MCU based inverter design

[baoshi]

Hi,
I'm designing a VFD driving circuit. One of the challenge is the driving chip needs -22V negative bias.
I found Dave has an inverter FF tutorial based on a MCU generate waveform. But it can only provide -VCC instead of "boost" the voltage lower.
So I came out the attached design, basically combining a boost converter with Dave's inverter.

Can someone scrutinize my design before I put it onto a board?

Thanks

Baoshi

[Marco]

Heh, nice effort to try to modify such a simple circuit until it does what you want to do ... but you get so far away from Dave's circuit that it stops making sense to even use it as part of your design.

You want a (inverting) buck boost converter with a P mosfet.

[baoshi]

Heh, nice effort to try to modify such a simple circuit until it does what you want to do ... but you get so far away from Dave's circuit that it stops making sense to even use it as part of your design.

You want a (inverting) buck boost converter with a P mosfet.

Thanks Marco,

I changed the design. Is this any good?