Voltage limiter with ic source
inrush current protector to protect capacitor from fast charging and let mosfets work as soft start + polarity protection in the same schematic
charge pump circuit or bootstrap (diodes + capacitors+ pwm signal)
some ics need minimum output current or continious conduction mode
multi sources diodes
hystarisis comparator
put capacitors with voltage divider
voltage regulator ic vs voltage reference ic
before any ic source we put capacitors for decobling and some times we need more than one parallel capacitor for lower esr and more smoothing