ETA3555

The ETA3555 is a high-efficiency, DC-to-DC step-down switching regulator, capable of delivering up to 5A of pulse load. It integrates an I 2 C interface that dynamically scales the output voltages on demand. The DCDC control block belongs to a new breed of high frequency synchronous Step-Down converter that combines the advantages of voltage mode control and Constant-OnTime control. Its adaptive Constant-On-Time control dynamicallychanges switch on time to achievea constant switching frequency. It does not have the minimum ontime constrain normally a fixed-frequency current mode Step-down requires, allowing it to go down to very low duty ratio without affecting loop stability. The voltage mode nature also provides a more superior load transient response and a seamless transition from PFM to PWM modes. Cycle-by-cycle current limit provides output short-circuit protection and an input OVP function guards ETA3555 against possible input voltage surge.