Data Sheet
March 17, 2006
QBK025A0B Series DC-DC Converter Power Modules:
36- 55Vdc Input, 12Vdc Output and 25A Output Current
* UL is a registered trademark of Underwriters Laboratories, Inc.
† CSA is a registered trademark of Canadian Standards Association.
‡ VDE is a trademark of Verband Deutscher Elektrotechniker e.V.
** ISO is a registered trademark of the International Organization of Standards
Document No: DS03-096 ver. 1.4
PDF name: qbus_qbk025a0b_ds.pdf
Applications
Distributed power architectures
Servers and storage applications
Optical and Access Network Equipment
Enterprise Networks
Options
Negative logic, Remote On/Off
Active load sharing (Parallel Operation)
Baseplate option (-H)
Auto restart after fault shutdown
Case ground pin
Features
Compliant to RoHS EU Directive 2002/95/EC (-Z
versions)
Compliant to ROHS EU Directive 2002/95/EC with
lead solder exemption (non-Z versions)
Delivers up to 25A Output current
High efficiency – 94% at 12V full load
Industry standard Quarter brick footprint
57.9mm x 36.8mm x 10.6mm
(2.28in x 1.45in x 0.42in)
Low output ripple and noise
Cost efficient open frame design
Intermediate input voltage range
Output overcurrent/voltage protection
Over-temperature protection
Single optimal regulated output
Wide operating temperature range (-400C to 850C)
Positive logic, Remote On/Off
CE mark meets 73/23/EEC and 93/68/EEC
directives§
UL* 60950-1Recognized, CSA† C22.2 No. 60950-1-
03 Certified, and VDE‡ 0805:2001-12 (EN60950-1)
Licensed
ISO** 9001 and ISO 14001 certified manufacturing
facilities
Description
The QBK025A0B series of DC-DC converters are an expansion of a new generation of DC/DC power modules
designed to support 12Vdc intermediate bus applications where multiple low voltages are subsequently generated
using discrete/modular point of load (POL) converters. The QBK025A0B series provide up to 25A output current in
an industry standard quarter brick, which makes it an ideal choice for small space, high current and 12V
intermediate bus voltage applications. The converter incorporates synchronous rectification technology and
innovative packaging techniques to achieve efficiency reaching 94% at 12V full load. This leads to lower power
dissipations such that for many applications a heat sink is not required. The output is fully isolated from the input,
allowing versatile polarity configurations and grounding connections. Built-in filtering for both input and output
minimizes the need for external filtering.
RoHS Compliant
Data Sheet
March 17, 2006
QBK025A0B DC-DC Power Modules:
36-55Vdc Input; 12Vdc Output Voltage; 25A Output Current
Tyco Electronics Power Systems 2
Absolute Maximum Ratings
Stresses in excess of the absolute maximum ratings can cause permanent damage to the device. These are
absolute stress ratings only, functional operation of the device is not implied at these or any other conditions in
excess of those given in the operations sections of the data sheet. Exposure to absolute maximum ratings for
extended periods can adversely affect the device reliability.
Parameter Device Symbol Min Max Unit
Input Voltage*
Continuous VIN -0.3 55 Vdc
Non- operating continuous VIN -0.3 75 Vdc
Operating Ambient Temperature All TA -40 85 °C
(See Thermal Considerations section)
Storage Temperature All Tstg -55 125 °C
I/O Isolation Voltage All 1500 Vdc
* Input over voltage protection will shutdown the output voltage when the input voltage exceeds threshold level.
Electrical Specifications
Unless otherwise indicated, specifications apply over all operating input voltage, resistive load, and temperature
conditions.
Parameter Device Symbol Min Typ Max Unit
Operating Input Voltage VIN 36 48 55 Vdc
Maximum Input Current IIN,max - - 9.5 Adc
(VIN=0V to 55V, IO=IO, max)
Inrush Transient All I2t - - 1 A2s
Input Reflected Ripple Current, peak-to-peak
(5Hz to 20MHz, 12µH source impedance; VIN=
48V, IO= IOmax ; see Figure 9)
All - 24 - mAp-p
Input Ripple Rejection (120Hz) All - -50 - dB
CAUTION: This power module is not internally fused. An input line fuse must always be used.
