Delta Q48SR User Manual

FEATURES

 High efficiency: 91% @ 3.3V/50A

 Standard footprint:

57.9x36.8x10.4mm (2.28”x1.45”x0.41”)

 Industry standard pin out

 Fixed frequency operation

 Wide output trim range 1.7V~3.6V

 Fully protected: OTP, OVP, OCP, UVLO

 No minimum load required

 Fast transient response

 Start up into pre-biased load

 Basic insulation

 ISO 9000, TL 9000, ISO 14001 certified

manufacturing facility

 UL/cUL 60950 (US & Canada) recognized,

and TUV (EN60950) certified

 CE mark meets 73/23/EEC and

93/68/EEC directives

Delphi Series Q48SR, 165W Quarter Brick Family
DC/DC Power Modules: 48V in, 3.3V/50A out

The Delphi Series Q48SR Quarter Brick, 48V input, adjustable single

output, isolated, open frame DC/DC converters are the latest offering

from a world leader in power systems technology and manufacturing —

Delta Electronics, Inc. This product family provides up to 165 watts of

power or up to 60A of output current in an industry standard footprint.

This product represents the next generation of design technology which

may be utilized to provide high levels of current at very low output

voltages required by today’s leading-edge circuitry. Utilizing an advanced

patented thermal and electrical design technology; the Delphi Series

Q48SR converters are capable of providing higher output current

capability with excellent transient response and lower common mode

noise. Featuring a wide operating output voltage range and high current

at low output voltages, these units offer more useable power over a wide

range of ambient operating conditions. The wide range trimmable output

feature allows the user to both reduce and standardize part numbers

across different and/or migrating voltage requirements. This model

covers the output range of 1.7V to 3.6Vat 50A.

OPTIONS

 Short lead lengths

 Non-latching over voltage protection

 Negative trim

 Positive on/off logic

APPLICATIONS

 Telecom/DataCom

 Wireless Networks

 Optical Network Equipment
 Server and Data Storage

 Industrial/Test Equipment

DATASHEET
DS_Q48SR3R350_12212004

1

Delta Electronics, Inc.

TECHNICAL SPECIFICATIONS

r

(TA=25°C, airflow rate=300 LFM, Vin=48Vdc, nominal Vout unless otherwise noted; mounted on board.)

PARAMETER

ABSOLUTE MAXIMUM RATINGS

Input Voltage

Continuous

Transient (100ms) 100ms 100 Vdc
Operating Temperature Refer to Figure 24 for measuring point -40 120 °C
Storage Temperature
Input/Output Isolation Voltage 1 minute 1500 Vdc

INPUT CHARACTERISTICS

Operating Input Voltage
Input Under-Voltage Lockout

Turn-On Voltage Threshold

Turn-Off Voltage Threshold

Lockout Hysteresis Voltage

Maximum Input Current 100% Load, 36Vin 5.9 A
No-Load Input Current 100 150 mA
Off Converter Input Current 10 20 mA
Inrush Current(I2t) 0.03 A2S
Input Reflected-Ripple Current P-P thru 12µH inductor, 5Hz to 20MHz 10 mA
Input Voltage Ripple Rejection 120 Hz 70 dB

OUTPUT CHARACTERISTICS

Output Voltage Set Point Vin=48V, Io=Io.max, Ta=25C 3.25 3.3 3.35
Output Voltage Regulation

Over Load Io=Io,min to Io,max ±2 ±5 mV

Over Line Vin=36V to 75V ±2 ±5 mV

Over Temperature Tc=-40C to 100C ±50 ±100 mV

Total Output Voltage Range over sample load, line and temperature 3.17 3.43 V
Output Voltage Ripple and Noise 5Hz to 20MHz bandwidth

Peak-to-Peak Full Load, 1µF ceramic, 10µF tantalum 30 100 mV

RMS Full Load, 1µF ceramic, 10µF tantalum 10 20 mV

Operating Output Current Range 0 50 A
Output DC Current-Limit Inception Output Voltage 10% Low 105 130 %

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 70 150 mV

Negative Step Change in Output Current 75% Io,max to 50% Io,max 70 150 mV

Settling Time (within 1% Vout nominal) 100 uS

Turn-On Transient

Start-Up Time, From On/Off Control 15 30 mS

Start-Up Time, From Input 15 30

Maximum Output Capacitance Full load; 5% overshoot of Vout at startup 20000 µF

EFFICIENCY

100% Load
60% Load 91 %

ISOLATION CHARACTERIS TICS

Input to Output 1500 Vdc
Isolation Resistance 10 MΩ
Isolation Capacitance 2000 pF

