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Single input dual output buck

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Morphling

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Hi
Can anybody suggest a non-isolated single input dual output buck converter?
 

for dual output you will need it to be a flyback or forward say. Remember that if in current mode and doing a dual output forwad or bridge, then the output inductors shoudl be coupled.

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Seriously,two bucks, interleave switched is nice for two outputs
 
This could be an example, assuming you want both loads to have some influence in the feedback loop. A single control system sends output to two inductors and two loads.

2619456400_1487796466.png


Although load voltages are not too different here, it should be possible to obtain different load voltages by playing with values, or changing connections among the inductors, etc.
 

good point, they are two in parallel but only have the one controller.
 

I'm actually trying to explore whether a single input dual output buck converter with less than four switches and/or less than two inductors is possible or not.
 

I'm actually trying to explore whether a single input dual output buck converter with less than four switches and/or less than two inductors is possible or not.

Make the inductor serve dual purpose by sending current in alternating directions through it.
The H-bridge attaches one of two bright white led's at appropriate times.



Spikes are diverted by the back-to-back zeners.
 

well i think you can do it dual output by having a "secondary" winding off the buck inductor.
 

Make the inductor serve dual purpose by sending current in alternating directions through it.
The H-bridge attaches one of two bright white led's at appropriate times.



Spikes are diverted by the back-to-back zeners.

how is this stepping down an input voltage?
 

1. You missed to specify the function of the second output, e.g. what are the intended output voltages.
2. I'm sure it's not possible with a regular buck topology which needs an individual storage inductor for each output.
 

how is this stepping down an input voltage?

If the inductor is reduced to 1nH then the led's receive over 400 mA. Therefore the buck converter is doing its job. This is a case of operating a buck converter so it steps down current. The led's automatically step down voltage to their built-in voltage.

I'm making my experiments around the concept of one buck converter. It would be easy and obvious to simply add a second buck converter, but the question seems to ask for something other than the obvious.

Perhaps this is meant to be an exercise in thinking outside the box? Here is another buck converter with dual outputs.



By designating 0V ground at the node between the loads, you can create bipolar supplies (by taking the negative supply at the bottom-most wire). Then a buck-boost operation might be in the picture (I think).
 

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