This power module can be used in a wide variety of applications, ranging from simple standalone operation to an
integrated part of a sophisticated power architecture. To preserve maximum flexibility, internal fusing is not included,
however, to achieve maximum safety and system protection, always use an input line fuse. The safety agencies
require a fast-acting fuse with a maximum rating of 15A (see Safety Considerations section). Based on the
information provided in this data sheet on inrush energy and maximum dc input current, the same type of fuse with a
lower rating can be used. Refer to the fuse manufacturer’s data sheet for further information.
Data Sheet
March 17, 2006
QBK025A0B DC-DC Power Modules:
36-55Vdc Input; 12Vdc Output Voltage; 25A Output Current
Tyco Electronics Power Systems 3
Electrical Specifications (continued)
Parameter Device Symbol Min Typ Max Unit
Output Voltage Set-point 12 VO, set 12 Vdc
(VIN=VIN,nom, IO=15A, Ta =25°C)
Output Voltage VO 11.4 12.6 Vdc
(Over all operating input voltage, resistive
load, and temperature conditions until end of
life)
Output Regulation
Line (VIN = VIN, min to VIN, max) All
0.2 %Vo
Load (IO = IO, min to IO, max) All
3 %Vo
Temperature (Tref =TA, min to TA, max) All
150 mV
Output Ripple and Noise on nominal output
(VIN =VIN, nom and IO = IO, min to IO, max,
RMS (5Hz to 20MHz bandwidth) All 70 mVrms
Peak-to-Peak (5Hz to 20MHz bandwidth) All 200 mVpk-pk
External Capacitance All CO, max 10,000 µF
Output Current 12V Io 0 25 Adc
Output Current Limit Inception (Hiccup Mode)
(Vo = 90% Vo, set ) 12V IO, lim 28.5 Adc
Efficiency 12V η __
94
%
VIN= 48V, TA=25°C, IO= IO, max A
Switching Frequency fsw 300 KHz
Dynamic Load Response
(dIO/dt=0.1A/µs; VIN=VIN, nom; TA=25°C)
Load change from IO = 50% to 75% of IO, max
Peak Deviation 12V Vpk 2 % VO
Settling Time (VO<10% peak deviation) ts 200 µs
Load change from IO = 50% to 25% of IO, max,
Peak Deviation 12V Vpk 2 % VO
Settling Time (VO<10% peak deviation) ts 200 µs
Isolation Specifications
Parameter Symbol Min Typ Max Unit
Isolation Capacitance Ciso 2000 pF
Isolation Resistance Riso 10 MΩ
General Specifications
Parameter Min Typ Max Unit
Calculated MTBF (IO=80% of IO, max, TA=25°C,
airflow=1m/s(200LFM)) 2,600,000 Hours
Weight 44 (1.55) g (oz.)
Data Sheet
March 17, 2006
QBK025A0B DC-DC Power Modules:
36-55Vdc Input; 12Vdc Output Voltage; 25A Output Current
Tyco Electronics Power Systems 4
Feature Specifications
Unless otherwise indicated, specifications apply over all operating input voltage, resistive load, and temperature
conditions. See Feature Descriptions for additional information.
Parameter Device Symbol Min Typ Max Unit
On/Off Signal interface
(VI = VI,min to VI, max; Open collector or equivalent
Compatible, signal referenced to VIN (-) terminal
Negative Logic: device code suffix “1”
Logic Low = module On, Logic High = module Off
Positive Logic: No device code suffix required
Logic Low = module Off, Logic High = module On
Logic Low Specification
Remote On/Off Current – Logic Low All Ion/off 1.2 mA
On/Off Voltage:
Logic Low All Von/off 0.0 1.2 V
Logic High – (Typ = Open Collector) All Von/off __ 5 V
Logic High maximum allowable leakage current All Ion/off 50 µA
Turn-On Delay and Rise Times
(IO= IO, max , VIN=VIN, nom, TA = 25 oC)
Case 1: Time until VO = 10% of VO,set from either
application of Vin with Remote On/Off set to On or
operation of Remote On/Off from Off to On with Vin
alread
y
a
pp
lied for at least one second.
