GE Industrial Solutions QBDW025A0B User Manual

GE

Data Sheet

QBDW025A0B Barracuda* Series; DC-DC Converter Power Modules

36-75Vdc Input; 12.0Vdc, 25.0A, 300W Output

RoHS Compliant

Features

 Compliant to RoHS II EU “Directive 2011/65/EU (-Z versions)
 Compliant to REACH Directive (EC) No 1907/2006

 High and flat efficiency profile >95.5% at 12V

, 40% to

dc

100% rated output

 Wide input voltage range: 36-75V
 Delivers up to 25A

output current

dc

dc

 Remote sense and output voltage trim
 Fully very tightly regulated output voltage

to 13.2Vdc

dc

§

Applications

 Distributed power architectures
 Intermediate bus voltage applications
 Servers and storage applications
 Networking equipment including Power over Ethernet

(PoE)

 Fan assemblies other systems requiring a tightly

regulated output voltage

Options

 Negative Remote On/Off logic (1=option code, factory

preferred)

 Auto-restart after fault shutdown (4=option code, factory

preferred)

 Base plate option (-H=option code)
 Passive Droop Load Sharing (-P=option code)

 Output voltage adjust: 8.1V
 Low output ripple and noise
 Industry standard, DOSA compliant, Quarter brick:

58.4 mm x 36.8 mm x 11.7 mm
(2.30 in x 1.45 in x 0.46 in)

 Constant switching frequency
 Digital interface with PMBus™ Rev 1.2 Compliance^
 Positive remote On/Off logic
 Output over current/voltage protection
 Digital interface with PMBus™ Rev.1.2 compliance
 Over temperature protection
 Wide operating temperature range (-40°C to 85°C)

#

 ANSI/ UL

60950-1-2011 Recognized, CAN/CSA† C22.2
No.60950-1-07, Second Edition + A1:2011 (MOD) Certified
IEC 60950-1:2005 (2nd edition) + A1:2009 and EN 60950­1:2006 + A11:2009 + A1:2010 + A12:2011, and VDE‡ 0805-1
Licensed

 CE mark 2006/96/EC directives
 Meets the voltage and current requirements for ETSI 300-

132-2 and complies with and licensed for Basic insulation
rating per EN60950-1

¤

 2250 Vdc Isolation tested in compliance with IEEE 802.3

PoE

standards

Description

The QBDW025A0B Barracuda series of dc-dc converters are a new generation of DC/DC power modules designed to support 9.6

-12Vdc intermediate bus applications where multiple low voltages are subsequently generated using point of load (POL)
converters, as well as other application requiring a tightly regulated output voltage. The QBDW025A0B series operate from an
input voltage range of 36 to 75Vdc and provide up to 25A output current at output voltages from 8.1V
standard quarter brick. The converter incorporates digital control, synchronous rectification technology, a fully regulated control
topology, and innovative packaging techniques to achieve efficiency approaching 96% peak at 12V
power dissipations such that for many applications a heat sink is not required. Standard features include output voltage trim,
remote sense, on/off control, output overcurrent and over voltage protection, over temperature protection, input under and over
voltage lockout, power good signal and PMBus interface.

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.

* Trademark of General Electric Company
^ PMBus name and logo are registered trademarks of SMIF, Inc.

# UL is a registered trademark of Underwriters Laboratories, Inc.
† CSA is a registered tradem ark of Canadian Standards Association.
‡ VDE is a trademark of Verband Deutscher Elektrotechniker e.V.

§ This product is intended for integration into end-user equipme nt . All of the required procedures of end-use equipm ent should be followed.
¤ IEEE and 802 are registered trademarks of the Instit ute of Electrical and Electronics Engineers, Incorporated.
** ISO is a registered trademark of the International O rganization of Standards.

May 9, 2013 ©2012 General Electric Company. All rights reserved. Page 1

to 12Vdc in a DOSA

dc

output. This leads to lower

dc

GE

Data Sheet

QBDW025A0B Barracuda Series; DC-DC Converter Power Modules

36-75Vdc Input; 12.0Vdc, 25.0A, 300W Output

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 device reliability.

