Almost every power supply has a control loop to maintain the output voltage at a constant value. In the design of a power supply, the aim is to optimize the control loop so that if the input voltage or load transients experience fluctuations, the deviations in the controlled output voltage from the setpoint are minimized.
An important relationship in this case is the size of the output capacitors in relation to the response speed of the switching regulator IC. If the loop’s response is particularly fast, smaller output capacitors can be used while keeping the output voltage within the permissible range. Thus, optimization of the switching regulator’s response speed reduces system cost as well as the space requirement for the circuit because smaller output capacitors can be used.