12 Tdelay
Enable with Vin ― 16 ― msec
Case 2: time for V
O to rise from 10% of VO,set to
90% of VO,set.
Tdelay
Enable with on/off ― 1 ― msec
Output voltage Rise time (time for Vo to rise from
10% of Vo, set to 90% of Vo, set)
Trise ― 1 ― msec
Over temperature Protection All Tref 125 °C
(See Thermal Considerations section)
Input Undervoltage Lockout VUVLO
Turn-on Threshold 35 36 V
Turn-off Threshold 32 34
V
Over voltage protection 12V 13 15 V
Data Sheet
March 17, 2006
QBK025A0B DC-DC Power Modules:
36-55Vdc Input; 12Vdc Output Voltage; 25A Output Current
Tyco Electronics Power Systems 5
Characteristic Curves
The following figures provide typical characteristics for QBK025A0B (12V, 25A) at 25ºC. The figures are identical
for either positive or negative Remote On/Off logic.
0
1
2
3
4
5
6
7
8
9
10
30 35 40 45 50 55
Io=25A
Io=12.5A
Io=0A
INPUT CURRENT, I
i
(A)
INPUT VOLTAGE, VO (V)
On/Off VOLTAGE OUTPUT VOLTAGE
V
ON/OFF
(V) (2V/div) V
O
(V) (5V/div)
TIME, t (500 µs/div)
Figure 1. Typical Input Characteristic at Room
Temperature.
Figure 4. Typical Start-Up Using Remote On/Off,
negative logic version shown.
70
75
80
85
90
95
100
0 5 10 15 20 25
Vin=36V
Vin=48V
Vin=55V
EFFCIENCY, η (%)
OUTPUT CURRENT, IO (A)
OUTPUT CURRENT, OUTPUT VOLTAGE
I
O
(A) (5A/div) V
O
(V) (500mV/div)
TIME, t (200 µs/div)
Figure 2. Typical Converter Efficiency Vs. Output
current at Room Temperature.
Figure 5. Typical Transient Response to Step
change in Load from 25% to 50% to 25% of Full
Load at Room Temperature and 48 Vdc Input.
OUTPUT VOLTAGE,
V
O
(V) (100mV/div)
TIME, t (1µs/div)
OUTPUT CURRENT, OUTPUT VOLTAGE
I
O
(A) (5A/div) V
O
(V) (500mV/div)
TIME, t (200 µs/div)
Figure 3. Typical Output Ripple and Noise at Room
Temperature and Io = Io,max .
Figure 6. Typical Transient Response to Step
Change in Load from 50% to 75% to 50% of Full
Load at Room Temperature and 48 Vdc Input.
55 Vin
48 Vin
36 Vin
Data Sheet
March 17, 2006
QBK025A0B DC-DC Power Modules:
36-55Vdc Input; 12Vdc Output Voltage; 25A Output Current
Tyco Electronics Power Systems 6
Characteristic Curves (continued)
11.7
11.8
11.9
12
12.1
12.2
12.3
36 41 46 51 56
Io=25A
Io=12.5A
Io=0A
OUTPUT VOLTAGE, V
O
(V)
INPUT VOLTAGE, Vin (V)
Figure 7. Typical Output voltage regulation vs. Input
voltage at Room Temperature.
OUTPUT VOLTAGE, V
O
(V)
OUTPUT CURRENT, IO (A)
Figure 8. Typical Output voltage regulation Vs. Output
current at Room Temperature.
11.7
11.8
11.9
12
12.1
12.2
0 5 10 15 20 25
Vin=36V
Vin=48V
Vin=55V
Data Sheet
March 17, 2006
QBK025A0B DC-DC Power Modules:
36-55Vdc Input; 12Vdc Output Voltage; 25A Output Current
Tyco Electronics Power Systems 7
Test Configurations
Note: Measure input reflected-ripple current with a
simulated source inductance (LTEST) of 12 µH. Capacitor
CS offsets possible battery impedance. Measure current
as shown above.
Figure 9. Input Reflected Ripple Current Test
Setup.