FEATURE CHARACTERISTICS

Switching Frequency 400 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 mA

Leakage Current Logic High, Von/off=15V 50 uA
Output Voltage Trim Range Across Pins 9 & 5, Pout <= max rated powe
Output Voltage Remote Sense Range Pout <= max rated power 10 %
Output Over-Voltage Protection Over full temp range; % of nominal Vout 115 130 145 %

GENERAL SPECIFICATIONS

MTBF Io=80% of Io, max; Ta=25°C, airflow rate=300 LFM 1.7 M hours
Weight 36 grams
Over-Temperature Shutdown Refer to Figure 24 for measuring point 125 °C

NOTES and CONDITIONS Q48SR3R350Nx A

Min. Typ. Max. Units

80 Vdc

-55 125 °C

36 48 75 Vdc

33 34 35 Vdc
31 32 33 Vdc

1 2 3 Vdc

91 %

1.7 3.6 V

Vdc

mS

2

ELECTRICAL CHARACTERISTICS CURVES

95

90

EFFICIENCY (%)

85

80

75

70

65

36Vin 48Vin 75Vin

60

10 20 30 40 50

OUTPUT CURRENT (A)

Figure 1: Efficiency vs. load current for minimum, nominal, and

maximum input voltage at 25°C. (Vout=3.3V)

95

90

24.0

36Vin 48Vin 75Vin

20.0

16.0

POWER DISSIPATION (W)

12.0

8.0

4.0

0.0
10 20 30 40 50

OUTPUT CURRENT(A)

Figure 2: Power dissipation vs. load current for minimum,

nominal, and maximum input voltage at 25°C. (Vout=3.3V)

24.0

36Vin 48Vin 75Vin

20.0

EFFICIENCY (%)

85

80

75

70

65

36Vin 48Vin 75Vin

60

10 20 30 40 50

OUTPUT CURRENT (A)

Figure 3: Efficiency vs. load current for minimum, nominal, and

maximum input voltage at 25°C. (Vout=1.7V)

16.0

POWER DISSIPATION (W)

12.0

8.0

4.0

0.0
10 20 30 40 50

OUTPUT CURRENT(A)

Figure 4: Power dissipation vs. load current for minimum,
nominal, and maximum input voltage at 25°C. (Vout=1.7V)

3

ELECTRICAL CHARACTERISTICS CURVES

94

92

EFFICIENCY (%)

90

88

24.0

36Vin 48Vin 75Vin

22.0

20.0

POWER DISSIPATION (W)

18.0

86

84

82

36Vin 48Vin 75Vin

80

1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.3

OUTPUT VOLTAGE (V)

Figure 5: Efficiency vs. output voltage for minimum, nominal, and
maximum input voltage at 25°C. (Iout=50A)

6.0

Io=50A Io=30A Io=5A

5.0

INPUT CURREN (A)

4.0

3.0

2.0

1.0

16.0

14.0

12.0

10.0

1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.3

OUTPUT VOLTAGE (V)

Figure 6: Power dissipation vs. output voltage for minimum,

nominal, and maximum input voltage at 25°C. (Iout=50A)

0.0
30 35 40 45 50 55 60 65 70 75

INPUT VOLTAGE (V)

Figure 7: Typical input characteristics at room temperature Figure 8: Turn-on transient at full rated load current (resistive

load) (5 ms/div). Top Trace: Vout; 1V/div; Bottom Trace:

ON/OFF input: 2V/div

4

ELECTRICAL CHARACTERISTICS CURVES

A

A

)

)

Figure 9: Turn-on transient at zero load current (5 ms/div).

Top Trace: Vout: 1V/div; Bottom Trace: ON/OFF input:
2V/div

Figure 10: 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), Bottom Trace: Iout (20
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.

/div). Scope

Figure 11: Output voltage response to step-change in load

current (75%-50%-75% of Io, max: di/dt = 2.5A/µs). Load
cap: 470µF, 35m
ceramic capacitor. Top Trace: Vout (100mV/div), Bottom
Trace: Iout (20
using a BNC cable (length shorter than 20 inches
the load between 51 mm to 76 mm (2 inches to 3 inches
from the module.

