Mini tutorials · Voltage regulation
Why regulate, energy and switches, linear vs switching, major topologies, inefficiency and limits, and what “good enough” means for DC accuracy vs transient response.
Foundation
Load voltage window · setpoint accuracy · load step & release · stay in band.
Series dropper 12→3.3 V @ 100 mA — load step and waste heat.
Series R · L · ceramic then bulk — |Zo| peak, load rate, damp with ESR.
Tall short pulse vs low steady — match areas, same average power.
Devices
Device map — symbol, silicon, ID–VDS family. Triode vs MOS saturation.
Resistor load line on the family. Saturation for gain · gm tangent.
Near the origin · RDS(on) · why 6 V vs 8 V gate matters.
Miller plateau · V×I overlap · why frequency costs energy.
Why N-channel high-side often needs a bootstrap/boost; P-channel high-side tradeoffs.
Absolute max / drive differences at a conceptual level — not a full GaN design course.
Linear path
Pass element, dropout, dissipation — when linear still wins.
Error amp, reference, loop — control vocabulary in power language.
Short bridge to Control Loops: PM/BW ↔ load-step behavior (link out for depth).
Switching topologies
Linear burns (Vin−Vout)I. Duty is the conversion knob. Family map.
Always down · when / operation / conducted ports (CIN harsh).
Always up · ports reversed vs buck (COUT harsh).
Negative rail · both ports rectified.
VIN above or below VOUT · quiet input, harsh output.
Invert like IBB · both cables quiet · C is the hot loop.
SEPIC’s job · quiet output (load cares) · SW to −VOUT.
Isolated store-then-dump · both ports harsh · not a SEPIC.
Negative iL · SW relaxation ring · light-load η (Linear-style modes).
Turns ratio · L = N² AL · series vs parallel windings.
Isolated buck · windings conduct together · Lout · not a flyback.
Limits & requirements
R_DS(on), diode drops, gate charge, copper/core, switching loss, quiescent current.
f_sw, V_in, V_out, duty limits — how low V_out can go for a given input and frequency.
e.g. ±3% DC over line/load/temp vs load-step droop and recovery — two different problems.