I'm trying to design a low-noise power supply for small-signal audio (+/-12-15V, ~1A). As part of this, I'm investigating advanced SMPS topologies like the SEPIC and Ćuk converters. Few controller/converter ICs mention support for these topologies in their datasheets, and the ones that do (such as the LM5001) seem to support a more common topology as well, usually boost. I also found an EE Times article on how to design a negative buck converter using a boost converter IC, and an app note that implements a buck-boost converter using a buck converter IC. What I have not found is a general list of which topologies are supported by each type of controller/converter. Thus, I have two questions:

  1. Can all converter ICs be used to implement multiple topologies?

  2. If so, which topologies are supported by each type of basic converter IC (buck, boost, etc.)?


An SMPS controller1 IC may support multiple converter topologies. But a single IC almost never supports all common converter types.

There is a family of converters derived from boost converter: flyback, SEPIC, boost proper. A controller that can do boost, usually can do the rest of the boost family too. Usually, one controller can't do both buck family and boost family.

1 SMPS controller IC drives external power switches. SMPS converter IC has power switches on board. Converter ICs tend to be less versatile than controllers.

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  • \$\begingroup\$ So the difference in transfer functions doesn't matter? \$\endgroup\$ – Adam Haun Feb 22 '16 at 21:06
  • \$\begingroup\$ Closed loop feedback adjusts to transfer function ( \$ \frac{1}{1-D} \$ for boost vs. \$ \frac{D}{1-D} \$ for SEPIC ). Although I suspect that feedback loop compensation (external to the IC) may be different. \$\endgroup\$ – Nick Alexeev Feb 22 '16 at 21:28

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