Ω

ESR solid electrolytic capacitor and 1µF

/div). Scope measurement should be made

. Position

Figure 12: 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 (L
battery impedance. Measure current as shown above.

) of 12 µH. Capacitor Cs offset possible

TEST

5

ELECTRICAL CHARACTERISTICS CURVES

E

Figure 13: Input Terminal Ripple Current, i
output current and nominal input voltage with 12µH source

impedance and 33µF electrolytic capacitor (500 mA/div).

Copper Strip

Vo(+)

10u 1u

Vo(-)

Figure 15: Output voltage noise and ripple measurement

test setup

SCOPE RESISTIV

, at full rated

c

LOAD

Figure 14: Input reflected ripple current, i

source inductor at nominal input voltage and rated load current

(5 mA/div).

Figure 16: 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.
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.

, through a 12µH

s

6

ELECTRICAL CHARACTERISTICS CURVES

3.5

3.0

2.5

OUTPUT VOLTAGE (V)

2.0

1.5

1.0

0.5

Vin=48V

0.0
0 10203040506070

LOAD CURRENT (A)

Figure 17: Output voltage vs. load current showing typical
current limit curves and converter shutdown points.

7

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 end­user’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.

When the input source is 60 Vdc 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.

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 20A 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.

8

9

n

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 over­voltage set point, the module will shut down and latch
off. Cycling the input power for one second resets the
over-voltage latch.

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.

The module will try to restart after shutdown. If the over­temperature condition still exists during restart, the
module will shut down again. This restart trial will
continue until the temperature is within specification.

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(+)

Sense(+)

ON/OFF

Sense(-)

Vi(-)

Vo(-)

Figure 18: 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(+)

Vo(+)

Sense(+)

Sense(-)

Vi(-)

Contact

Resistance

Figure 19: 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
allowed increase is the larger of either the remote
sense spec or the trim spec, 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 does not exceed the maximum rated
power.

Vo(-)

Contact and Distributio

Losses

10

FEATURES DESCRIPTIONS (CON.)

−

K

K

Ω

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
SENSE(+) or SENSE(-). The TRIM pin should be left
open if this feature is not used.

Figure 20: Circuit configuration for trim-up (increase output

voltage)

If the external resistor is connected between the TRIM
and SENSE (+) pins, the output voltage set point
increases (Fig. 24). The external resistor value
required to obtain a percentage of output voltage

change △% is defined as:

⎡

)Rtrim_up(∆

= kk

⎢
⎣

()

V

ref

−∆+

∆

where
Vonom = nominal Vout (3.3V or 1.8V)
Vref = 1.225V
∆ = trim expressed as decimal fraction, i.e. 10% is written
as 0.1

Ex. When trim up to 3.6V from 3.3V
Vonom = 3.3V
Vref = 1.225V

∆ = (3.6-3.3)/3.3 = 0.0909

()

×

0909.0*225.1

Ω=Ω−

283.20211

⇒

=−

⎤

V1V

refonom

⎥
⎦

225.10909.13.3
10

1110

Ω−Ω

Ω×

KupRtrim

Figure 21: Circuit configuration for trim-down (decrease

output voltage)

If the external resistor is connected between the TRIM
and SENSE (-) the output voltage set point decreases
(Fig. 21). The external resistor value required to obtain

a percentage output voltage change △% is defined

as:

ΚΩ

10

Rtrim_down

()

=∆ k11

Ω−

∆

where
Vonom = nominal Vout (3.3V or 1.8V)
∆ = trim expressed as decimal fraction, i.e. 40% is
written as 0.4

Ex. When trim down to 1.7V from 3.3V

Vonom = 3.3V
∆ = (3.3-1.7)/3.3 = 0.4848

K

downRtrim 627.911

10

Ω=Ω−=− KK

4848.0

The output voltage can be increased by both the remote
sense and the trim, however the maximum increase
allowed is the larger of either the remote sense spec or
the trim spec, 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.

Output voltage

2.5V 30.25

2.0V 14.38

Figure 22: Trim resistor value example for popular output

voltages. Connect the resistor between the TRIM and
SENSE (-) pins.

Resistor value (

k )

11

THERMAL CONSIDERATIONS

A

Y

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’’).

