Buck voltage regulation, an essential part of distributing power from a DC supply to its points of load (POLs), has typically been implemented with a PWM circuit. The PWM duty cycle is varied to accommodate the required voltage reduction. However a couple of factors have applied increasing pressure to regulator design. Firstly, power density is being forced up as continuously more powerful devices are designed onto boards without corresponding increase in footprint. Secondly, DC power supply voltage levels are tending to rise to minimize distribution losses, while device voltages are reducing to increase internal...
