QTS48T46096 DC-DC Converter Data Sheet
441-Watt
@
48Vin Quarter-Brick Bus Converter
Applications
• Intermediate Bus architectures
• Telecommunications equipment
• LAN/WAN
• Data processing
Features
• RoHS lead-free and lead-solder-exempt
products are available
• Delivers up to 500 watts with a 55 VDC input
• Cost-effective, single-board design
• 5:1 Fixed ratio converter
• Ultra-high efficiency over 97%
• 0.48” maximum height (12.2 mm)
• Narrow input range 36 – 55 VDC
• Parallel operation (3 units)
• Input-to-output isolation: 1500 VDC
• Start-up into high capacitive load
• Low conducted and radiated EMI
• Output overcurrent protection
• Input undervoltage lockout
• Input overvoltage shutdown
• Overtemperature protection
• Approved to UL 60950-1/ CAN/CSA-C22.2 No.
60950-1-03, and TUV approved to EN 60950-1,
IEC 60950-1
Description
The QTS48T46096 bus converter provides a 5:1 fixed ratio, isolated, step-down voltage. Output voltage is directly
proportional to input voltage with a conversion ratio of 5:1; at 48 VDC the resulting output voltage would be
9.6 VDC. The converter provides ultra-high efficiency over 97%; as a result very little heat is dissipated and a heat
sink is not required.
The QTS48T46096 is an excellent choice for intermediate bus applications where multiple output voltages are
required and a 9.6 V rail will be used to power “Point of Load” devices.
Model Selection
Model Input
Voltage
VDC
Input
Current,
Max ADC
Output
Voltage
Vout,@ 48Vin
VDC
Output
Current (A)
Output
Ripple/Noise,
mV p-p (max.)
Typical
Efficiency @
48Vi, 39.5A
QTS48T46096-NCAP
36-55
9.3
9.6
46
250
97.3
This product is intended for integration into end-use equipment. All the required procedures for CE marking of end-use equipment should be
followed.
ZD-02076 Rev 2.1 Page 1 of 7 www.power-one.com
QTS48T46096 DC-DC Converter Data Sheet
441-Watt
@
48Vin Quarter-Brick Bus Converter
Absolute Maximum Ratings
Stresses in excess of the absolute maximum ratings may cause performance degradation, adversely effect long-
term reliability, and cause permanent damage to the converter.
Parameter Conditions/Description Min Max Units
Input Voltage Continuous 0 55 VDC
Operating Temperature *Case Temperature (Q11) -40 125 °C
Storage Temperature -40 125 °C
* If necessary the factory will provide an assembly drawing upon request to locate Q11
Environmental and Mechanical Specifications
All specifications apply over specified input voltage, output load, and temperature range, unless otherwise noted.
Parameter Conditions/Description Min Nom Max Units
Shock (Half-sinewave, 6ms), 3 axes 50 g
Sinusoidal Vibration GR-63-CORE, Section 5.4.2 1 g
Weight 1.7/48 Oz/g
Water Washing Standard process Yes
MTBF
(Po= 260 W, TA = 30°C)
Per Bellcore TR-NWT-000332 3.5 MHrs
Isolation Specifications
All specifications apply over specified input voltage, output load, and temperature range, unless otherwise noted.
Parameter Conditions/Description Min Nom Max Units
Insulation Safety Rating Functional
Isolation Voltage Input to Output 1500 VDC
Isolation Resistance 10 MOhm
Isolation Capacitance 1100 pF
Input Specifications
All specifications apply over specified input voltage, output load, and temperature range, unless otherwise noted.
Parameter Conditions/Description Min Nom Max Units
Input Voltage Continuous 36 48 55 VDC
Turn-On Input Voltage Ramping Up 33 35 37 VDC
Turn-Off Input Voltage Ramping Down 31 32 33 VDC
Output Rise Time Time from Vo @ 10% of nominal to
Vo @ 90% of Nominal, w/ Load =
365 W resistor + 3000 µF capacitor
0.5 2 ms
Input Reflected Ripple Current Full Load, 12 µH source inductance
50 mA p-p
Inrush Transient Vin=Vin.max 1 A2s
Input Overvoltage Shutdown
Turn-off voltage threshold
Turn-on voltage threshold
Vin
57
55
59.5
58
ZD-02076 Rev 2.1 Page 2 of 7 www.power-one.com
QTS48T46096 DC-DC Converter Data Sheet
441-Watt
@
48Vin Quarter-Brick Bus Converter
Output Specifications
All specifications apply over specified input voltage, output load, and temperature range, unless otherwise noted.