Parameter Device Symbol Min Max Unit

Input Voltage*

Continuous V

IN

Operating transient  100mS 100 Vdc
Non- operating continuous V

Operating Ambient Temperature All T

IN

A

(See Thermal Considerations section)

Logic Pin Voltage (to SIG_GND or VO(-))
TRIM/C1, C2, ADDR0, ADDR1, CLK, DATA, SMBALERT

Storage Temperature All T
I/O Isolation Voltage (100% factory Hi-Pot tested) All

All V

pin

stg

 

* 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 75 Vdc
Maximum Input Current

(VIN=0V to 75V, IO=I
Input No Load Current

(VIN = V

, IO = 0, module enabled)

IN, nom

Input Stand-by Current

(VIN = V

, module disabled)

IN, nom

)

O, max

All I

All I

External Input Capacitance All 100 - - F

Inrush Transient All I2t - - 1 A2s

Input Terminal Ripple Current

(Measured at module input pin with maximum specified input
capacitance and ൏ 500uH inductance between voltage source
and input capacitance)

5Hz to 20MHz, VIN= 48V, IO= I

Omax

All - 350 - mA

Input Reflected Ripple Current, peak-to-peak
(5Hz to 20MHz, 12H source impedance; V

; see Figure 10)

I

Omax

= 48V, IO=

IN

All - 40 - mA

I

IN,max

IN,No load

IN,stand-by

-0.3 75 Vdc

80 100 Vdc

-40 85 °C

-0.3 3.6 Vdc

55 125 °C

2250 Vdc

- - 12 Adc

80 mA

22 mA

rms

p-p

Input Ripple Rejection (120Hz) All - 25 - 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 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 30 A (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.

May 9, 2013 ©2012 General Electric Company. All rights reserved. Page 2

GE



Data Sheet

QBDW025A0B Barracuda Series; DC-DC Converter Power Modules

36-75Vdc Input; 12.0Vdc, 25.0A, 300W Output

Electrical Specifications (continued)

Parameter Device Symbol Min Typ Max Unit

Output Voltage Set-point
(V

IN=VIN,nom

(Adjustable via PMBus)

Output Voltage
(Over all operating input voltage (40V to 75V), resistive
load, and temperature conditions until end of life)

Output Voltage (VIN=36V, TA = 25ºC) All V

Output Regulation [V

Line (VIN= V
Load (IO=I
Load (IO=I
Temperature (TA = -40ºC to +85ºC) All

Output Ripple and Noise on nominal output

(VIN=V

External Output Capacitance

For C

Output Current All I
VOUT_OC_FAULT_LIMIT (Default)

(Adjustable via PMBus)
Efficiency
V

IN=VIN, nom

IO=100% I

IO=40% I

Switching Frequency f

Dynamic Load Response

dIO/dt=1A/10s; Vin=Vin,
(Tested with a 1.0F ceramic, a 10F tantalum, and
470

Load Change from IO = 50% to 75% of I
Peak Deviation
Settling Time (V

Load Change from IO = 75% to 50% of I
Peak Deviation
Settling Time (V

, IO=12.5A, TA =25°C)

All V

All w/o -P

-P Option

= 40V]

IN, min

IN, nom

IN, min

to I

O, min

to I

O, min

and IO=I

to V

) All

IN, max

) All w/o -P

O, max

), Intentional Droop -P Option

O, max

O, min

to I

)

O, max

RMS (5Hz to 20MHz bandwidth) All

Peak-to-Peak (5Hz to 20MHz bandwidth) All

>5000uF, IO must be < 50% I

O

O, max

during T

rise

.

All C

All I

, TA=25°C

O, max, VO

to 100% I

O, max

= V

All  95.9 %

O,set

= V

O, max , VO

; TA=25°C;

nom

All  95.5 %

O,set

F capacitor and across the load.)

