## IBA bus

### Intermediate Bus Architecture

The IBA, [Intermediate Bus Architecture] is not a data bus at all, but more of a power distribution scheme.
The Intermediate Bus Architecture exists between the main power converter, say after a 48 volt power converter board but before the individual card Point-Of-Source [POS] regulators.

The Intermediate Bus Architecture began its deployment in the telecommunications industry so 48 volts is usually used as the example internal chassis voltage.
An equipment chassis receives 125 volts ac and converts that into a common 48 volt dc voltage. All the circuit boards in the systems [chassis] receive the 48 volts as the IBA power bus.
Each individual cards than converts the 48 volt power into an intermediate voltage [5 volts for example] by a intermediate bus converter which is then bussed to what ever source the board requires via individual POS voltage converters. So the main difference between this approach and some early approach is that a card has an intermediate voltage converter between the main card voltage supplied [48 volts] to the card and the voltage(s) supplied to the IC. So each individual voltage converter doesn't convert between between 48 volts and 5 volts or 3 volts, but instead converts between an intermediate voltage [5 volts] and 3 volts.

Older approaches may have reduced a voltage within a chassis and then bussed that voltage to each of the cards in the chassis. For example the chassis might use a power supply that converts the individual voltages and bus those out to each card. So the old system could have one large 48 volt to 5 volts dc converter, which supplied 5 volts to each card. In an IBA system the 48v would be delivered to the card converted to 5V and then sent to smaller POS converters which would then reduce that voltage to 5v, 3.3v, 1,8 volts and so on.

Note a Point-Of-Source regulator [Voltage Regulator Manufacturers] is a regulator placed at the source that requires the voltage. A POS regulator is really defining it's location next to the source [or load depending on how it's viewed] and says nothing about the regulator it self [just its location].

The PMBus is a term used to describe the Power Management Bus.
The PMBus is used to communicate between different devices in power system architecture.

I am not aware of any standard or specification which defines IBA.

In addition to the terms; Intermediate Bus Architecture, and IBA, I have also seen the term I-Bus used to imply the same thing.
Point-of-Source regulation is also called Point-of-Load regulation.
Any voltage regulator can be a POL regulator; just place the device next to the point that requires the voltage.

IBC Modules; Intermediate Bus Converters

Murata {Intermediate Bus Converters}

Ericsson {IBA non-regulated bus converters, 40-72 volt input, 480 watts}

Maxim {50 Watt Internal Bus Architecture Power Supply; IBA}

TDI {Intermediate Bus Converter Modules, Hot-Plug}

Tyco Electronics {Eight-Brick Intermediate Bus Converters}

Vicor {1 or 2 VI Chip BCMs mounted on a PCB, 1/4 Brick format. 600 watt, 3V to 48 volts}

Intermediate Bus Converters are isolated DC to DC converters, while POL converters are non-isolated DC to DC converters.

Isolated DC-to-DC converters use a transformer to isolate the input voltage from the output voltage, just like a normal power supply.
The non-isolated Point-Of-Load converter would be any normal DC to DC voltage regulator.

Modified 1/9/12