PSU for Electrical Music Instruments

Seyfullah,

There are many possible solutions.   I would start with the Webench Power Architect:

https://webench.ti.com/webench5/power/webench5.cgi?origin=landing_page&app=powerarchitect&lang_chosen=en_US

You can input your requirements for the 3 rails.  I have submitted your requirements and the tool returned:

Supply 1, LM25085, 12.7 V @ 2.9 A

Supply 2, TPS563200, 6.5 V @ 1.1 A

Supply 3, LM25088-2, -13 V @ 2.8 A

Undoubtedly there are many other possible solutions.  Alternately you can use the regular Webench design tool and input your individual rails:

Entering the requirements for your first rail returned 111 possible design solutions.  You can brows thru them to pick out the features that best fit your needs and the level of complexity you are comfortable with.  If you are a power novice, you may want to focus on modules (easiest) or integrated switch converters (moderate) and avoid controllers (hardest).  You mention controller above.  Are you required to use a controller?  Can you use a converter with integrated FETs or module?

Let me address your individual concerns:

For lowest ripple and noise, you can use an LDO follower after your switching supply.  You will need to raise the output of the switcher to Your desired Vout plus the drop out voltage of the LDO.  Unfortunately, we do not have a negative output LDO rated above 1.5 A.  You may need to use a secondary output filter instead, unless you can split that output into two 1.5 A outputs.

Which is best is dependent on your unique requirements.  You can probably find a single converter that will satisfy all three requirements.  However Webench suggested that three different converters be used.  You can use the links above to browse solutions.

There may be some advantage to operating at a synchronized identical frequency.  Many converters will support that feature, but most likely you will have to supply the external clock.  You may find it beneficial to operate each converter out of phase, however the main benefits of out of phase synchronization are on the input side of the supply.  An additional complication is that your negative output inverting buck boost circuit will require the clock (and any other control circuits) to be level shifted.

Yes you can design them all on the same PCB.  Make sure to follow the layout guidelines for each converter that you use.  Pay special attention to the inverting buck boost.  The IC ground acts as teh negative output voltage in that topology.

Another possibility could be a single supply with 3 isolated outputs, but you probably are not interested in designing your own custom transformer.

Let us know if you have further questions.