:

O,max

All

<10% peak deviation)

O

:

O,max

All

<10% peak deviation)

O

O, set

V

O

V

O

O

11.97 12.00 12.03 V

11.76

11.68

11.15








 

0.2

0.2

12.24 V

12.32 V




% V
% V

0.40 Vdc

O, max

O

O,lim

sw

V

pk

ts

V

pk

ts






0

2

70

200








10,000 F

0 25 Adc



30.25



150 kHz


__

__
__

300
700

300
700


__

__

% V

mV

mV

mV

mV

V

A

s

s

dc

dc

dc

dc

O, set

O, set

O, set

rms

pk-pk

dc

pk

pk

General Specifications

Parameter Device Symbol Typ Unit

Calculated Reliability Based upon Telcordia SR-332 Issue
2: Method I, Case 3, (I

=80%I

O

, TA=40°C, Airflow = 200

O, max

LFM), 90% confidence

All MTBF

All FIT

3,598,391

277.9

Hours

109/Hours
Weight – Open Frame 47.4 (1.67) g (oz.)
Weight – with Base plate option 66.4 (2.34) g (oz.)

May 9, 2013 ©2012 General Electric Company. All rights reserved. Page 3

GE

g

Data Sheet

QBDW025A0B Barracuda Series; DC-DC Converter Power Modules

36-75Vdc Input; 12.0Vdc, 25.0A, 300W Output

Isolation Specifications

Parameter Symbol Min Typ Max Unit

Isolation Capacitance C
Isolation Resistance R

iso

iso


10

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

Remote On/Off Signal Interface

(VIN=V
Negative Logic: device code suffix “1”

Lo
Positive Logic: No device code suffix required
Logic LO = module Off, Logic HI = module On

Logic LO Specification

On/Off Thresholds:

Remote On/Off Current – Logic LO (Vin =100V) All I

Logic LO Voltage All V
Logic HI Voltage – (Typ = Open Collector) All V
Logic HI maximum allowable leakage current

(V
Maximum voltage allowed on On/Off pin All V

TON_DELAY and TON_RISE (Adjustable via PMBus)

T

delay

application of Vin with Remote On/Off set to On (Enable
with Vin); or operation of Remote On/Off from Off to On
with Vin already applied for at least 150 milli-seconds
(Enable with on/off). (I
* Increased T

T

rise

C
* Increased T

modules.
Load Sharing Current Balance
(difference in output current across all modules with
outputs in parallel, no load to full load)

Remote Sense Range All V
VOUT_COMMAND

(Adjustable via PMBus)
VOUT_OV_FAULT_LIMIT (Adjustable via PMBus)

OT_FAULT_LIMIT (Adjustable via PMBus) All T
Input Undervoltage Lockout (Adjustable via PMBus)

VIN_ON

VIN_OFF
Input Overvoltage Lockout

(Adjustable via PMBus)
Turn-off Threshold [VIN_OV_FAULT_LIMIT]

Turn-on Threshold
(follows VIN_OV_FAULT_LIMIT -7V)

Pull down resistance of PGOOD pin
Sink current capability into PGOOD pin (V

May 9, 2013 ©2012 General Electric Company. All rights reserved. Page 4

IN, min

to V

, Signal referenced to V

IN, max

ic LO = module On, Logic HI = module Off

= 2.0V)

on/off

=Time until VO = 10% of V

O=IO, max

due to startup for parallel modules.

delay

from either

O,set

)

=Time for VO to rise from 10% to 90% of V

>5000uF, IO must be < 50% I

O

when Vo exists at startup for parallel

rise

O, max

during T

PG

terminal)

IN-

280

-0.3

2.0

 



 


 

 

 

 

V

O,set-

+2.5V



33 35 36 Vdc
31 33 34 Vdc





rise

=2.2V)

O,set

.

