The nonsynchronous rectifying type, which has been in use for years, features a simple circuit for a switching regulator, with an efficiency barely topping 80%. Subsequently, the appearance of battery-powered applications drawing relatively large power and requiring high efficiency, such as notebook PCs, has led to the development of a succession of ICs for synchronous rectifying switching regulators capable of delivering superior efficiency. Aided by innovations that have facilitated the design of the synchronous rectifying type requiring complex control and circuitry, this type of switching regulator, offering a maximum efficiency close to 95%, has gradually become predominant.