Would you need the buck converter if running from a 220volt AC line?
I think for the sake of the parts, yes. I will present two application
scenarios where I think this is a good idea:
Let's say that you are yacking away (using your chosen form of modulation) on
some band using one of these
as yet magic amplifiers. Simultaneously, your neighbor switches off their
highly inductive personal pleasuring
device and your coax falls out of your PL259 as you are a lazy sot and have not
ever bothered to solder the shell.
You now have a mains impulse and an open on the drain. Pfft! Vdd max is
exceeded and you are cursing all solid
state amplifiers. You can design the output stage for opens, but you have to
trust your Vdd to do so.
Another example from my professional RF domain, making plasma for lasers:
Anyone familiar with this application
understands that the pre-breakdown impedance of an RF excited laser tube is
large. (oops forgot to say purely (hopefully) resistive).
The amplifier has to be able to withstand a repeated very large impedance. We
modulate the lasers at about 30-50Khz,
so the high impedance condition occurs more often then your neighbor with
the... you know... device.
I care less about boost conversion because a sag in the mains when your
neighbor 'switches on' does not harm your
parts. In linear applications of these parts a sag in Vdd will result in a
temporary increase in IMD, although I can not claim
to fully understand the mechanism behind this.
George
K0IW
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