, For

All I

All w/o -P

All w/o-P

T

w/ -P T

w/ -P

All w/o -

P

w/ -P T

-P

Option

All V

All V

All
All

on/off

on/off

on/off

on/off

on/off

Enable with Vin

delay,

Tdelay, Enable with

on/off

Enable with Vin

delay,

T

delay, Enable with

on/off

T

rise

rise

I

diff

Sense

8.1

O, set

O,limit

ref

1000

 











140

85

78



pF

M

310 A

0.8 Vdc

14.5 Vdc

10 A

14.5 V

dc

150 ms

10 ms

180* ms

40* ms

15 ms

300* ms

3 A

0.5 Vdc

13.2 Vdc

V

O,set-

+5.0V







150

15

V

dc

°C

V

dc

V

dc



mA

GE

Data Sheet

QBDW025A0B Barracuda Series; DC-DC Converter Power Modules

36-75Vdc Input; 12.0Vdc, 25.0A, 300W Output

Digital Interface Specifications

Unless otherwise indicated, specifications apply over all operating input voltage, resistive load, and temperature conditions. See
Feature Descriptions for additional information.

Parameter Conditions Symbol Min Typ Max Unit

PMBus Signal Interface Characteristics

Input High Voltage (CLK, DATA) VIH 2.1 3.6 V
Input Low Voltage (CLK, DATA) VIL 0.8 V
Input high level current (CLK, DATA) IIH -10 10 A
Input low level current (CLK, DATA) IIL -10 10 A

Output Low Voltage (CLK, DATA, SMBALERT#) I

Output high level open drain leakage current
(DATA, SMBALERT#)

Pin capacitance CO 0.7 pF

PMBus Operating frequency range
(* 5-10 kHz to accommodate hosts not
supporting clock stretching)

Measurement System Characteristics

Output current reading range
Output current reading blanking I

Output current reading resolution

Output current reading accuracy 16.5A< Iout <25.0A I
Output current reading accuracy (absolute

difference between actual and reported values)
V

reading range V

OUT

V

reading resolution

OUT

V

reading accuracy

OUT

VIN reading range
VIN reading resolution
VIN reading accuracy
Temperature reading resolution
Temperature reading accuracy

=2mA VOL 0.4 V

OUT

=3.6V I

V

OUT

OH

0 10 A

Slave Mode FPMB 5* 400 kHz

1.65A< Iout <16.5A

I

OUT(RNG)

OUT(BNK)

I

OUT(RES)

OUT(ACC)

I

OUT(ACC)

OUT(RNG)

V

OUT(RES)

V

OUT(ACC)

V

IN(RNG)

V

IN(RES)

V

IN(ACC)

T

(RES)

T

(ACC)

1.6500 63.9375 A
0 1.5875 A

62.5 mA

-5.0 -1.4 3.0 %

-1.7 2.5 A

0 15.9997 V

0.244 mV

-2.0 0.6 2.0 %

0 127.875 V

125 mV

-4.0 0.8 4.0 %

0.25

-5.0 5.0 %

May 9, 2013 ©2012 General Electric Company. All rights reserved. Page 5

GE

Data Sheet

QBDW025A0B Barracuda Series; DC-DC Converter Power Modules

36-75Vdc Input; 12.0Vdc, 25.0A, 300W Output

Characteristic Curves

The following figures provide typical characteristics for the QBDW025A0B (12V, 25A) at 25ºC. The figures are identical for either
positive or negative Remote On/Off logic.

(A)

i

INPUT CURRENT, I

INPUT VOLTAGE, VO (V) OUTPUT CURRENT, IO (A)

EFFCIENCY,  (%)

Figure 1. Typical Input Characteristic. Figure 2. Typical Converter Efficiency vs. Output

Current.

(V) (200mV/div)

O

(V) (50mV/div)

O

V

OUTPUT VOLTAGE,

(A) (10A/div) V

TIME, t (2s/div)

Figure 3. Typical Output Ripple and Noise, Io = I

o,max

O

OUTPUT CURRENT OUTPUT VOLTAGE

I

.

Figure 4. Typical Transient Response to 0.1A/µs Step

TIME, t (500 s/div)

Change in Load from 50% to 75% to 50% of Full Load,
Co=470µF and 48 Vdc Input.

(V) (20V/div)

IN

(V) (5V/div) V

O

V

OUTPUT VOLTAGE INPUT VOLTAGE

TIME, t (20 ms/div) TIME, t (5 ms/div)

Figure 5. Typical Start-Up Using Vin with Remote On/Off
enabled, negative logic version shown.