Note: Use a 1.0 µF ceramic capacitor and a 10 µF
aluminum or tantalum capacitor. Scope measurement
should be made using a BNC socket. Position the load
between 51 mm and 76 mm (2 in. and 3 in.) from the
module.
Figure 10. Output Ripple and Noise Test Setup.
LOAD
CONTACT AND
SUPPLY
I
I
CONTACT
V
I
(+)
V
I
(–)
V
O1
DISTRIBUTION LOSSES
RESISTANCE
I
O
V
O2
Note: All measurements are taken at the module terminals.
When socketing, place Kelvin connections at module
terminals to avoid measurement errors due to socket
contact resistance.
Figure 11. Output Voltage and Efficiency Test
Setup.
Design Considerations
Input Source Impedance
The power module should be connected to a low
ac-impedance source. A highly inductive source
impedance can affect the stability of the power
module. For the test configuration in Figure 9, a
100µF electrolytic capacitor (ESR<0.7Ω at 100kHz),
mounted close to the power module helps ensure
the stability of the unit. Consult the factory for further
application guidelines.
Safety Considerations
For safety-agency approval of the system in which
the power module is used, the power module must
be installed in compliance with the spacing and
separation requirements of the end-use safety
agency standard, i.e., UL 1950, CSA C22.2 No.
60950-00, and VDE 0805:2001-12 (IEC60950 3rd
Ed).
If the input source is non-SELV (ELV or a hazardous
voltage greater than 60 Vdc and less than or equal
to 75Vdc), for the module’s output to be considered
as meeting the requirements for safety extra-low
voltage (SELV), all of the following must be true:
The input source is to be provided with
reinforced insulation from any other hazardous
voltages, including the ac mains.
One VIN pin and one VOUT pin are to be
grounded, or both the input and output pins are
to be kept floating.
The input pins of the module are not operator
accessible.
Another SELV reliability test is conducted on
the whole system (combination of supply
source and subject module), as required by the
safety agencies, to verify that under a single
fault, hazardous voltages do not appear at the
module’s output.
Note: Do not ground either of the input pins of the
module without grounding one of the output
pins. This may allow a non-SELV voltage to
appear between the output pins and ground.
The power module has extra-low voltage (ELV)
outputs when all inputs are ELV.
The input to these units is to be provided with a
maximum 15 A fast-acting (or time-delay) fuse in the
unearthed lead.
Data Sheet
March 17, 2006
QBK025A0B DC-DC Power Modules:
36-55Vdc Input; 12Vdc Output Voltage; 25A Output Current
Tyco Electronics Power Systems 8
Feature Description
Remote On/Off
Two remote on/off options are available. Positive
logic remote on/off turns the module on during a
logic-high voltage on the ON/OFF pin, and off during
a logic low. Negative logic remote on/off turns the
module off during a logic high and on during a logic
low. Negative logic, device code suffix "1," is the
factory-preferred configuration. To turn the power
module on and off, the user must supply a switch to
control the voltage between the on/off terminal and
the VI (-) terminal (Von/off). The switch can be an
open collector or equivalent (see Figure 12). A logic
low is Von/off = 0 V to I.2 V. The maximum Ion/off
during a logic low is 1 mA. The switch should
maintain a logic-low voltage while sinking 1 mA.
During a logic high, the maximum Von/off generated
by the power module is 15 V. The maximum
allowable leakage current of the switch at Von/off =
15V is 50 µA. If not using the remote on/off feature,
perform one of the following to turn the unit on:
For negative logic, short ON/OFF pin to VI(-).
For positive logic: leave ON/OFF pin open.
V
O
(+)
V
O
(–)
V
I
(–)
+
–
I
on/off
ON/OFF
V
I
(+)
LOA
D
V
on/off
Figure 10. Circuit configuration for using
Remote On/Off Implementation.
Overcurrent Protection
To provide protection in a fault output overload
condition, the module is equipped with internal
current-limiting circuitry and can endure current
limiting for a few mili-seconds. If the overcurrent
condition persists beyond a few milliseconds, the
module will shut down and remain latched off. The
overcurrent latch is reset by either cycling the input
power or by toggling the on/off pin for one second. If
the output overload condition still exists when the
module restarts, it will shut down again. This
operation will continue indefinitely until the
overcurrent condition is corrected.
