Hi all,
I'd like to design for my own use a 5A laboratory power supply, and
control it digitally, via a DAC (not a digital potentiometer, since
I want a lot of resolution. BTW: I also want to produce DC+AC (50Hz
or more), so the DAC is the most obvious solution).
While the choice of the linear voltage regulator at the end was
between the MIC29502BT and the LM1084IT-ADJ, the more I thought about
it, and the more I'd rather prefer (intuitively/instinctively at least)
a boosted opamp solution instead.

Why would I prefer a boosted opamp over the voltage regulator solution?

1) A boosted opamp can also sink current, not only source it.
2) I could feature / control polarity inversion (let away DC+AC).
3) Given the right choice of booster and opamp, it can also be faster.
4) DAC control would be even easier.

is my reasoning correct?

If it is, I will finally go for the boosted opamp solution, but I have
some final doubts:

1) Bipolar NPN/PNP transistors or N/P Channel MOSFETs?
2) Split supply opamp+booster or RtR single supply opamp + H-Bridge?
   The latter would double the output voltage ability, at the expense
   of some cross-over distortion (I know that I'm talking about a low
   frequency poweramp rather than a true power supply..).
3) To minimize heat dissipation I would like to control the power grid
   (where the booster is attached) via a PWM + capacitor filter. Both
   the DAC and PWM, of course, would be handled by a PIC + software.

Any thoughts / comments / advice?

Thanks,
TPM
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