May 9, 2013 ©2012 General Electric Company. All rights reserved. Page 6

(V)(2V/div)

ON/OFF

(V) (5V/div) V

O

V

OUTPUT VOLTAGE On/Off VOLTAGE

Figure 6. Typical Start-Up Using Remote On/Off with Vin
applied, negative logic version shown.

GE

Data Sheet

QBDW025A0B Barracuda Series; DC-DC Converter Power Modules

36-75Vdc Input; 12.0Vdc, 25.0A, 300W Output

Characteristic Curves (continued)

(V)

O

OUTPUT VOLTAGE, V

INPUT VOLTAGE, Vin (V) OUTPUT CURRENT, IO (A)

Figure 7. Typical Output Voltage Regulation vs. Input
Voltage.

Figure 9. Typical Output Voltage Regulation vs. Input
Voltage for the –P Version.

(V)

O

OUTPUT VOLTAGE, V

INPUT VOLTAGE, Vin (V) OUTPUT CURRENT, IO (A)

(V)

O

OUTPUT VOLTAGE, V

Figure 8. Typical Output Voltage Regulation vs. Output
Current.

Figure 10. Typical Output Voltage Regulation vs. Output
Current for the –P Version.

(V)

O

OUTPUT VOLTAGE, V

.

May 9, 2013 ©2012 General Electric Company. All rights reserved. Page 7

GE

Data Sheet

QBDW025A0B Barracuda Series; DC-DC Converter Power Modules

36-75Vdc Input; 12.0Vdc, 25.0A, 300W Output

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 11. 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 12. Output Ripple and Noise Test Setup.

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 13. Output Voltage and Efficiency Test Setup.

SUPPLY

CONTACT

RESISTANCE

CONTACT AND

DISTRIBUTION LOSSES

O1

V

I

I

V

V

I

(+)

I

(–)

V

O

I

LOAD

O2

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 10, a 100F electrolytic capacitor, C
(ESR<0.7 at 100kHz), mounted close to the power module
helps ensure the stability of the unit. If the module is
subjected to rapid on/off cycles, a 330F input capacitor is
required. 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.,
UL60950-1 2
VDE0805-1 EN60950-1 2

nd

Ed., CSA C22.2 No. 60950-1 2nd Ed., and

nd

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 V

pin and one V

IN

pin are to be grounded, or

OUT

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 safety extra-low voltage (SELV)
outputs when all inputs are SELV.

The input to these units is to be provided with a maximum
30 A fast-acting (or time-delay) fuse in the unearthed lead.

The power module has internally generated voltages
exceeding safety extra-low voltage. Consideration should be
taken to restrict operator accessibility.

,

in

May 9, 2013 ©2012 General Electric Company. All rights reserved. Page 8

GE

Data Sheet

QBDW025A0B Barracuda Series; DC-DC Converter Power Modules

36-75Vdc Input; 12.0Vdc, 25.0A, 300W Output

Feature Descriptions

Overcurrent Protection

To provide protection in a fault output overload condition,
the QBDW025A0B module is equipped with internal current­limiting circuitry and can endure current limiting
continuously. If the overcurrent condition causes the output
voltage to fall below 4.0V, the module will shut down. The
module is factory default configured for auto-restart
operation. The auto-restart feature continually attempts to
restore the operation until fault condition is cleared. 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.
The IOUT_OC_WARN threshold level, IOUT_OC_FAULT
threshold level, and IOUT_OC_FAULT_RESPONSE can be
reconfigured via the PMBus interface. If the
FAULT_RESPONSE is reconfigured to remain latched off
following an overcurrent shutdown, the overcurrent latch is
reset by either cycling the input power, or by toggling the
on/off pin for one millisecond.

Output Overvoltage Protection

The module contains circuitry to detect and respond to
output overvoltage conditions. If the overvoltage condition
causes the output voltage to rise above the limit in the
Specifications Table, the module will shut down. The
QBDW025A0B module is factory default configured for auto­restart operation. The auto-restart feature continually
attempts to restore the operation until fault condition is
cleared. If the output overvoltage condition still exists when
the module restarts, it will shut down again. This operation
will continue indefinitely until the overvoltage condition is
corrected.