Thermal Derating

Heat can be removed by increasing airflow over the
module. The module’s maximum hot spot temperature
is 120 degrees C at 80% load and the measured
location is illustrated in Figure 18. 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.

FACING PWB

PWB

MODULE

AIR VELOCIT
AND AMBIENT

TEMPERATURE

MEASURED BELOW

THE MODULE

IR FLOW

Note: Wind Tunnel Test Setup Figure Dimensions are in millimeters and (Inche

Figure 23: Wind tunnel test setup figure dimensions are in

millimeters and (inches)

50.8 (2.0”)

12.7 (0.5”)

THERMAL CURVES

Figure 24: Hot spot location

＊

The allowed maximum hot spot temperature is defined at 120

℃

and 80% load.

Output Current(A)

55

50

45

40

35

30

25

20

15

10

5

0

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85

Figure 25: Output current vs. ambient temperature and air

velocity (V

Output Current(A)

55

50

45

40

35

30

25

20

15

10

5

0

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85

Figure 26: Output current vs. ambient temperature and air

velocity (V

Q48SR3R350(Standard) Output Current vs. Ambient Temperature and Air Velocity

Natural

Convection

100LFM

200LFM

300LFM

400LFM

500LFM

600LFM

=48V, V

in

Q48SR3R350(Standard) O utput Current vs. Ambient Temperature and A ir Velocity

Natural

Convection

100LFM

200LFM

300LFM

400LFM

500LFM

600LFM

=48V, V

in

@ Vin = 48V, Vo = 3.3V (Tranverse Orientation)

=3.3V )

out

@ Vin = 48V, Vout = 2.5V (Transverse Orientation)

=2.5V )

out

Ambient Temperature (℃)

Ambient Temperature (℃)

Output Current(A)

55

50

45

40

35

30

25

20

15

10

5

0

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85

Figure 27: Output current vs. ambient temperature and air

velocity (V

Q48SR3R350(Standard) Output Current vs. Ambient Temperature and Air Velocity

Natural

Convection

100LFM

200LFM

300LFM

400LFM

500LFM

600LFM

in

@ Vin = 48V, Vout = 1.8V (Transverse Orientation)

=48V, V

=1.8V )

out

Ambient Temperature (℃)

12

MECHANICAL DRAWING

Pin No. Name Function

1
2
3
4
5
6
7
8

Notes:

1
2
3

-Vin
ON/OFF
+Vin
+Vout
+SENSE
TRIM

-SENSE

-Vout

Pins 1-3, 5-7 are 1.00mm (0.040”) diameter
Pins 4 and 8 are 1.50mm (0.060”) diameter
All pins are copper with Tin plating

Negative input voltage
Remote ON/OFF
Positive input voltage
Positive output voltage
Positive remote sense
Output voltage trim
Negative remote sense
Negative output voltage

13

PART NUMBERING SYSTEM

Q 48 S R 3R3 50 N R A

Form Factor Input

Voltage

Q - Quarter

Brick

48V S - Single R - Single

Number of

Outputs

Product

Series

Board

Output

Voltage

3R3 - 3.3V

Output

Current

50 - 50A N - Negative

ON/OFF

Logic

P - Positive

Pin

Length

R - 0.170”
N - 0.145”
K - 0.110”

Space Option Code

A - Standard

Functions

MODEL LIST

MODEL NAME INPUT OUTPUT EFF @ 100% LOAD

Q48SR1R840NR A 36V~75V 2.7A 0.8V - 1.9V 40A - 72W 87%

Q48SR1R860NR A 36V~75V 4.0A 0.8V - 1.9V 60A - 108W 88%

Q48SR3R335NR A 36V~75V 4.2A 1.7V - 3.6V 35A - 115W 90%

Q48SR3R350NR A 36V~75V 5.9A 1.7V - 3.6V 50A - 165W 91%

* Please contact us for factory pre-set fixed output voltages

CONTACT:

USA:

Telephone:
East Coast: [phone]
West Coast: [phone]
Fax: [phone]

[e-mail]

Email:

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

www.delta.com.tw/dcdc

Europe:

Telephone: [phone]
Fax: [phone]
Email:

[e-mail]

.

Asia & the rest of world:

Telephone: [phone] x6220
Fax: [phone]

[e-mail]

Email:

14