An auto-restart option is also available. An auto-
restart feature continually attempts to restore the
operation until fault condition is cleared.
Input Undervoltage Lockout
At input voltages above or below the input
under/over voltage lockout limits, module operation
is disabled. The module will begin to operate when
the input voltage level changes to within the under
and overvoltage lockout limits.
Overtemperature Protection
These modules feature an overtemperature
protection circuit to safeguard against thermal
damage. The circuit shuts down and latches off the
module when the maximum device reference
temperature is exceeded. The module can be
restarted by cycling the dc input power for at least
one second or by toggling the remote on/off signal
for at least one second.
Output Over Voltage Clamp
The output overvoltage clamp consists of a control
circuit, independent of the primary regulation loop,
that monitors the voltage on the output terminals
and clamps the voltage when it exceeds the
overvoltage set point. The control loop of the clamp
has a higher voltage set point than the primary loop.
This provides a redundant voltage control that
reduces the risk of output overvoltage.
Data Sheet
March 17, 2006
QBK025A0B DC-DC Power Modules:
36-55Vdc Input; 12Vdc Output Voltage; 25A Output Current
Tyco Electronics Power Systems 9
Thermal Considerations
The power modules operate in a variety of thermal
environments and sufficient cooling should be
provided to help ensure reliable operation.
Thermal considerations include ambient
temperature, airflow, module power dissipation, and
the need for increased reliability. A reduction in the
operating temperature of the module will result in an
increase in reliability. The thermal data presented
here is based on physical measurements taken in a
wind tunnel.
Heat-dissipating components are mounted on the
top side of the module. Heat is removed by
conduction, convection and radiation to the
surrounding environment. Proper cooling can be
verified by measuring the thermal reference
temperature (TH). Peak temperature (TH) occurs at
the position indicated in Figure 13. For reliable
operation this temperature should not exceed the
listed temperature threshold.
Figure 13. Location of the thermal reference
temperature TH.
The output power of the module should not exceed
the rated power for the module as listed in the
Ordering Information table.
Although the maximum TH temperature of the power
modules is 110 °C - 115 °C, you can limit this
temperature to a lower value for extremely high
reliability.
Heat Transfer via Convection
Increased airflow over the module enhances the
heat transfer via convection. The thermal derating
figures (14-16) show the maximum output current
that can be delivered by each module in the
respective orientation without exceeding the
maximum TH temperature versus local ambient
temperature (TA) for air flows of 1 m/s (200 ft./min)
and 2m/s (400 ft./min).
Note that the natural convection condition was
measured at 0.05 m/s to 0.1 m/s (10ft./min. to 20
ft./min.); however, systems in which these power
modules may be used typically generate natural
convection airflow rates of 0.3 m/s (60 ft./min.) due
to other heat dissipating components in the system.
The use of Figures 14 - 15 are shown in the
following example:
Example
What is the minimum airflow necessary for a
QBK025A0B operating at VI = 48 V, an output
current of 12A, and a maximum ambient
temperature of 70 °C in transverse orientation.
Solution:
Given: VI = 48V, Io = 12A, TA = 70 °C
Determine required airflow (V) (Use Figure 14):
V = T1 m/sec. ( 200 ft./min.) or greater.
0
5
10
15
20
25
30
0 20406080100
Natural Convection
1m/s
(
200LFM
)
2m/s
(
400LFM
)
3m/s
(
600LFM
)
OUTPUT CURRENT, IO (A)
LOCAL AMBIENT TEMPERATURE, TA (°C)
Figure 14. Output Current Derating for the
QBK025A0B in the Transverse Orientation with no
baseplate; Airflow Direction from Vin(+) to Vin(-); Vin
= 48V.