The VOUT_OV_FAULT threshold level and VOUT_OV_FAULT
_RESPONSE can be reconfigured via the PMBus interface. If
the FAULT _RESPONSE is reconfigured to remain latched off
following an overvoltage shutdown, the overvoltage latch is
reset by either cycling the input power, or by toggling the
on/off pin for one millisecond.

Overtemperature Protection

The modules feature an overtemperature protection circuit
to safeguard against thermal damage. The circuit shuts
down the module when the default maximum device
reference temperature is exceeded. The module is factory
default configured to automatically restart once the
reference temperature cools by ~25°C.

The OT_WARNING and OT_FAULT threshold levels and
OT_FAULT_RESPONSE can be reconfigured via the PMBus
interface. If the FAULT _RESPONSE is reconfigured to remain
latched off following an overtemperature shutdown, the
overtemperature latch is reset by either cycling the input
power or by toggling the on/off pin for one millisecond.

Input Under Voltage Lockout

When Vin exceeds VIN_ON, the module output is enabled,
when Vin falls below VIN_OFF, the module output is
disabled. VIN_ON and VIN_OFF can be reconfigured via the
PMBus interface. A minimum 2V hysteresis between VIN_ON
and VIN_OFF is required.

May 9, 2013 ©2012 General Electric Company. All rights reserved. Page 9

Input Over Voltage Lockout

The QBDW025A0B module contains circuitry to detect and
respond to input overvoltage conditions. If the overvoltage
condition causes the input voltage to rise above the limit in
the Specifications Table, the module will shut down. The
module is factory default configured for auto-restart
operation. The auto-restart feature continually monitors the
input voltage and will restart the module when the level falls
7V below the VIN_OV_FAULT level.

The VIN_OV_FAULT threshold level can be reconfigured via
the PMBus interface.

Remote On/Off (i)

The module contains a standard on/off control circuit
reference to the V
remote on/off logic options are available. Positive logic
remote on/off turns the module on during a logic HI voltage
on the ON/OFF pin, and off during a logic LO. Negative logic
remote on/off turns the module off during a logic HI, and on
during a logic LO. Negative logic, device code suffix "1," is
the factory-preferred configuration. The On/Off circuit is
powered from an internal bias supply, derived from the
input voltage terminals. 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 V
The switch can be an open collector or equivalent (see
Figure 14). A logic LO is V

during a logic LO (Vin=48V, On/Off Terminal=0.3V) is

I

on/off

147µA. The switch should maintain a logic LO voltage while
sinking 310µA. During a logic HI, the maximum V
generated by the power module is 8.2V. The maximum
allowable leakage current of the switch at V
10µA. If using an external voltage source, the maximum
voltage V
terminal.

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 V
For positive logic: leave ON/OFF pin open.

Figure 14. Remote On/Off Implementation.

on/off

(-) terminal. Two factory configured

IN

(-) terminal (V

IN

= -0.3V to 0.8V. The typical

on/off

on/off

on the pin is 14.5V with respect to the VIN(-)

(-).

IN

on/off

on/off

= 2.0V is

).

GE

C2

Data Sheet

QBDW025A0B Barracuda Series; DC-DC Converter Power Modules

36-75Vdc Input; 12.0Vdc, 25.0A, 300W Output

Feature Descriptions (continued)

Load Sharing

For higher power requirements, the QBDW025A0 power
module offers an optional feature for parallel operation (-P
Option code). This feature provides a precise forced output
voltage load regulation droop characteristic. The output set
point and droop slope are factory calibrated to insure
optimum matching of multiple modules’ load regulation
characteristics. To implement load sharing, the following
requirements should be followed:

 The V

 V

 It is permissible to use a common Remote On/Off signal to

 These modules contain means to block reverse current

 When parallel modules startup into a pre-biased output,

 Insure that the load is <50% I

 If fault tolerance is desired in parallel applications, output

(+) and V

OUT

connected together. Balance the trace resistance for each
module’s path to the output power planes, to insure best
load sharing and operating temperature balance.

must remain between 40Vdc and 75Vdc for droop

IN

sharing to be functional.

start all modules in parallel.

flow upon start-up, when output voltage is present from
other parallel modules, thus eliminating the requirement
for external output ORing devices. Modules with the –P
option will self determine the presence of voltage on the
output from other operating modules, and automatically
increase its Turn On delay, T
Specifications Table.

e.g. partially discharged output capacitance, the T
automatically increased, as specified in the Feature
Specifications Table, to insure graceful startup.

all parallel modules have started (load full start > module

time max + T

T

delay

ORing devices should be used to prevent a single module
failure from collapsing the load bus.

