Why IBAs work better for you

Technical Article
The advantages of Intermediate Bus Architectures
Why IBAs work better for you
In recent years IBA (Intermediate Bus Architecture)
and PoL (point-of-load) power have become familiar
terms in the electronics industry. But what are the
advantages of IBA over the more the traditional DPA
(Distributed Power Architecture)?
What is a DPA?
A front-end power supply generates a DC voltage that is ‘bussed’
around the system (either at 24V or 48V) with individual brick
converters supplying each load with their required voltage. This
architecture provides isolation from the power supply to each card and
from card to card. However, in many applications - when no isolation
is required or very low voltages are needed - this type of system has
limitations and can be costly.
AC/DC Power
Supply
DC/DC
Brick
3.3Vdc
DC/DC
Brick
2.5Vdc
DC/DC
Brick
1.8Vdc
Load
Load
Load
Load
Load
Load
What is an IBA?
Isolation
Barrier
AC/DC Power
Supply
24V/48V Bus
An intermediate bus converter (or multiples in parallel for higher power
applications) provide power to the intermediate bus - typically at 5V or
12V DC.
PoL converters then convert from this voltage right at the point of
requirement. This removes the need for high current pcb tracking
which is expensive, occupies valuable pcb space, and wastes power
due to copper losses.
PoL
Intermediate
Bus Converter
PoL
PoL
PoL
PoL
PoL
www.cd4power.com
1.3Vdc
1.8Vdc
1.5Vdc
1.2Vdc
1.0Vdc
0.8Vdc
Load
Load
Load
Load
Load
The IBA advantage
In many applications, moving to an intermediate bus system using
point-of-load converters can bring considerable financial savings as
well as performance benefits, including:
• Improved efficiency
By placing highly efficient converters right at the point of demand,
pcb design becomes easier with lower losses. EMC performance is
also improved as high current pcb tracking is reduced.
• Reduced cost and size
By utilising lower cost non-isolated PoL modules to supply each
voltage rail the number of relatively expensive half and quarter bricks
converters is dramatically reduced. This not only reduces the cost,
but also saves space on the pcb. Bus converters are also more simple
in their design – and consequently less expensive - than traditional
brick converters because high levels of voltage regulation are not
needed (this regulation is performed by PoL converters in an IBA).
• Improved transient response
Due to their design and positioning close to the load itself, PoL
converters offer excellent transient load response as demanded by
today’s DSP, FPGA and ASIC processor chips.
• More functionality
Functional features, such as load sequencing or tracking (the
sequence in which supply voltages are powered up and down), are
all easily achievable with today’s highly specified PoL converters.
Digital control via a data bus is also now available, offering on-the-fly
PoL re-configuration of PoL transient response, output voltage, etc.
C&D Technologies
With the widest range of power electronics products available today,
C&D Technologies has all the components you need for your IBA
- from the AC input right down to the point of load.
Bus converters, on-board AC/48VDC power modules, high
specification processor support DC/DC converters and even
inductors for filtering and isolation can also be sourced from C&D’s
high quality product portfolio.
Load
The IBA Advantage Page of 2
Technical Article
The advantages of Intermediate Bus Architectures
Examples of IBA products
Front End Power supply - D1U-W-1600-48 AC/DC
Total output power
Form factor
Output Voltage
Rated Output Current
Vdc1
Vdc2
Iout-1
Iout-2
Input Voltage Range
Efficiency
Input Connector
Output Conenctor
Features
1600W
1U height x 120.6mm(W) x 305(D)
48V
3.3 or 5V
33A
6A
90-264Vac
90.6%
IEC 320 C20
FCI Powerblade #51732-021
Active Power Factor Correction
Active Current Share
Hot-plug
I2C Interface
EMI Class A
Bus Converters
Output
Voltage
Rated
Output
Current
Total
Output
Power
Input
Voltage
(Nom)
Input
Voltage
Range
Isolation
Voltage
Efficiency
Package
style
Product
12Vdc
15A
180W
48Vdc
36-55Vdc
2.25kVdc
96%
1/8 Brick
EUS15-120
12Vdc
20A
240W
48Vdc
36-55Vdc
2.25kVdc
96%
1/8 Brick
EUS20-120
PoL Converters (with user-selectable output voltage)
Output
Voltage
0.75-5V
0.75-5V
0.75-5V
0.75-5V
0.75-5V
0.75-5V
Rated
Output
Current
6A
6A
10A
10A
10A
10A
Total
Output
Power
30W
30W
50W
50W
80W
80W
Input
Voltage
(Nom)
12Vdc
12Vdc
12Vdc
12Vdc
12Vdc
12Vdc
Input
Voltage
Range
8.3-14Vdc
8.3-14Vdc
8.3-14Vdc
8.3-14Vdc
8.3-14Vdc
8.3-14Vdc
Efficiency
Package style
Product
95%
95%
95%
95%
94%
94%
Open Frame SIP
Open Frame SMD
Open Frame SIP
Open Frame SMD
Open Frame SIP
Open Frame SMD
LSN2-6A, D12
LSM2-6A, D12
LSN2-10A, D12
LSM2-10A, D12
LSN2-16A, D12
LSM2-16A, D12
If you require more details and datasheets for these or any other C&D products please got to www.cd4power.com.
www.cd4power.com
The IBA Advantage Page of 2