Peak current detector based control of DC-DC buck converter for portable application

This paper presents a control scheme for DC-DC converters designed for battery operated systems. These systems require very high efficiency to prolong the battery life The inductor peak current is maintained constant either by oscillator on/off time control or monoshot on time control. But these types of control require a fixed and accurate value of inductor and they require preprogramming of monoshot/oscillator. The proposed control scheme uses a peak current detector for the inductor peak current detection. Therefore it rules out maintaining a very precise value of inductor size and any kind of preprogramming. A design and its implementation have been carried out in a 1.5 μ BiCMOS process and both simulation and experimental results are presented.