(-) pins of all parallel modules must be

OUT

, as specified in the Feature

delay

rise

(for a single module) until

O,MAX

time).

rise

is

Remote Sense

Remote sense minimizes the effects of distribution losses by
regulating the voltage at the remote-sense connections (See
Figure 15). The SENSE(-) pin should be always connected to

(–).The voltage between the remote-sense pins and the

V

O

output terminals must not exceed the output voltage sense
range given in the Feature Specifications table:

(+) – VO(–)] – [SENSE(+) ]  0.5 V

[V

O

Although the output voltage can be increased by both the
remote sense and by the trim, the maximum increase for
the output voltage is not the sum of both. The maximum
increase is the larger of either the remote sense or the trim.
The amount of power delivered by the module is defined as
the voltage at the output terminals multiplied by the output
current. When using remote sense and trim, the output
voltage of the module can be increased, which at the same
output current, would increase the power output of the
module. Care should be taken to ensure that the maximum
output power of the module remains at or below the
maximum rated power (Maximum rated power = Vo,set x
Io,max).

May 9, 2013 ©2012 General Electric Company. All rights reserved. Page 10

Figure 15. Circuit Configuration for remote sense.

Configurable Control Pins

The QBDW025A0B contains two configurable control pins,
T/C1 and C2, referenced to the module secondary SIG_GND.
See Mechanical Views for pin locations. The following table
list the default factory configurations for the functions
assigned to these pins. Additional configurations can be
accomplished via the PMBus command,
MFR_CPIN_ARA_CONFIG. Following the table, there is a
feature description for each function.

Pin

Designation/Function

T/C1

On/Off (O) Power Good w/o -P Factory Default

Trim On/Off (O) w/o -P Via PMBus
Trim

On/Off (O) Power Good with -P Factory Default

Power Good w/o -P Via PMBus

Module

Code

Configuration

Remote On/Off(o)

The module contains an additional remote on/off control
input On/Off(o), via either the T/C1 or C2 pin, reference to the

(-) terminal. The factory default configuration is set to

V

O

ignore this input, unless activated by the PMBus command,
MFR_ CPIN_ON_OFF_CONFIG. This command is also used to
configure the logic for the On/Off(o) pin. Positive logic
remote on/off turns the module on during a logic HI voltage
on the ON/OFF pin, and off during a logic LO. Negative logic
remote on/off turns the module off during a logic HI, and on
during a logic LO. The On/Off(o) circuit is powered from an
internal bias supply, referenced to SIG_GND. To turn the
power module on and off, the user must supply a switch to
control the voltage between the On/Off (o) terminal and the

(-) terminal (V

V

O

or equivalent (see Figure 13). A logic LO is V

0.8V. The typical I
switch should maintain a logic LO voltage while sinking
TBDµA. During a logic HI, the maximum V
by the power module is TBDV. The maximum allowable
leakage current of the switch at V
using an external voltage source, the maximum voltage

on the pin is 3.3V with respect to the Vi(-) terminal.

V

on/off

If not using the Remote On/Off(o) feature, the pin may be left
N/C.

(o)). The switch can be an open collector

on/off

(o) during a logic LO is 330µA. The

on/off

(o) = 2.0V is 130µA. If

on/off

(o) = -0.3V to

on/off

(o) generated

on/off

Feature Descriptions (continued)

Power Good, PG

The QBDW025A0B module provides a Power Good (PG)
feature, which compares the module’s output voltage to the
module’s POWER_GOOD_ON and POWER_GOOD_OFF