ABSTRACT
Practically all electronic systems work with DC power rails, which are usually derived from a commercial AC utility source or a limited-energy battery pack. Due to reasons related to political, environmental, and consumer pressures, saving energy, a green environment, electromagnetic compatibility, and safety aspects drive the power supply designer to be very optimistic about the overall structure of a power supply subsystem. With more feature-packed processor-based systems becoming the norm, particularly in portable systems, multiple DC power rails are required. Another important aspect of the modern power management systems is the transient response of the power rails for load currents with fast slew rates, due to common situations such as the processors transitioning between sleep and wake-up modes.