Parameter Conditions/Description Min Nom Max Units
Output Voltage over line load and
temperature
6.8 11.5 VDC
Output Current Io 0 46 A
Load Regulation Vo 300 500 mV
Turn-on overshoot Vo 3 %
Transient response
25% load step change @ 1A/µs
(% of Vo nominal)
Vo
± 4
%
Admissible Load Capacitance Irated, Nom Vin 3000 µF
Output Current Limit Threshold
Latch-Off (recycle power or toggle
shutdown pin to re-start)
Po 110% 130% 150%
Switching Frequency 240 kHz
Feature Specifications
All specifications apply over specified input voltage, output load, and temperature range, unless otherwise noted.
Parameter Conditions/Description Min Nom Max Units
Shutdown (ON/OFF)
Negative Logic
Converter ON
Source Current
Converter OFF
Positive Logic
Converter ON
Open Circuit Voltage
Converter OFF
On/Off signal is low – converter is ON
ON/OFF pin is connected to -Vin
On/Off signal is low–converter is OFF
ON/OFF pin is floating
-0.5
2.5
2.5
-0.5
0.8
1
37
37
5
0.8
VDC
mADC
VDC
VDC
VDC
VDC
Overtemperature Protection Average board temperature +130 +140 °C
Current Share Accuracy See Page 4. “Parallel Operation” 5 10 %
ZD-02076 Rev 2.1 Page 3 of 7 www.power-one.com
QTS48T46096 DC-DC Converter Data Sheet
441-Watt
@
48Vin Quarter-Brick Bus Converter
Characteristic Curves
Efficiency Vs Line, Load
85.00
87.00
89.00
91.00
93.00
95.00
97.00
99.00
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Load (%)
Efficiency (%)
36
48
55
Figure 1. QTS48T46096 Efficiency vs. Output Load
Figure 2 shows the recommended connections for
the QTS48T46096 converter.
Figure 2. Typical Application of QTS48T46096
The QTS48T46096 converter does not require any
external components for proper operation. However,
if the distribution of the input voltage to the converter
contains significant inductance, a capacitor C1 may
be required to enhance performance of the
converter. A minimum of a 100 µF electrolytic
capacitor with the ESR<0.5Ω at 100 kHz is
recommended for the QTS48T46096.
Refer to the “Inrush Current Control Application
Note” on www.power-one.com for suggestions on
how to limit the magnitude of the inrush current.
For output decoupling we recommend using a 10 µF
low ESR tantalum (AVX TPSC106M025R0500 is
used in our test setup) and a 1 µF ceramic capacitor.
Note, that the capacitors do not substitute the
filtering required by the load.
Shutdown Feature Description
The ON/OFF pin in the QTS48T46096 converter
functions as a normal soft shutdown. It is referenced
to the –Vin pin (see Figure 2). With the positive
logic, when the ON/OFF pin is pulled low, the output
is turned off and the unit goes into a very low input
power mode.
With negative logic, when the ON/OFF pin is pulled
low, the unit is turned on.
An open collector switch is recommended to control
the voltage between the ON/OFF pin and the -Vin
pin of the converter. The ON/OFF pin is pulled up
internally, so no external voltage source is required.
The user should avoid connecting a resistor between
the ON/OFF pin and the +Vin pin.
When the ON/OFF pin is used to achieve remote
control, the user must take care to insure that the pin
reference for the control is really the -Vin pin. The
control signal must not be referenced ahead of EMI
filtering, or remotely from the unit. Optically coupling
the information and locating the optical coupler
directly at the module will solve any of these
problems.
Note:
If the ON/OFF pin is not used, it can be left floating (positive logic),
or connected to the -Vin pin (negative logic).
Parallel Operation
The following precautions must be observed when
operating two or more QTS48T46096’s in parallel:
1. The inputs of all units must be attached to
the same voltage source
2. The PCB trace resistance into each unit
should be equalized as much as is practical.
3. The enable pins must be tied together and
operated as a single unit.
4. The undervoltage lockout start-up point will
vary from unit to unit, therefore the dv/dt of
the input source as it rises from 0V to its final
value will affect the ability of the parallel
units to turn on into a load equal to more that
the maximum rated load of 1 unit. The dv/dt
of the rising edge of the input voltage must
be greater than 2V/msec. If three units are
to be operated in parallel, it is strongly
recommended that the maximum load
current be limited to the maximum current
rating of a single unit until the output voltage
exceeds 90% of the rated output voltage.
5. The accuracy of the current sharing will be
affected by the series impedance between
each unit at the load. Balancing these
impedances will enhance the current share
accuracy.
ZD-02076 Rev 2.1 Page 4 of 7 www.power-one.com
QTS48T46096 DC-DC Converter Data Sheet
441-Watt
@
48Vin Quarter-Brick Bus Converter
6. Figure 3 shows the recommended airflow
direction, unit orientation and temperature
variation of three paralleled units with 10%
current share accuracy. Please note that the
maximum power available will be reduced by
up to 10% due to current share accuracy.