Data Sheet
March 17, 2006
QBK025A0B DC-DC Power Modules:
36-55Vdc Input; 12Vdc Output Voltage; 25A Output Current
Tyco Electronics Power Systems 10
Thermal Derating Curves
0
5
10
15
20
25
30
0 20406080100
Natural Convection
1m/s
(
200LFM
)
2m/s
(
400LFM
)
3m/s
(
600LFM
)
OUTPUT CURRENT, IO (A)
LOCAL AMBIENT TEMPERATURE, TA (°C)
Figure 15. Output Current Derating for the
QBK025A0B (Vo = 12V) in the Transverse Orientation
with baseplate.
0
5
10
15
20
25
30
0 20406080100
1m/s
(
200LFM
)
2m/s
(
400LFM
)
3m/s
(
600LFM
)
OUTPUT CURRENT, IO (A)
LOCAL AMBIENT TEMPERATURE, TA (°C)
Figure 16. Output Current Derating for the
QBK025A0B (Vo = 12V) in the Transverse Orientation
with baseplate and 0.25-inch high heatsink.
0
5
10
15
20
25
30
0 20406080100
1m/s
(
200LFM
)
2m/s
(
400LFM
)
3m/s
(
600LFM
)
OUTPUT CURRENT, IO (A)
LOCAL AMBIENT TEMPERATURE, TA (°C)
Figure 17. Output Current Derating for the
QBK025A0B (Vo = 12V) in the Transverse Orientation
with baseplate and 0.5-inch high heatsink.
Data Sheet
March 17, 2006
QBK025A0B DC-DC Power Modules:
36-55Vdc Input; 12Vdc Output Voltage; 25A Output Current
Tyco Electronics Power Systems 11
Layout Considerations
The QBK025 power module series are low profile in
order to be used in fine pitch system card
architectures. As such, component clearance
between the bottom of the power module and the
mounting board is limited. Avoid placing copper areas
on the outer layer directly underneath the power
module. Also avoid placing via interconnects
underneath the power module.
For additional layout guide-lines, refer to
FLTR100V10 data sheet.
Post Solder Cleaning and Drying
Considerations
Post solder cleaning is usually the final circuit-board
assembly process prior to electrical board testing. The
result of inadequate cleaning and drying can affect
both the reliability of a power module and the
testability of the finished circuit-board assembly. For
guidance on appropriate soldering, cleaning and
drying procedures, refer to Tyco Electronics Board
Mounted Power Modules: Soldering and Cleaning
Application Note (AP01-056EPS).
Through-Hole Lead-Free Soldering
Information
The RoHS-compliant through-hole products use the
SAC (Sn/Ag/Cu) Pb-free solder and RoHS-compliant
components. They are designed to be processed
through single or dual wave soldering machines. The
pins have an RoHS-compliant finish that is compatible
with both Pb and Pb-free wave soldering processes.
A maximum preheat rate of 3°C/s is suggested. The
wave preheat process should be such that the
temperature of the power module board is kept below
210°C. For Pb solder, the recommended pot
temperature is 260°C, while the Pb-free solder pot is
270°C max. Not all RoHS-compliant through-hole
products can be processed with paste-through-hole
Pb or Pb-free reflow process. If additional information
is needed, please consult with your Tyco Electronics
Power System representative for more details.
Data Sheet
March 17, 2006
QBK025A0B DC-DC Power Modules:
36-55Vdc Input; 12Vdc Output Voltage; 25A Output Current
Tyco Electronics Power Systems 12
Mechanical Outline
Dimensions are in inches and (millimeters).
Tolerances: x.xx in. ± 0.02 in. (x.x mm ± 0.5 mm) [unless otherwise indicated]
x.xxx in ± 0.010 in. (x.xx mm ± 0.25 mm)
TOP
VIEW
SIDE
VIEW
BOTTOM
VIEW
36.8
(1.45)
57.9
(2.28)
4.6
(.18) MIN
1.57 (.062) DIA SOLDER PLATED
PIN SHOULDER, 5 PLCS
1.02 (.040) DIA SOLDER PLATED
PIN, 5 PLCS
0.25
(.010)MIN 2.36 (.093) DIA SOLDER-PLATED
PIN SHOULDER, 2 PLCS
1.57 (.062) DIA SOLDER-PLATED
PIN, 2 PLCS
3.6
(.14)
7.62
(.300) 3.81
(.150)
11.43
(.450)
15.24
(.600)
VI(-)
VI(+)
ON/OFF
50.8
(2.000)
10.8
(.43)
15.24
(.600)
VO(-)
VO(+)
CASE
PARALLEL
10.5
(.41)
*Top side label includes Tyco name, product designation, and data code.
