DATASHEET
DS_S48SS05002_06082006 Delta Electronics, Inc.
1
Telecom/DataCom
Wireless Networks
Optical Network Equipment
Server and Data Storage
Industrial/Test Equipment
Delphi Series S48SS, 15W Family
DC/DC Power Modules: 48V in, 5V/2A out
The Delphi Series S48SS, surface mountable, 48V input, single output,
isolated DC/DC converters are the latest offering from one of the
world’s largest power supply manufacturers ― Delta Electronics, Inc.
This product family provides up to 15 watts of power or up to 4.5A of
output current (for 3.3V and below) in an industry standard footprint.
With creative design technology and optimization of component
placement, the Delphi Series Small Power converters possess
outstanding electrical and thermal performance, as well as extremely
high reliability under highly stressful operating conditions. All models
are protected from abnormal input/output voltage and current
conditions. An encapsulated version is available for the most robust
performance in harsh environments.
APPLICATIONS
FEATURES
High efficiency: 84% @ 5V/2A
Standard footprint
Surface mountable
Industry standard pin out
Low profile: 0.48”
Fixed frequency operation
Input UVLO, Output OCP, OVP
No minimum load required
2:1 input voltage range
ISO 9001, TL 9000, ISO 14001,
QS9000, OHSAS18001 certified
manufacturing facility
UL/cUL 60950 (US & Canada)
Recognized, and TUV (EN60950)
Certified
CE mark meets 73/23/EEC and
93/68/EEC directives
DS_S48SS05002_06082006
2
TECHNICAL SPECIFICATIONS
(TA=25°C, airflow rate=300 LFM, Vin=48Vdc, nominal Vout unless otherwise noted.)
PARAMETER NOTES and CONDITIONS S48SS05002NRFA
Min. Typ. Max. Units
ABSOLUTE MAXIMUM RATINGS
Input Voltage
Continuous 80 Vdc
Transient (100ms) 100ms 100 Vdc
Operating Temperature Refer to Figure 12 for the measuring point -40 100 °C
Storage Temperature -55 125 °C
Input/Output Isolation Voltage 1 minute 1500 Vdc
INPUT CHARACTERISTICS
Operating Input Voltage 36 48 75 V
Input Under-Voltage Lockout
Turn-On Voltage Threshold 33.8 34.5 35.8 V
Turn-Off Voltage Threshold 32.0 33.5 34.5 V
Lockout Hysteresis Voltage 0.5 1.5 2.5 V
Maximum Input Current 100% Load, 36Vin 0.5 A
No-Load Input Current 25 mA
Off Converter Input Current 1 m
A
Inrush Current(I2t) 0.01 A2s
Input Reflected-Ripple Current P-P thru 12µH inductor, 5Hz to 20MHz 5 mA
Input Voltage Ripple Rejection 120 Hz 55 dB
OUTPUT CHARACTERISTICS
Output Voltage Set Point Vin=48V, Io=50%Io.max, Tc=25°C 4.90 5.00 5.10 V
Output Voltage Regulation
Over Load Io=Io,min to Io,max ±5 ±25 mV
Over Line Vin=36V to 75V ±5 ±15 mV
Over Temperature Tc=-40 ℃to 100 ℃ 100 300
pp
m/℃
Total Output Voltage Range Over sample load, line and temperature TBD TBD V
Output Voltage Ripple and Noise 5Hz to 20MHz bandwidth
Peak-to-Peak Full Load, 1µF ceramic, 10µF tantalum 50 100 mV
RMS Full Load, 1µF ceramic, 10µF tantalum 15 25 mV
Operating Output Current Range 0 2 A
Output DC Current-Limit Inception Output Voltage 10% Low 2.4 3.4 4.4 A
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 75 100 mV
Negative Step Change in Output Current 75% Io,max to 50% Io.max 75 100 mV
Settling Time to 1% of Final value 600 µs
Turn-On Transient
Start-Up Time, From On/Off Control 35 50 ms
Start-Up Time, From Input 35 50 ms
Maximum Output Capacitance Full load; 5% overshoot of Vout at startup 470 µF
EFFICIENCY
100% Load 82 84 %
ISOLAT ION C HARACTER ISTICS
Isolation Voltage 1500 V
Isolation Resistance 100 MΩ
Isolation Capacitance 500 pF
FEATURE CHARACTERISTICS
Switching Frequency 290 kHz
ON/OFF Control, (Logic Low-Module ON)
Logic Low Von/off at Ion/off=1.0mA 0 0.8 V
Logic High Von/off at Ion/off=0.0 µA 15 V
ON/OFF Current Ion/off at Von/off=0.0V 1 m
A
Leaka
g
e Current Lo
g
ic Hi
g
h
,
Von/off=15V 50 u
A
Out
p
ut Volta
g
e Trim Ran
g
e
A
cross Trim Pin & +Vo or
–
Vo
,
Pout≦max rated -10 +10 %
Out
p
ut Ove
r
-Volta
g
e Protection Over full tem
p
ran
g
e
;
% of nominal Vout 115 125 140 %
GENERAL SPECIFICATIONS
Calculated MTBF Io=80% of Io, max; Tc=40°C 3 M hours
Weight 12.5 grams
DS_S48SS05002_06082006
ELECTRICAL CHARACTERISTICS CURVES
50
55
60
65
70
75
80
85
90
0.511.52
OUTPUT CURRENT (A)
EFFICIENCY (%)
36Vin 48Vin 75Vin
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
0.5 1 1.5 2
OUTPUT CURRENT (A)
POW ER DISSIPATION (W
)
36Vi n 48Vin 75Vin
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 input characteristics at room temperature Figure 4: Turn-on transient at full rated load current (resistive
load) (10 ms/div). Top Trace: Vout (2V/div); Bottom Trace:
ON/OFF Control (2V/div).
