polyphase boost converter

Hmm. Polyphase is most useful at highish power levels, which is not what I’d instantly associate with a boost converter.

The boost topology has that nasty unstable zero at higher loads. You know: regulator goes into CCM, power demand goes up, duty cycle increases. The power is delivered after the switch opens, so that increases the response delay, increasing the sag, the controller overreacts,… i.e. the behavior that slope compensation is intended to fix.

Figuring out how to do slope compensation in a polyphase converter might be a challenge.

Cheers

Phil Hobbs (Whose switcher designs to date are all below 20 watts)

The advantage is that one might use a few small fets and inductors. I designed an 80 amp three-phase buck regulator once because a single-phase version was burning the paint off my inductors.

Fair enough, if you can make the slope compensation work. Of course, assuming the load regulation is adequate, you could also make the loop slow enough that it doesn’t matter.

Cheers

Phil Hobbs

We might have an FPGA in the loop, so we can do tricky things. Most everything seems to have an FPGA lately.

Well, with an FPGA you can probably jack up the frequency till the zero doesn't bother you. Bigger hammers and all that.

Cheers

Phil Hobbs