(At 48 volts in, the maximum power available
would be 350 W X 3unit X 90% derating =
945 W)
The QTS48T46096 converter is designed for natural
or forced convection cooling. The maximum
allowable output current of the converter is
determined by meeting the derating criteria for all
components used in the converter. For example,
the maximum semiconductor junction temperature is
not allowed to exceed 125 °C to ensure reliable long-
term operation of the converter. Contact Power-One
for the complete list of the derating criteria.
Figure 3. Three units in parallel with 50 V input voltage,
900 W output power, 70 °C ambient, and 200 LFM airflow.
Safety Considerations
The QTS48T46096 converter features 1500 Volt DC
isolation from input to output. The input-to-output
resistance is greater than 10 MΩ. This converter is
provided with functional insulation between input and
output circuits according to all IEC60950 based
standards. Nevertheless, if the system using the
converter needs to receive safety agency approval,
certain rules must be followed in the design of the
system. In particular, all of the creepage and
clearance requirements of the end-use safety
requirements must be observed. These documents
include UL60950 - CSA60950-00 and EN60950,
although other or additional requirements may be
needed for specific applications.
The QTS48T46096 converter has no internal fuse.
The external fuse must be provided to protect the
system from catastrophic failure. The fuse with a
rating not greater than 10 A is recommended. The
user can select a lower rating fuse based upon the
highest inrush transient at the maximum input
voltage and the maximum input current of the
converter, which occurs at the minimum input
voltage. Both input traces and the chassis ground
trace (if applicable) must be capable of conducting a
current of 1.5 times the value of the fuse without
opening. The fuse must not be placed in the
grounded input line, if any.
In order for the output of the QTS48T46096
converter to be considered as SELV (Safety Extra
Low Voltage) or TNV-1, according to all IEC60950
based standards, one of the following requirements
must be met in the system design:
• If the voltage source feeding the module is SELV
or TNV, the output of the converter may be
grounded or ungrounded.
• If the voltage source feeding the module is ELV,
the output of the converter may be considered
SELV only if the output is grounded per the
requirements of the standard.
• This information is provided for guidance only
and the user is responsible for any design
considerations regarding safety.
Thermal Considerations
AIRFLOW DIRECTION
The graph in Figure 4 and Figure 5 show the
maximum output current of the QTS48T46096
converter at different ambient temperatures under
both natural and forced (transverse airflow direction,
from pin 1 to pin 3) convection.
For example, the QTS48T46096 operating at 48Vin,
70 °C can deliver up to 33.6A reliably with 200 LFM
forced air.
ZD-02076 Rev 2.1 Page 5 of 7 www.power-one.com
QTS48T46096 DC-DC Converter Data Sheet
441-Watt
@
48Vin Quarter-Brick Bus Converter
0
5
10
15
20
25
30
35
40
45
50
20 30 40 50 60 70 80 90
Ambient Temperature (C)
Output Current (A)
400 LFM
300 LFM
200 LFM
100 LFM
50 LFM
Figure 4. Thermal Derating Curve Vin = 36V, Varying Airflow (Input Voltage Constant)
0
5
10
15
20
25
30
35
40
45
50
20 30 40 50 60 70 80 90
Ambient Temperature (C)
Output Current (A)
400 LFM
300 LFM
200 LFM
100 LFM
50 LFM
Figure 5. Thermal Derating Curve Vin = 48V, Varying Airflow (Input Voltage Constant)
ZD-02076 Rev 2.1 Page 6 of 7 www.power-one.com
QTS48T46096 DC-DC Converter Data Sheet
441-Watt
@
48Vin Quarter-Brick Bus Converter
Mechanical Drawing
Ordering Information
Options Suffixes to add to part number
Remote ON/OFF Positive- Standard, -P suffix
Negative-Standard, -N suffix
0.180”- Standard, add “CA” suffix
0.145”- Add “CB” suffix
Pin Length
0.110”- Add “CC” suffix
Paralleling Option Paralleling add “P” suffix (standard)
RoHS Add to Part Number
RoHS lead solder
exempt 1No RoHS character required.
RoHS compliant for
all six substances
Add "G" as the last character of the part number.
1 The solder exemption refers to all the restricted materials except lead in solder.
2 Example: QTS with negative logic, 0.180 Pin and Paralleling the resulting part number is QTS48T46096-NCAP
Notes:
1. NUCLEAR AND MEDICAL APPLICATIONS - Power-One products are not designed, intended for use in, or authorized for use as critical
components in life support systems, equipment used in hazardous environments, or nuclear control systems without the express written
consent of the respective divisional president of Power-One, Inc.
2. TECHNICAL REVISIONS - The appearance of products, including safety agency certifications pictured on labels, may change depending on
the date manufactured. Specifications are subject to change without notice.
ZD-02076 Rev 2.1 Page 7 of 7 www.power-one.com