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DS_S48SS05002_06082006
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ELECTRICAL CHARACTERISTICS CURVES
Figure 5: Turn-on transient at zero load current (10 ms/div). Top
Trace: Vout (2V/div); Bottom Trace: ON/OFF Control (2V/div).
Figure 6: Output voltage response to step-change in load
current (50%-75%-50% of Io, max; di/dt = 0.1A/µs). Load
cap: 10µF, 100m
Ω
ESR tantalum capacitor and 1µF
ceramic capacitor. Top Trace: Vout (50mV/div), Bottom
Trace: Iout (1A/div).
Figure 7: Test set-up diagram showing measurement points for
Input Reflected Ripple Current (Figure 8).
Note: Measured input reflected-ri
p
ple current with a simulated
source Inductance (LTEST
)
of 12 µH. Capacitor Cs offset possible
battery impedance.
Figure 8: Input Reflected Ripple Current, is, at full rated
output current and nominal input voltage with 12µH source
impedance and 68µF electrolytic capacitor (2 mA/div).
DS_S48SS05002_06082006
ELECTRICAL CHARACTERISTICS CURVES
StripCopper
Vo(-)
Vo(+)
10u 1u SCOPE RESISTIV
E
LOAD
Figure 9: Output voltage noise and ripple measurement test
setup. 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: Output voltage ripple at nominal input voltage and
rated load current (20 mV/div). Load capacitance: 1µF ceramic
capacitor and 10µF tantalum capacitor. Bandwidth: 20 MHz.
0.0
1.0
2.0
3.0
4.0
5.0
6.0
0.0 1.0 2.0 3.0 4.0 5.0
LOAD CURRENT (A)
OUTPUT VOLTAGE (V)
Vin=48V
Figure 11: Output voltage vs. load current showing typical
current limit curves and converter shutdown points.
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DS_S48SS05002_06082006
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THERMAL CURVES:
Top View
S48SS05002NR A Output Current vs. Ambient Temperature and Air Velocity @Vin < 60V
0.0
0.3
0.6
0.9
1.2
1.5
1.8
2.1
80 85 90 95 100
Ambient Temperature (℃)
Output Current(A)
Natural
Convection
100LFM
200LFM
300LFM
400LFM
500LFM
600LFM
Figure 12: Case temperature measurement location.
Pin locations are for reference only. Figure 13: Output current vs. ambient temperature and air
velocity (Vin<60V)
S48SS05002NR A Output Current vs. Ambient Temperature and Air Velocity @Vin =75V
0.0
0.3
0.6
0.9
1.2
1.5
1.8
2.1
75 80 85 90 95 100
Ambient Temperature (℃)
Output Current(A)
Natural
Convection
100LFM
200LFM
300LFM
400LFM
500LFM
600LFM
S48SS05002NR A Power Dissipation vs. Ambient Temperature and Air Velocity
0.0
0.3
0.6
0.9
1.2
1.5
1.8
2.1
2.4
2.7
75 80 85 90 95 100 105
Ambient Temperature (℃)
Power Dissipation (Watts)
Natural
Convection
100LFM
200LFM
300LFM
400LFM
500LFM
600LFM
Figure 14: Output current vs. ambient temperature and air
velocity (Vin=75V) Figure 15: Power dissipation vs. ambient temperature and air
velocity
DS_S48SS05002_06082006
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 1A 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 if the system in which the
power module is to be used must meet safety agency
requirements.
When the input source is 60Vdc or below, 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:
The input source must be insulated from any
hazardous voltages, including the ac mains, with
reinforced insulation.
One Vi pin and one Vo pin are grounded, or all the
input and output pins are kept floating.
The input terminals of the module are not operator
accessible.
A SELV reliability test is conducted on the system
where the module is used to ensure that under a
single fault, hazardous voltage does not appear at
the module’s output.
Do not ground one of the input pins without grounding
one of the output pins. This connection may allow a non-
SELV voltage to appear between the output pin and
ground.
