout
This limit includes any increase in voltage due to remote
sense compensation and output voltage set point
adjustment (trim).
Vi(-)
Vi(+)
Vo(-)
Vo(+)
Sense(+)
Sense(-)
Resistance
Contact Contact and Distribution
Losses
Figure 17: Effective circuit configuration for remote sense
operation
If the remote sense feature is not used to regulate the
output at the point of load, please connect SENSE(+) to
Vo(+) and SENSE(–) to Vo(–) at the module.
The output voltage can be increased by both the remote
sense and the trim; however, the maximum increase is
the larger of either the remote sense or the trim, not the
sum of both.
DS_V48SR1R825_09262012
9
FEATURES DESCRIPTIONS (CON.)
When using remote sense and trim, the output voltage
of the module is usually increased, which increases the
power output of the module with the same output
current.
Care should be taken to ensure that the maximum output
power does not exceed the maximum rated power.
Output Voltage Adjustment (TRIM)
To increase or decrease the output voltage set point,
connect an external resistor between the TRIM pin and
either the SENSE(+) or SENSE(-). The TRIM pin
should be left open if this feature is not used.
Figure 18: Circuit configuration for trim-down (decrease
output voltage)
If the external resistor is connected between the TRIM
and SENSE (-) pins, the output voltage set point
decreases (Fig. 18). The external resistor value
required to obtain a percentage of output voltage
change △% is defined as:
KdownRtrim 2.10
511
Ex. When Trim-down -10% (1.8V×0.9=1.62V)
KKdownRtrim 9.402.10
10
511
Figure 19: Circuit configuration for trim-up (increase output
voltage)
If the external resistor is connected between the TRIM
and SENSE (+) the output voltage set point increases
(Fig. 19). The external resistor value required to obtain
a percentage output voltage change △% is defined
as:
KupRtrim 2.10
511
1.225 ) (100 Vo11.5
Ex. When Trim-up +10% (1.8V×1.1=1.98V)
KupRtrim 3.212.10
10
511
10225.1 )10100(8.111.5
The output voltage can be increased by both the remote
sense and the trim, however the maximum increase is
the larger of either the remote sense or the trim, not the
sum of both.
When using remote sense and trim, the output voltage
of the module is usually increased, which increases the
power output of the module with the same output
current.
Care should be taken to ensure that the maximum
output power of the module remains at or below the
maximum rated power.
DS_V48SR1R825_09262012
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THERMAL CONSIDERATIONS
Thermal management is an important part of the system
design. To ensure proper, reliable operation, sufficient
cooling of the power module is needed over the entire
temperature range of the module. Convection cooling is
usually the dominant mode of heat transfer.
Hence, the choice of equipment to characterize the
thermal performance of the power module is a wind
tunnel.
Thermal Testing Setup
Delta’s DC/DC power modules are characterized in
heated vertical wind tunnels that simulate the thermal
environments encountered in most electronics
equipment. This type of equipment commonly uses
vertically mounted circuit cards in cabinet racks in which
the power modules are mounted.
The following figure shows the wind tunnel
characterization setup. The power module is mounted
on a test PWB and is vertically positioned within the
wind tunnel. The space between the neighboring PWB
and the top of the power module is constantly kept at
6.35mm (0.25’’).
Note: Wind Tunnel Test Setup Figure Dimensions are in millimeters and (Inches)
12.7 (0.5”)
MODULE
AIR FLOW
50.8 (2.0”)
FACING PWB
PWB
AIR VELOCITY
AND AMBIENT
TEMPERATURE
MEASURED BELOW
THE MODULE
Figure 20: Wind tunnel test setup
Thermal Derating
Heat can be removed by increasing airflow over the module.
To enhance system reliability, the power module should
always be operated below the maximum operating
temperature. If the temperature exceeds the maximum
module temperature, reliability of the unit may be affected.
THERMAL CURVES
Figure 21: Temperature measurement location
The allowed maximum hot spot temperature is defined at 127
℃
.
