Abstract
Battery size of portable electronic devices is restricted by compact device form factors. To effectively utilize the relatively limited battery power, highly efficient DC-DC converters are employed. As portable devices remain in stand-by mode most of the time, improving light load efficiency is essential. In this paper, fast transient control method and linearly scaled gate-driving technique are used to improve the transient response and light-load efficiency of dc-dc converter. The transient response of dc-dc converter is closely related to the waiting time of the device to resume normal operation from standby. The fast transient control operates under a voltage controlled Pulse-Width Modulation mode during steady state and saturation mode during transient. Light load efficiency of DC-DC converter depends on frequency dependent losses and gate driving losses. The optimum gate driving voltage can be accurately modeled by a linear function of the load current to minimize frequency dependent loss. This is achieved by maintaining constant switching frequency and output ripple voltage. Simulation results show 5% increase in light-load efficiency with an overall efficiency of 90% and the transient recovery time of a 450 mA step load change to be less than 9μs.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