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DS_S48SS05002_06082006
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Ex. When trim-down –10% (5V × 0.9 = 4.5V)
[]
ΚΩ=−
+×
×
−
=− 96.5249.6
016.01.05 1.005.47381.35
downRtrim
Vo(+)
Vo(-)
Trim
Rtrim-up
Figure 17: Circuit configuration for trim-up (increase output
voltage)
If the external resistor is connected between the TRIM
and Vo - the output voltage set point increases. The
external resistor value required to obtain a percentage
output voltage change △Vo% is defined as:
[]
ΚΩ−
−∆
=− 49.6
016.05 668.11
upRtrim Vo
Ex. When trim-up +10% (5V × 1.1 = 5.5V)
[]
ΚΩ=−
−×
=− 62.1749.6
016.01.05 668.11
upRtrim
Care should be taken to ensure that the maximum
output power of the module remains at or below the
maximum rated power.
Remote ON/OFF
The remote on/off feature on the module can be eithe
r
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/of
f
terminal and the Vi(-) terminal. The switch can be an
open collector or open drain. If the remote on/off feature
is not used, please short the on/off pin to Vi(-) fo
r
negative logic and let the pin open for positive logic.
ON/OFF
Vi(-)
Vi(+) Vo(+)
Trim
Vo(-)
Figure 18: Circuit Configuration for Remote ON/OFF
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 (hiccup mode).
The modules will try to restart after shutdown. If the
overload condition still exists, the module will shut down
again. This restart trial will continue until the overload
condition is corrected.
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 latch off. The
over-voltage latch is reset by either cycling the input
power or by toggling the on/off signal for one second.
Output Voltage Adjustment (TRIM)
To increase or decrease the output voltage set point, the
modules may be connected with an external resistor
between the TRIM pin and either the Vo+ or Vo -. The
TRIM pin should be left open if this feature is not used.
Vo(+)
Vo(-)
Trim trim-down
R
Figure 16: Circuit configuration for trim-down (decrease output
voltage)
If the external resistor is connected between the TRIM
and Vo+ pins, the output voltage set point decreases.
The external resistor value required to obtain a
percentage of output voltage change △Vo% is defined
as:
[]
ΚΩ−
+∆
∆−
=49.6
016.05 05.47381.35
down-Rtrim Vo Vo
DS_S48SS05002_06082006
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 or a heat sink is
6.35mm (0.25”).
Thermal Derating
Heat can be removed by increasing airflow over the
module. Figure 13 and 14 show maximum output is a
function of ambient temperature and airflow rate. The
module’s maximum case temperature is +100°C. 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.
Note: Wind Tunnel Test Setup Figure Dimensions are in millimeters and (Inches)
10 (0.4”)
MODULE
A
IR FLOW
50.8
(
2.0”
)
FACING PWB PWB
AIR VELOCIT
Y
AND AMBIENT
TEMPERATURE
MEASURED BELOW
THE MODULE
Figure 19: Wind tunnel test setup
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DS_S48SS05002_06082006
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MECHANICAL DRAWING
Pin No. Name Function
1 +Vout Positive output voltage
2 -Vout Negative output voltage
3 Trim Output voltage trim
4 NC No Connection
5 NC No Connection
6 NC No Connection
7 NC No Connection
8 ON/OFF ON/OFF Logic
9 NC No Connection
10 NC No Connection
11 -Vin Negative input voltage
12 +Vin Positive input voltage
DS_S48SS05002_06082006
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PART NUMBERING SYSTEM
S 48 S S 050 02 N R F A
Form
Factor Input
Voltage Number of
Outputs Product
Series Output
Voltage Output
Current ON/OFF
Logic Pin Type Option
Code
S- Small
Power
48V S- Single S- SMD 050- 5.0V 02- 2A N- Negative
P- Positive
R- SMD
Pin F- RoHS 6/6
(Lead Free)
A- standard
Function
MODEL LIST
MODEL NAME INPUT OUTPUT EFF @ 100% LOAD
S48SS1R805NRFA 36V~75V 0.5A 1.8V 5.0A 80.0%
S48SS2R504NRFA 36V~75V 0.5A 2.5V 4.5A 83.0%
S48SS3R303NRFA 36V~75V 0.5A 3.3V 3.0A 84.0%
S48SS3R304NRFA 36V~75V 0.6A 3.3V 4.5A 86.0%
S48SS05002NRFA 36V~75V 0.5A 5.0V 2.0A 84.0%
S48SS05003NRFA 36V~75V 0.6A 5.0V 3.0A 86.5%
S48SS12001NRFA 36V~75V 0.6A 12V 1.25A 86.5%
CONTACT: www.delta.com.tw/dcdc
USA:
Telephone:
East Coast: (888) 335 8201
West Coast: (888) 335 8208
Fax: (978) 656 3964
Email: DCDC@delta-corp.com
Europe:
Phone: +41 31 998 53 11
Fax: +41 31 998 53 53
Email: DCDC@delta-es.com
Asia & the rest of world:
Telephone: +886 3 4526107 ext 6220
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.