†Option Feature, Pin is not present unless one these options specified.
Data Sheet
March 17, 2006
QBK025A0B DC-DC Power Modules:
36-55Vdc Input; 12Vdc Output Voltage; 25A Output Current
Tyco Electronics Power Systems 13
Mechanical Outline for module with base plate.
Dimensions are in millimeters and (inches).
Tolerances: x.x mm ± 0.5 mm ( x.xx in. ± 0.02 in.) [unless otherwise indicated]
x.xx mm ± 0.25 mm ( x.xxx in ± 0.010 in.)
TOP
VIEW
SIDE
VIEW
BOTTOM
VIEW
*Bottom side label includes Tyco name, product designation, and data code.
†Option Feature, Pin is not present unless one these options specified.
Data Sheet
March 17, 2006
QBK025A0B DC-DC Power Modules:
36-55Vdc Input; 12Vdc Output Voltage; 25A Output Current
Tyco Electronics Power Systems 14
Recommended Pad Layout
Dimensions are in inches and (millimeters).
Tolerances: x.xx in. ± 0.02 in. (x.x mm ± 0.5 mm) [unless otherwise indicated]
x.xxx in ± 0.010 in. (x.xx mm ± 0.25 mm)
50.80
(2.000)
Vo (+)
Vo (-)
15.24
(.600)
V
I
(+)
V
I
(-)
†
†
ON/OFF
3.6
(.14)
10.8
(.43)
57.9
(2.28)
36.8
(1.45)
1.02 (.040) DIA PIN, 5 PLCS
1.57 (.062) DIA PIN, 2 PLCS
CASE
Data Sheet
March 17, 2006
QBK025A0B DC-DC Power Modules:
36-55Vdc Input; 12Vdc Output Voltage; 25A Output Current
World Wide Headquarters
Tyco Electronics Power Systems, Inc.
3000 Skyline Drive, Mesquite, TX 75149, USA
+1-800-843-7497
(Outside U.S.A.: +1-972-284-2626)
www.power.tycoelectronics.com
e-mail: techsupport1@tycoelectronics.com
Europe, Middle-East and Africa Headquarters
Tyco Electronics (UK) Ltd
Tel: +44 (0) 1344 469 300
Latin America, Brazil, Caribbean Headquarters
Tyco Electronics Power Systems
Tel: +56 2 209 8211
India Headquarters
Tyco Electronics Systems India Pte. Ltd.
Tel: +91 80 841 1633 x3001
Asia-Pacific Headquarters
Tyco Electronics Singapore Pte. Ltd.
Tel: +65 6416 4283
Tyco Electronics Corporation reserves the right to make changes to the product(s) or information contained herein without notice. No liability is assumed as a result of their
use or application. No rights under any patent accompany the sale of any such product(s) or information.
© 2003 Tyco Electronics Power Systems, Inc., (Mesquite, Texas) All International Rights Reserved.
Document No: DS03-096 ver. 1.4
PDF name: qbus_qbk025a0b_ds.pdf
Ordering Information
Please contact your Tyco Electronics’ Sales Representative for pricing, availability and optional features.
Table 1. Device Codes
Input Voltage Output
Voltage
Output
Current
Efficiency Connector
Type Product codes Comcode
48V (36-55Vdc) 12V 25A 94% Through hole QBK025A0B1 108998663
48V (36-55Vdc) 12V 25A 94% Through hole QBK025A0B1Z CC109107884
Table 2. Device Options
Option Suffix
Negative remote on/off logic 1
Auto-restart 4
Pin Length: 3.68 mm ± 0.25 mm (0.145 in. ± 0.010 in) 6
Case ground pin (offered with aseplate option only) 7
Basic Isolation -B
Base Plate option -H
Active load sharing (Parallel Operation) -P
RoHS Compliant -Z
