A system and a method are disclosed for suppressing load transients in
radio frequency power amplifier switching power supplies. A power supply
control circuit is provided that includes a switcher circuit and a low
drop out circuit. Load transients are suppressed by generating a preload
control signal that activates an active current source either in the
switcher circuit or in the low drop out circuit. The active current
source counteracts a decrease in the switcher operating voltage when a
load transient is present. Load transients are also suppressed by
generating a step control signal that activates a transistor in a
feedback resistor divider network in the switcher circuit to increase the
switcher operating voltage during a load transient. The preload and step
control signals are reset when the load transient has ended.