V48SR1R825(standard) Output Current vs. Ambient Temperature and Air Velocity
@Vin = 48V (Either Orientation)
0
5
10
15
20
25
50 55 60 65 70 75 80 85
Natural
Convection
100LFM
300LFM
200LFM
400LFM
Ambient Temperature (℃)
Output Current (A)
500LFM
600LFM
Figure 22: Output Current vs. Ambient Temperature and Air
Velocity @ Vin=48V (Either Orientation)
DS_V48SR1R825_09262012
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PICK AND PLACE LOCATION RECOMMENDED PAD LAYOUT (SMD)
SURFACE-MOUNT TAPE & REEL
DS_V48SR1R825_09262012
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LEADED (Sn/Pb) PROCESS RECOMMEND TEMP. PROFILE
Note: The temperature refers to the pin of V48SR, measured on the pin +Vout joint.
LEAD FREE (SAC) PROCESS RECOMMEND TEMP. PROFILE
Temp.
Time
150℃
200℃
100~140 sec.
Time Limited 90 sec.
above 217℃
217℃
Preheat time
Ramp up
max. 3℃/sec.
Ramp down
max. 4℃/sec.
Peak Temp. 240 ~ 245 ℃
25℃
Note: The temperature refers to the pin of v48SR, measured on the pin +Vout joint.
DS_V48SR1R825_09262012
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MECHANICAL DRAWING
Surface-mount module Through-hole module
Pin No.
Name
Function
1
2
3
4
5
6
7
8
+Vin
ON/OFF
-Vin
-Vout
-SENSE
TRIM
+SENSE
+Vout
Positive input voltage
Remote ON/OFF
Negative input voltage
Negative output voltage
Negative remote sense
Output voltage trim
Positive remote sense
Positive output voltage
DS_V48SR1R825_09262012
14
PART NUMBERING SYSTEM
V
48
S
R
1R8
25
N
R
F
A
Type of
Product
Input
Voltage
Number of
Outputs
Product
Series
Output
Voltage
Output
Current
ON/OFF
Logic
Pin
Length/Type
Option Code
V –1/16
brick
48V
S - Single
Regular
1R8 – 1.8V
25 - 25A
N- Negative
P- Positive
R - 0.170”
N - 0.145”
K - 0.110”
M - SMD
F- RoHS 6/6
(Lead Free)
A - Standard Functions
MODEL LIST
MODEL NAME
INPUT
OUTPUT
EFF @ 100% LOAD
V48SR1R225NRFA
36V~75V
1.2A
1.2V
25A
84.0%
V48SR1R525NRFA
36V~75V
1.4A
1.5V
25A
85.0%
V48SR1R825NRFA
36V~75V
1.6A
1.8V
25A
87.0%
V48SR2R520NRFA
36V~75V
1.8A
2.5V
20A
89.0%
V48SR3R320NRFA
36V~75V
2.4A
3.3V
20A
90.5%
V48SR05013NRFA
36V~75V
2.3A
5.0V
13A
91.0%
V48SR12005NRFA
36V~75V
2.3A
12V
5.5A
91.0%
V48SR15004NRFA
36V~75V
2.3A
15V
4.4A
91.0%
Default remote on/off logic is negative and pin length is 0.170”
For different remote on/off logic and pin length, please refer to part numbering system above or contact your local sales office.
CONTACT: www.deltaww.com/dcdc
USA:
Telephone:
East Coast: 978-656-3993
West Coast: 510-668-5100
Fax: (978) 656 3964
Email: DCDC@delta-corp.com
Europe:
Phone: +31-20-655-0967
Fax: +31-20-655-0999
Email: DCDC@delta-es.com
Asia & the rest of world:
Telephone: +886 3 4526107 ext 6220-6224
Fax: +886 3 4513485
Email: DCDC@delta.com.tw
WARRANTY
Delta offers a two (2) year limited warranty. Complete warranty information is listed on our web site or is available upon
request from Delta.
Information furnished by Delta is believed to be accurate and reliable. However, no responsibility is assumed by Delta for its
use, nor for any infringements of patents or other rights of third parties, which may result from its use. No license is granted
by implication or otherwise under any patent or patent rights of Delta. Delta reserves the right to revise these specifications
at any time, without notice.
